Tag Archives: rebuilding ford Y engines

New Life for a 1955 ‘P’ Code 292 Police Engine

When David Church acquired a 1955 Ford Customline two door sedan, it was found that it was originally ordered as a law enforcement car with the P code 292 and a three speed standard transmission. A little back tracking finds that the car was purchased new in North Carolina and when found by David, still had the 1967 North Carolina license plates on it but was now sitting in a South Carolina field.  It had been well over 40 years since the car had been last registered and state inspected.  Although that car had been sitting in a field for a number of years, a bit of fuel poured into the ‘Teapot’ 4V carburetor and a battery boost gets it started.  It drives itself up and onto a trailer for the trip back to Mississippi.  The odometer is showing 60K miles but when looking at suspension, pedal wear, and general oil and grease build up at various parts of the car, the assumption is the car has 160K miles instead.  More time elapses and now the car is undergoing a complete restoration including an engine rebuild.  The engine rebuild is where I come into the picture.

In researching the old sales literature, it’s found that the advertised horsepower for the standard transmission equipped police engine is 188. Looking at some of the other 1955 year model 292 horsepower ratings finds that the Thunderbird standard shift engine is rated at 193HP while the Mercury standard shift engine is rated at 188HP just like the Police engine.  Delving deeper into the differences does find that the Thunderbird 292 has 8.1:1 compression ratio versus 7.6:1 for the Police and Mercury engines.  Going through the parts manuals does find the Thunderbird engine using the ECL heads while the Police and Mercury standard shift engines uses the ECK head castings.  It would appear the only difference between the Ford Police engine and the Mercury engine when equipped with the standard transmission is just the valve covers as both are identical otherwise.  The 1955 Ford Police cars using the Mercury engine is no surprise as the 1954 Ford Police cars used the Mercury 256 engine rather than an upgraded 239 version.

Click on pictures for larger images

Teardown of this police engine finds that it’s still a standard bore engine with all appearances that the bottom end had never been into before. The block is an ECK casting with a June 4, 1955 casting date while both cylinder heads and the intake manifold have July 6, 1955 casting dates.  Deciphering the stamped build date on the front valley cover rail finds the engine being assembled on July 7, 1955 on the third shift. If those dates are correct, there’s obviously no inventory of parts sitting loose for these engines as they are being assembled almost as fast as some of the parts are being cast and machined.  The crankshaft journals looked pristine but the rear thrust surface at the center main journal was wasted (badly worn).  While the crankshaft could be potentially welded up in that area and re-machined, it was decided to simply replace the crankshaft with another and start fresh.  As it works out, another standard journal crankshaft with minimal wear was sourced and used without having to grind the journals undersize.

The ECK-C heads have the 1.78” intake valves which was the intermediate intake valve size for the Y engines. The guides and valves are replaced along with new valve springs and valve locks.  The original two piece retainers are replaced with single piece units.  There was a problem with the early production Police engines dropping valves when being aggressively driven (over-revved) so there was a service bulletin issued instructing dealers to replace the valve springs on any police engines being brought in for service.  Now that more than sixty years has past, the aged valves and especially the exhausts are noted for their propensity in coming apart.  With that in mind, retaining the original valves is risky and putting a warranty on the engine if retaining them is out of the question.  The desire is for this engine to last at least another sixty years so it’s a no brainer in replacing all the valves.  The new valve springs are set up at 76 lbs closed pressure and 230 lbs. pressure at 0.410” valve lift.  No port work is being performed simply to keep the engine in a close to ‘as delivered’ state as would have been supplied from Ford originally.

All the combustion chambers are cc’ed and while it’s found that both cylinder heads are similar in chamber volumes, they are very much on the large side in that they are averaging 83.4cc’s. Some reverse engineering finds that the ‘as delivered’ compression ratio was 7.53:1 with the original steel shim head gaskets in place.  Before coming across the appropriate sales paperwork and service bulletins, it was initially believed that the engine was suppose to have 8.5:1 compression ratio.  Service Bulletin #973 and the sales literature for the Police car option puts this to rest as it states that the standard shift Police 292 was indeed rated at 7.6:1 CR.  The automatic transmission equipped 292 Police engines were rated at 198HP and with 8.5:1 CR.

