CHOOSING THE RIGHT OIL FOR FLAT TAPPET CAM BREAK-IN

All oils are not created equal.

by Mike Mavrigian

photos by author

Avoiding flat tappet cam failure can be as simple as using the correct oil during break-in.

Chances are you’ve run into this problem first-hand, or know a builder who has shared his horror stories. We’re talking about flat tappet camshaft failures during break-in. In recent years, there has been a rash of cam problems and, in too many cases, the cam makers have unjustifiably shouldered the blame. The problem does not lie with the camshafts. Rather, the problem is caused by the engine oil used during break-in.

Because of mandates by the EPA, a vital element of the oil mix, commonly called ZDDP, has been drastically reduced in standard engine oils that are intended for the late-model street vehicle. In short, if the oil doesn’t contain enough ZDDP, it doesn’t offer adequate anti-scuff protection for the initial break-in of flat tappet cams. Let’s face it, when a customer’s brand new cam gets wiped out through no fault of yours, life can be frustrating to say the least.

ZDDP (zinc dialkyl dithio phosphate) is an anti-wear and antioxidant, initially developed in 1930 as an antioxidant to prevent engine bearing corrosion. ZDDP also features excellent anti-scuff and anti-wear properties. In the 1960s, ZDDP featured a zinc level of 0.07 percent when high-performance flat tappet camshafts were common. At that time, new camshafts were phosphate coated as well and the combination worked well to protect new camshafts and lifters from premature wear, especially during break-in.

In the 1970s, zinc levels increased to 0.09 percent because ZDDP is an excellent antioxidant. As engines became more powerful, oil recipes changed as well, becoming more complex with more functional additives such as friction modifiers, antioxidants, detergents, etc. Friction modifiers gained further popularity to aid fuel economy, with zinc content increasing to 0.2 percent in the 1980s and early 1990s.

By the way, ZDDP is only one acronym for this anti-wear/antioxidant content. It’s also referred to as ZDP or ZZDP. Why? Who knows and who cares?

So if ZDDP is so cool, why has it been reduced to the point where it’s causing flat tappet cam problems? Phosphorous is a well-known contamination source for catalytic converters (some refer to it as converter poison). The limit for phosphorous dropped to 0.10 percent, which means that the zinc level dropped as well. In 2004, with Tier 2 emissions standards, OEM warranties changed to 10 year/100,000 miles, and phosphorous dropped again to 0.08 percent, with zinc down to 0.09 percent.

Engine oils, in general, are vastly superior to oils made in the past, a major factor responsible for some engines being able to last for 250,000 miles or so. Also, today’s metallurgy is better. The issue here is high-performance flat tappet cam lobe wear during the break-in period. Aggressive cams with high spring loads compound the problem. This issue does not affect roller cams, since there’s no scuff wear issue with rollers.

In a nutshell, whether in a direct or indirect manner, the EPA has told the oil makers to ignore older (i.e. flat tappet cam) engines and to make an oil that avoids converter damage (thereby reducing emissions) in late model cars, and the hell with the restoration and performance market. Marie Antoinette once told the French peasants to eat cake. The EPA has basically told car guys to fend for themselves. Either expression is offensive as hell.

We could say that this entire problem could have been avoided if we (the engine community) were properly informed about the change in oil make-up. In that case, we could have made a point to search for specific break-in oils that did contain adequate ZDDP levels. Instead, many of us learned the hard way by needlessly wiping out otherwise perfectly good camshafts during break-in runs. At this point, it’s a case of too little too late. Let’s all send a big fat thank you to the government and the major oil marketing companies for making our lives a living hell.

WHAT’S THE ANSWER?

To avoid flat-tappet cam lobe damage during break-in, naturally you must continue to apply the specific cam lobe and lifter assembly lube that’s recommended by the cam maker, plus you can install low-rate valve springs for the break-in.

In addition, you can and should use one of the few currently-available engine oils that do contain sufficient ZDDP. These oils are available, but you need to remember to specifically purchase these oils and dedicate them for flat tappet cam break-ins.

Engine oils that are specifically designed for use in diesel applications will usually feature more zinc than passenger car gas engine oils. However, diesel engines are coming under greater scrutiny as well in an effort to further reduce emissions nationwide. So, while a dedicated diesel oil may be better than a passenger gas engine oil in terms of zinc content, you can’t automatically assume that any diesel oil contains enough ZDDP to protect a new flat tappet cam.

According to the tech boys at Crane Cams, oils that they are currently aware of that are compatible for flat tappet cam break-in include Shell Rotella T, Chevron Delo 400 and Mobil DELVAC. All three of these are classified as diesel oils. Crane did note that Rotella T has apparently been modified with a slight cutback on zinc (rumor has it that zinc was reduced from 1,400 ppm to 1,200 ppm), but that should not be enough to cause problems.

I have heard other unsubstantiated rumors, however, that Rotella’s zinc has more recently been further reduced to 800 ppm (and possibly even further), but we could not get that rumor qualified in time for this article. Crane did note that if a questionable oil is to be used (where the user is not sure of the ZDDP content), a friction modifier such as GM EOS should be added for break-in. However, no additional friction modifier additives should be added to a break-in oil that is documented as flat-tappet-break-in safe.

When we spoke with the folks at Redline, they did mention that while they do not currently offer a break-in oil, they do have plans to introduce a ZDDP additive in the future. So, nothing at the moment, but possibly down the road.

A call to the tech department at Valvoline corrected an issue that is currently misunderstood among some builders. While Valvoline does offer an Off Road 20W-50, that is not the oil recommended for flat tappet cam break-in. Instead, they advised using their VR1 Racing Oil, an SM-rated oil that features 1,300 ppm of zinc. They also noted that while a common misconception is that SM-rated oils are considered unacceptable for this application, that this is simply not the case.

Castrol has recently introduced its new CASTROL SYNTEC 20W-50, which reportedly “contains increased zinc levels for extra engine wear prevention … uses proprietary additives and base oils to reduce metal-on-metal contact of aging engine parts … engineered to increase wear protection for classic cars with flat tappet camshafts.” While this oil may be fine and dandy for day-to-day use in flat-tappet engines, because it is a synthetic oil, in good conscience we can’t recommend it specifically for break-in since it’s never a good idea to break in any engine (flat tappet or roller) with a too-slippery synthetic oil with regard to ring seating and flat tappet lifter rotation.

Lake Speed Jr. at Joe Gibbs Driven noted that they developed their dedicated BR break-in oil specifically to meet the needs of flat-tappet cam applications, which contains a whopping 2,800 ppm zinc. Speed told us that they developed this oil in order to be able to use the same oil for break-in and for complete dyno sessions. Gibbs also offers a special Assembly Grease for lobe and lifter lube during assembly.

