All posts by Ted Eaton

Hopping Up The 272

Although there were a multitude of Ford 272 Y-Block engines used in both cars and trucks, they are pretty much disregarded as the basis for a high performance build and for that matter, as a replacement engine when a 292 or 312 is available instead.  While building a high performance 272 Y has been on the ‘like to do’ list for awhile, it has been a hard sell when the larger Y engines simply make those higher power numbers much easier to come by.  That all changed recently when a customer wanted to use the original 272 block from their 1956 Ford pickup as the basis for a new engine in that same truck. In this instance, they wanted modern performance upgrades applied to it including a pair of Mummert aluminum heads.

Stock 272 with two barrel carb and single exhaust system.

The block itself was still a standard bore and in finding that 1.2mm compression rings were available for a 3.658” bore, the block was bored so it was essentially 0.033” over the stock bore size.  While the new compression rings dropped in width from the stock 5/32” (0.156”) widths to 1.2mm (0.047”), the oil rings reduce from the stock 3/16” (0.188”) widths to 3.0mm (0.118”).  The 272 crankshaft was still std/std on the journals and was subsequently reground so it was 0.010” undersize on the mains.  The rod journals were offset ground which increased the stroke from 3.3” to 3.48”.  The new rod journal diameter is now 2.000” where it had been 2.188”.  This necessitated the use of new connecting rods which is where a set of Eagle 6.125” long H-Beam rods come into play.  These do use a 0.927” diameter wrist pin versus the stock pin diameter of 0.912”.  Although the rod journals were slightly widened to a 1.810” dimension during the grinding operation, they were still not wide enough to accommodate the out of the box H-Beam rods being used.  The new rods were narrowed to fit accordingly as further widening the rod journals would increase the possibility for the oil holes being exposed in the journal filets.  Narrower than stock rod bearings were available and these did not require any modifications.  The stroke change along with the metric rings and larger wrist pin diameter called for a custom piston set which was supplied by Diamond Pistons.  These have a 1.885” compression height versus the 1.760”-1.777” that is found in the stock replacement 272 and 292 pistons.  Once all the rotating parts were assembled and dry fitted, the rotating assembly along with the flywheel, clutch disk, and pressure plate assembly were precision balanced.  The balancing bob-weight value for the rotating assembly is 1606 grams which is considerably lighter than stock.  The final cubic inch for this combination ends up being 293 with the static compression ratio calculating to be 9.7:1 with the pistons sitting 0.005” above the deck and using Best Gasket head gaskets with 10.0cc combustion volumes.

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Oil modifications include adding a groove in the center cam journal hole of the block.  This allows oil to flow behind the cam bearing to interconnect the three holes located there and eliminates the possibility that the oil flow to the top end will be restricted by a worn cam bearing in the future. The oil filter adapter also has an additional pair of 5/16” holes added alongside the slot that already resides there to insure an adequate flow of oil to the filter.  The oil pump itself is a rebuilt gerotor style of oil pump.  The oil pan is the original rear sump pan but has a pair of baffles added to prevent the oil from moving or sloshing forward under braking conditions.

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An ‘angry’ sounding camshaft was requested so a new Isky grind was developed for this combination.  This grind started out using the Seventies era Crower Monarch camshaft as a starting point. That older Crower grind has been used successfully in the dyno mule but with new lobe profiles being available, this new grind does have more aggressive ramps on the lobes thus providing more net valve lift while also reducing the advertised duration numbers.  The ‘as ground’ lobe centers are also reduced a couple of degrees to give a choppier idle.  The new Isky camshaft is a symmetrical grind where both the intake and exhaust lobes are the same.  Advertised duration is 272°, the 0.050” duration is 238°, the lobes are ground on 108° centers, and the lobe lift is 0.320”.  The camshaft is installed in the engine at 4° of crankshaft advance or at 104° intake lobe centerline.  Harland Sharp 1.6:1 roller rockers are being used which puts the lift at the valve before valve lash is taken into account at 0.512”.  The shaft to rocker clearance is set at 0.002” which allows the overflow tubes to be eliminated and oiling to the rockers is now pressurized.  Completing the list of valve train parts are Hylift Johnson tappets and Smith Brothers 8.100” effective length pushrods.