To compound issues with the compression ratio already being to the low side, the wrist pins in the replacement pistons are 0.023” closer to the piston tops and when also taking into account for switching to a composition head gasket rather than the original steel shim style, the compression ratio lowers another full ½ point making it 7.05:1. Zero decking the block only brings the compression ratio back to 7.5:1 so it’s going to take some head milling to get the compression ratio back up to the original advertised 7.6:1.  But at this point, the plan does deviate in that the desired compression ratio should at least be what the automatic transmission cars were.  To that end, the new target compression ratio is 8.5:1.  To attain that, the decks are milled an average of 0.035” to get the pistons level with the decks.  The amount of milling required to reduce the chamber volume 1cc on the ECK-C heads is ~0.0056”.  A little bit of math indicates that the heads must be milled 0.070” to get the chamber volumes down to 71cc.  Internal bracing within the coolant areas of the heads is sufficient enough to permit this amount of milling on these particular heads.  To insure that the intake manifold fits correctly, the intake sides of the heads are milled 0.080” which pretty much puts the intake gasket surface parallel with the valve cover rail.  As a side note, It’s always recommended to mill the intake side of the heads when possible rather than the intake manifold as this still allows the intake manifold to not be cylinder head specific and can be repurposed later on another set of heads.  All this machine work gets the calculated compression ratio back up to 8.5:1.

The block is fresh bored and honed for a replacement set of Silv-O-Lite 0.030” over cast pistons, the mains are align honed, and the decks are fresh machined so that Best Gasket composition head gaskets can be used rather than the original steel shim head gaskets. The piston to wall clearance is 0.0025” when all the machine work is finalized.  The pistons are sitting level with the decks at TDC which essentially gives a quench clearance of 0.046” which is the head gasket thickness.  The connecting rod big ends are resized with a new set of ARP rod bolts torqued in place while the wrist pin ends get new bronze bushings. With all the block machine work complete, the rotating assembly is dynamically balanced.  The bobweight value is 2070 grams and includes the 14 grams used as an oil value.

The camshaft is replaced with a NOS FoMoCo replacement supplied by David Church. It’s still in its original round cardboard tube but the part number is long faded away.  The center journal is cross drilled for upper end oiling rather than the grooved journal found on the 1956 and newer replacement camshafts.  The specs on this particular camshaft are as follows:

Advertised duration: 231½° Int / 235½° Exh

Lobe lift: 0.256” Int / 0.263” Exh

Calc valve lift: 0.366” Int / 0.376” Exh

Lobe centerline: 112½°

Duration at 0.050”: 196½° Int / 198° Exh

Cam is installed at 111½° Intake lobe C/L

Once the new set of Hy-Lift Johnson lifters are lubed and placed in their respective lifter bores, the pre-lubed camshaft is gently slid into place. The camshaft turns freely within the new bearings so all is well.  With the cam retainer bolted in place, the camshaft end play is at 0.006” which is within spec.  A note here about lubing the cam and tappets; the moly lube is used only on the lifter faces and camshaft lobes but the shanks of the lifters and cam journals are lubed with a quality engine oil.  It’s important that the lifters turn freely in their lifter bores and using oil instead of the moly lube insures this.  The moly lube if used on the lifter shanks can actually inhibit lifter rotation which then potentially brings a lifter/lobe failure to the forefront.  What happens in the first sixty seconds of running pretty much dictates the ultimate life expectancy of the cam and lifters.

Before installing the Hastings single moly piston rings on the pistons, they are placed and squared within the cylinder bores to check ring end gaps. The replacement rings are not a ‘file to fit’ set but ring end gaps are checked as a safety precaution against being too tight.  With some tweaking, the ring end gaps are finalized at 0.018” for the top rings and 0.014” for the second rings.  Once this is done, the rings are removed from the individual bores and placed on the pistons going into those particular bores.  The rings are installed on the pistons using a ring installing tool rather than twisting them on to the pistons.  Using a ring installation tool minimizes the chance for breakage while also eliminates the potential for any ‘twist’ to be imparted into the rings when installing them without the aid of a ring tool.

