Tag Archives: Ford

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

Y-Block Ford – Dual Quad Testing on Aluminum Heads – Part II

With the iron 113 heads on the dyno mule, the Edelbrock #257 2X4 intake that had been ported by Joe Craine did exceed those numbers generated by the stock Mummert intake and single four barrel carb combination.  Now it was time to install the aluminum heads on the 312+ dyno mule and see how those same dual quad manifolds would fare.

As a result of changing the ported iron ‘113’ heads to a pair of CNC ported Mummert aluminum heads, it was necessary to establish a new target baseline.  The same stock Mummert intake and 750 cfm vacuum secondary Holley that had been used for the iron head baseline was again used for the aluminum head baseline.  While the iron heads made a peak number of 311 HP in the single four barrel format, the aluminum head baseline jumps to 375 HP with nothing but a cylinder head change.  This does give the dual quad intake testing a much higher target value to aim for.

The dual quad intake testing with the aluminum heads now gets more definitive simply due to the flow restrictions that were taking place in the iron heads being minimized.  This will allow any flow restrictions in the manifolds and carb pairs to come to the forefront.  With that in mind, the same intakes that were run on the iron heads are also run on the aluminum heads.  But added to the fray are also the Fenton, Edmunds, Hogan, and the ported Edelbrock FM255 intakes among others.

Here is a quick summary of how the different intakes performed on the aluminum heads without getting into the various carbs or other variables that were tested on each intake.  This particular list is ordered from worst to best using the best carb combination for each intake that was tested.

1. Edmunds D427                                       330 HP@5400, 343 TQ@3300

2. Ford EDB-C 1956 – modified        331 HP@5400, 352 TQ@4400

3. Ford ECG-D 1957 – stock                336HP@6000, 352TQ@3500

4. Ford EDB-C 1956 – stock                 338 HP@5200, 369 TQ@4200

5. Edelbrock 257 – Hogged out          339 HP@6100, 337 TQ@4900

6. Fenton D427                                             342 HP@5400, 364 TQ@4200

7. Edelbrock 257 – stock                         351 HP@6000, 355 TQ@4500

8. Mercury ECZ-C stock                          357 HP@6100, 367 TQ@4300

9. Edelbrock FM255 stock                     359 HP@6000, 370 TQ@4400

10. Hogans Tunnel Ram                           361 HP@6100, 342 TQ@5200

11. Mercury ECZ-C ported                    366 HP@6200, 375 TQ@4400

12. Edelbrock 257 – Ported by JDC     369 HP@6200, 378 TQ@4400

13. Edel FM255 – Ported by JDC        378 HP@6200, 370 TQ@4600

So with that being said, here are the breakdowns for each manifold that was tested.  The manifolds are now listed in the order in which they were run and tested on the 322” mule engine.

Click on picture for larger images.

Ported Edelbrock #257 Intake:

Upon establishing the single four barrel baseline value, the Edelbrock #257 intake that had been ported by Joe Craine was the first of the dual quad intakes to be reinstalled on the aluminum headed +060 over 312.  While that particular intake was the best of the lot on the iron heads and actually exceeded the baseline target for those heads, it came up just shy of the revised baseline or target for the aluminum heads.  This intake was tested with several pairs of carbs and here are the results for the best tuneup for each pair of carbs.  I’ll add that jetting changes on two carbs and especially the Teapots can be very time consuming.

L1434 Teapots (1957 2X4 carbs)    332 HP@5500, 365 TQ@3700

600cfm Edelbrocks                                 362 HP@6100, 367 TQ@4300

500cfm Edelbrocks                                 363 HP@6100, 366 TQ@4500

L1094-1 Linc Teapots (60P/82S jets)369 HP@6200, 378 TQ@4400

Carter AFB carbs

Carter AFB carbs 

Click on pictures for larger images.


Merc ECZ-9424-C Intake (ported):

Next on the list was the hard to find 1956 Mercury dual quad intake.  In looking at this manifolds outward appearance, this one was originally based on the Edelbrock FM255 intake. There was already some prior port work performed on this intake and based on its overall performance, it was a good performer back in the day.  Here are the results with a variety of carbs tested upon it.

1956 Mercury Carter carbs (vac sec)        347 HP@6000, 353 TQ@4500

L1161-2 Teapots with KM mods                 354 HP@6000, 362 TQ@4400

L1094-1 Linc Teapots (60P/82S jets)       366 HP@6200, 375 TQ@4400


Click on pictures for larger images.


1956 Ford EDB-9425-C Intake (stock):

This was the ’56 Ford offering which had the center to center carb spacing much closer together than the ’56 Mercury intake that was just tested.  The rear carburetor sits further forward on this manifold and appears to be more flow restricted as a result.  Here are the results for this intake.