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The cylinder heads are the Mummert aluminum heads.  These have had sanding rolls taken to the ports and bowls for a simple cleanup with emphasis being placed on not making the ports any larger.  Other than this mod, the heads are used as delivered.  ARP head bolts fasten the heads to the block while Best Gaskets are used throughout the engine to seal it up. The intake manifold selected for this build is an older Edelbrock #573 three deuce manifold topped off with three new Edelbrock 94 carburetors.  Linkages are progressive where the center carburetor is about 2/3 open before the end carbs start opening.  A PCV valve system is also added which allowed the original road draft tube hole in the side of the block to be blocked off.  The PCV valve itself is located in the valley cover using a rubber grommet to hold the valve in place.

PCV Valve hookup. Click on picture for larger image.

Once engine assembly is complete, the engine is prepared for running on the dyno.  The crankcase gets six quarts of API-SN Valvoline 10W-40 conventional oil along with a Wix 51515 oil filter.  After pre-lubing the engine, the MSD #8383 billet distributor is installed.  The distributor is set up with the blue bushing (21°) and with the light silver and light blue springs so that the mechanical advance curve is all in by 3200 rpms.  The engine is started up and ran at the prerequisite 2000-2500 rpms for twenty minutes and during this time, the engine is repeatedly put under a load to speed up the piston ring break-in.  Once the engine has been ‘run in’ the valve train is checked for any problems and a ‘hot’ valve lash adjustment is performed.  After resetting the valve lash so it is at 0.024” in hot conditions, the engine is restarted and brought up to 3200 rpms where the total ignition timing is set at 37° BTDC. No problems are found so all is good to go for general carburetor tune up and dyno testing. When attempting to get the engine to idle at a reasonable low speed, it would not continue to run at anything less than 1300-1400 rpms.  It was first thought that a serious vacuum leak was the culprit but re-examining all the different gaskets and seals found no problems.  Inserting some wires into the idle feed restrictions within all three carburetors did help so a phone call to Edelbrock had me taking a different approach.  In talking to the Edelbrock technician, the camshaft is just a bit wild for these carbs and as such, the carburetor signal is reduced which in turn is making the idle circuit too lean.  The fuel atomization nozzles were removed from each carburetor and the idle feed restrictions are reduced in size from 0.063” to 0.052” which in turn fixes the lean condition in the idle circuits.  The engine can now idle down to 750 rpms without any obnoxious fuel smells which would have indicated being too rich.  As a matter of reference, all three carbs have idle circuits and power valves.

Carb tops are off to modify air bleeds.

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The engine was dynoed both before and after the carburetor modifications and it was noted that full throttle performance was not affected by the carburetor modifications.  Torque values are stout throughout the rpm band and the horsepower numbers peak at 355 at 6100 rpms.  The torque peaks out at 331 lbs/ft at 4800 rpms but averages 321 lbs/ft from 3100 to 6400 rpms.  This engine has a very flat torque curve which makes it a work horse at any rpm.  The dyno sheet is included at the end of this article.

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So there you have it.  The 272 can be worked over so it’s a power house just like its 292 and 312 big brothers.  While there’s no definitive data to state otherwise, the smaller cubes with this combination should actually be more fuel efficient in the long haul than that which is experienced with the larger engines.  That is assuming one can drive this with a light touch on the accelerator pedal and not be tempted to continually test the acceleration capabilities. Until next time, Happy Y motoring.  Ted Eaton.

This article was previously published in the Y-Block Magazine, July-August 2014, Issue #123, Vol 21, No. 4

Unported Iron Heads Can Still Make Over A HP To The Cubic Inch

By using just the right combination of parts, exceeding that magic 1HP to cubic inch ratio is indeed possible while still doing it with a pair of unported iron Ford Y-Block heads. The key here is in using a modern piston ring design and maximizing the compression ratio while still being able to have an engine that will run on available pump gasoline.  Not to be left out are the intake, carburetor, camshaft, and cylinder head choices which are also just as important.

For this build, the engine is going back into Karol Miller’s 1956 Ford Victoria with a T86 3 speed/overdrive.  The rear gearing is currently 3.22:1 which is going to drop the rpms significantly when the car is in overdrive mode. This makes low rpm torque production even more important.  Because this car is not going to be sitting dormant in a garage very much, fuel efficiency needs to be reasonable so the camshaft choice becomes critical in making power while still being efficient.

