BLOCKS: All 59 series blocks are identified as 59A 59AB 59L, 590, 59X, 59Y, and 59Z and 59 without a letter. The 59L,X,Y, & Z blocks were supposedly military and were thought to have used stronger materials (higher nickel and carbon content) in order to meet tougher military spec’s. I do remember boring a 59Z block in the early fifties that nearly burned the boring bar up it was so hard! The machinist said he’d never seen such a hard block and he’d been boring them since the mid thirties! So maybe there is something to the military tale. Other knowledgeable sources have held that the L blocks were Canadian truck blocks and had thicker walls than any other 59 series blocks. I don’t know whether it’s true or not. However, I do kncw we bored several L blocks to 3-7/16” during my race days in Texas without ever having any problem. The block identification letters are located just below the 59 block designation on the clutch housing.

About boring: I believe all of the 59 and 8BA blocks will take a bore safely of 3-3/8” and still have about 0.120’ wall left. This is because core shifting was not as prevalent as it was in the earlier 21 & 24 stud engines. My current 59 no letter block has a bore of 3-3/8”±0.020” and still has 0.124” of wall left. No problems have showed up yet. I also believe the wall thickness is the same on all of the 59 and 8BA series blocks. Several publications state the same thing. I doubt old Henry would have redesigned his castings just to make thicker walls on some doesn’t sound right to me. Walls on a street engine should not be thinner than 0.090” after boring. I do know we called Ed Iskendarian in the fifties and asked him about wall thickness on a race engine we were building. He stated that 0.060’ was sufficient wall thickness, but that he got real worried when the walls were only 0.040”! Well we bored it to> where there was 0.060” left and it blew up the first night out in the middle of the main! !!! Sure ran hard though! I think you get wall waving during periods of high stress if they’re that thin and the pistons will seize and cause the engine to self-destruct.

FANS:
Ford recommends fans turn 1-1/2 times the crankshaft speed on flathead engines in order to adequately cool at slow speeds and at idle. This can be adjusted by varying the pulley diameters. Turning these faster will usually produce excessive fan noise although they will cool at slow speeds. Turning them less will usually cause the engine to heat while idling or at low speeds. It’s always bugged me that Henry would say this and then turn around and put the fan on the crankshaft, example would be the ‘40 Ford/Mercs, and expect them to run cool.

TEMPERATURE:
Flatheads normal range of engine temperature is 180-200 degrees F. Remember that plain water in a non-pressurized system boils at 202 degrees in mile-hi Denver and you can see how really close these old Fords run to boiling. Speaking of boiling. It must be avoided in a non-pressurized cooling system because it’ll damage the engine. As we know, boiling causes bubbles in any coolant. These steam bubbles are in direct contact with the cylinder itself. Since there is no cooling within the bubble, an extremely hot spot is instantly created in the cylinder itself. When the ring passes such a spot, the ring will actually weld itself momentarily to the cylinder wall!!!!! It doesn’t slow the piston, but the weld breaks a small particle off the surface of the cylinder. These appear as shadows on the cylinder walls. Sometimes these shadows will get as big as 1/8”!!!! ! These intense hot spots seriously weaken the cylinder and should be avoided at all costs. One recent 59L block I tore down had about 50 of these shadows ranging from half the size of a pin head to almost 1/16’!!!!! It had been in a car with a non-pressurized system with a very minor compression leak.

COMPRESSION RATIOS:
The Edelbrock compression ratio chart is based on a stock relief in the block. The compression ratio chart increases 0.3 of a point for each 1/8” increase in stroke. Boring oversize does not affect the compression ratio to any degree. ... but it definitely affects the compression pressure.

RINGS:
I’m real fussy about the positioning of the ring gaps when I build any engine. Yeah, yeah..... I’ve heard that all the gaps will become lined up every so many million revolutions or so. I cannot believe this will happen. Reasoning??? What makes the rings rotate? The rings are rotated when they contact the angular circular scores on the cylinder walls made by the insertion and retraction of the cylinder hone stones, right? The honing scores are exactly the same at the top, middle, and bottom of the cylinder since the hone was moved at a uniform rate if it was done correctly. Then each ring contacts an equal amount and angle of scores..., which will rotate each ring exactly the same amount. I’m assuming lots of things here including each ring has exactly the same amount of tension against the cylinder. I seriously doubt the ring gaps ever line up. If they did, the engine would smoke so bad and, considering how long it would take to move the rings so the gaps were no longer lined up, for such an extended length of time that we’d be arrested for pollution. So I’m real fussy about the positioning of the gaps since I believe they never line up.
First I determine which side of the piston has the thrust. Say an engine turns clockwise when viewed from the front. It follows that the thrust side of the pistons on the drivers side will be on the bottom side of the pistons. And the thrust side of the pistons on the passengers side will be on the top side of the pistons. Having determined the thrust, I arrange the rings on a 3 ring piston as follows.