Dick Glady, a highly respected racing oil expert who has worked in the racing oil industry for decades, of American Refining Group, makers of Brad Penn Racing oils, informed us that their entire line of racing oils has never been reduced of its zinc content. All of their racing oils still contain favorable levels of zinc and contain special cuts that enhance oil cling and anti-scuff properties.

While many of American Refining Group’s race engine customers use its 20W-50 racing oil for break-in, dyno and competition use, the company has also introduced a dedicated break-in oil for flat tappet cam engines called Penn Grade 1. This is a straight 30W oil with high levels of zinc and special anti-scuff properties, and is specially formulated to promote proper piston ring seating during break-in as well. This is definitely a premium break-in oil.

To summarize, while there are a handful of engine oils out there that are reportedly safe to use for flat tappet cam break-in, the select few for which we have definite approval include the Brad Penn Penn Grade 1, the Joe Gibbs MicroZol BR and Valvoline’s VR1 Racing oils. Coat the lobes and lifter faces with the cam maker’s approved assembly lube, use one of these oils, and you should be good to go.

Both rod and main bearings must feature a ­specified amount of crush area in order to achieve bearing lock-in within the housing.

The bearing shell outer edges (approaching the parting line areas) are larger than the saddle, which adds to the lock-in placement of the ­bearing shells.

Dirt particles or embedded blasting shot left behind in the housing face can push the bearing inward, creating a high spot between the bearing and shaft, which leads to damage of the bearing’s outer layers. This will restrict oil clearance and can cause localized overload, friction, heat and will lead to bearing failure.

Oil film is formed during shaft rotation. As rotation begins, the oil film is generated, which travels around the circumference of the shaft, literally lifting the shaft into a centered location.

This view shows the damage that results from trapped particles behind the bearing. Note the bearing wear on the face (left). A metal chip that was trapped behind the bearing during assembly distorted the bearing wall ­inward against the shaft, causing wear through the overlay into the copper-lead base.

Through the analyzing of elasto-hydrodynamic lubrication (EHL), we see the difference in oil pressure peaks with H-beam (left) and I-beam connecting rods.

During TDC on the exhaust stroke, the bearing housing may begin to ­elongate, creating a greater bearing clearance at the top of the rod bearing.

Bearing cavitation damage can begin to occur when the shaft pulls away from the oil film abruptly, creating vapor bubbles. Once the bubbles break, this cavitation erosion can slowly begin to erode the bearing face.

This view shows the bearing construction of a Clevite TriArmor bearing, including the steel backing, cast copper/lead layer, babbitt outer layer and the moly/graphite surface coating.

Moly/graphite anti-friction coating needn’t be applied to the thrust faces of main bearings, since it’s common for builders to fine-tune crankshaft thrust by sanding the thrust surface of the bearing.

CLEARANCES VS. CAVITATION ­EROSION

Cavitation erosion of a bearing occurs when rapid movement of the shaft away from the bearing surface causes vapor bubbles to form in the oil film. When these bubbles break, the resulting force causes erosion of the bearing soft overlay layer. Appearance and location of cavitation erosion will differ with operating conditions due to varying load patterns in different engine applications.

According to Havel, the nickel dam in the H-series and copper-indium intermetallic compound in the V-series helps to resist further penetration. Prolonged exposure will eventually result in erosion of the nickel or copper-indium dam. H-series bearings feature a thicker nickel dam to resist cavitation longer. Eventual penetration of the nickel dam causes copper particles to break loose, enter the clearance gap and become embedded into the bearing surface.

So far, the most effective means of controlling cavitation erosion seems to be a reduction in bearing clearance. This has worked in IRL and NASCAR applications. As an example, Aurora IRL engines running 0.0028″ rod clearance experienced cavitation erosion, but those running a slightly decreased clearance of 0.0020″ showed little or no cavitation erosion.

BUILDERS’ VIEWS

In order to gain further insight from a race engine builder’s perspective, we spoke with three noted builders. Following are their comments.

We’ve tested cryogenic treatments on main and rod bearings but, while cryo treatment has its place in other areas, they haven’t seen a benefit in terms of bearings. The new coating for the TriArmor bearings is far superior to the original coating and holds up very well. The new coatings have improved a ton. Oil clearances have definitely become tighter, with 0.0011-0.0015″ now becoming commonplace, especially due to smaller journal sizes and the use of synthetic oils (depending on the application, they’re running 0-10 up to 20-50 weights, with the majority using 10-30 and 10-40).

Depending on the application, our engines are running less oil pressure, and less parasitic drag (we’ve taken full advantage of oil shedding coatings to help reduce drag). The only secret I’ll share is our method of installing rod bearings. Instead of finger-pressing them into place, we roll the bearing shells into place in a back and forth motion for improved seating uniformity, which removes any high spots.

Ray Jager
Power Source Racing Engines
Fox Lake, IL

Unlike a few years ago, there are actually quite a few similarities between street high-performance engines and race engines in terms of bearing applications. Race engine bearings used to run gobs of clearance, upwards of 0.003″ or so, based largely on the oils we were using. Today, with thinner synthetics and improved oiling systems, we’re able to run tighter clearances in the neighborhood of 0.0015″ on rod bearings, and sometimes less. Today we’re able to do this while still providing better bearing life and decreasing friction at the same time. Granted, we pre-heat our oil before the engine is started in order to get optimum flow from the start, so it’s a more controlled environment as opposed to what a street engine will see.

In an effort to save weight, our main journals are down to 2″. Our main bearings clearances get down to almost as tight as the rod bearing clearances. We ball-mic each and every bearing to verify thickness and we even check for straightness, allowing us to categorize bearings. However, the Clevite bearings are so precisely made that we can pretty much just run them out of the box. Once in a while, we do mix and match bearings to achieve desired clearances, but we prefer not to.

Sometimes we’ll run a half-under on one side and a standard on the other side. Clevite TriArmor bearings are already coated, but not on the thrust faces. That’s good, since we sometimes lap the thrust faces on a granite block in order to fine-tune out thrust clearance.

As far as crank oil holes are concerned, we simply deburr the holes to break off the edge. Years ago, we used to radius-sweep the holes, but you get too much bleed-off doing that, so now we simply deburr the holes, removing as little material as possible. Since Cup engines run flat tappet cams, we use a mineral oil for break-in. Once we know that everything is seated and ready to go, we then switch to a synthetic for track use. We do pay close attention to the zinc phosphate content of the break-in oil, since inferior levels of the scuff protection can cause severe problems during break-in.

Dennis Borem
Pro Motor Engineering
Mooresville, NC

When we select bearing sizes, we pay attention to not only suggested clearance, but we also take into account the bearing surface from an anticipated load standpoint, as well as bearing speed, based on journal circumference.

