PROJECT FLATHEAD, PART 2

She’s done. In this article, we’ll cover crankshaft balancing, valvetrain and crankshaft assembly.

How do you like the plug wire routing? I’ll cover this in a later article installment. I’m considering having the water pump pulleys polished and chrome plated. By the way, the water pump/alternator belt pulley alignment is perfect. If the belt looks whacky here, it’s simply an optical illusion due to the photo angle.

Build, text and photos by Mike Mavrigian

Following is the second installment of the 8BA flathead build. I feel that I need to clarify a few things at this point. This particular build is intended to provide a primer for a first-time flathead build. Of course, I could have performed several additional upgrades, but while I did perform a few modifications, this build is not intended as an example of a build that features all of the potential bells and whistles. I didn’t perform valve relieving or porting, and I didn’t install a blower setup, etc.

I only mention this in case a reader wonders why I didn’t “go the full route” in terms of the upgrade mods that are possible (porting, billet main caps, main cap girdle, roller cam, etc.). If I decide to build another flathead in the future, at that point I’ll go further in terms of performance modifications.

This first trip into “flathead land” is really meant to serve as a basic overview of this type of build, with a few aftermarket and custom mods thrown in for good measure. So in case you’re wondering “why didn’t he do this, or why didn’t he do that,” now you know. For my first flattie, I had to start somewhere.

CRANKSHAFT BALANCE

As you may recall from Part 1 of this series, during the first test fitting, I encountered a piston-to-head clearance issue, so I turned to G.L. Heller Company in Whitehouse, OH to CNC lathe-cut the piston domes. Here a G.L. Heller technician digitizes our combustion chambers to obtain depth and profile radius data.

Once the piston domes were trimmed on the CNC lathe, Heller verified dome height.

Crankshaft balancing (internal) was performed at Gressman Powersports in Fremont, Ohio. No headache challenges presented themselves, so the job went relatively smoothly.

Individual components were first weighed to both verify piston matching weight and connecting rod matching weight (to check for variances in weight). Individual parts were weighed in order to establish our needed bobweights.

In order to assemble the balancing bobweights, each component (pistons, pins, rings, rod bearings and rods) were individually weighed. Our Scat connecting rod big ends were all factory weight matched at 412 grams.

Our Egge pistons (with pins) weighed in at 442.5 grams each.

The Scat connecting rods weighed in at 412 grams at the reciprocating (big) end, and 161 grams at the pin (small) end. Total rod weight was also weighed at a repeating 573 grams.

Rod bearings (one rod’s pair of shells) weighed 35 grams. Piston pin locks (pair) weighed 3 grams. Piston rings (per piston) weighed 40 grams, and we allowed an estimated 6 grams for parasitic (clinging) oil. Considering rod big ends and rod bearings twice (two per crank pin), our total bobweight package was determined at 1545.5 grams.

With bobweights loosely positioned on the crank pins, Scott Gressman centered each bobweight using a handy spacer. This saves time as compared to checking centering by measuring.

Once located, the bobweights were secured. Prior to spinning the crank.

Each bobweight was attached to the crank (90-degrees apart), centered onto each crank rod pin. In order to quickly center the bobweights, Scott Gressman places a pre-determined-thickness shim on one side of the bobweight and pushes the bobweight base against the shim, then tightens the bobweight base to the crank (then removing the spacing shim).

Once the crank was initially spun, we were 34 grams heavy on the rear counterweight and 36 grams heavy on the front counterweight. Scott removed the excess weight by initially drilling material from the counterweight faces and re-spinning for a second check. After realizing that the imbalance was being “chased” along the radius of the counterweights, he moved the crank to his lathe and machined excess material from counterweight faces (saving a bunch of time as opposed to drilling), then making smaller material drill-removal corrections until he had achieved a balance of about +/- 0.5 gram (certainly much closer than really needed).

One thing to note regarding crankshaft balancing: there really is no need to drive yourself nuts in an attempt to achieve an “absolute zero” balance, since in dynamic operating conditions, parasitic oil will cling and throw in varying amounts, so chasing a true zero balance is frankly unrealistic. Especially for a street performance engine, achieving crank balance to within a couple of grams is acceptable. The flathead crank is an internally balanced unit (balancing the crank alone, without the need to attach the pulley or flywheel during balancing. This simply requires the use of a zero-balanced pulley and flywheel).

While chasing crank balance, weight was initially removed by drilling material from the counterweights.

To avoid “chasing” weight from across the radius of the counterweights, Scott removed material from the faces on his lathe, followed by a nit-picky balance finish by removing remaining weight on the drill press.

Once the crankshaft had been balanced, the crank was thoroughly washed and rinsed to remove any machining particles (with rifle-brush cleaning through the oil passages).

IMPORTANT FUEL PUMP NOTE!

The original location for the mechanical fuel pump is at the top rear of the intake manifold. The fuel pump mounts atop the intake manifold, and the fuel pump pushrod engages the cam’s eccentric by passing (vertically) through a steel bushing located in the rear floor of the lifter valley. The steel bushing features a machined groove around its outer perimeter, with a small orifice hole in the groove. The groove allows oil (pushing up through the main passage) to pass around this groove and run forward through the lifter oiling tube. The small orifice hole in the bushing allows feed oil to enter the bushing inner diameter and lube the fuel pump rod.