L1268 Teapots (1956 2X4 carbs)         327 HP@5500, 360 TQ@3700

L1434 Teapots (1957 2X4 carbs)         333 HP@5500, 363 TQ@3500

L1094-1 Linc Teapots (60P/82S jets)  338 HP@5200, 369 TQ@4200



Merc ECZ-9424-C Intake (stock):

Another 1956 Mercury 2X4 intake but this time it’s a stock and unmodified version.  Here are the results.

L1434 Teapots (1957 2X4 carbs)            344 HP@5500, 364 TQ@3500

L1094-1 Linc Teapots (60P/82S jets)  357 HP@6100, 367 TQ@4300


Click on pictures for larger images.


Edelbrock FM255 2X4 Intake (stock):

This is the Edelbrock intake originally designed for the ‘55/56 heads and was the predecessor to the highly touted Edelbrock #257.  This intake is also the basic design for the 1956 Mercury dual quad intakes which also posted similar performance numbers.  Here are the results.

L1434 Teapots (1957 2X4 carbs)         342 HP@6100, 358 TQ@4500

GM Carter 1.050” mech sec 4V carbs 356 HP@5800, 368 TQ@4500

L1161-2 Teapots with KM mods          358 HP@6100, 362 TQ@4500

L1094-1 Linc Teapots (60P/82S jets) 359 HP@6000, 370 TQ@4400


Click on pictures for larger images.


Fenton ‘D427’ dual quad intake:

Here are the results for the Fenton intake which was an unmolested version (no porting).  This intake has ‘D427’ cast on its bottom which leads me to believe that many of the Fenton manifolds were using some of the older Edmunds molds in which to cast them up.

1956 Mercury Carter carbs (vac sec)  324 HP@6000, 357 TQ@3300

L1161-2 Teapots with KM mods           338 HP@5400, 354 TQ@4500

GM Carter 1.050” mech sec 4V carbs 341 HP@5400, 362 TQ@4400

L1094-1 Linc Teapots (60P/97S jets)  342 HP@5400, 364 TQ@4200


Click on pictures for larger images.


Edmunds ‘D427’ Intake (stock):

Same drill, just another intake.  This time it’s with an Edmunds intake with the ‘D427’ part number cast on its bottom.

L1434 Teapots (1957 2X4 carbs)          321 HP@5400, 357 TQ@3500

L1094-1 Linc Teapots (60P/82S jets)  322 HP@5400, 351 TQ@3900

L1161-2 Teapots with KM mods           330 HP@5400, 343 TQ@3300


1956 Ford EDB-9425-C w/mods:

And now back to the 1956 Ford dual quad intake but one that has been heavily ported in the plenum openings somewhere along the way.  The carb openings themselves had been enlarged to accommodate carb adapters to fit later model carbs to it.  The individual four carb bore holes had been converted to the kidney shaped holes as found on the 1957 ECG 2X4 intake manifolds. This particular manifold had also been heavily milled on the intake gasket surfaces which had the port openings smaller than they needed to be.

L1434 Teapots (1957 2X4 carbs)          321 HP@5400, 354 TQ@3500

L1161-2 Teapots with KM mods           329 HP@5400, 352 TQ@3300

L1094-4 Linc Teapots (57P/82S jets)  331 HP@5400, 352 TQ@4400


Hogans 2X4 Tunnel Ram:

This was a unique piece that falls in the sheet metal intake category and had been drag raced previously on the Church Brothers 1955 Thunderbird with much success.  On their iron headed engine, it had made a best of 490 HP but when replaced by a nicely ported Blue Thunder intake with a single four barrel carb, 510 HP came to the forefront.  While the Hogans intake is in the shop to see what can be done to its innards (plenum mods) to get it back on par with the single four intake, it is being run again with its ‘as supplied’ plenum with a myriad of carb pairs as part of this dual quad test.  Here are the results.

L1094-1 Linc Teapots (60P/82S jets)  311 HP@6200, 307 TQ@5100

L1094-4 Linc Teapots (57P/82S jets)  324 HP@5900, 324 TQ@5200

Street Demon 625 cfm carbs                   350 HP@6100, 345 TQ@4900

L1161-2 Teapots with KM mods           354 HP@6000, 329 TQ@5300

Predator 930 cfm variable venturi      356 HP@6100, 352 TQ@5000

L7996 450 Holleys w/mech secs           360 HP@5800, 344 TQ@5400

L4224 660 Cntr Sqtr Holleys                 361 HP@6100, 342 TQ@5200


Click on pictures for larger images.