In higher-end engines, where you plan to run smaller journals sizes, you really need to pay attention to the load-carrying capabilities.

In order to provide adequate oil delivery, we sometimes drill extra oil holes in the bearings and partial-radius grooves in the housing or saddle area of the mains to create multiple oil supply points. This is especially important in engines that use smaller bearings and will experience higher loads.

We try to run a fairly high crush while maintaining this within an acceptable range. Considering bearing load and journal and housing deflection, we want to make sure that the bearing is securely held in place. Where you have oil films that are in the tenths of thousands clearance, the bearing gets very hot. If you don’t have adequate crush, you won’t get enough heat transfer. Avoid taking housings to their maximum size to avoid inadequate heat transfer.

In many of our high-load builds, we modify the crankshaft journal oil holes in order to drive more oil to the rods. As you shrink the rod journal diameter, the load goes up. In order to get extra oil to the rod bearings, we create a slight teardrop groove to the crank main oil holes. We slightly groove the leading edge (attack side) of the oil hole. As the crankshaft rotates, this slight teardrop-shaped cavity fills with oil and is then force-pumped into the oil hole, increasing boost pressure.

This can cure problems with rod bearings that were otherwise seeing too much load. This can be done with a grinder, but we usually perform this on a CNC machine. However, you need to pay strict attention to the dimensions of the teardrop groove in terms of width, length and depth. Generally speaking, this teardrop groove is usually around 0.300″ to 0.400″ in length. If the groove is too aggressive, you could start starving the mains for oil. The specific profile of this groove controls the amount of oil pressurizing into the rod.

Understanding the specific engine’s oiling system is key. For example, in OHC engines, where hydraulics are responsible for much of the valve control, you need to maximize oiling efficiency to make sure that sufficient oil gets delivered to the top of the engine quickly.

As far as bearing clearances are concerned, for street engines that see higher loads, we tend to run somewhere around 0.003″ for mains and around 0.0025″ for rods.

We work within a window of about 0.001″ and keep a pretty tight tolerance range.
For engines that will see lots of heat for extended periods, such as endurance engines or marine engines, we tend to run tighter bearing clearances, to compensate for the fact that clearances will loosen under hot conditions.

Mike Schropp
Livernois Motorsports
Dearborn, MI

FINE-TUNING BEARING CLEARANCE ON UNDERSIZED CRANKS

In an effort to aid engine builders in fine-tuning their bearing clearances, MAHLE Clevite recently introduced half-size H-series performance bearings. New part numbers include 0.009″, 0.011″, 0.019″ and 0.021″ rod and main bearings. These special-size bearings offer greater latitude in choosing bearings for performance engines that feature an undersize-ground crankshaft. By taking advantage of these new bearings, builders can easily achieve specific bearing clearances of +/- a half-thousandths of an inch. For example, using a pair of 0.009″ bearings will reduce bearing clearance by 0.001″ compared with normal 0.010″ bearings.

Similarly, clearance can be increased by 0.001″ by using a pair of 0.011″ bearings. It is also possible to use one 0.009″ bearing shell in combination with a regular 0.010″ shell to reduce clearance by 0.0005″, etc. These special half-size bearings are currently available for w wide range of Chevy, Ford and Chrysler applications. All bearings feature TriArmor construction and MAHLE Clevite’s unique moly graphite coating that’s distributed in a PTFE (polymer) carrier.

A WORD ABOUT COATINGS

If you’re having bearings coated, avoid applying anti-friction coating to the parting line surfaces. A 0.0003″ coating on the parting line faces can increase the total bearing crush effect by 0.0012″, which can create an initially distorted bore. As the coating extrudes from the parting line surfaces, the bearing may then lose its tight fit in the housing. Also, notes Clevite’s McKnight, coating should not be applied to main bearing thrust faces. “Since engine builders will often sand the coating off of the thrust faces in order to achieve the desired end play,” he said.

RACE BEARING TECH

The bearing gurus at Clevite share insight regarding current and future rod and main bearing development.

Installed bearing sets create a slightly eccentric bore, which promotes oil film capture and enables the rotational movement of the shaft to generate a hydroplane of oil film around the circumference.

Bearing crush is critical to holding the bearing in place. With the cap installed, this exerts radial pressure, forcing the bearing backs outward radially.

When big bucks and series championships are on the line, every nuance is considered. Bearings are no exception.

According to MAHLE Clevite’s Bill McKnight, top NASCAR Cup teams are carefully selecting bearings and measuring each. They will typically order about 500 bearings and check each individual bearing shell for height (in terms of crush factor) and thickness, etc. They’ll carefully categorize each bearing as tight, loose or intermediate, which then allows them to pick and choose bearings depending on the specific engine application.

The trend among the Cup teams is to run tighter clearances, creating higher oil film pressure.

McKnight also noted that some teams are buying Clevite bearings from a proprietary facility in Scotland whose technicians painstakingly measure and package sets guaranteed to be exact matches. “These measured-and-matched bearings are rather expensive, costing around $30 each, so only teams with very healthy budgets are taking advantage of this,” McKnight said. “NASCAR engine developers are also currently testing cryogenic treatment of bearings to determine if this offers any benefit, but the jury is still out with regard to this. All teams are definitely taking advantage of bearing surface coatings, which is no longer considered a questionable approach. The use of anti-friction and oil-embedding coatings have definitely proven their worth.”

McKnight noted that Clevite’s first effort at cryogenically treating race bearings for drag applications was made during the summer of 2007 for the top fuel and funny car teams, the hardest users of bearings we have. Tests continue, improvements look to be small, perhaps 5-7 percent, but when you’re using all we’ve got in a bearing and still asking for more, that may be enough. The treatment consists of freezing finished product at well below -300F for seven to eight hours.

Clevite has made a running change in the TriArmor, coated bearings. Improved coating durability is the result without sacrificing any of the features of the original bearing, except for a darker blue color to the coating. The change was a running production change last spring so most, if not all, of the line is new material when you order parts from your supplier. Clevite also supplies the custom bearing coaters with Clevite race bearings for their production (including HM Elliott, Calico and Polydyne). Coated bearings are very popular in the professional ranks of both circle track and drag racing-friction reduction and resistance to scuffing are two key benefits.

In the NASCAR realm, a few changes have been instituted. Standardizing on a minimum size of 1.850″ for the rod pins and 1.999″ for the mains is now completed. Clevite has numerous choices for these engines, including both H series and V series materials, 2.000″ main sets, main sets allowing teams who ran a 2.017″ main journal last year to use those same blocks with a 2″ crank (.017, .018, .019″-under sets) narrowed rod shells, dowel holes in some sets, extra clearance sets and inventory on the older sizes still used by some teams (1.770″ rods and 2.300″ main, RO7 blocks).

