The BG fuel log is adjustable for length, allowing bowl-to-bowl spacing to be set by simply slipping the male tube inside the female tube.

The male tube section of the BG fuel log features three sealing O-rings.

Fitting the BG fuel rail to our Dominator was a piece of cake. I installed the Race Pumps fuel pressure regulator to the inlet of the fuel rail.

The BG fuel rail came with a pair of carb standoff extensions that allowed the fuel rail to clear the carb perfectly.

During fuel line plumbing, I used all –8 AN hose, hose ends and adapters. I installed a Trick Flow billet aluminum 40-micron fuel filter at the inlet of the regulator.

Although some drag racers use air filters and some don’t, I thought it wise to protect our baby. This K&N X-Stream filter measures 14 inches in diameter and five inches in height, with a pleated lid, so our big-daddy carb can suck from the perimeter and from the top. Other size combinations are also available.

The K&N filter kit included a base adapter and stud kit. I used another Cam Motion Top Seal knob to secure the K&N filter top.

Our Jones Racing two-stage vacuum pump will provide a consistent 15 inches of vacuum (negative pressure) inside our mill.

The vacuum pump mounting bracket features an adjustable slot for easy belt service and tension adjustment.

The vacuum pump features a radius-tooth pulley with aluminum belt guides.

The drive hub assembly from Jones Racing allows mounting the drive pulleys for our alternator and vacuum pump.

The drive hub arrangement features a number of aluminum spacer rings, that can be swapped around to achieve desired pulley location.

Our initial distributor offered a very neat low profile, but the large diameter of the head made installation impossible due to a lack of intake plenum clearance, so I switched out to a smaller-diameter-head MSD.

The MSD Pro-Billet distributor (P/N 85501) provided the intake manifold plenum clearance that we needed.

Our MSD distributor features a slip collar, allowing installed height adjustability.

In order to fit the Dart block, the nose of the drive gear was shortened and reduced in diameter (see the machined section that contrasts here with the machinist blue dye).

During distributor-height adjustment, I made sure that the distributor shaft’s oil groove lined up with the block’s oil passage.

The final distributor height brought the underhead chamfer a bit close to the slip collar, so I ground the top of the hold-down clamp for proper fit.

Our MSD 8.5mm Super Conductor spark plug wire kit.

I went a bit overboard with plug wire clamps in an effort to nail all of the wires down to prevent them from flopping around. I made two L-brackets that attach to the rear manifold bolts to provide a mounting spot for the four-wire MSD wire dividers.

The MSD wire dividers feature a snap-on/off cap for easy wire servicing. The divider base is secured to the custom L-brackets via an 8 x 32 stainless-steel button head screw and nyloc nut.

DEI’s spark plug boot protector sleeves are offered in a variety of colors, but I chose blue for this build.

The DEI sleeves feature a heat-resistant Kevlar weave.

The smaller-diameter rolled end snugs over the spark plug boot.

The rolled end of the heat shield sleeve features an internal metal ring that snugs the sleeve onto the boot. This prevents the sleeve from walking off of the boot and eliminates the need to secure the sleeves with zip ties.

I routed the plug wires under the exhaust ports. The sleeves protect the boots from heat and protect the wires from abrasion as well.

Our valve covers are Moroso’s welded aluminum big block units.

The standard method of securing the valve covers involves the use of 1/4-inch x 20 socket head cap screws (provided with the covers). However, I decided to install 1/4-inch x 20 x 4-inch studs in the heads, allowing me to use knurled aluminum knobs for clamping.

The knobs (from Cam Motion) are designed for use with air cleaners, but I thought that they’d be practical for valve cover use since no tools are required. They may seem a bit large in diameter, but they’re super-easy to handle.

Cam Motion offers these Top Seal knobs in two different heights and in a variety of colors.

I didn’t need the height offered by the tall design, so I went with the short version for the sake of appearance and clearance (no need to have ‘em sticking up further for no reason).

The Cam Motion Top Seal knobs are equipped with O-rings, which provide grip and sealing when used to clamp air cleaner lids. For my use on the valve covers, I simply removed these O-rings.

The blue valve cover knobs may look a bit large, but they’re very user-friendly. Hey, they kinda match the blue spark plug boot sleeves too.

The Victor Reinz valve cover gaskets feature a stainless core sandwiched between the rubberized cork layers, making them nice and stable, so they won’t slip in/out of location.

We had a choice of upper plenum boxes for our Profiler intake manifold, allowing us to use either one carb or two. For this build, I opted for a single Holley 1,150 cfm Dominator.

The Dominator carb, with its 1,150 cfm volume, should provide adequate air/fuel for our nutty cam and Big Chief II heads.

CARBURETOR/FUEL PLUMBING

Our big-gulp carb is Holley’s Ultra Dominator (P/N 0-80673), an 1,150 cfm race carb that features billet metering blocks, three-circuit metering, mechanical secondaries and oversized sight windows for easy float adjustment. Recommended fuel pressure is 5-7.5 psi. The anodized billet metering blocks feature changeable idle feed restrictors for easier tuning of the idle system with no drilling, in addition to changeable emulsion jets for infinite metering tuning.