(1] The oil expander ring gap is positioned opposite the piston thrust side.
(2) The two steel segmented oil rings are positioned 1/2” to 3/4” on each side of the gap in the oil expander ring.
(3] The bottom compression ring gap is positioned directly over the wrist pin and faces towards the front of the block.
(4) The top compression ring gap is positioned directly over the wrist pin and faces towards the rear of the block.

By positioning the gaps like this, no ring gap is positioned on the thrust side of the piston. The thrust side of the piston receives a lot more pressure during combustion and, if a gap is located on that side, the pressure will cause the gap to expand. This expanding gap creates a lot of un-needed ring pressure against the cylinder walls. This results in excessive ring drag and wear and promotes blow-by.
Incidentally, I check each steel segment ring to determine which side is to go towards the top of the piston. Yes I said steel segment rings are directional! There is an up and down to these even though they’re not marked. Place one of these thin rings between the uppermost joint crease of your thumb and the uppermost joint crease of your index finger. Now squeeze your thumb and finger towards each other so the ring is forced to bend. Notice how the segment ring bends either up or down? For this discussion, let us say this ring bent upward. Now flip the ring over and repeat the process. Notice the segment ring now bends downward! It’ll bend only one way! This is because of the way the molecules arrange themselves when they manufacture the rings or so I’ve been told. Now flip the ring back the way it was so the bend is upward.
This is the way the ring is to be installed on the piston the upward bend always goes towards the top of the piston. This applies to both of the segment rings. It may be confusing, but try it and you’ll quickly catch on.

VALVE GUIDES:
Split valve guide clearances are 0.004”.

VALVE SPRINGS:
Springs with close wound coils are to have the close wound coils at the guide end to hinder coil binding.

TAPPETS:
Tappet bases have a 96” convex radius. A flat base is okay, but convex is preferred. Tappets with a concave radius should not be used as they will quickly destroy a camshaft.

OIL, PUMPS, AND PRESSURE:
The ‘36 thru early ‘48 used the “long body” oil pump. In late ‘48 through ‘49, Ford used the “short body” pump (the screen pickups are different for the short and long body pumps) . These had straight cut gears and were rated at 60 psi. per Ford. In ‘50, helical cut gears were introduced and are rated at 80 psi. per Ford. There were no further changes in the oil pumps through ‘53. The ‘50 and newer relief spring specifications call for the tension to be between 78 and 87 oz. when compressed to 1.380”. Stretching the oil pump relief spring will increase pressure.
The stock 59 block relief valves, located in the front of the block, were rated at 40 psi.. On these blocks, I replace the oil pressure relief spring in the block with the spring and ball from a late ‘48 and newer oil pump. Additionally, I stretch these springs about 1/4”. I tried plugging the block oil pressure relief with a screw to see what it did to my oil pressure. It increased it about 10 lbs over using the stretched spring and ball from a late ‘48 pump.
A built-up street engine should carry oil pressure in the 80 psi. range while a race engine should carry about 100 lbs. because of the increased lower end clearances.
Something somebody may know. I’ve often wondered about lOw/40 oil. At what oil temperature does the oil change from 10 wt. to 20 wt.? From 20 wt. to 30 wt.? From 30 wt. to 40 wt.? I’ve written letters to Castrol and Valvoline without getting any reply whatsoever! Anyone know??????
Also, I asked them what do you have if you mix a quart of 20 wt. with a quart of 30 wt.? 2 quarts of 25 wt.? No answer to that either! Hot Rod Magazine said I’d have one quart of 20 wt. and one quart of 30 wt. This is an answer???? No wonder I quit subscribing to them!

MAIN BOLTS ON 8BA BLOCKS:
These blocks use cap screws on the mains. Only the front main bolts are full shouldered and they do not use a washer. Washers are used on all of the other cap screws.

MAIN BOLT TIGHTENING SEQUENCE:
Tighten the rear main first, then the front, and the center one last.

OIL CAPACITIES:
Ford manuals state the 59 series capacity is 5 quarts of oil while the SPA series capacity is 4 quarts of oil. Both specifications are without an oil filter! These capacities agree with Motor Manuals, Chilton Manuals, and lubrication charts like Texaco etc.. The SPA dip stick indicates full with 4 quarts so there’s no problem here since it conforms to the book. But the 59 series dip stick shows full with only 4 quarts or one quart less than their spec’s! If you put in 5 quarts as Ford spec’s call for, it’s a quart above the full mark! I’ve checked my 59 block with different dip sticks and pans on it and it stays the same. I’ve checked several 59 engines that are original or stock with the correct pans, dip sticks, and dip stick tube. They show the same thing as mine 4 quarts puts the oil at the full mark on the dipstick! Which do you use 4 or 5? Remember these quantities DO NOT INCLUDE AN OIL FILTER. I use 5 quarts in my 59 series block and have filed a line at the 5 quart level.