As NASCAR teams continue to narrow the rod bearings in search of less friction and more horsepower, the locating lug on the bearing insert has been placed very close to the edge of the bearing, creating what might be considered a stress point. Clevite is currently in phase-two testing of a new indentless lug insert for those applications. This provides a smooth, uninterrupted surface at the parting line. The company expects to start shifting the production of NASCAR rod shells to that design some time in 2008.

Also for drag racing applications, pro teams, many of whom are using Clevite off-the-shelf race bearings, are starting to take a look at what the NASCAR teams have been doing. Reduced mass, lower friction and coatings are all subjects being talked about at the track. One way to look at it is if your engine bearings look really good at teardown for refreshing the motor, you’re probably leaving something on the table in terms of performance improvements. Now, bear in mind, for the vast majority of racers, there are easier places to get more horsepower than engine bearing modifications but, for those at the very top levels, perhaps not.

BEARING DESIGN AND ­CONSTRUCTION

Six criteria that must be considered in terms of high-performance bearings include bearing construction and materials; proper housing and shaft geometry; proper bearing geometry; proper surface finishes; sufficient supply of clean oil; and adequate oil viscosity.

In terms of construction, cast bearings provide superior strength as opposed to sintered bearings produced from powdered metal. Sintered bearings lack the continuous copper phase that is needed for strength. A high-performance bearing produced using a steel back, a cast copper-lead primary layer, a nickel dam (laid on top of the copper-lead mass) and a lead/tin/copper overlay provide the best performance for bearings used in high-stress applications.

In short, all high-performance bearings are of the cast copper-lead type.
Main and rod bearing shells feature a slight projection area when installed in the saddle or cap. When the cap is installed and fully tightened to specification, this crush height forces the bearing shells to attempt to expand outward, applying radial pressure concentrically around the bearing housing. This creates the proper geometric shape of the bearing I.D. and locks the bearing in place, preventing bearing movement relative to the bearing housing.

Contrary to popular belief, the small locating tangs/grooves featured adjacent to bearing parting lines are not responsible for locking the bearings in place. These tangs and grooves serve to locate the bearings during assembly only. The installed radial pressure is the primary force responsible for locking the bearings in place. Bearing shells are also slightly larger across the open end as compared to the housing (saddle/cap). When forced into the housing, this slight interference fit also holds the individual bearing shells in place during the assembly process.
Bearing shells are slightly tapered (thinner) approaching and at the parting line.

This creates an eccentric I.D. that promotes a pressurized oil film as the shaft rotates, allowing the oil film to compress and expand as the shaft rotates. This creates a hydroplaning effect, providing an oil film to quickly establish between the journal surface and the bearing. This is the reason that rod bearings are not grooved because you want to create a hydroplaning effect for maximum oil travel between the bearing and journal. The bearing I.D. eccentricity also dictates how an installed bearing I.D. is to be measured. The tightest areas (in terms of minimum clearance between the bearing and journal) will always be at the top and bottom (12 o’clock and 6 o’clock) positions, so bearing I.D. must be measured between these two points.

Performance bearings use a maximum amount of crush. If you over-compress the bearing, you’ll create a thick spot on the bearing wall, possibly minimizing clearance and oil travel. If you have insufficient crush, the bearing will be loose, resulting in bearing surface polishing or fretting (metal transfer).

According to Clevite’s John Havel, if you’re faced with slight geometry problems regarding journal geometry or misalignment, a good choice is Clevite’s V-series bearing, which features a 0.0010″ lead/indium overlay and no nickel dam. This bearing offers a softer surface edge that will be more forgiving if you’re dealing with slight misalignment. The P-series features a 0.0005″ lead/tin/copper overlay. The H-series rod bearings feature a 0.0005″ lead/tin/copper overlay, and the H-series main bearings feature a 0.0010″ lead/tin/copper overlay.

GENERAL CLEARANCE RECOMMENDATIONS

Start with 0.0010″ of clearance per inch of journal diameter. For example: 2.100″ journal diameter X 0.0010 = 0.0021″ clearance. For high-performance applications, add 0.0005″. If, for example, initial clearance is determined to be 0.0021″, add 0.0005″ for a final clearance of 0.0026″. From this point, tighten clearance as your experience dictates in specific applications.

Note: Use of a dial bore gauge is always the recommended method for measuring oil clearance. Instead of measuring journal diameter and then measuring installed bearing diameter, zero the bore gauge at the actual journal diameter. When you measure bearing diameter, you’ll obtain a direct clearance reading without the need to perform math procedures, avoiding potential math mistakes.

Havel emphasizes that if clearance modification is needed, do not increase or decrease clearance by modifying housing size outside of tolerance limits. An undersized housing will over-crush the bearing and an oversized housing will reduce crush and bearing retention.

Currently, Clevite utilizes finite element analysis computer modeling to examine the elastic deflections of all bearing-related areas. EHL, or elasto-hydrodynamic lubrication, allows engineers to more accurately determine the affects of dynamic forces in relation to forces and oil clearances. This understanding of loads, metal deflection and affects on clearance has allowed a more precise view of what the bearings are subjected to, and furthers engineers’ ability to develop bearings that will function properly in high-stress dynamic racing applications.

LS1 chamber.

LS1 intake ports. All except L92 and LS7 feature cathedral style intake ports.

Cathedral intake ports measure approximately 3 1/8″ in height.

Cathedral intake ports measure approximately 1″ in width.

Exhaust ports are D-shaped.

The LS6 heads feature a casting number of 243.

A view of LS6 intake ports.

Heads feature pushrod clearance reliefs.

The LS7 heads feature casting No. 8452.

Full view of LS7 rectangular intake ports.

Ported LS7 intake ports.

All Gen III/IV heads feature beehive-style single valve springs and small retainers.

Beehive springs take advantage of coil shape to ­minimize unwanted harmonics, eliminating the need for dual damper springs.

LS1 and LS6 heads require a rail for rocker mounting. The mounting bosses in the head casting are machined flat to accept this rail.

The LS7 needs no rail. Pedestals are machined with a female radius for paired-up rocker shafts.

LS7 intake rockers feature an offset.

In some applications, exhaust valves are hollow with sodium. photo courtesy Katech

Roller lifters are ­registered to prevent rotation in lightweight composite lifter trays.

Each lifter tray holds four lifters. The tray is secured in place to the head with a center bolt.

Camshafts are unique to the Gen III/IV engines. (photo courtesy Katech)

Here’s a close-up of a CNC ported combustion chamber on an LS6 head. (photo courtesy Katech)

Katech’s “Street Attack” 7.0L LS7. (photo courtesy Katech)

Katech’s LS7 crate engine. (photo courtesy Katech)

LS6 equipped with a supercharger. (photo courtesy Katech)

All Gen III/IV engines feature individual ignition coil packs. (photo courtesy Katech)

In addition to four vertical main cap bolts, each main cap also features one side-entry bolt per side.