This bushing would have been removed prior to block machining/cleaning and must be reinstalled.

However, the OE style mechanical fuel pump may not be sufficient to feed a multiple-carb setup (making an electric pump the wise choice).

It’s important to note that if you don’t run the mechanical fuel pump, the small oil hole in the bushing will allow oil to escape under pressure, resulting in a slight  reduction of oil pressure (I admittedly don’t know exactly how much of a drop would occur). So, if you don’t plan to run the mechanical fuel pump, you need to block this small orifice hole in the bushing (via brazing) before press-fitting the bushing into the block.

The factory bushing at the fuel pump shaft bore is seen here. This needs to be modified if you plan to run an electric fuel pump, and to install a breather tube at the rear of the intake manifold at the OE fuel pump location.

Here is the OE fuel pump shaft bushing removed from the block. The circumferential groove allows oil to flow to the valley oil tube, while the small orifice provides oil feed to the mechanical fuel pump shaft. If you plan to install a breather in place of the mechanical fuel pump, this orifice hole must be plugged. This can be accomplished by brazing the hole shut.

I opted to make an aluminum sleeve that is interference-fit into the OE bushing. This is simply an alternative way to block off the orifice hole. I machined a stop-hat at the top to prevent accidentally driving the sleeve too far into the bushing.

I will admit that I didn’t realize this problem until after reinstalling the cleaned bushing into the block. Rather than remove the camshaft and the rear cam bearing (in order to drive the steel bushing out of the block again), I decided to take an easier route. Since the goal is simply to block off the small orifice hole in the bushing, I made an aluminum insert tube on my lathe. The tube press fits into the bushing, leaving the vertical drain hole open (from lifter valley to rear cam bearing) while still allowing oil to run around the bushing’s outer groove. In my particular case, my steel bushing’s I.D. measured 0.441”. I machined the aluminum tube with an outer diameter of 0.4425” (for a 0.0015” interference fit). I started with a 0.500” O.D. aluminum tube, machining the main body down to the 0.4425” O.D., but leaving a 0.500” diameter top flange (hat) to serve as a dead-stop during installation. I also turned down the bottom tip area of the tube to 0.040” (about 0.250” from the bottom) to aid in initial entry and centering.

If you opt to make this insert tube, use my dimensions as a general reference only, since your pump rod bushing’s inner diameter may differ. Original factory tolerances and age can easily combine to result in bushing diameter variance. Measure your bushing I.D. first.

Of course, if you bothered to read this, you’ll already be aware of the procedure, so brazing the orifice shut will be the simple solution, in which case you won’t need to fabricate this insert tube.

I wanted to mention this so that you’re aware of the need to block off the small oil feed hole in the fuel pump rod bushing in case you don’t plan to run the mechanical pump. If you braze the orifice shut before installing the bushing, be sure to carefully grind the braze area flush with the bushing’s outer groove to avoid blocking oil flow around this groove.

Once all test fitting and machining was accomplished, the valvetrain was addressed. Because the lifters must be in place prior to installing the valves, naturally the camshaft must be installed first.

Three new camshaft bearings (supplied by Egge) were installed to the block. The cam bearings are dedicated per location. This is straightforward, requiring aligning the bearing oil holes to the oil feed holes in the main saddles. Once the bearings were installed, camshaft journal oil clearance was checked at 0.0015” on all three bearing locations.

The new Isky flat tappet camshaft was carefully cleaned (removing any packaging surface protectant, dust, etc. The cam was then lubricated using Isky’s supplied cam lube for all lobes and Royal Purple Max Tuff on all journals. The cam was carefully inserted, avoiding any nicking of the cam bearings. Camshaft free rotation was verified.

The rear of the camshaft features a gear that drives the oil pump, and the front features a flange for mounting the timing gear and a nose gear for distributor drive.

The Egge-supplied Isky flat-tappet cam features 0.320″ valve lift and 264 degrees duration (intake and exhaust). This stick should provide a mild rumpety-rump for a classic vintage hot rod idle.

The camshaft nose features a flange for timing gear mounting and a drive gear for the distributor.

The rear of the camshaft features a drive gear for the oil pump.

With lobes coated with Isky cam lube and the journals coated with Royal Purple Max Tuff, the cam was gently slid into position.

With the cam fully seated, it was again checked for smoothness of rotation.

CAM GEAR

The Egge camshaft timing gear was installed to the cam nose with four 5/16” x 24 x 5/8” hex head grade 8 bolts, along with an original Ford cam bolt locking plate. The four mounting holes are not symmetrical, so the cam gear bolt holes will only align in one location. I applied a drop of thread locker onto each bolt’s threads, positioned the locking plate and installed the bolts, tightening to a value of 18 ft-lbs. Once the bolts were fully tightened, I bent the locking tabs against the bolt heads to prevent loosening. Note: the aluminum center hub of the cam gear features a very slight interference fit to the mounting flange hub. Tighten the bolts evenly in a criss-cross fashion to evenly draw the hub onto the cam nose flange.

The Egge phenolic timing gear features asymmetric mounting holes, so it will only align to the camshaft nose flange in one location.