Because the block that comes out of the car is already 0.110” over and is badly worn, another block is picked out.  The C1AE block selected for this build has a May 25, 1961 casting date and while it had already been previously bored 0.040” over, it is heavily worn again at this point.  The block is sonic tested and deemed a good candidate for an additional over-bore.  Prior to doing any machine work to the cylinders, the two center ‘steam’ or vent holes in the decks were plugged.  The cylinders clean up at 0.070” over the stock bore size which will have the cubic inches coming in at 303 using a stock 3.3” stroke crankshaft.  The center cam hole in the block is modified with an interconnecting groove between the three holes there to insure adequate oiling to the top end of the engine.  Adding that groove has become a standard activity on Y engine builds at this shop as it alleviates any concerns about the new cam bearings pushing babbit into the camshaft journal groove and subsequently shutting off the oil supply to the top.  While there are a couple of other fixes for this, the machined groove is my own preferred option for increasing the oil supply to the top end of the engine.

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As an upgrade to the performance and efficiency, it’s decided to go with a modern ring design.  For this engine, 1.2mm metric rings will be used for both the top and 2nd grooves with a 3.0mm oil ring finishing up the ring package.  The original 2nd ring thickness was 3/32” which equates back to a 2.4mm ring.  The new ring package cuts this in half which in theory cuts cylinder wall drag in half.  But the metric rings also have less radial thickness which further reduces the ring drag.

The connecting rod choice could have gone with either the longer 292 rod or the shorter 312 rod.  While the shorter rod tends to allow for more torque production by lieu of an earlier piston movement from TDC, the drawback is an increase in the cylinder wall wear.  The longer rod on the other hand does allow for an increased dwell time at TDC which in turn will help to deter any detonation issues that could be encountered as a result of maximizing the compression ratio for both power production and fuel efficiency.  Piston skirt friction will also see a reduction with the longer rod versus that with a shorter rod.  Because fuel efficiency is being considered, a set of ‘longer’ C2AE rods will be used for this build and are prepped and resized with new ARP rod bolts being installed.

Diamond Pistons supplies a set of custom flat top pistons for this build which permits the use of the aforementioned 1.2mm rings.  These pistons have a wrist pin height of 1.792” and use a stock dimension 0.912” diameter wrist pin.  The piston to wall clearance for this combination is maintained at 0.004”.  The final deck height for the block after all the machine work is complete is 9.750”.

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The remainder of the short block build presents no problems.  The crankshaft comes from a 272 and is still a flawless standard on both the main and rod journals.  In fact the clearance on the rod journals is still on the snug side with the replacement standard size bearings which is where a set of the red/blue bearings that use to be available from Ford would have come in handy.  While the rod bearing clearance is on the snug side, it’s not so tight that it will be a problem.  Once the engine has been mocked up and the decks machined for a zero piston to deck clearance, the rotating assembly is precision balanced with the crankshaft being balanced to an 1890 gram bobweight value.  A small amount of overbalance is also included in the bobweight calculation which tends to extend the overall engine life. The oil pump is a stock gerotor oil pump that has simply been disassembled, examined for problems, and reassembled.

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The cylinder heads came off the original worn engine and had been worked on not that many miles ago.  They are a set of 113 castings which already had hard seats previously installed.  While the exhaust valves were okay to reuse, the intakes were replaced with a new set of 1.92” stock sized valves.  In measuring the pads at the exhaust side of the heads, it was found that both heads had had ~0.080” removed from them in the past.  While that sounds extreme, the heads are factory posted and looked to have been running okay like this.  In cc’ing the heads after reinstalling the valves and hardware, the combustion chambers are averaging 62.3cc’s.  Calculating the static compression ratio for this combination has it at 9.57:1.

The camshaft selected for this build is an Isky grind with the following specs:

Duration at 0.020”: 264°I, 272°E

Duration at 0.050”: 228°I, 238°E

Lobe lift: 0.298”I, 0.320”E

Valve lift: 0.459”I, 0.493”E before valve lash

Ground on 110° lobe centers

Installed at 105½° intake lobe centerline

(4½° advanced)

With a stock link style timing chain set in place, the camshaft was sitting more than nine degrees advanced which was unacceptable in this case.  Instead, a Rollmaster roller timing set with the multi-indexed crank gear is used which makes camshaft phasing much simpler.  The dynamic compression ratio calculations when taking into account the 4½° of cam advance and using the 6.309” long connecting rods is 7.99:1.  This engine will like premium fuel which is typically recommended anyhow simply due to the reduced amounts of ethanol in premium fuel versus that in the lower grades.  The valve train is topped off with a set of rebuilt 1956 1.54:1 rocker arms and a set of 7.964” effective length tubular pushrods.