The Gen III and Gen IV blocks feature the thrust bearing located at the No. 3 main.

The center valley on this LS6 block features two knock sensor bung ­locations.

The LS7 blocks feature an easy-to-find cast-in “7.0L” identification on the right front outer wall.

Crankshafts feature a reluctor timing wheel. The unit shown here is a forged crank from Callies. (photo courtesy Katech)

All Gen III/IV engines feature a front-mount crank-driven ­gerotor style oil pump that is keyed to the crank snout.

While early Gen III LS1 engines featured perimeter-bolt valve covers, all later versions use the center-bolt style over. The ­covers shown here are made by Katech.

LS1 and LS6 engines feature two different length (short/long) primary head bolts (10mm x 100mm and 10mm x 155mm) in addition to 8mm x 45mm inboard pinch bolts. The LS2 and LS7 engines use the shorter 100mm bolts only, along with the pinch bolts.

OE connecting rods for all except LS7 are PM (powdered metal).

OE pistons feature a moly/graphite skirt coating, screen-printed onto the skirts.

The OE PM connecting rods feature cracked caps for dedicated cap registry.

Whenever servicing cracked cap rods, the caps must be kept with their ­respective rods. Katech tells us that for any high performance application, ­superior aftermarket rod bolts should be installed in place of the OE TTY bolts.

Pistons require clearance at the pin bosses because of the crank reluctor wheel (only at No. 8 piston, but all pistons are the same due to balance).

The LS7 uses forged titanium ­connecting rods as OE. (photo courtesy Katech)

LS1 cylinder heads feature a No. 853 casting identification.

CAMSHAFTS

All LS series camshafts are of the roller style. The LS series of engines utilize a camshaft timing sensor. To provide a signal to the sensor, 1997-2004 LS engines feature a machined reluctor on the camshaft, located immediately in front of the No. 5 main cam journal. Camshafts from 2005 and later eliminate this reluctor, with cam timing picked up at the cam sprocket.

An incorrect rumor has it that when using the stock valve train geometry, the safe maximum camshaft lift must be kept to 0.570″, since the rockers begin to dig into the valve tips beyond that lift. However, Katech’s Newman told me that this isn’t true, since World Challenge race engines that they’ve built typically feature as much as 0.595″ lift with no problems.

By the way, standard LS series OE rocker arm ratio is 1.70:1. The LS7 features 1.80:1 rockers.

All LS heads feature PM (powdered metal) valve seats and powdered metal guides (this PM formulation provides the lubricity of bronze and the longevity of cast iron guides).

All LS1, LS6 and LS2 heads feature tall cathedral-style intake ports. The LS7, L92 and LS3 heads feature rectangular intake ports.

All LS heads, with the exception of the LS7, feature as-cast chambers and ports. The LS7 heads feature CNC-machined chambers, intake ports and exhaust ports.

According to Katech, all cylinder heads within the LS family are physically interchangeable among blocks, with the exception of the LS7 heads. The LS7 cylinder heads cannot be mounted to other LS blocks, as the wider valve layout would result in valves contacting the bores. Also, the L92 head cannot be used on the LS1. Valve clearance must be verified before performing any head swap.

A variety of OE Gen III heads are available, including an iron small port (initially used on the 4.8L truck engine), the LS1 aluminum head, the LS6 aluminum head with 63cc chambers, the LS4 aluminum head with 67cc chambers and LS6 heads with larger ports and larger chambers.

FIRING ORDER

All LS series (Gen III and IV) engines feature a firing order of 1-8-7-2-6-5-4-3. This represents four cylinder swaps as compared to the standard (Gen I and Gen II) smallblock/bigblock Chevy order of 1-8-4-3-6-5-7-2.

FASTENERS

All OE threaded fasteners in the LS series of engines are metric. There are no imperial-format (inch) fasteners anywhere in the original-equipment build.
All OE cylinder head bolts, main cap bolts and rod bolts require torque/angle tightening.

There are also no NPT threads found anywhere (water jackets, etc.). Instead, straight metric plugs that featured that use O-ring seals.

VALVES

Some engines feature solid stems, while others feature hollow, sodium-filled exhaust stems. The LS7 uses titanium intake valves and hollow sodium exhaust valves.

LIFTERS

All LS series engines feature a roller lifter, and all feature a 0.842″ lifter diameter. Instead of using dogbones or metal finger-trays to locate the roller lifters (to prevent lifter rotation in their bores), special LS-only composite plastic “lifter trays” are used. These trays each hold four lifters. The cylinder block features a large recessed area above each set of four lifters to accept these trays. During assembly or disassembly, the lifters are held by the trays, allowing a complete set of four lifters and their tray to be installed or removed as a set (lifters and tray together).

ROCKERS

All LS series rocker arms are semi-roller type, featuring a trunion bearing at the pivot. All LS rockers are interchangeable for intake and exhaust except L92, LS3 and LS7 rockers. LS7 rockers are unique, as the intake rocker features an offset, and the LS7 rocker ratio is higher at 1.80:1, as opposed to 1.70:1 for all other LS engines.

CYLINDER HEAD GASKETS

Early LS engines featured composite type cylinder head gaskets. Around 2002, GM switched to MLS head gaskets.
All remaining gaskets throughout the engines are formed elastic seal type gaskets that are reusable (depending on condition of course).

PISTONS

OE stock pistons are hypereutectic type. Aftermarket forged pistons are readily available from most piston makers. Depending on the specific crank, LS type piston No. 8 may require a narrower profile at the pin bosses in order to clear the crankshaft reluctor wheel (used for picking up crankshaft timing). This is especially important if a stroker crank is being used. Piston deck height (LS1) is 0.008″ above deck.

VALVE SPRINGS

All LS series heads feature beehive-shaped springs (these feature smaller diameter upper and lower coils for superior damping of spring harmonics). All OE spring retainers are steel, even in the LS7. This single beehive spring design eliminates the need for dual springs, and also allows the use of smaller and lighter retainers.

CONNECTING RODS

All LS rods are constructed of forged powdered metal (PM) with cracked caps, with the exception of the LS7, which features forged PM titanium connecting rods.
While the standard smallblock/bigblock Chevy engine featured an offset connecting rod, the LS series features on-center connecting rods (pin bore in relation to big end bore). DO NOT use offset connecting rods in any Gen III engine!

According to Katech, the OE rods are surprisingly strong, while the primary weak point is the rod bolt. Changing to high performance aftermarket rod bolts is recommended. At this point in time, there are plenty of aftermarket forged rods from which to choose, to provide even greater durability than the OE PM rods. The OE rod bolt is 9mm, but Katech offers a 10mm rod bolt to work with OE rods.