The timing gear is secured to the cam flange with four bolts, locked by both thread locking compound and a locking tab unit.

This closeup shows a locking tab bent against the bolt hex. This provides positive insurance against bolt loosening.

OUR CAMSHAFT SPECS

ISKY P/N 818800

Grind No. 88

Type: Solid flat tappet

Cam lift…..0.334” (intake and exhaust)

Valve lift…..0.320” (intake and exhaust)

Duration…..264 deg (intake and exhaust)

Lobe center…..108 deg

Valve lash…..0.012” cold, 0.010” hot

Note: Isky offers several additional grinds for the 8BA flathead, including bumpsticks featuring 0.325” cam lift w/260 deg advertised duration; 0.364” cam lift w/249 deg; 0.414” cam lift w/258 deg; and 0.430” cam lift w/280 deg. (five grinds total for the 8BA engine).

OIL PUMP IDLER GEAR

The oil pump is located at the left rear of the block. The pump features a gear that is driven by the camshaft’s rear gear, via an oil pump idler gear.

With the idler gear shaft, gear and shaft bushing clean and lubed, insert the shaft into the gear with the round head of the shaft mated to the side of the gear with the raised boss. The side of the idler gear that features a flat, full face (the side with the raised boss) faces towards the rear (outward towards the transmission). The side of the gear with the concave face faces the front of the engine. If you install the gear with the raised boss facing forward, the gear will stick out too far and not properly engage the gear on the cam. Other flathead books have made this confusing, with poor photos and poor descriptions. Hold the gear (without the shaft) into place, meshed with the cam gear. The required orientation of the gear will be obvious.

Insert the gear by hand, meshing the gear teeth to the teeth on the rear of the camshaft. Insert the shaft into the shaft hole in the block as far as you can by hand. Using a clean brass drift and a hammer, tap the shaft into the block (while verifying that the gear rotates smoothly on the shaft…make sure the shaft isn’t cocked and jamming in the gear’s bore).

Gently continue to tap the shaft into place until it gently bottoms out. Check for endplay (gear clearance fore/aft). Ours had about 0.001” of endplay.

Apply a thin coat of RTV to both sides of a new idler gear cover gasket, and install the rear cover to the block using five 5/16” x 18 x ¾” hex head bolts (with Loctite 242 on the threads and loc washers). I tightened all bolts to a value of 15 ft-lbs.

The oil pump idler gear consists of a gear guides on a short shaft.

Before installing the idler gear assembly, generously lube the guide shaft and gear bushing.

Insert the idler gear assembly into the recess at the left of the camshaft and allow the idler gear to mesh with the cam’s drive gear.

This view shows the idler gear fully installed. Excuse the dripping lube.

I glass-bead-blasted the original rear gear cover, applied etching primer and a semi-gloss black engine enamel.

The rear cover plate was installed using an Egge-supplied gasket (along with a thin film of RTV) and five new bolts with loc washers.

VALVES, SPRINGS & LIFTERS

Once the camshaft has been installed, clean and lube each lifter, coating the face with high pressure lube (I used the cam assembly lube provided with the Isky cam). I also coated the outer lifter bodies with Royal Purple Max Tuff assembly lube. The lifters features hex-headed adjusters. Turn these in first, shortening the effective lifter length (this avoids any unwanted preload at the valves during assembly). The adjuster hex heads require a 7/16” wrench. Note that the adjuster threads are tight on purpose, in order to prevent unwanted loosening during engine operation. Insert all lifters into their bores and rotate slightly to distribute the lube in the bores.

In order to install the intake and exhaust valves, you must first pre-assemble each valve. First, install a new sealing O-ring onto each guide. The insert the valve into the guide, drop the valve spring and retainer over the stem, compress the spring (using a valve spring compressor tool) and install the keepers. Slowly release spring tension and verify that the keepers properly secure the retainer.

Lube the guide and O-ring seal and insert the valve assembly into the block. The O-ring will resist the entry a bit, so slight pressure will be required to fully insert the assembly. Once the valve assembly is fully inserted, use the special flathead valve spring tool to pull the spring and valve assembly inward. Install the C-clip retainer onto the guide (into the clip groove on the guide body). Access inside the lifter valley is tight, so plan to use lots of patience.

All valvetrain components, along with pistons, rods and bearings, were carefully organized on my Lista workbench.

Each Egge valve was meticulously cleaned to verify the abscence of packing grease and dust particles.

All Egge-supplied valve springs, retainers and locks were also carefully cleaned of any surface contaminants.

The Egge-supplied iron valve guides were carefully cleaned as well. Rubber guide seals were also supplied in the Egge kit.

The Egge valve lifters were also carefully washed to remove any handling/packing films or particles.

The lifters feature a series of four spanner-wrench holes and a threaded valve adjuster. It’s a good idea to thread the adjusters in a bit to ease valve installation.

I coated each lifter face with Isky’s cam lube, and the bodies with Royal Purple Max Tuff. Each lifter had a pre-assigned lifter bore location (I organized this during the initial test-fitting). The lifters were placed into their respective lifter bores and rotated to again verify smooth operation.

The valve guides feature a wide base groove to accept the guide seal. The narrow groove at the center area will accept the locking C-clip that will secure the valve assembly in the block. Note: Be sure to lube and install the guide seal to the guide before assembly of the valve and spring.