In order to handle fuel feed to our mega-displacement carb, I installed a BG P/N 170021 adjustable-length fuel log (adjustable for bowl inlet match-up), a pair of BG fuel inlet extension fittings P/N 140023 (7/8 x 20 x -8 swivel), a Trick Flow -8 TFS-23001 inline billet fuel filter, a BG fuel pressure gauge (P/N 170124) and RacePump’s fuel pressure regulator (P/N 5010).

The BG adjustable fuel log is pretty cool. In order to adjust length, simply slide the two ends apart or closer together by hand. One tube slides inside the mating tube, internally sealed with a series of three special O-rings, so no tools are required to adjust the log tube length. Either end may be used for the fuel inlet (each end features a 3/8-inch NPT female thread), and one end features two 1/8-inch NPT ports to allow mounting a fuel pressure gauge on either side (depending on how you orient the log). Install the two extension fittings to the carb, adjust the log length to align to the fittings and install, tightening evenly (back and forth between the two fittings to prevent binding).

The BG pressure gauge is also very neat. It’s internally dampened without the use of liquid (since a liquid-filled gauge might be affected by engine heat and lead to
inaccurate readings). I plumbed everything using Earl’s -8
stainless braided hose. At the fuel pump outlet, I used a 45-degree -8 hose end. At each side of the filter, I used -8 straight hose ends. At the entry of the fuel pressure regulator, I used a -8 straight hose end attached to a -8 male to 1/2-inch NPT male adapter (the bottom inlet port of the regulator features a 1/2-inch NPT thread).

AIR FILTER

Although not needed for the dyno run itself, I opted for a way-cool K&N X-Stream air cleaner assembly, (P/N 66-3090). This assembly features a 14-inch x 5-inch-high round open-element filter in addition to an open-element top. The kit included all mounting hardware, including a neoprene base gasket for the Dominator, a chrome steel base, a 5/16-inch x 18 male to 1/4-inch x 20 female adapter, a length of 1/4-inch x 20 all-thread, two steel washers, one rubber washer and 1/4-inch x 20 nuts. The only fiddling involves cutting the all-thread to length to accommodate the filter height. Install the 5/16-inch to 14-inch adapter to the carb and install a 1/4-inch x 20 jam nut on the all-thread (against the adapter top). Install a 1/4-inch x 20 nyloc locknut onto the all-thread. Install the base gasket, the steel baseplate and the round filter.

Lay a straightedge across the top of the round filter element, and position the top of the nyloc nut three turns below the bottom of the straightedge. Next, remove the all-thread (keep the nyloc nut in place). Mark the all-thread at a point 1.250 inches above the top of the nyloc nut and cut off the excess all-thread at this mark (you want 1.250 inches of thread exposed above the nyloc nut). Deburr and chamfer the cut all-thread. Reinstall the all-thread stud. Place one steel washer on the all-thread, resting the washer onto the top of the nyloc nut. Install the top filter element, making sure that it’s seated into the steel baseplate. Install the rubber washer onto the exposed stud, followed by a steel washer and a 1/4-inch x 20 nut.

K&N supplies a nyloc nut for the top of the stud, but I opted for a burgundy-anodized Top Seal billet aluminum knurled air cleaner lid knob (1/4-inch x 20 internal thread) that I obtained from Cam Motion. These knobs (available in short and tall versions) look way cool and provide convenient hand operation for air filter servicing. An O-ring is featured on the underside (seated in a milled groove) to prevent slippage and unwanted loosening.

THERMOSTAT HOUSING

I installed a blue anodized aluminum thermostat housing/intake filler assembly from Jeg’s (P/N 53012). This features a 1.5-inch diameter radiator hose connection. The two-piece design allows you to flip the lower housing to orient the hose nipple to either the right or left side of the engine. The lower housing seals to the manifold via our Victor race gasket (aluminum core with silicone seals). The upper neck seals to the main housing with a built-in O-ring seal. An overflow nipple screws into the neck via a 1/8-inch NPT thread. The rear of the main housing features two 1/4-inch NPT and one 3/8-inch NPT female ports, which I sealed off with NPT plugs (these could be used for additional coolant plumbing, gauge or sensor attachment, etc.).

For a pressure cap, I chose Moroso’s 24-pound race cap (P/N SDC-63324).

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). 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 VP 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 seven quarts 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, Gressman hit the starter and much to my relief, she fired and ran (I’m always antsy whenever a fresh motor first comes alive). Gressman allowed her to run for a few minutes at around 1,400-1,500 RPM while monitoring the vitals. We immediately had about 65 pounds 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, Gressman shut her down and re-checked hot valve lash, setting all valves at 0.028 inches.