The intake manifold is the old reliable ECZ-B intake found on the 1957 and up four barrel equipped Y’s.  The four holes at the carb base were opened up so it was dual slots and the transitions going to the lower ports ground on to open up the flow some.  While it took about forty minutes to machine the dual slots at the carb base, the porting on the inside of the manifold took less than five.

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With engine assembly now complete, the engine is prepared for running in on the dyno.  Six quarts of Valvoline 10W-40 conventional oil fills the pan and a Wix 51515 oil filter completes the package.  The engine is initially started up with the shop’s 750 cfm HP Holley in place as this is a proven performer.  The carburetor sits atop a 1″ tall four hole phenolic carb spacer.  Once the engine is started up and run in, the valve train is checked for any problems and there are none.  After the engine has been allowed to thoroughly cool down to put a completed heat cycle into the new valve springs, some dyno pulls are made.  The engine immediately makes 308 HP and with some timing adjustments, jumps to 316 HP with the HP Holley on it.  Karol’s 1956 Lincoln Teapot carb is put on the engine with an appropriate adapter and after jetting adjustments, it’s making 294 HP.  But that carb simply has a hard time idling with this camshaft and has other issues with it that will require some serious work.  There’s an older model 4010 750 cfm Holley sitting here that is tried and that carb runs nicely and clicks off a 315 HP number without any jet changes.  Based on Harry Hutten’s recent performance with the Summit 750 carb that he is using on his ’60 Merc, a similar Summit 750 carb is ordered for this combination.  Two days later the carb arrives at which point it’s immediately installed on the engine which is still sitting on the dyno.  The engine idles well and with a three number increase in jetting on the secondary side only, another 315 HP number pops up.

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At this point, the engine is deemed good to go and reinstalled back in the 1956 Ford Victoria chassis.  The engine was dynoed on a Friday and is back in the car and running on the following Saturday.  That’s a quick turnaround.  Since then the car has been driven around and drives without issue even with the 3.22 rear gears.  Starts up good when cold and actually runs on the cool side with no heating issues at all.  The exhaust lets you know that this is not a stock Y though.  There’s a nice rumble from the pipes and that hard rush of air hitting the pants legs lets you know that the compression is there also.  While it hasn’t been driven around enough yet to get an accurate mpg number, the fuel mileage doesn’t appear to be bad though based on the 120 miles it was driven around locally before going back home.

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The sonic test sheet and dyno sheet are also included at the end of this article.  Until next time, happy Y motoring.    Ted Eaton.

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This article was previously published in The Y-Block Magazine, Jan-Feb 2015, Issue #126.

Stock Ford Y build or modified? Here are two different approaches.

I was recently given the opportunity to rebuild a pair of Ford 292 Y-Block engines with each going into 1963 F100 pickups.  While both engines started life out as 1963 two barrel pickup engines, one was a restoration project while the other was to be a mildly hopped up version.  The engine for the restoration pickup was to be built as close to stock as possible while the other engine was to use the normal performance upgrades such as four barrel intake and carburetor, larger valved heads, and a better than stock camshaft.



Machine work for the stock engine includes boring the cylinders 0.040” over and grinding the crankshaft 0.010” undersize for both the rod and main journals.  The 3.790” bore puts the cubic inches at 298.  The C1TE heads are upgraded with hardened seats for the exhausts with the new replacement valves remaining the stock sizes. The combustion chamber volumes for these heads after milling are 76.2cc.  The 1.43:1 rocker arm assemblies are rebuilt using new Schumann rocker arm shafts while the camshaft is a stock replacement grind with the following specs:

Duration at 0.020”: 211°I, 228°E

Duration at 0.050”: 195°I, 195°E

Lobe lift: 0.258”

Valve lift: 0.369” before valve lash

Ground on 113° lobe centers

Installed at 104° intake lobe centerline

The connecting rods are reconditioned with new ARP rod bolts, the big ends being resized, and new wrist pin bushings installed. The replacement cast pistons are fitted to the bores with 0.0025” clearance and sit 0.020” below the decks at TDC after a cleanup mill had been performed on the decks.  The static compression ratio for this engine is 7.8:1 while the dynamic compression ratio calculates to be 7.5:1.  The rotating assembly is precision balanced using a 2100 gram bobweight value once all the basic machine work was complete.