Short block assembly goes together without any issues. The bearing clearances were previously micrometer checked and it’s verified that the rod bearing clearance is ~0.0015” and main bearing clearance is ~0.0022”.  The rod bearing clearances were tightened up by using a std bearing in one half the rod and a 0.001” oversize bearing in the other half.  The rod side clearances are checking out at 0.018”-0.025”.  As a tip here, when the rod bolts were being torqued to their respective journals, a feeler gauge was being used between the rod pairs to take up all the clearance or ‘slack’. This prevents the rods from twisting during the torquing operation thus preventing the bearing from being unseated and/or sitting crooked within the rod bores.

With the short block together, the camshaft is degreed in and with the stock link timing chain setup, the cam is sitting at 1° advance or at 111½° intake lobe centerline. In keeping with the original intent of having this engine make it’s advertised horsepower rating, the camshaft is left at 1° advance rather than broaching a new keyway slot in either the cam gear or crank gear in which to further advance the cam timing.  While advancing the camshaft in this particular case would help low end grunt and idle, it would be counter-productive to making the rated horsepower ratings.  At the conclusion of degreeing in the camshaft, the crankshaft is rotated to put the #1 piston back on TDC before removing the degree wheel.  The timing cover, timing pointer, and damper are then installed to insure that the TDC on the damper is aligned accurately to the pointer.  Any discrepancies between the two are taken care of by simply bending the pointer accordingly in which to compensate.  The damper (freshly rebuilt by Damper Doctor) is then removed so that the remainder of the engine can be assembled and painted.  The damper is to remain flat black so it’s off the engine when the remainder of the engine is painted with high heat primer and then final coated with Bill Hirsch Ford ‘T-Bird’ Red.  A little bit too orange for my taste but it is the right shade of Ford Red for this application.  After engine painting is complete, the damper is reinstalled.

It’s now just a matter of taking care of the little details before installing the engine on the dyno. Some of those details include checking out the Load-O-Matic distributor with its new breaker points and related parts, new spark plugs and wires, replacement wire looms, the addition of six quarts of Valvoline 10W-40 conventional grade oil, and a Wix 51515 oil filter.  The original cartridge oil filter goes to the wayside and is replaced with the newer spin on style.  In this case, some items simply don’t need to remain original.  A 4oz bottle of ZDDPlus is added to the crankcase as additional insurance that the Zinc/Phosphorus amounts are sufficient for break in.  Before installing the distributor, the engine is pre-lubed to guarantee that oil has filled the oil filter and various passages as well as having adequate cranking oil pressure.  The original List #1074-1 Holley Teapot 4V carburetor looks clean and usable so it’s not taken apart at this point and is installed on the intake along with the original ½” phenolic carb spacer.  Fuel in poured into the top vent hole in the carb so that the fuel pump does not have to work at filling the carb when attempting the first start of the engine.

With the engine on the dyno, it starts up immediately without any fanfare and is brought up to a fast idle for both the camshaft and piston ring break in. The engine is being run with a set of headers instead of exhaust manifolds as this provides a more accurate way to monitor the air fuel mixtures.  While the camshaft is being broken in, the engine is repeatedly being loaded and unloaded against the dyno water brake so that the piston rings can seat in much more quickly.  After allowing the engine to completely cool in which to put a completed heat cycle in the engine, it’s then restarted for some power testing.

The first series of dyno pulls nets a best of 181HP and 266 TQ. The original List #1074-1 Teapot carb is being troublesome with the accelerator pump having a weak shot and the numbers are down from what was expected so the carb is changed out to a List #1164-2 carb off of a 1956 Thunderbird with a 312 engine.  The Thunderbird carb had been freshly kitted and with it installed on the engine, it makes a clean pull netting 191HP/267TQ.  The original ECK-T 1074-1 carb is then disassembled, cleaned, and rebuilt using a Daytona Carb Parts #603 ethanol friendly carburetor kit.  With the rebuilt carb reinstalled on the engine, the engine is now responsive when winging the throttle with no hesitation or dead spot.  The dyno likes it too with 192HP/280TQ numbers coming to the forefront.  The carb jets remain stock as 50’s in the primaries and 86’s in the secondary sides.  The engine is making its best power numbers and idles well with the Load-O-Matic distributor set at 12° initial timing and the valves set at 0.019” hot.  At this point, the engine comes off the dyno and is ready for reassembly back into the chassis.