According to Newman at Katech, the LS6 will safely over-bore to the same diameter as the LS1, but the LS6 features a sturdier engine case and is a better choice for overboring than the LS1. Newman noted that the larger-displacement LS2 is a less-expensive and superior block than either the LS1 or LS6, and offers much more interchangeability with LS6 OE production parts. Confusing, isn’t it? Welcome to the LS.

How large a displacement can you easily obtain by increasing bore diameter and stroke?

According to Katech’s Newman, the LS1 or LS6 (originally 345 CID) can be sized to a max of 414 CID using a 4.000″ stroke. The LS2 (originally 364 CID) can be easily oversized to 427 CID max as well. Newman noted that 414 CID is the biggest you can go with a dry sleeve on the LS1/LS6. The LS2 can go to 427 CID with a dry sleeve.

Modifications intended to achieve greater strength and durability include changing to forged crankshafts, connecting rods and pistons, billet main caps, replacement connecting rod bolts, the use of head and main studs and oil pump modification, among other tricks. Oil pump mods include disassembly, deburring the pump inside and out, porting the oil entrance, polishing the pressure relief section and reassembly.

Editor’s Note: The majority of the information presented here was graciously provided to us by Katech Performance. Katech has been around for over 30 years and has built a vast array of championship-winning race engines. Katech has also been closely involved with GM during the development of the LS series of engines, and has developed an extremely wide range of performance engine components for this engine series.

I would like to extend our sincere appreciation to both Caleb Newman and Jason Harding at Katech Engine Development for their courtesy, time and expertise in helping to prepare this information for our readers.

UPCOMING PROJECT

Now that we’ve provided an overview of the LS engine family, it’s time to get our hands dirty once again. We’ll soon begin to build a special LS project engine during 2008 and rest assured that we’ll supply all of the details as we go, with a dyno run at the completion of the build.

LS ENGINE TECH

The current new ­generations of GM ­engines are here to stay and ­represent the hot ticket for today’s and ­tomorrow’s ­hot-dog smallblocks for both street ­performance and racing applications. It’s time to get up to speed.

by Mike Mavrigian

photos by author

LS6 aluminum 5.7L block.

LS2 aluminum 6.0L block.

The Gen III and Gen IV (Gen IV is the most current) family of GM smallblock engines. With the LS1 debuted in 1997, the LS, or Gen III, has been in consumers’ hands now for over 10 years and is beginning to gain momentum in the performance aftermarket. It’s painfully obvious that it’s high time we started taking an in-depth look at the new smallblock, which is predicted to be as popular as the original Gen I Chevy smallblock that began production back in 1955.
The Gen III engine started from scratch, a clean sheet of paper in terms of design. Aside from cylinder bore spacing, rod journal diameter and lifter diameter, the Gen III has nothing in common with previous smallblocks.

The entire Gen III family of engines includes more than 5.7 and 6.0L versions. Included are the 4.8L LR4, the 5.3L LM4, 5.7L LS1 and LS6, 6.0L LQ4 and 6.0L LQ9.

Truck and SUV Gen III engines featured iron blocks with iron heads and, in some applications, iron blocks with aluminum heads. The Escalade is the only SUV application that used an aluminum block and aluminum heads.
In Corvette, Camaro, Firebird, GTO and Cadillac CTS-V applications, all LS1 and LS6 engines featured aluminum blocks with aluminum heads.

GEN III SIMILARITIES TO GEN I

4.400″ bore spacing
2.10″ rod journal diameter
Valve train oiling through the pushrods
0.842″ lifter diameter
Single-piece rear main seal (similar to late Gen I and Gen II)

GEN III DIFFERENCES

Here are the primary design changes that represent the basics of the Gen III engine:
Block deck height is 9.240″ (up from 9.025″)
Firing order is 1-8-7-2-6-5-4-3 (Gen I/II is 1-8-4-3-6-5-7-2)
Bank offset changed to 0.9488″ (from previous 0.8800″)
Y-skirt block
Cast aluminum sump
No distributor provision
Lighter weight (approx. 430 lbs. vs. Gen I 531 lbs.)
Connecting rod length is 6.098″ (vs. previous 5.700″)
On-center beam connecting rods (no offset)
Piston pin diameter 0.940″ (vs. previous 0.927″)
Crank thrust has moved from the rear to the No. 3 main bearing
Cam-to-crank centerline distance is 4.914″ (vs. previous 4.521″)
The crankshaft flange has moved 0.40″ closer to the rear of the block
Water temperature is controlled on the intake side of the water pump
Replicated ports vs. mirrored ports

HEAD BOLTS

According to Katech’s Jason Harding, the LS1 and LS6 feature two different length hex-head cylinder head bolts (10mm x 100mm and 10mm x 155mm), later LS2, LS7, LS3 and L92 engines use only the 10mm x 100mm head bolt length.

Additional pinch bolts at the inboard edge of the cylinder head uses 8mm x 45mm hex head bolts. All LS heads require 10 primary cylinder head bolts, plus five 8mm pinch bolts. All primary head bolts are TTY (torque-to-yield) type and feature OEM thread locking compound. All head bolts enter blind holes, so none are open to water or oil.

BLOCK AND CRANK NOTES

All LS blocks feature a 4.400″ bore spacing and a bank angle of 45 degrees. The OE aluminum blocks are cast from 319 aluminum and feature vent holes (cast or drilled) in the main webs.

The LS series of blocks and cranks feature the thrust bearing located at the No. 3 main as compared to the rear-located early Chevy engines. Engine rotation is clockwise.

Note: While the Chevy service manuals may note that the damper bolt should not be re-used, this is not because the damper bolt is TTY, because it’s not. Rather, they recommend damper bolt replacement only because the underside of the bolt head features an OE friction-reducing contact surface that may be worn away on a damper bolt that has been installed and removed.

All LS series blocks feature individual main caps that are secured with a total of six bolts. This includes four primary (vertical) bolts plus two side bolts that enter through the outside of the block, above the pan rail. Because of this side-bolt design, which offers superior rigidity, main caps cannot be ground to reduce the bore size if align-boring is needed, as this would throw the side bolts out of register. If the main bores must be machined in order to correct a roundness or center issue, oversize-O.D. main bearings would then be required. The LS7 is the only version that came OE with billet main caps. All other LS main caps are PM steel. However, Caleb Newman with Katech noted that small changes can still be made to the caps without throwing them away, as a small bit of clearance exists at the side holes.

LS series engines utilize a front-mounted keyed, crank-driven oil pump.
All LS cranks are cast, again with the exception of the LS7 cranks, which are forged.