Topping off the engine assembly is the original two barrel intake manifold and the Autolite 1.02” venturi two barrel carburetor.  The stock distributor is retained and is upgraded with a Pertronix electronic ignition conversion.  The engine is filled with six quarts of Valvoline 10W-40 conventional oil along with a Wix 51515 oil filter and is readied for running on the DTS engine dyno.

After the engine has been broken in on the dyno, the valve covers are removed with careful attention towards any premature valve train wear.  There is none so all is good.  The valves are ‘hot’ adjusted to 0.019” lash and some power pulls are made to insure that the timing and jetting are where they need to be.  After making minor tuning adjustments, the horsepower peaks at 153 at 3800 rpms and the torque peaks at 267 lb/ft at 2500 rpms.  It becomes evident that the original two barrel carb is a major player in holding back any serious rpm capability.  On the flip side of this, the engine idles very smoothly and at a very low rpm.

I will add that the engine was tested with a set of headers feeding into dual mufflers.  The installation of the original crossover pipe with a single exhaust pipe system being used will cut the HP power numbers and torque values back a bit further based on previous exhaust system testing results.

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The second F100 engine has the cylinders bored 0.050” over stock thus putting the cubic inches right at 300.  The cylinders are sized so that the piston to bore clearance is 0.0035” and the decks are machined so that the pistons are level with the decks (zero decks).  A flawless standard journal crankshaft is available so no grinding of the shaft is required in this instance.  The connecting rods are reconditioned with new ARP rod bolts being installed and once this is done, the rotating assembly is precision balanced using a 2070 gram bobweight value.

The camshaft selected for this build is an Isky grind with the following specs:

Duration at 0.020”: 264°I, 272°E

Duration at 0.050”: 228°I, 238°E

Lobe lift: 0.298”I, 0.320”E

Valve lift: 0.426”I, 0.458”E before valve lash

Ground on 112° lobe centers

Installed at 108½° intake lobe centerline

(3½° advanced)

The cylinder heads are the ‘big letter’ ECZ-G heads with one of them being posted and the other is not.  The heads are rebuilt with hardened exhaust seats and lightly milled with the combustion chambers measuring 69.2 cc’s when all is done.  The static compression ratio using the Best Gasket composition head gaskets is 8.75:1 while the dynamic compression ratio calculates to be 7.17:1.  This engine will run fine on the lower grades of gasoline if necessary.

The rocker arms are the original 1.43:1 units that have been refurbished and mounted on new Schumann rocker arm shafts.  The pushrods are oem style tubular units measuring 7.940” effective length.  The engine is topped off with an iron ECZ-B four barrel intake and the carburetor selected is a new Summit 600 cfm unit which sits on top of a 1” four hole spacer.  This carburetor is similar in construction and appearance to the older flat top Autolite carbs that were popular on Ford engines in the Sixties.

The crankcase is filled with six quarts of Valvoline 10W-40 oil along with a Wix oil filter and readied for run in.  After running for a given period of time on the dyno, the valve train is thoroughly checked over for problems and none are found.  Once the initial tuning is completed, the engine is peaking at 269 HP at 5400 rpms and 306 lbs/ft torque at 3300 rpms.  While this engine does exhibit good idle characteristics, the exhaust is still letting you know that the camshaft is no longer stock.

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So there you have it.  Here are two engines that started life out similarly but went two different directions on the rebuilds; one being stock and the other being modified for additional performance.  While the stock engine was less expensive to build, many of the extra costs incurred on the hopped up engine was in obtaining the four barrel intake, G heads, and the new carburetor.  The Isky camshaft is also slightly more expensive than the stock camshaft but the costs for the machine work, pistons, rings, bearings, and gaskets for each engine were very similar.  The addition of ECZ-G cylinder heads, ECZ-B 4V intake, 600 cfm carburetor, and Isky camshaft to a stock engine in this case makes for a 76% improvement in power.  The stock engine is making 0.51 HP/CI while the modified engine is making 0.90 HP/CI.  That’s quite an improvement by just adding the right combination of parts.  The dynometer sheets for each engine are at the end of this article.

Until next time, Happy Y Motoring.  Ted Eaton.


Click on dyno sheets for larger images.

This article was originally published in The Y-Block Magazine, Nov-Dec 2014, Issue #125.