Using a valve spring compressor, and after the guide seal has been installed to the guide, install the valve spring, retainer and valve stem locks.

A valve assembly, ready for installation.

Lubricate the guide seal well. Use caution to avoid tearing the seal during insertion into the block.

Inserting the valve assembly into the guide bore.

A C-clip retainer will secure the valve assembly in the block.  Always use new clips.

Here I’ve inserted a C-clip retainer onto a guide for illustrative purposes. The bent tang must angle towards the valve stem tip (towards the lifter).

The same type of claw-foot pry bar that was used for valve removal is needed for valve installation.

While it may be difficult to see details in this photo, the pry bar is used to compress the spring, which pulls the guide down towards the valley. Once the narrow retainer clip groove in the guide is exposed, the C-clip is inserted (a white towel was laid on the opposite side to protect the block paint if the bar slipped).

This closeup shows a C-clip installed.

In order to adjust valve lash, you’ll need a pair of lifter locking tools and a 7/16″ open-end wrench. The two specialty tools are mirror images. One works for one cylinder’s lifter, while the other tool works for the adjacent lifter for the same cylinder.

The specialty lifter locking tool in place. One side of the tool engages to one lifter to serve to stabilize the tool, while the other end of the tool features a tang that locks into one of the four holes at the top of the lifter. This prevents the lifter from rotating during adjustment.

With the locking tool in place, and with the appropriate camshaft lobe at its base circle, here we adjust one lifter. Once this lifter is adjusted, we use the other (mirror image) tool to adjust the adjacent lifter. Cold lash was set at 0.012″. Note: the adjuster screws feature very tight threads (designed to hold adjustment), so you’ll need to use some muscle.

CRANKSHAFT INSTALLATION

With the cam and cam timing gear installed, it was time to install the crankshaft.

First, the upper rear main seal must be installed. A cast aluminum rear seal housing (original Ford) seats into a register in the block. I applied a bead of Valco aluminum RTV to the outer radius of the housing and slipped the housing into the block. This was an easy fit with no interference issue. I carefully rocked the housing left/right to achieve a just-below-deck position of each housing end relative to the block pan rail surface (just make sure each end is placed at the same depth…almost flush but just below the surface. I then allowed the RTV to cure for a few hours.

The upper seal was then installed into the rear seal housing. Instead of using the original type white rope seals, I used square-profiled graphite braided seals, which are much easier to work with…very flexible and graphite impregnated. Egge thoughtfully provides this improved rear seal in their very compete gasket set.

I placed the upper seal section into the rear seal housing, pressing it into the seal housing groove by rolling a clean socket wrench along the seal while pressing the seal into place (rolling it with pressure applied to a large-diameter socket wrench). I centered the seal, leaving the same length protruding at each end (the seal is longer than needed and must then be trimmed). Once the seal was fully seated into the housing, I used a new razor and carefully trimmed each end, leaving about 1/32” protruding out beyond the pan rail surface.

Graphite impregnated braided “square profile” seals are used for the rear main sealing. These are very flexible and easy to shape into their seal channels in the block and oil pan.

The rear main seal at the block (upper seal) seats into a cast aluminum seal housing. This housing must be installed to the block first (immediately behind the number 3 main bearing saddle). The concave side (seen here) is installed facing toward the front of the block.

The upper rear seal housing is installed to the block (using a light coat of RTV for retention). make sure that both sides of the housing are flush to the pan rail surface.

Insert the braided seal into the seal housing channel, and use a large-diameter socket wrench to “roll” the seal fully into the channel. Once fully seated, trim the excess ends using a new razor (leaving about 1/32″ or so above the pan rail surface). Actually, the seal comes with a thin spacer and a blade for accurate trimming.

Next, the block main bearing saddles were again cleaned to remove any oils, as were the main bearing caps. The upper and lower main bearing shells were carefully cleaned and dried as well (remember: never place oil on the backside of a main bearing). With the upper main bearings installed in the block saddles and the lower main bearings installed into their respective main caps, all bearing surfaces were then coated with Royal Purple Max Tuff assembly lube (including the rear bearing’s thrust faces).

With the crank timing gear installed, and after once again carefully cleaning and inspecting the crankshaft for absolute cleanliness, the crankshaft was laid onto the upper main bearings. Note: since the cam gear is already in place, the cam and crank gears must mesh while aligning the timing dots on each gear. With the cam gear’s dot facing the bottom of the block, the crank is installed with its gear dot facing the top of the block (the two dots must meet together….once the block is rotated upright in its normal position, the cam gear dot is at 6 o’clock and the crank gear dot is at 12 o’clock). Naturally, with the block upside-down on the stand, the cam gear will be placed with its dot at your view’s 12 o’clock position and the crank gear will be at your view’s 6 o’clock position.

Once the dots are aligned, make sure that the crank is fully resting on its upper main bearings. The rear of the crank may be tilted upwards just a tad because of the new rear main upper seal, but this will settle as you begin to install the rear main cap.

The crank uses three main bearings. The thust bearing locates at the rear (number 3) main bore location. Always carefully wipe and inspect saddles and bearings to remove any oils or dust particles.