The first hard pull, with timing set at 27 degrees, netting 1,098 horsepower at 7,150 RPM. A second pull, with timing at 30 degrees, yanked 1,105 horsepower at 7,150 RPM. The final pull, at 32 degrees timing and, with the camshaft retarded 3 degrees, produced 1,115 horsepower 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 lbs./ft. On our best horsepower pull, the highest torque reading was 863.4 lbs./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

5,200……….844.4……….836.0
5,300……….846.8……….854.5
5,400……….851.9……….875.9
5,500……….855.8……….896.2
5,600……….860.5……….917.5
5,700……….863.9……….937.6
5,800……….864.2……….954.4
5,900……….863.3……….969.8
6,000……….862.5……….985.4
6,100……….863.7……….1,003.1
6,200……….860.1……….1,015.4
6,300……….858.5……….1,029.8
6,400……….855.5……….1,042.4
6,500……….854.0……….1,056.9
6,600……….850.5……….1,068.8
6,700……….848.0……….1,081.8
6,800……….842.5……….1,090.8
6,900……….835.9……….1,098.1
7,000……….829.5……….1,107.6
7,100……….823.0……….1,115.5
7,200……….811.4……….1,112.3
7,300……….798.1……….1,109.3

In the 5,700-6,200 RPM range, average Fuel A lbs./hr. was 174.5. Fuel B lbs./hr. was 170.9. A/F ratio was 14.79 (max 15.31). Average volumetric efficiency was 113.6 percent.

Gressman 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 horsepower. Unfortunately, we had only a limited timeframe to use the dyno, but for an initial out-of-the-box run, 1,115 horsepower 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 for one that is requested by a customer.

Source Box

ARP Inc.
For more information,
Dial 1-800-652-0406, ext. 17401

ATI Performance Products
For more information,
Dial 1-800-652-0406, ext. 17402

BG Fuel Systems
For more information,
Dial 1-800-652-0406, ext. 17403

Cam Logic (Bolton Conductive Systems)
For more information,
Dial 1-800-652-0406, ext. 17404

Cam Motion Inc.
For more information,
Dial 1-800-652-0406, ext. 17405

Clevite Engine Parts
For more information,
Dial 1-800-652-0406, ext. 17406

Crane Cams Inc.
For more information,
Dial 1-800-652-0406, ext. 17407

Dart Machinery
For more information,
Dial 1-800-652-0406, ext. 17408

Diamond Racing Products
For more information,
Dial 1-800-652-0406, ext. 17409

Fall Automotive Machine
For more information,
Dial 1-800-652-0406, ext. 17410

Gear Head Tools
For more information,
Dial 1-800-652-0406, ext. 17411

Goodson Tools & Supplies
For more information,
Dial 1-800-652-0406, ext. 17412

Gressman Powersports
For more information,
Dial 1-800-652-0406, ext. 17413
Holley Performance Products/Lunati
For more information,
Dial 1-800-652-0406, ext. 17414

Jesel Valvetrain Inc.
For more information,
Dial 1-800-652-0406, ext. 17415

Jones Racing Products
For more information,
Dial 1-800-652-0406, ext. 17416

Manton Racing Products
For more information,
Dial 1-800-652-0406, ext. 17417

Meziere Enterprises Inc.
For more information,
Dial 1-800-652-0406, ext. 17418

Moroso Performance Products
For more information,
Dial 1-800-652-0406, ext. 17419

MSD Ignition
For more information,
Dial 1-800-652-0406, ext. 17420

Pro-Filer Performance Products
For more information,
Dial 1-800-652-0406, ext. 17421

Race Pumps
For more information,
Dial 1-800-652-0406, ext. 17422

Royal Purple LTD.
For more information,
Dial 1-800-652-0406, ext. 17423

Sunnen Products Co.
For more information,
Dial 1-800-652-0406, ext. 17424

Trick Flow Specialties
For more information,
Dial 1-800-652-0406, ext. 17425

VALVE COVERS

The 1/4-inch x 20 x 3.5-inch socket head cap screws supplied with the Moroso valve covers are fine, and function perfectly. But, being the anal dolt that I am, I wanted to dress things up a bit more. I installed stainless-steel 1/4-inch x 20 x 4-inch studs into the heads (purchased from McMaster-Carr under P/N 95412A558), and then secured the valve covers with Cam Motion’s Top Seal blue anodized billet aluminum knurled hand knobs. I selected their short-hat version at 0.637 inches tall (they also offer tall-top models at 1.136 inches high). All of their knobs feature a 1.50-inch diameter knurled hand-knob. The knobs are offered with either 1/4-inch x 20 or 5/16-inch x 18 female threads.

Granted, these knobs are intended for air cleaner lid use and may appear a bit large in diameter for valve cover use, but they’re extremely functional, adding a bit of convenience for hand-servicing the valve covers. Although this setup may be totally unnecessary, I thought it looked cool and the quick no-tool servicing would definitely come in handy in the pits.

In order to provide an oil-fill location, I installed a Jones Racing weld-in -12 female bung to the roof of the left side valve cover to serve as an oil fill port. This is sealed with a Jones Racing screw-in aluminum plug that features an O.D. hex and a sealing O-ring. Since we’re using the Jones Racing vacuum pump system, the engine needs to be sealed, so a valve cover breather was a no-no. Installing the bung required cutting a 1 5/8-inch hole in the cover (8 7/8 inches from the front wall, inline with the second pair of valve cover bolt locations, in an area where I knew I’d have a clear shot for oil fill between rocker arm locations).

In addition, a -12 weld-in male fitting was needed on the front wall of each valve cover in order to plumb to the Jones Racing vacuum pump. For each valve cover, a 3/4-inch hole was drilled and the male weld-on fitting was surface-mounted to the valve cover wall and Tig welded around the perimeter of the fitting’s hex.
Saeco, a local fab shop in nearby Wadsworth, Ohio, performed the Tig
welding of all three fittings (since yours truly doesn’t own a Tig, and doesn’t know how to use it even if he had one).