While a horsepower rating of 188 doesn’t sound like much by today’s standards, this was a serious performer back when it was new. This engine was just the precursor of things to come as the following year started seeing larger valves and experimentation with more aggressive camshaft grinds.

All for now and until next issue, Happy Y Motoring. Ted Eaton.

Originally published in The Y-Block Magazine, Issue #147, July-August 2018

A Tale Of Two 330 Inch Y-Blocks

I recently had the opportunity to assemble a pair of Ford Y-Block engines that were very similar to each other and then dyno test each.  Both engines had the same bore and stroke, the same camshaft grind, and the final static compression ratio (SCR) on each was very similar.  The main differences were in the cylinder heads and intake manifolds.  While one engine was slated for use in a standard transmission equipped ’54 Ford car for both street driving and some spirited road racing, the other was to be used in a ’56 Ford pickup as a daily driver with air conditioning and an automatic transmission.  The road race engine is using ported oem iron ‘G’ heads while a set of Mummert aluminum heads are used on the daily driver pickup engine.

Each engine required a camshaft that would be very drivable in stop and go traffic.  For this, the same part number Iskenderian camshafts are used with the duration at 0.050” being 228°/238° on the intakes & exhausts respectively.  The advertised duration is 260°/272° while the lift at the valves with 1.6 rockers is .477”/.512”.  The split duration format is being used for a variety of reasons including the use of full exhaust systems, better low rpm intake manifold vacuum, and improved torque characteristics in the lower rpm band.  The camshafts are ground on 110° lobe centers and both are installed 3° advanced or at 107° intake lobe centerline.

Rollmaster timing sets are used and also common to both engines are Harland Sharp 1.6:1 roller tipped rockers.  MSD p/n #8383 MSD billet distributors are responsible for routing the fire to the spark plugs.  Both blocks have a machined groove added behind the center cam bearing to alleviate the potential for any future top end oiling problems.  Two extra 5/16” holes are added to the oil filter plates to insure adequate flow capacity from the oil pump to the oil filter.  Other than this pair of modifications, the block oiling systems remain virtually as delivered from Ford.  The aluminum rocker arms are using pressurized oil with the factory overflow tubes being eliminated.  Rocker to shaft clearance is set at 0.002”.

Both engines use 312 crankshafts where the main journals are reground to a standard 292 size.  The rear seal journals are also reground to the 292 sizes while retaining the rear main seal crankshaft oil slingers.  The rod journals are offset ground to a 3.580” stroke utilizing 2.000” journals.  Because both crankshafts had been previously reground undersize, the maximum amount of stroke that would normally be available with standard size rod journal cranks was not available.  The connecting rods are manufactured by Eagle and incorporate 6.125” center to center lengths.  While the pickup engine uses a rebuilt factory style harmonic damper, the car engine uses one of the new Innovators West harmonic dampers.  Both engines have some overbalance added to the crankshafts during the balancing procedure.

The bore sizes are 3.832” and the wrist pin compression height on the pistons is also the same being 1.830”.  The piston tops do vary though due to the differences inthe combustion chambers on the cylinder heads being used.  Because both engines are being targeted to use readily available 91-93 octane premium pump gasoline, the dynamic compression ratio (DCR) is being limited to 8.0:1.  That meant to use the Mummert aluminum cylinder heads, the piston for that combination would require a 8cc dish netting a final static compression ratio of 9.7:1.  The pistons for the iron headed engine would be a conventional flat top piston and would end up being 9.5:1 for the SCR.  The selected piston rings for both engines are manufactured by Total Seal and and are conventional in design while being 1.5mm for the top and second grooves and 3.0mm for the oil ring.



Click on pictures for larger images  

The iron headed engine for the 1954 Ford uses a pair of ‘posted’ ECZ-G cylinder heads.  These had hardened exhaust seats suitable for unleaded fuels installed before going to the porting table.  Along with the new stock diameter valves, Isky beehive valve springs and retainers are also installed.  The closed valve spring pressure is 130 lbs while over the nose or open pressure is 295 lbs.  Final combustion chamber volumes after milling are 68.9cc.  This set of heads would use a Mummert aluminum single four barrel intake.