With all three upper main bearings in place, again carefully wipe the bearing surfaces to remove any particulates. Once you’re certain that the bearing surfaces are clean, apply a liberal amount of lubricant. I prefer Royal Purple Max Tuff engine assembly lube. It’s sticky and super-slippery, and does a great job of lubricating the bearings during initial start.

Our Scat stroker crank. I performed a final wash and inspection to make sure that the crank was absolutely clean.

Tapped holes at the outboard side of the pin areas feature plugs (sealing off the access drilled passages that were performed during creation of bearing oil passages).  Remove these plug, apply thread locking compound or thread sealer and reinstall tight.

Scat did a really nice job of chamfering the oil holes in the crank journals. When you clean the crank, be sure to run a clean rifle brush (with solvent) through each oil passage, followed by blowing with compressed air, washing, rinsing and blowing again.

With the block positioned upside-down, rotate the camshaft to position the dot on the timing gear at the 12 o’clock position (facing the bottom of the block). When the crank is lowered into position, the timing dot on the crank gear must align with the cam’s timing gear dot.

The oil slinger features concave and convex sides. The concave side (the dished side) must face outward toward the end of the crank snout.

A crank pulley spacer is required (placed onto the snout after the crank gear is in place). If you’re using a one-piece rubber front seal, you need a smooth-O.D. spacer (left). If using the traditional rope type front seal, you need the original type spacer that features spiral grooves (right). You can make a smooth spacer or you can purchase one from Luke’s. I opted for the one-piece seal, so I installed the smooth spacer.

With the rear key (for the gear) installed into the snout, and the crank timing gear installed, the oil slinger is then slipped onto the snout (this registers onto the gear key). The pulley spacer is then slipped onto the snout. The front key (for the pulley) may be installed afterwards, prior to pulley installation.

An alternative to using the traditional two-piece front rope seal, Speedway offers a rubber one-piece seal. This offers easier installation and theoretically better sealing.

Clean the main bearing caps to remove any oils or other contaminants. Once the lower bearing shells have been installed to the caps, I applied Royal Purple Max Tuff to the bearing surfaces. Prepare all three main caps/bearings prior to crank installation.

Here the crank has been fully installed. Due to the nature of the main cap register design, tighten the main cap bolts lightly, then rotate the block upright and continue to tighten the main cap bolts in several steps while checking crank free rotation.

Remember to align the gear timing dots during crank installation. In this photo, I’ve applied a black mark on the oil slinger to indicate the position of the cam gear dot.

I applied ARP moly lube to the main bolt threads and under the bolt heads and finger-tightened both bolts on each main cap.

I first began to tighten the rear cap, in order to settle the rear of the crank against the upper rear seal, tightening the rear cap bolts to a value of 10 ft-lbs. I then snugged the No. 2 cap bolts to 10 ft-lbs, followed by the front cap bolts at the same value. I gently rotated the crank a few degrees after each pair of cap bolts were snugged. Because of the radius-groove register design of the main caps, this helped to “settle” the cap alignments. After all cap bolts were tightened to 10 ft-lbs, I then rotated the block upright. With the weight of the crank on the main caps, I gently knocked the crank back and forth (front to rear and rear to front within the crank’s endplay range), again to aid in main cap alignment. I then continued to tighten the main cap bolts, starting with the center cap at 20 ft-lbs, the rear cap at 20 ft-lbs and the front cap at 20 ft-lbs. After each cap was snugged to this value, I gently rotated the crank a few degrees as before. I continued in this manner (second cap, third cap and front cap locations) to 30 ft-lbs and then to 40 ft-lbs.

Once all cap bolts were tightened to 40 ft-lbs, I then rotated the block upside down and continued my main cap bolt tightening. I tightened (in the same order as before) to 50 ft-lbs, then to 75 ft-lbs, then to 85 ft-lbs, and finally to 100 ft-lbs. I checked crank rotation after each tightening phase. While the crank rotated easily with two fingers previously (without the rear seal), even with the seal in place, I rotated the crank using a beam-type torque wrench to check for rolling resistance. The beam needle hardly moved, with resistance at about a mere 4 ft-lbs.

I realize that my main cap tightening procedure may seem a bit anal and overkill, but I simply don’t like the register design of the flathead main caps (not precise enough). I feel that by gradually creeping up on final torque in this manner provided greater assurance of obtaining cap alignment relative to the crank centerline. The result of my time-consuming procedure: the crank rolls like butter.

FRONT CRANK SEAL

Originally, Ford used a two-piece rope seal at the crank snout. While new rope seals are readily available, to make life easier I purchased a 1-piece rubber lipped seal from Speedway (no messing with seating the rope pieces, and less chance of a leak). However, the front seal rides on a steel spacer sleeve that drops onto the crank snout (between the oil slinger and damper/pulley). The original sleeve features a spiral groove to help keep the rope seal lubricated. This grooved sleeve won’t work with the 1-piece seal, so I obtained an aftermarket sleeve from Luke’s Custom Machine. This is simply a steel tube machined at a height of 1.095”, with an I.D. of 1.310” and an O.D. of 1.626”, with a smooth outer surface (no grooves).