VACUUM PUMP

Jones Racing supplied a vacuum pump system featuring its lightweight billet aluminum vacuum pump VP-9100C. This is a two-stage gear-style vacuum pump that runs at 50 percent of engine speed and pulls a constant 15 psi, providing enhanced piston ring seal. The negative pressure created by the pump results in less resistance on the pistons during the compression downstroke, resulting in faster piston acceleration. This constant vacuum also helps to draw parasitic oil from the rotating assembly (theoretically increasing power) and allows the oil pump to function with less resistance, which should increase oil flow.

I mounted the pump on the lower right engine side. In order to provide clearance for the water pump neck, Jones supplied an extension bracket that shares the two block mounting bolts for the crank trigger sensor bracket.

In order to provide a mounting for the crank pulleys (for both our vacuum pump and our Jones Racing alternator), we installed Jones’ DH-8101-B BBC drive hub and their DHM-8101-B (3.500 inches x 1.125 inches O.D.) mandrel. The drive hub (and the hollow mandrel) secure to the crank snout with a 1/2-inch x 20 x 6-inch bolt. In addition, to prevent the drive hub from rotating independently, the hub
features two 3/16 inch roll pins. This required drilling a pair of 0.190-inch holes in the face of the damper (on the recessed flat face that surrounds the crank snout). The roll pins were pressed into the drive hub and the roll pins engage into the holes drilled in the damper.

The drive hub mandrel threads into the drive hub (featuring a left-hand thread) and features a 1/8-inch keyway slot that runs the entire length of the mandrel.
Once I mocked up the crank snout pulley and spacer assembly for proper pulley
alignment to both the alternator and vacuum pump pulleys, I removed the pulleys and spacers. I installed a 0.250-inch-thick spacer against the drive hub, then installed a key for the alternator drive pulley. The alternator drive pulley and its guide plates were slipped on, followed by three aluminum spacer rings (one 3/8-inch and two 1/2-inch thick spacers), followed by the vacuum pump drive pulley, one 1/2-inch spacer and finally the billet aluminum nose cup, loc washer and the 1/2-inch x 20 x 6-inch crank snout bolt. The array of aluminum spacers (in various thicknesses) allows you to tune the spacing of the pulleys on the mandrel.

In order to achieve fine-tuning of the vacuum pump’s pulley to the pump’s drive pulley on the crank mandrel, by loosening three set screws in the pump’s pulley, you’re able to slide the pulley fore/aft on the pump’s shaft for perfect belt alignment. Once alignment is determined, tighten the set screws. Access holes in the pump pulley allow easy entry for a hex wrench for servicing the set screws.
Routing the plumbing for the vacuum pump was super-simple. I made a pair of -12 hose assemblies using 90-degree -12 hose ends at each end of the two hoses.

The two outlet ports on the pump are plumbed directly to the -12 male weld-in fittings on the front face of each valve cover. The single outlet (exhaust) port from the pump will be plumbed to a remote breather in the dyno shop. Assembly of the -AN hoses was straightforward, in terms of installing the hose ends to the hoses (by the way, I used swivel-type hose ends at the valve cover locations to enable easy clock-position adjustment for a precise hose-end-to-fitting alignment).

The only special step involved inserting a section of Jones Racing’s flat-wound internal support coil into each hose length. This ensures the stability of the vacuum hose, preventing any potential restriction that might occur if the hose began to collapse internally under vacuum.

Initially, this was the pain in the butt part of the job. The stainless steel support coil must be wound counterclockwise to minimize its diameter (bringing the coils together, forming a tube), and then push-fed into the hose, pretty much one to three coils at a time. I lubed the inside of the hose with engine oil to ease insertion, but this was time consuming and frustrating in the beginning until I developed the knack.

I installed one hose end, installed the support coil, then installed the second hose end. The internal support coil comes in a 4-foot length. I cut two pieces with a snip, one for each hose. I tailored the coil length to match the full hose length between the hose ends (with the ends of the coil about 1/2-3/4 inches shy of each hose end). By the time I finished installing the support coils in the two vacuum hoses, I had resurrected just about every cuss word in my vocabulary. Of course, after fitting these two hoses, I felt like a pro.

ALTERNATOR SETUP

I mounted the Jones Racing alternator on the left side, using the existing threaded holes on the block face. The Jones mounting bracket fit like a friggin’ glove and it’s pretty to boot. Belt adjustment is a breeze, thanks to a heim-joint-ended LH/RH thread hex body turnbuckle. This is without a doubt the best-fitting and easiest-to-install custom alternator setup I’ve ever had the pleasure to install. Jones offers a multitude of alternator bracket configurations (for high-mount, low-mount, LH, RH, etc.), but I really like this little bugger. This is a nice application for both race engines and street rod builds, offering both form and function that would please even the most finicky customer. Very pro.