The Mummert aluminum heads for the 1956 Ford pickup are stock out of the box pieces utilizing the ‘as supplied’ valve springs and hardware.  The closed spring pressure is 110 lbs while open pressure is 300 lbs.  The intake manifold for this engine would be an older model Blue Thunder single four barrel intake.  There was no need for the heat riser passage in the intake to be blocked off due to the heat passages in the heads not being opened up.  ARP 7/16” head bolts are used to fasten the heads to the block on both engines.

Before decking the blocks, the steam holes were drilled, tapped and plugged.  Because neither set of heads has steam holes and both vehicles have high radiator fill points, the steam holes in the block are not required.  Plugging the holes also helps to strengthen the blocks in that area.

The oil pans do vary on each engine but simply due to the differences in the vehicles in which they are going in.  The ’54 car uses a front sump pan that is modified for additional oil capacity while the ’56 pickup uses a rear sump pan that has had a gate put into it to stop the forward slosh of the oil during braking.  The oil pumps for both engines are rebuilt gerotor pumps.  These were chosen over new casting spur gear pumps as the georotor design has fewer cavitation issues along with less heat transfer into the oil itself.  There are enough differences in oil pump design for its own article which is being saved for later.

The engines are started up using a full complement of Valvoline 10W-40 oil and Wix oil filters.  No extra additives are used as this particular oil has the required levels of zinc & phosphate (ZDDP) for the older flat tappet camshafts.  The camshafts and lifters however were thoroughly lubed with the Isky supplied molybdenum lube during the engine assembly which takes care of the initial lubrication requirements during startup.  While the camshaft is being broken in, the water brake on the dyno is repeatedly loaded and unloaded so that the piston rings can be seated in during the same time frame.  Once this operation has been completed, the engines are allowed to thoroughly cool to help put a completed heat cycle into the valve springs.  This single operation significantly prolongs the life of the valve springs versus going straight into dyno pulls without a cooling cycle.

Both engines were started up with a known ‘good’ carburetor and in this case it’s a 750 cfm vacuum secondary Holley.  The road race engine does gets a 600 cfm vacuum secondary Holley that’s heavily modified by lieu of the rules for one of the racing venues requiring nothing larger than a rated 600 cfm carburetor.  That 600 carb actually outperforms the 750 carb in this rare case on both ends of the rpm scale and that is in part attributed to the superior work that was done to the carb metering circuits rather than the rated cfm difference.  The aluminum headed engine had a 600 cfm double pumper carb available for testing and while it had excellent lowend dyno numbers, the 750 carb had better higher rpm numbers.



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The differences in power output between the two engines primarily rests with the cylinder heads.  The ported iron heads peaked at 361 HP while the stock out of the box aluminum heads peaked at 404 HP.  I’ve included dyno sheets for both engines and in this particular instance also supply sheets showing the performance differences between the carbs that were used.  As a general rule, the smaller sized carbs will help low end torque values while the larger sized carbs help topend horsepower.  As with any generalized rules, there are exceptions.

All for now and until next time, happy Y motoring.  Ted Eaton.



Click on images for larger pictures.

Originally published in Y-Block Magazine, Issue #111, Jul-Aug 2012, Vol 19, No.4

Not A Race Engine But Maybe It Should Be – 318″ Ford Y-Block

The aluminum heads continue to impress and even more so on the engines built to be daily drivers.  A case in point here is an aluminum headed 318 inch Ford Y-Block built for Jim Culver’s 1956 Ford Club Sedan.  Once the noise from the dyno session had died down, Jim’s engine had peaked at 429 HP and 388 ft/lbs of torque.  And this is from an engine designed to run on readily available pump gasoline and being a daily driver.  The quick math on this combination is a 1.35:1 HP/CID ratio which is more than respectable.

The foundation for this engine starts out as a 1967 date coded C2AE 292 block which is taken out to a +060” overbore.  The only oil galley modification performed to this block is machining a groove in the center camshaft bore behind the cam bearing.  This simply insures a constant supply of oil making its way up to the rockers even in the event the center cam journal groove presses itself into the cam bearing material.  The mains are align honed and the decks are machined so that the piston tops are level with the decks (zero decked).  The finished deck height for this particular block ends up being 9.750”.