The spacer sleeve features about a 0.001” interference fit (snout diameter is 1.627”). Installation requires either tapping it onto the snout using an aluminum or brass tube and a hammer, or you can simply heat the sleeve in a convection oven (heat to about 300 degrees for about 15 minutes) and slide the sleeve onto the snout. Just remember that the crank timing gear and oil slinger must first be in place before installing the spacer sleeve.

Due to the length of this article, I’ll cover piston and connecting rod assembly and installation, timing cover, water pump and cylinder head installation in the next article (Part 3). Regardless, I’ve included all clearance specs, including rods, here for your convenience.

CRANK & ROD CLEARANCE

SPECS & RESULTS

FORD SPECS

Main bearing clearance………….0.000” to 0.003”

Crank endplay…………………..0.002” to 0.006”

Rod bearing clearance…………..0.0005” to 0.003”

Rod side clearance………………0.006” to 0.020”

OUR MEASURED RESULTS

Main bearing clearance………….0.0025”

Crank endplay……………………0.003”

Rod bearing clearance……………0.002”

Rod side clearance……………….0.020”

8BA BORE/STROKE

OE BORE………………………….3.1875

OE STROKE………………………3.750

3.1875 X 3.1875 X 3.750 X 0.7854 X 8 CYL = 239 CID

OUR BORES………………………3.3125 (+0.125”)

OUR STROKE…………………….4.125

3.3125 X 3.3125 X 4.125 X 0.7854 X 8 CYL = 284.39 CID

FIRING ORDER

1-5-4-8-6-3-7-2

(right bank, front to rear cyls 1-2-3-4;  left bank, front to rear cyls 5-6-7-8)

(distributor rotation: clockwise)

PISTON TO WALL CLEARANCE…………0.003”

PISTON RING GAPS

OE…………Top 0.007 min, 2nd 0.007 min, oil rail 0.015 min

OUR RINGS….Top 0.019”, 2nd 0.014”, oil rail 0.015

FASTENER TORQUE VALUES

MAIN BOLTS……………..……105 ft-lbs

ROD BOLTS……………..……..45 ft-lbs (w/ARP moly) (stretch not to exceed 0.0047”)

(our rod bolts are ARP 8740  3/8” dia. x 1.600” shank length)

CYL HEAD BOLTS……….……60 ft-lbs (in three steps)

(60 ft-lbs per Edelbrock. OE spec is 65-70)

WATER PUMPS……………….. 23-28 ft-lbs

CAMSHAFT TIMING GEAR…..15-20 ft-lbs

INTAKE MANIFOLD BOLTS….12 ft-lbs, followed by a final 24 ft-lbs

TIMING COVER…………………13-18 ft-lbs

OIL PUMP TO BLOCK………….12-15 ft-lbs

OIL PUMP COVER PLATE……..  7-10 ft-lbs

OIL PUMP PICKUP……………..80 in-lbs

OIL PAN………………………… 15-18 ft-lbs

FLYWHEEL TO CRANK……… 75-85 ft-lbs

EXHAUST MANIFOLD……….. 25-30 ft-lbs

WATER OUTLETS…………….. 12-15 ft-lbs

CLUTCH PRESSURE PLATE…. 17-20 ft-lbs

BELLHOUSING TO BLOCK….. 37-42 ft-lbs

STARTER BOLTS……………… 15-20 ft-lbs

OE FUEL PUMP…………………   6-9 ft-lbs

GEN/ALTERNATOR BRACKET…55-70 ft-lbs

Note: This engine build project was performed, as are all of our engine projects, at the author’s custom shop, Birchwood Automotive Group, in Creston, Ohio. All build and photo work is routinely handled at this location, utilizing our clean engine assembly room, outfitted with Lista professional-grade cabinets and workbenches.

ORIGINAL FORD FLATHEAD CRANK SPEC CHART

Check bearing journals with a quality micrometer. Take four measurements on each journal (checking side to side and also checking 90º apart on rotation).
Model Year Crankshaft Overall Length Main Bearing
Journal
Connecting Rod
Journal
1937 Ford 60hp 20.82″ 1.9990″ 1.5990″
1938 Ford 60hp 20.82″ 1.9990″ 1.5990″
1939 Ford 60hp 20.82″ 1.9990″ 1.5990″
1940 Ford 60hp 22.88″ 2.0990″ 1.6990″
1932 Ford 65hp (babbit type) 24.47″ 1.9990″ 1.9990″
1933 Ford 75hp (babbit type) 24.47″ 1.9990″ 1.9990″
1934 Ford 85hp (babbit type) 24.47″ 1.9990″ 1.9990″
1935 Ford 85hp (babbit type) 24.47″ 1.9990″ 1.9990″
1936 Ford 85hp (babbit type) 24.47″ 1.9990″ 1.9990″
1936 Ford 85hp LB (insert type) 24.47″ 2.3990″ 1.9990″
1937 Ford   85hp 24.47″ 2.3990″ 1.9990″
1938 Ford   85hp 24.47″ 2.3990″ 1.9990″
1939 Ford   85hp 26.03″ 2.4990″ 1.9990″
1940 Ford   85hp 26.03″ 2.4990″ 1.9990″
1941 Ford   90hp 26.03″ 2.4990″ 1.9990″
1942 Ford   90hp 2.4990″ 1.9990″
1946 Ford 100hp 2.4990″ 2.1390″
1947 Ford 100hp 2.4990″ 2.1390″
1948 Ford 100hp 2.4990″ 2.1390″
1949 Ford 100hp 2.4990″ 2.1390″
1950 Ford 100hp 2.4990″ 2.1390″
1951 Ford 100hp 2.4990″ 2.1390″
1952 Ford 110hp 2.4985″ 2.1385″
1953 Ford 110hp 2.4985″ 2.1385″
1939 Mercury   95hp 2.4990″ 2.1390″
1940 Mercury   95hp 2.4990″ 2.1390″
1941 Mercury 100hp 2.4990″ 2.1390″
1942 Mercury 100hp 2.4990″ 2.1390″
1946 Mercury 100hp 2.4990″ 2.1390″
1947 Mercury 100hp 2.4990″ 2.1390″
1948 Mercury 100hp 2.4990″ 2.1390″
1949 Mercury 110hp 2.4990″ 2.1390″
1950 Mercury 110hp 2.4990″ 2.1390″
1951 Mercury 112hp 2.4985″ 2.1390″
1952 Mercury 125hp 2.4985″ 2.1390″
1953 Mercury 125hp 2.4985″ 2.1390″