PROJECT 632 PART 6:DELIVERANCE

With assembly complete, it was time to light the candle.

by Mike Mavrigian

all photos by author

Well, the motor was final-assembled and run on the dyno. Although we didn’t hit our hoped-for 1,200 horsepower, we did manage a 1,115 horsepower run. With further tuning, we know the potential is there.
First, let’s cover the final stages of engine assembly, involving the
ignition system, fuel system and vacuum pump setup.

DISTRIBUTOR

You may recall from our last issue that I accidentally ordered the wrong distributor from MSD (P/N 8558, the Pro Billet low-profile distributor). There’s nothing wrong with the unit, but the large five-inch diameter head wouldn’t clear our tunnel ram plenum box. I recently obtained a replacement (MSD P/N 85501).

This is one of MSD’s Pro Billet units, featuring a lockout (no mechanical advance). It should work well with our crank trigger setup. Upon checking distributor fit, I found that the nose of the bronze distributor gear contacted the block (touching a boss inside the block at about the 1 o’clock position as you stare down into the distributor bore). Instead of stripping back down to a bare block to grind clearance, I followed Scott Gressman’s advice by applying machinist blue to the bronze gear assembly, inserting the distributor as fully as possible and rotating the crank one full revolution. Upon removing the distributor, I noticed a contact path around the perimeter of the gear nose (not the gear itself, but at the very bottom of the gear assembly nose). Since my lathe was down, Jody Holtrey at Medina Mountain Motors in Creston, Ohio (a mere stone’s throw from my office) removed about 0.070 inches from the bottom of the nose. In addition, he reduced the outer diameter of the nose by 0.020 inches, from the newly-cut bottom, up 0.250 inches. Finally, the bottom nose area was radiused into a bullet shape. With the right rear oil gallery plug removed from the block, I could view the distributor shaft’s oil band location relative to the block’s oil gallery, verifying that the distributor shaft’s oil band was in the oil path.

I carefully measured the distance from the top of the intake manifold distributor boss to the top of the oil pump intermediate shaft, which measured at 8.096 inches. Knowing that I wanted 0.200 to 0.250 inches of distributor-to-shaft engagement, I then knew that the distance from the bottom of the distributor gear’s key to the underside of the distributor’s slip collar should be approximately 8.346 inches. This provided me with a rough distributor depth target.

I was able to adjust the distributor depth via the distributor’s slip collar to achieve
distributor-to-intermediate shaft engagement of about 0.225 inches. With the distributor bottomed out, I then raised the distributor (using the slip collar adjustment) about 0.010 inches. I then rotated the crank two full revolutions, removed the distributor and inspected the bronze gear for evidence of a contact pattern relative to the cam’s gear. Once I was satisfied with shaft engagement and gear mesh, I final-tightened the distributor slip collar.

Once all height adjustment was complete, I cleaned the distributor shaft and gear and applied a coat of Royal Purple Max Tuff engine assembly lube to the shaft, gear and engagement key before final-installing the distributor.

The MSD distributor was supplied with a pair of rubber O-rings for the shaft. While some guys don’t bother with the O-rings, I followed Gressman’s advice by installing only the upper O-ring, the theory being that the absence of the lower O-ring allows a bit of oil to dribble down to the shaft during engine operation.

I used the MSD distributor hold-down bracket P/N 8110. Due to the set height of the distributor, I ran out of clearance for this beefy hold-down clamp. In order to fit the clamp between the top of the slip collar and the chamfered area of the distributor underhead, I ground the tops of both clamp arms down by about 0.030 inches.

PLUG WIRES

The MSD 8.5mm Super Conductor spark plug wires were then routed along the
bottom of the heads and cut to length. The distributor-end terminals and boots were installed, and the wires were connected to the distributor cap following the special firing order required by the Crane billet camshaft. Our firing order is 1-8-7-3-6-5-4-2 (big block Chevy order, with cylinders 4 and 7 swapped).

Our selected spark plugs are Autolite P/N AR3932 (0.750-inch reach plugs, per Dart’s recommendation for the Big Chief II heads). I set plug gap at 0.024 inches (they were all close to this gap straight out of the box).

In order to provide extra protection for the spark plug boots and wires from exhaust heat, I installed a set of DEI’s new Protect-A-Boots. These “cool” booties feature an internal metal ring at the small end, allowing you to nudge the boot small end over the plug boot ends for a snug fit that insures good retention of the thermal-guard boots. This is a nice feature, eliminating the need to secure the boots with tie straps.

In order to provide a degree of tidiness to the plug wires, I used MSD’s plug wire
spacers (P/N 8841) to serve as wire separators. In addition, to prevent the wires from flopping around at the rear of the block, I made two 90-degree aluminum brackets using 1-inch-wide x 0.125-inch-thick aluminum strap that secure to the two rear intake manifold bolts and extend down across the rear faces of the heads. These brackets provided an anchoring base for a pair of four-wire MSD Pro-Clamp wire separator blocks (from kit P/N 8843). I secured one four-wire block to each aluminum bracket with one 10 x 32 button head screw (I tapped a 10 x 32 hole in each bracket).

She’s a tall bugger for sure, measuring 42 inches from top to bottom.

The engine is now equipped with an external vacuum pump and race alternator.