The crankshaft is an original 292 cast piece that’s offset ground to a 3.480” stroke with 2.000” journals.  The main journal sizes end up being 0.010” under a standard 292 size.  The connecting rods are 6.250” long Eagle H-Beams and required having their big end widths narrowed to fit within the 1.810” crankshaft journal widths.  Other than the narrowing of the connecting rod big end widths, the rods remain relatively unmodified.  The rod bearings being used are out of the box Clevite ‘narrower than stock’ pieces that did not require any modifications.

The pistons are made by Wiseco and are sized for the 3.810” bore with a wrist pin compression height of 1.760” and use 0.927” wrist pins instead of the stock Y sized 0.912” pins.  The rings are metric and are 1.5mm for both the top and second grooves and 3.0mm for the oil ring.  Metric rings are used for the reduced surface area at the cylinder wall and also for the reduced radial tension by lieu of a reduced radial land thickness.  The piston top itself is a flattop design with a trio of anti-detonation slots added to their tops.

      Click on picture for larger image

The camshaft is a custom Isky symmetrical grind with the advertised duration being 270°, the 0.050” duration being 242° and the advertised gross lift with 1.6:1 rockers being 0.563”.  The cam itself is ground on 107° lobe centers and is installed 2° advanced or at a 105° intake lobe centerline.   The tappets are Hylift Johnson and are U.S. made.  The 5/16” diameter pushrods are manufactured by Smith Brothers and these actuate a set of Harland Sharp 1.6:1 roller tipped rocker arms.  A roller timing chain set keeps all the pertinent parts moving in the right directions.

The heads are out of the box Mummert ‘ready to run’ aluminum units and measure out at 60cc’s for the combustion chamber volumes.  The static compression ratio for Jim’s engine is 10.0:1 while the dynamic compression ratio calculates to be 7.7:1.  Best Gasket head gaskets are being used along with ARP head bolts to keep fluids and combustion pressures in their places.  Unlike iron heads where the headers can be bolted up to the heads without any gaskets for dyno testing, the aluminum heads do require some measure of protection.  For this a set of copper exhaust gaskets from ‘Relics Exhaust Gaskets’ were used as these can be used numerous times on dyno engines.

The oil pump is a rebuilt aluminum gerotor pump from an early Sixties Y engine.  The relief spring is shimmed an additional 0.085” which provides a solid ~65 psi of hot oil pressure under throttle.  Low rpm oil pressure is still controlled by the bearing clearances themselves.  The oil pan is an unmodified stock front sump unit with a factory equipped baffle.

Valvoline 10W-40 oil (API SN rated) is used for the break-in with no additional additives being used.  The ZDDP or zinc-phosphate amount in this particular grade of oil is adequate for flat tappet camshafts and still matches the ZDDP content in the older ‘SJ’ oils.  When in doubt about the ZDDP content in a specific oil, pulling up the manufacturers MSDS (Material Safety Data Sheet) sheet typically gives the zinc amounts in that oil.  On a side note, I’ve a list of over two dozen items that can cause cam lobe and/or lifter failure and any one of those items by itself can be a show stopper.  Granted that the ZDDP content in the oil is one of them, it’s not near as catastrophic as many of the others.  I’ll publish that list in a future article.


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Two different carburetors were used during the dyno session.  The carb off Jim’s 312 was a 625 cfm Road Demon while the other carb tested was a 750HP series Holley with List #80529-1.  Both carbs incorporate vacuum secondaries.  It was noted that in using the 625cfm Demon that the vacuum levels were increasing in the upper rpm band.  This is typically a very good indicator of under-carburetion.  In using the 750 cfm Holley (which actually flows in the 825 cfm range) the peak horsepower increased while at the same time the vacuum levels stayed more reasonable in the upper rpm band.  The peak torque values also increased when using the larger cfm carburetor.  The dyno sheets for both carb tests are included at the conclusion of this article.

Until next time, happy Y motoring.  Ted Eaton.


 click on individual sheets for larger versions.

This article originally published in Y-Block Magazine, Issue #109, Mar-Apr 2012, Vol 19, No.2