Crankshaft specification chart courtesy Van Pelt Parts & Service

(Author’s note: Van Pelt Parts & Service in Cincinnati, OH is a great source of information regarding OE flathead specs, and for many used and NOS flathead parts)

MY PARTS AND PART NUMBERS

Block…………………………Original 1949-1953 8BA

Crankshaft……………………Scat 286-9-239-4125-2000 (4.125” stroke)

Connecting rods………….….Scat 2-239-7000-2000 (7.000”)

Piston/pin set…………….… Egge EP994-8.125

Ring set (Total Seal)……….. Egge SRTCR6276-8

Valves (16) …………………  Egge S1821

(note: intake and exhaust valves are identical)

Valve springs (16) ………..…Egge VS651

Valve guides (16)  ………..…Egge G614

Adjustable lifters (16) …….…Egge VL36

Connecting rod bearings……..Egge CB610.000 (STD)

Main bearings (King) ………..Egge MBS3351SI.000 (STD)

Cam bearings…………………Egge F-1

Cam gear (Republic Gear Co.)  Egge TG2700

Crank gear (S.A. Gear)……… Egge TG2701

Oil pump (Melling)  …………Egge P-307 NEW

Gasket set (Best Gaskets) ……Egge RS521C

RH water pump ………………Egge WP-1231 NEW

LH water pump….……………Egge WP-1232 NEW

Camshaft (Isky)……………… 818800

Cylinder heads………………. Edelbrock 1115

Intake manifold……………… Edelbrock 1109

Carburetors…………………..  BG Demon 98

Distributor…………………… MSD 8573

Crank pulley………………….Fluidampr 600203

Alternator…………………….Tuff Stuff  7781A

Spark plug wires………………MSD 31229 (8.5mm, universal w/90-deg plug boots)

Velocity stacks………………..Eelco 6430

OUR SOURCES FOR THIS FLATHEAD PROJECT

BEST GASKETS

11558 E. Washington Blvd., Suite F

Whittier, CA 90606

888-333-2378

www.bestgasket.com

BG FUEL SYSTEMS/BARRY GRANT

(Demon 98 carburetors)

1450 McDonald Rd.

Dahlonega, GA 30533

706-864-8544

www.barrygrant.com

BIRCHWOOD AUTOMOTIVE GROUP

(the author’s engine build & fabrication facility)

10205 Wooster Pike Rd.

Creston, OH 44217

330-435-6347

www.birchwoodautomotive.com

BOSCH MOTORSPORTS

(spark plugs)

2800 S. 25th Ave.

Broadview, IL 60155

919-846-2115

www.boschusa.com

CWT INDUSTRIES

4708 S. Old Peachtree Rd., Unit 300

Norcross, GA 30071

800-449-1849

www.cwtindustries.com

EDELBROCK CORP.

(P/N 1115 cylinder heads and P/N 1109 intake manifold)

2700 California St.

Torrance, CA 90503

800-416-8628

www.edelbrock.com

EGGE MACHINE CO.

(pistons, main bearings, rod bearings, cam bearings, gaskets, valves, valve guides, valve guide seals, valve springs, retainers, keepers, Melling oil pump, Isky cam and lifters, cam gear, crank gear, …….)

11707 Slauson

Sante Fe Springs, CA 90670

800-866-3443

www.egge.com

FLATHEAD JACK

1561 Third Ave.

Walnut Creek, CA 94597

888-993-2233

www.flatheadjack.com

FLUIDAMPR

180 Zoar Valley Rd.

Springville, NY 14141

716-592-1000

www.fluidampr.com

FRAGOLA PERFORMANCE SYSTEMS

888 W. Queen St.

Southington, CT 06489

866-337-2739

www.fragolaperformancesystems.com

GEARHEAD TOOLS

(TM Machine Products)

24773 Avenue Rockefeller

Valencia, CA 91355

800-733-4463

www.gearheadtools.com

G.L. HELLER CO.