CRITICAL: BUY QUALITY

Performance aftermarket fastener manufacturers offer much higher tensile strength fasteners that are specifically designed for racing applications. ARP, for example, offers threaded fasteners that boast 170,000 psi, 190,000 psi and 220,000 psi. In other words, instead of hitting the local hardware store or Internet source for imported who-knows-what-or-where-they-came-from fasteners, stick with reputable U.S. firms that are dedicated to supplying pro race engine and car builders.

Be aware that a lot of overseas junk is floating around out there, some of it counterfeit (low grade junk marked as Grade 8, etc.). If you want to screw on a dash plaque, feel free to grab whatever works. When it comes to stainless-steel fasteners, you can get burned very easily if you opt to buy unknown brand fasteners. The alloy mix is critical in terms of fastener strength.

If you want stainless stuff, buy only known performance fastener brands (again, ARP is but one example). They’ve selected the proper grade of stainless for specific automotive applications that will provide the performance and durability required. Buying generic stainless-steel fasteners can result in major grief down the road. When you’re building an engine or are about to assemble a chassis, don’t take chances. Know what you’re buying!

GRADES OF STAINLESS STEEL

18-8……………..Excellent corrosion resistance. Rockwell hardness B70. Minimum tensile strength 70,000 psi. Just a step above Grade 2 steel in terms of strength.
Type 316………..Better corrosion resistance (alloy contains moly). Minimum Rockwell hardness B70. Minimum tensile strength 70,000 psi.
Type 400………..Lower corrosion resistance but slightly stronger. Contains more carbon than 18-8 or 316. Minimum Rockwell hardness C28. Minimum tensile strength 75,000 psi.
ASTM F594 18-8 and Type 316….Same as 18-8 and 316 but meets strict ASTM standards.
ASTM A194 Grade 8M strain-hardened Type 316………Minimum Rockwell hardness C34. Minimum tensile strength 90,000 psi. Slightly greater strength than Grade 2 steel.
Alloy 20……..Also called carpenter 20. Most resistant to stress corrosion and high-temperature sulfuric acid. Rockwell hardness B89. Minimum tensile strength 85,000 psi.

GALVANIC CORROSION

Galvanic corrosion occurs when dissimilar metals are in contact with one another. Especially in salt water conditions, a small electrical current flows from one metal to another. One metal will begin corroding faster than normal, acting as the anode, and the other metal will corrode more slowly than normal (acting as the cathode). The result is that the anode material will corrode much faster than the cathode material. Galvanic corrosion can be avoided by using only similar metals (e.g., steel bolt in steel components, or aluminum bolts in aluminum components). Also, by using stainless-steel nuts on stainless-steel bolts, steel nuts on steel bolts, etc. However, we all know that in some cases, dissimilar metals will be assembled (installing stainless-steel nuts on steel bolts, etc.). In order to avoid galvanic corrosion (sometimes called electrolysis), apply a small amount of moly anti-seize compound or thread-locking compound to the threads before assembly to act as an insulator between the two metals.

Grade 8 steel bolt. Eight radial markings identify a grade 8 bolt, which should feature a minimum 150,000 psi tensile strength.

L9 (Grade 9) steel bolt. Rated at 180,000 psi tensile strength. These bolts feature a slightly taller-than-normal head thickness. A series of nine radial marks accompany the L9 mark.

Grade 8.8 metric steel bolt. This features a minimum tensile strength of 116,030 psi. In terms of strength, a metric 8.8 is roughly equivalent to a Grade 8 inch-format bolt.

Grade 10.9 metric steel bolt. In terms of strength, this is roughly equivalent to a Grade 8 inch-format bolt.

METRIC NUT GRADES

The grade system for nuts is a number that represents 1/10 of the specified proof load stress (in kgf/mm2). The proof load stress corresponds to the minimum tensile strength of the highest grade bolt that can be used with that nut.

GRADE CAUTION

Although it is common for Grade 5 bolts to feature three slash marks and for Grade 8 bolts to feature six slash marks for identification purposes, it’s important to note that not all Grade 5 or Grade 8 bolts will feature these marks! Quite often, specialty bolts (made for an automaker’s specific requirements) may not feature any marks at all, or may feature a unique symbol. If you’re performing a restoration, it’s best to stick with factory-original bolts where grade may be in question. Otherwise, if the bolt head isn’t marked (blank head), and if you don’t know where the bolt came from, you should assume that it features a hardness grade of less than 5 and shouldn’t be used. If the bolt was produced by a known quality maker, such as ARP, you can be sure that the bolt is correct for the application recommended by the maker. I’m simply saying that if you don’t know where a bolt came from, and it’s not marked, throw it away and buy known-quality bolts instead.

GRADES OF STEEL

Threaded fasteners are graded or classed to identify their hardness and tensile strength. When choosing fasteners for a performance car or race car build, never blindly assume that harder is always better. Bolts, screws, studs and nuts should be chosen for the application at hand. Lower grade or lower class fasteners will tend to stretch more easily than higher grade or class fasteners, and higher grades/classes will be more resistant to stretching but may provide either overkill or damage to components that need to move more easily under thermal conditions. By the same token, don’t always assume that you can use chromed or stainless fasteners anywhere you like, since they may not be up to the task. When bolts are chrome plated, they may become more brittle and less elastic as a result of hydrogen embrittlement during the electroplating process.