The LS1 and LS6 blocks, though sharing the same dimensions, differ somewhat, with the LS6 block featuring slight changes in main web design for crossover breathing (the LS6 block main webs are slightly skeletonized).

Crankshaft counterweights are cam-ground to clear piston skirts. Cam grinding also makes crank balancing a bit easier.

Newman noted that Katech developed a proprietary process for sleeving up to a 4.125″ bore on the LS2. If stock bores are desired, it’s more cost effective to buy a new block. If sleeving is required for an aluminum block, all eight cylinders are bored to size, then honed to size for each individual liner. The new liners are installed at 270 degrees F and are then torqued three times during the cooling process. Liner bottoms must also be notched for rod clearance. The block is then decked, the main caps are installed, and the main bore is bored or honed. The block is then double-vacuum impregnated. The liners are then bored and honed for individual piston fit.

Katech notes that a GM performance Parts Race Case is available that features 356 aluminum, Siamesed bores, steel billet main caps and 7/16″ main and head bolt locations. This block will accept 4.125″ bores.

The vacuum pump and alternator setup hangs low, leaving the head area clean.

Belt tension adjustment on radius tooth setups don’t require much tension at all, which removes a bit of stress from the crank. The tooth engagement alone provides a positive pulley drive.

Routing the -12 plumbing from the vacuum pump to the valve covers allowed a simple path for the hoses that doesn’t obstruct anything.

A Jegs billet aluminum water neck housing features a 24-pound Moroso cap and three available threaded ports on the backside for attaching extra water lines and/or a temperature sensor.

Yes, I checked rocker arm clearance at the valve covers. No problem. The Moroso welded aluminum covers are very light and sleek.

Why is this guy smiling? Hey, the assembly is done and it’s been a long time coming. Maybe I can sneak in a day or two for some fly fishing.

As usual, I performed the entire build on a Goodson engine cart. With a roll-around design, an upper drip/work tray and lower storage tray; these carts are my favorites.

Our engine at Gressman Powersports during dyno mounting.

Gressman’s Superflow dyno features a cooling tower through which our cooling system was managed.

Gressman’s exhaust headers are fitted with thermocouplers to monitor exhaust gas temperature at individual cylinders.

Following the first test-run at low RPM, Scott Gressman makes a minor fuel mixture adjustment. Our Holley Dominator performed superbly, virtually out of the box. We made no jet changes at all during our brief dyno session.

The BG fuel rail performed perfectly, with no leaks. The three O-rings in the sliding tube system do indeed provide proper sealing. We adjusted the Race Pumps fuel pressure regulator to settle at about 9 pounds pressure.

After test running and full warm-up, Gressman re-checks valve lash, setting intakes and exhausts at 0.028 inches.

Gressman ran the dyno board. Here he makes a few last-minute system checks. Our first pull yanked 1,098 horsepower, not bad for an out-of-the-box run. Our best pull netted 1,115 horsepower.

Following a couple of test runs to perform our pre-flight checks, the air feed stack is installed and we’re ready to make our first hard pull.

 

THE DYNO RUN

For better or worse, the moment of truth was finally upon us. In the later afternoon of September 19, I transported the engine to Gressman Powersports in Fremont, Ohio (only about 90 miles from my shop).  Scott Gressman maintains a SuperFlow engine dynomometer. On the way to Gressman’s shop, I stopped at a race fuel distributor and picked up 10 gallons of VO 114-octane leaded race fuel (at a whopping $13.86 per gallon!).

The next day, Gressman’s crew mounted the engine to the dyno stand and connected the fuel and cooling plumbing, wired the Meziere electric water pump, installed their thermocoupler-equipped exhaust headers, etc. Prep took about one hour.

After adding 7 qts of 30-weight oil to the sump, the distributor was removed and the oil pump drive shaft was rotated with a cordless drill to pump oil through the engine for priming. Initial timing was set at 25 degrees. All timing adjustments were made at the MSD crank trigger sensor (by moving the sensor in relation to the trigger wheel).

With everything in place, Scott hit the starter and much to my relief, she fired and ran (I’m always antsy whenever a fresh motor first comes alive). Scott allowed her to run for a few minutes at around 1,400 – 1,500 RPM while monitoring the vitals. We immediately had about 65 lbs of oil pressure (which bumped to 80 psi during pulls), and no leaks occurred anywhere on the motor.

After allowing the engine to warm up, Scott shut her down and re-checked hot valve lash, setting all valves at 0.028”.

The first hard pull, with timing set at 27 degrees, with a pull netting 1,098 HP at 7,150 RPM. A second pull, with timing at 30 degrees, yanked 1,105 HP at 7,150 RPM. The final pull, at 32 degrees timing, and with the camshaft retarded 3 degrees, produced 1,115 HP at 7,150 RPM.

Torque wasn’t as high as we had expected, to be honest. The best we pulled (on the first run) was 882.0 lb-ft. On our best horsepower pull, the highest torque reading was 863.4 lb-ft. We had expected torque to be in the mid-to-high 900 range. But again, these are still respectable numbers, and with further tweaking, we feel very confident that there’s more to be had.

 

 

OUR FINAL DYNO PULL

 

RPM           TORQUE            HP

5200                                                 844.4                                             836.0

5300                                                 846.8                                             854.5

5400                                                 851.9                                              875.9

5500                                                 855.8                                              896.2

5600                                                 860.5                                              917.5

5700                                                 863.9                                              937.6

5800                                                864.2                                             954.4

5900                                                  863.3                                              969.8

6000                                                  862.5                                              985.4

6100                                                   863.7                                            1003.1

6200                                                   860.1                                            1015.4

6300                                                   858.5                                            1029.8

6400                                                   855.5                                            1042.4

6500                                                   854.0                                            1056.9

6600                                                   850.5                                            1068.8

6700                                                   848.0                                            1081.8

6800                                                   842.5                                             1090.8

6900                                                   835.9                                              1098.1

7000                                                   829.5                                              1107.6

7100                                                   823.0                                               1115.5

7200                                                   811.4                                                1112.3

7300                                                   798.1                                                1109.3

 

In the 5700 – 6200 RPM range, average Fuel A lb/hr was 174.5. Fuel B lb/hr was 170.9. A/F ratio was 14.79 (max 15.31). Average volumetric efficiency was 113.6%.

 

 

Scott felt comfortable that with more timing tweaks, and perhaps switching to dual 1050 carbs, we would likely hit somewhere between 1,150 to 1,200 HP. Unfortunately, we had only a limited timeframe to use the dyno, but for an initial out-of-the-box run, 1,115 HP isn’t bad at all. I was surprised at how incredibly responsive the engine was. She snapped revs quicker than a hungry dog chowing-down a bowl of Kibbles. And the horrific shriek she made at high revs was both scary and wonderful. She’s definitely a nasty lil’ rat.