(CNC machining…CNC lathe-cutting our pistons)

6246 Industrial Parkway

Whitehouse, OH 43571

419-877-5122

GOODSON TOOLS & SUPPLIES

(our micrometers, burette, thread chasers, misc. tools)

156 Galewski Dr.

Winona, MN 55987

800-533-8010

www.goodson.com

GREBER POWDER COATING

313 Clark St.

Elyria, OH 44035-6105

440-322-3685

GRESSMAN POWERSPORTS

(full machine shop services)

904 Lime St.

Fremont, OH 43420

419-355-8980

www.gressmanpowersports.com

H&H FLATHEADS

(variety of flathead components)

4451 Ramsdell Ave.

La Cresenta, CA 91214

818-248-2371

www.flatheads-forever.com

LENOVO

(engine room computer monitor)

1009 Think Place

Morrisville, NC 27560

866-426-4008

www.lenovo.com

LISTA INTERNATIONAL

(pro-level engine room cabinets and workbenches)

106 Lowland St.

Holliston, MA 01746

800-722-3020

www.listaintl.com

LUKE’S CUSTOM MACHINE & DESIGN

(variety of custom flathead components)

1457 Charlotte Rd.

North Vancouver, BC V7J1H1

604-980-8617

www.lukescustommachine.com

MAC TOOLS

(my shop’s assorted hand tools)

505 N. Cleveland Ave.

Westerville, OH 43082

800-622-8665

www.mactools.com

MEDINA MOUNTAIN MOTORS

(full machine shop services)

199 Factory St.

P.O. Box 192

Creston, OH 44217

330-435-6236; 866-218-7467

www.medinamountainmotors.com

MELLING SELECT PERFORMANCE

P.O. Box 1188

Jackson, MI 49204

517-787-8172

www.melling.com

MSD IGNITION

(our ready-to-install billet distributor, spark plug wires)

1490 Henry Brennan Dr.

El Paso, TX 79936-6805

915-857-5200

www.msdignition.com

PRW INDUSTRIES

193 West Orangethorpe Ave.

Placentia, CA 92870

714-792-1000

www.prw-usa.com

PUROLATOR FILTERS

(canister type oil filter cartridge)

3200 Natal St.

Fayetteville, NC 28306

800-526-4250

www.pureoil.com

ROYAL PURPLE LTD.

(Max Tuff assembly lubricant)

1 Royal Purple Ln.

Porter, TX 77365

888-382-6300

www.royalpurple.com

SCAT ENTERPRISES

(stroker crankshaft and forged rods)

1400 Kingsdale Ave.

Redondo Beach, CA 90278-3983

310-370-5501

www.scatcrankshafts.com

TOTALLY STAINLESS

(stainless steel fastener selection)

P.O. Box 3249

Gettysburg, PA 17325

800-767-4781

www.totallystainless.com

TUFF STUFF PERFORMANCE ACCESSORIES

(alternator)

9004 Madison Ave.

Cleveland, OH 44102

800-331-6562

www.tuffstuffperformance.com

VAN PELT SALES & SERVICE

4525 Bells Ave. #135

Cincinnati, OH 45244

800-299-7496

www.vanpeltsales.com

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  • John D. Berkheimer

    I get to read your articles quite often in Motor, and this publication. They are always top quality and always very informative. Reading this one on my PC and having a 22″ monitor made the pictures even better. Super article! When I was 16 back in 1960 I belonged to a car club called the “axle snappers” who had a NHRA D class dragster with a flathead and hilborn inj. We held the record for many years with a 10:49 when we won class at the Detroit nationals in 1960. The engine in your article is really cool, and it needs a special car for a home. Well done.

    John D. Berkheimer, former mopar tech for 20 years, recently retired auto instructor at Thaddeus Stevens College of Technology for 26 years, and left brain car enthusiast. johndb@ptd.net

  • Rbaskins

    Very nice article. I built a 3-5/16″ x 4-1/8″ 8BA Flathead in 1961 (Sophomore in High School) with the help of Danny Kilcup of Portland, OR doing the machine work. I also used the Isky 88 “Full Race” 264 degree camshaft. I used Edelbrock 8.5:1 (for stock Ford) heads and an Offenhauser triple manifold with offset generator bracket. The stroker kit was from Speed-o-motive in El Monte, CA and if I remember right, I paid $112.00 for it. The camshaft turned out to be very mild for that cubic inch displacement, and it never really had the “cammed up” idle that I had hoped for. Later I sold the engine and installed an Isky 400 Junior track grind cam for the buyer. That cam was much more radical. I'll always love the Flathead Fords. I still have one in a '52 Ford F-1 with Marmon-Herrington all wheel drive. The motor in the F-1 is an .080″ over Mercury with 268 cubic inches. I built it over 33 years ago and it's never been back apart since.

    Bob Baskins, former Ford Tech, and High School Auto Shop teacher, now retired.

    rbaskins@aol.com

  • precisionengine

    Thanks for your very kind comments. Very much appreciated.

  • http://www.glheller.com Sales

    Thanks for including G L Heller Company in your article. If anyone is interested in contacting us for further information or possible job quotes, please visit our new website: http://www.glheller.com Through the site you can email Gary or Todd, who will be more than happy to handle your inquiry. Thanks!