Stainless fasteners, depending on grade, may not be able to withstand forces encountered in some engine and chassis applications. Stainless steel is an alloy of low carbon steel and chromium, offering enhanced corrosion characteristics.
A common misconception among hot rodders is that stainless steel is stronger than regular steel, which isn’t the case. Because of the low carbon content in stainless steel, stainless steel cannot be hardened.

When compared to steel, stainless steel is slightly stronger than an un-hardened Grade 2 steel fastener, but is significantly weaker than hardened Grade 5 or Grade 8 fasteners.

Grade 2 is a standard hardware grade steel, generally unacceptable for any automotive applications.

Grade 5 bolts are hardened for increased strength and are the most common bolts found in automotive applications. Grade 5 bolt heads feature three radial lines as a marking.

Grade 8 bolts have been hardened more than Grade 5 bolts, and feature six evenly spaced radial lines on the head as a marking. Grade 8 bolts are stronger than Grade 5 bolts, and are typically used for demanding applications such as suspension components.

Alloy steel bolts are made from a high-strength steel alloy (not to be confused with stainless steel), and are further heat treated for added strength. Alloy steel bolts are typically not plated, resulting in a dull black finish.

In other words, don’t pick fasteners based only on appearance, especially for applications such as engine assembly, suspension, steering and brake systems. Do your homework and use the specific metals and grades recommended for specific applications.

(Note: Grades are used to identify fractional fasteners; while class is used for metric fasteners.)

GRADE 2…….Made from C1006-C1022, C1215, 12L13 or 12L14 steel. For use in only low-strength applications. Minimum Rockwell hardness B49. Minimum tensile strength is only 44,225 psi.
GRADE 5…….Made from steels such as C1008-C1026. For use in medium-strength applications, with a Rockwell hardness of C25. Minimum tensile strength is 120,000 psi.
GRADE 8……Made from stronger alloy steel such as C1021-C1045, for high-strength applications. Minimum Rockwell hardness C24. Tensile strength is minimum of 150,000 psi.
GRADE 9……Commonly called L9. Rockwell hardness C38-42. Minimum tensile strength 180,000 psi.
CLASS 4/4.8/5.8…..Comparable to Grade 2. Minimum Rockwell hardness is B71. Tensile strength is 60,900 psi minimum.
CLASS 6………….Comparable to Grade 2. Minimum Rockwell hardness is B89, and minimum tensile strength is 87,000 psi.
CLASS 8………….Comparable to Grade 5. Minimum Rockwell hardness is C20. Minimum tensile strength is 116,000 psi.
CLASS 10…………Comparable to Grade 8. Minimum Rockwell hardness is C32. Minimum tensile strength is 150,800 psi.
CLASS 12…………Exceeds Grade 8. Made from alloy steel C1035 and C1045. Minimum Rockwell hardness is C39. Minimum tensile strength is 176,900 psi.

THREADED FASTENER GRADES

by Mike Mavrigian

photos by author

Grade 5 steel bolt. Three radial line marks. Theoretically, this bolt will feature a 120,000 psi minimum tensile strength.

The grade label specifies the minimum strength properties the fastener is intended to meet. Industrial fasteners are also marked with a label that identifies the maker of the fastener. Grade markings on domestic fasteners meet ASTM and SAE specs, while metric fasteners meet ISO and SAE specs.

Bolts whose heads are unmarked can be assumed to carry a grade of either 1, 2 or 4. These bolts will be made from low or medium carbon steel. At best, they may be cold-drawn, but certainly have not been tempered.

Contrary to popular opinion, there are more than only three grades of bolts (the most popular being grades 3, 5 and 8). There are about 17 grades (other grades may exist in aerospace or other niche industries).

A threaded fastener’s grade indicates its tensile strength and hardness. The higher the clamping load required, the higher the grade you’ll need. In automotive applications, although it’s difficult to make broad generalizations, you’ll need at least Grade 8 (or 12.9 in metric) for high-clamping load applications, such as connecting rods, cylinder heads and main caps, flywheel bolts, clutch cover bolts, etc. Never use any threaded fastener below a Grade 5 (or 8.8 metric) for any automotive application, regardless of the area of use. Always follow the vehicle or aftermarket component maker’s recommendation for fastener grade.

Grade 5 fasteners are made from medium-carbon steel that has been quenched and tempered. Minimum tensile strength is 120,000 psi for bolts up to one-inch diameter (tensile strength drops for diameters larger than 1 inch). Grade 5 bolt heads are marked with three radial lines. Rockwell hardness for bolts up to one-inch diameter is usually C25-34.

Grade 8 fasteners generally feature a minimum tensile strength of 150,000 psi and a Rockwell hardness of C38-39. Conventionally, a head marking of six radial lines indicate Grade 8.

Grade 9 fasteners (also called by trade names L9, PFC9, Tru-Torq and Bow Malloy) feature taller heads and 180,000 psi tensile strength and Rockwell hardness C38-42.

INCH NUT GRADES

As far as nuts are concerned, there are basically three grades: 2, 5 and 8. In general terms, always use a nut of the same or higher grade as the bolt in use. Grade 2 nuts don’t have to be marked. All Grade 5 and Grade 8 nuts (in the one-quarter-inch to one-and-a-half-inch range) do require markings.