 

I have no illusions that we’ve created the best of anything. I know full well that many of our readers could pull bigger horsepower and torque with various tweaks to cam profile, ignition timing and fuel delivery. But, what we’ve accomplished in this build series definitely lays the groundwork for this type of build. We hope you’ve enjoyed the project and above all, we hope that the information we’ve provided is of some benefit. I think that the information (in terms of component selection and prep) provides a very good guideline for a similar build that you may have in mind, or one that is requested by a customer.

 

 

 

 

PRODUCT SUPPORT

Thanks to the following for their involvement in this project…

 

 

ARP INC.

1863 Eastman Ave.

Ventura, CA 93003

805-339-2200

www.arp-bolts.com

 

 

ATI PERFORMANCE PRODUCTS

6747 Whitestone Rd.

Baltimore, MD 21207

410-298-4343; 800-284-3433

www.atiracing.com

 

 

BG FUEL SYSTEMS

1450 McDonald Rd.

Dahlonega, GA 30533

706-864-8544

www.barrygrant.com

 

 

 

CAM LOGIC

(Bolton Conductive Systems)

1164 Ladd Rd.

Walled lake, MI 48390

248-669-7080

www.camlogicsystem.com

 

 

CAM MOTION, INC.

2092 Dallas Dr.

Baton Rouge, LA 70806

225-926-6110

www.cammotion.com

 

 

 

CLEVITE ENGINE PARTS

1350 Eisenhower Place

Ann Arbor, MI 48108-3282

734-975-7938

www.engineparts.com

 

 

 

CRANE CAMS, INC.

530 Fentress Blvd.

Daytona Beach, FL 32114-1200

386-252-1151

www.cranecams.com

 

 

 

DART MACHINERY

353 Oliver St.

Troy, MI 48084

248-362-1188

www.dartheads.com

 

 

 

DIAMOND RACING PRODUCTS

23003 Diamond Dr.

Clinton Twp, MI 48035

586-792-6620

www.diamondracing.net

 

 

FALL AUTOMOTIVE MACHINE

3519 Jackman Rd.

Toledo, OH 43612

419-473-1557

 

 

GEAR HEAD TOOLS

P.O. Box 21887

Carson City, NV 89721-1887

877-245-0014

www.HearHeadTools.com

 

 

GOODSON TOOLS & SUPPLIES

156 Galewski Dr.

Winona, MN 55987

800-533-8010

www.goodson.com

 

 

GRESSMAN POWERSPORTS

904 Lime St.

Fremont, OH 43420

419-355-8980

www.gressmanpowersports.com

 

 

HOLLEY PERFORMANCE PRODUCTS

1801 Russellville Rd.

Bowling Green, KY 42101

270-782-2900

www.holley.com

 

 

 

JESEL VALVETRAIN INC.

1985 Cedarbridge Ave.

Lakewood, NJ 08701

732-901-1800

www.jesel.com

 

 

 

JONES RACING PRODUCTS

72 Annawanda Rd.

Ottsville, PA 18942

610-847-2028

www.jonesracingproducts.com

 

 

 

 

LUNATI

(see Holley Performance Products)

 

 

MANTON RACING PRODUCTS

558 Birch St., Bldg 4

lake Elsinore, CA 92530

951-245-6565

www.mantonpushrods.com

 

 

MEZIERE ENTERPRISES INC.

220 S. Hale Ave.

Escondido, CA 92029-1719

760-746-3273; 800-208-1755

www.meziere.com

 

 

 

MOROSO PERFORMANCE PRODUCTS

80 Carter Dr.

Guilford, CT 06437

203-453-6571

www.moroso.com

 

 

MSD IGNITION

1490 Henry Brennan Dr.

El Paso, TX 79936-6805

915-857-5200

www.msdignition.com

 

 

PRO-FILER PERFORMANCE PRODUCTS

P.O. Box 217

New Carlisle, OH 45344

937-846-1333

www.profilerperformance.com

 

 

RACE PUMPS

222 Hillcrest Dr.

High Point, NC 27262

336-476-9583

www.racepumps.com

 

 

 

ROYAL PURPLE, LTD.

One Royal Purple Lane

Porter, TX 77365

888-382-6300

www.royalpurple.com

 

 

SUNNEN PRODUCTS CO.

7910 Manchester Ave.

St. Louis, MO 63143-2793

800-772-2878; 314-781-2100

www.sunnen.com

 

 

TRICK FLOW SPECIALTIES

285 WEST AVE.

TALLMADGE, OH 44278

330-630-5560

www.trickflow.com

Even though the drive hub system will be clamped to the crank snout with the 6-inch long center bolt to prevent the possibility of independent hub rotation, two roll pins are installed to the hub. The countersunk inside face of the ATI Super Damper was then drilled to accept these roll pins.

Plumbing the vacuum pump is very straightforward. The two -12 vacuum inlet ports (seen here) are plumbed to the valve covers. A single -12 exhaust port (located on the opposite side of the pump body) is plumbed to a remote breather.

Although the prospect of a stainless-steel braided hose collapsing under vacuum may seem remote, Jones Racing suggests the installation of a flat-wound support coil to eliminate this concern.

In order to connect the vacuum pump plumbing to the valve covers, I had a -12 male AN fitting Tig welded to the front face of each valve cover.

I always use dedicated aluminum AN wrenches for any aluminum AN connection. This greatly minimizes the chance of burring the aluminum hose end assembly or marring the anodized finish.

The vacuum pump pulley is mounted to a shaft that registers on a long keyway groove, allowing you to adjust the fore/aft pulley position for perfect alignment to the drive pulley. Three set screws lock the pump pulley in place, and Jones Racing provides access holes in the pulley for these set screws.

Since we’re using a vacuum pump, the engine must be sealed (so I couldn’t install a breather on a valve cover). In order to provide an oil-fill port, we welded a bung to the roof of the left side valve cover. A Jones Racing threaded cap (O-ring sealed) plugs the hole.

In order to provide radiator hose clearance for the water pump, Jones Racing supplied an extension bracket. This mounts to the block, behind the crank trigger sensor bracket.

The drive hub spacers on the mandrel allowed easy alignment for both alternator and vacuum pump pulleys.

90 degree-12 AN hose ends were used at both pump and valve cover locations.

Although function was more of a concern than appearance, the blue (hose end, valve cover knobs, oil fill plug and plug wire boot sleeves) helped to provide a bit of contrast against the aluminum background.

The 65-amp race alternator from Jones Racing is light and the mounting brackets were superb. Note the heim-joint adjuster. Jones told us that this is an intelligent alternator that won’t rob horsepower. Jones Racing also builds this alternator in-house.

The alternator bracket assembly fit perfectly, with no massaging required.