The identification marks may be handled in one of three ways: grade 5 nuts may be marked with a single dot on the face of the nut and a radial or circumferential line at 120-degrees counterclockwise from the dot; or a dot at one corner and a radial line at 120-degrees clockwise from the nut; or one notch at each of the six corners of the nut. Grade 8 nuts may be marked with a dot on the nut face, with a radial or circumferential line at 60-degrees counterclockwise from the dot; or a dot at one corner and a radial line at 60-degrees clockwise; or two notches at each of the nut’s six corners. Why can’t this be simpler, with one type of mark for each grade? It’s one of life’s great mysteries. It sounds as though there were too many cooks in the kitchen when this whole scenario was devised.

METRIC GRADES

As with most things metric, the numbers actually mean something. When a metric bolt head is marked for grade identification, you’ll see two or three digits with a decimal point. The first number refers to 1/10 of the minimum tensile strength (in kgf/mm2, it’s not important for you to understand the increments of measure used here; simply know that the numbers actually represent the bolt’s strength properties). The second figure, following the decimal point, represents 1/10 of the ratio between the minimum yield stress and the minimum tensile strength, expressed as a percentage. As an example, let’s consider a bolt head marked with a identification 8.8 label. The first number represents 1/10 the bolt’s minimum tensile strength (in this case, 80 kgf/mm2). The second number represents 1/10 of the ratio between tensile and yield. The higher the second number, the longer it takes to bring the bolt to yield.

Wanna know more? The first one or two numbers (the number before the decimal point) indicates minimum tensile strength in Mpa. (Note: Mpa is the symbol for megapascals, which is a metric unit of pressure or stress equal to one Newton per square millimeter, which equals about 145.038 pounds per square inch). The final number (after the decimal point) indicates 1/10 of the ratio between minimum yield stress and minimum tensile stress. For example: if the bolt head is marked 8.8, this indicates a minimum tensile strength of 800 Mpa (about 116,030 psi) and a yield stress of 0.8 x 800, or 640 Mpa (about 92,824 psi). Metric screws are manufactured in Grades 3.8 to 12.9, but for automotive applications, common grades include 8.8, 10.9 or 12.9 (tensile strength increases as the numbers grow).

If we want to approximately compare metric grades to U.S. grades, a metric 8.8 is roughly equivalent to a Grade 5. Grade 10.9 is roughly equal to a Grade 8; and 12.9 is roughly equal to a Grade 9. Metric nuts are marked with a single or double numerical symbol (8, 10 or 12). Always match bolts and nuts of comparable grades (use a Grade 8 nut with a Grade 8 bolt; use a metric grade 10 nut with a 10.9 grade bolt, etc.). When dealing with metric fasteners, the 8.8 bolts are similar to a Grade 5. If you need higher tensile strength in metric, stick to 10.9 or 12.9.

The higher the first number, the stronger the bolt in terms of tensile strength. The higher the second number, the longer it will take to enter the yield point.
Note: Metric steel bolts are only required to show a grade mark if they are 6mm and larger and/or are Grade 8.8 or higher. Nuts must be grade labeled if they are Grade 8 or higher.

Routing the plug wires in aluminum tubing for this custom engine was simply an exercise in “being different.” The tube nuts and sleeves that meet the spark plug boots are for cosmetics only (the nuts and sleeves are epoxied in place).

Straight 3/8-inch tubing runs from the fuel log to the carburetor inlets. Since I wanted to color-coordinate this build, I had all of the tube nuts and tube sleeves anodized in a violet color at a custom anodizing shop.

This custom street rod engine takes full advantage of metal tubing for all of its fuel and vacuum plumbing.

I even hard-plumbed the PCV valve, again using 3/8-inch tubing a -6 tube nuts and -6 adapters.

The hard fuel line is rigidly mounted from the mechanical fuel pump to the carb. Here the hard line, equipped with a -6 tube nut and sleeve, attaches to a -6 90-degree adapter that features a male -6 flare for the tube nut attachment and a female -6 at the opposite end to mate to the -6 male adapter fitting on the pump (the fuel pump inlet fitting is capped here using a -6 sealing cap while the engine was on display).

The fuel feed for this engine features 3/8-inch aluminum tubing. A three-way -6 male adapter allows fuel transfer from the pump to both carb bowl inlets. A 90-degree male/male -6 adapter connects the main tube run to the rear carb bowl.

This hard-tube plumbing setup was made for nitrous feed to a Honda engine’s intake manifold runners. This setup features -4 AN tube nuts/sleeves. A bit of patience and a hand-held tubing bender was all that was required to achieve a neat and symmetrical tubing layout.

Hand-held tubing benders are readily available. This inexpensive bender (from Rigid Tools) is one of the nicer hand-held benders I’ve used.

Before bending the tube-and definitely before flaring-remember to slip the tube nut and tube sleeve onto the tube. If you forget, you’ll need to cut the tube and start over.

With the tube bent and flared, and with the tube sleeve and tube nut in place, the assembly is ready to thread onto a male AN fitting.

This nitrous oxide plumbing setup features 37-degree cone jets that mate to the tube flare and the tube sleeve.