Stock Edelbrock #257 Intake:

The Edelbrock 257 has long been considered to be the gold standard of YBlock dual quad intakes.  Here are the results for the stock Edelbrock #257.

L1434 Teapots (1957 2X4 carbs)          328 HP@5500, 353 TQ@4200

1956 Mercury Carter carbs (vac sec)  331 HP@6100, 352 TQ@3400

L1094-1 Linc Teapots (60P/82S jets)  333 HP@6100, 354 TQ@4200

L1161-2 Teapots with KM mods           344 HP@6100, 353 TQ@4400

GM Carter 1.050” mech sec 4V carbs 345 HP@6100, 358 TQ@4400

Street Demon 625 cfm carbs                   351 HP@6000, 355 TQ@4500


Edelbrock #257 “Hogged Out”:

On this particular intake, the plenum dividers under each carb had been completely removed which played havoc with the carburetor signal.  This intake had been run previously on the iron heads and was the worst performer of the manifolds tested on those heads.  It did not fare much better on the aluminum heads while low end throttle response proved to be even worse with the better flowing aluminum heads.  As a result, dyno pulls had to be started at 3500 rpms rather than the normal 2500 rpm start.  While one pair of carbs were run on this manifold in an inline setup, a pair of Offenhauser crossram adapters were also utilized and tested in an effort to help save the manifold.  Here are the results.

Inline: Street Demon 625 cfm carbs    272 HP@5100, 293 TQ@4600

Crossram: 660 Holley cntr squirters   339 HP@6100, 331 TQ@4500

Crossram: 625 Street Demon carbs     339 HP@6100, 337 TQ@4900

Those open plenums were not at all happy with the carbs sitting directly above them.  Installing the crossram adapters which both lengthened the runners as well as shielded the bottom of the carb directly from the ports was worth an easy 67 horsepower.  Even with a 67 HP gain, that manifold still comes in at the lower performance end of the list and still lower in output numbers than an unmodified #257 intake.  The lesson here is to be cautious in porting these manifolds as it is quite easy to go the wrong direction when attempting to increase the power levels.



Click on pictures for larger images.


Ported Edelbrock FM255:

With the results being much better with Joe Craine porting the Edelbrock 257, it was decided to also see what Joe could do with the Edelbrock FM255 intake.  The stock FM255 actually performed better than the stock 257 so it stood to reason that a ported FM255 might also perform better than a ported 257.  Here are some of the results.

1956 Mercury Carter carbs (vac sec)  347 HP@6000, 359 TQ@3300

L9776 450 cfm mech sec Holley           349 HP@6100, 354 TQ@4500

L1434 Teapots (1957 2X4 carbs)          350 HP@6000, 362 TQ@3400

GM Carter 1.050” mech sec 4V carbs 353 HP@6100, 359 TQ@4400

L8007 390 cfm vac sec Holley               353 HP@6100, 360 TQ@3400

L1094-1 Linc Teapots (60P/82S jets)  361 HP@6100, 370 TQ@4400

L1094-4 Linc Teapots (57P/82S jets)  361 HP@6100, 371 TQ@4400

L1161-2 Teapots with KM mods           362 HP@6100, 362 TQ@4400

But this is where things get interesting.  It’s observed that the mechanical secondary carbs have some severe reversion coming back up through them when loading the engine at 2200-2500 rpms.  To alleviate this, a 2” HVH tapered carb spacer is installed under each carb. But going with what Joe Crane had seen in some air flow testing, the spacers were tested in both the conventional right side up configuration and upside down.  The upside down configuration looked like a better fit to the four holes existing in the carb adapters that were being used to accommodate using modern carburetors on the teapot flanged intake.  The spacers being upside down peaked at 372 HP with the 660 cfm carbs.  Regardless of looking better, the spacers being right side up while using the same carbs netted 378HP.  That’s a 6 HP change that didn’t cost anything but the time it took to reverse the spacers.  It becomes obvious at this point that there is no end to the number of variants that can be tested.

With the same L9776 450 cfm Holley carbs reinstalled but with the upside down HVH spacers now under them, there is an eighteen horsepower increase.  That’s pretty substantial for just a pair of carb spacers being installed.  The pair of 660 cfm center squirter Holleys are then bolted on with the spacers being tested in both positions and the performance again steps up another notch.  Here are the final numbers for both sets of these carbs.

L9776 450 cfm mech sec Holley   367 HP@6100, 350 TQ@3300

L4224 660 cntr sqrtr Holleys        378 HP@6200, 370 TQ@4600

The Offenhauser crossram adapters worked so well on the ‘hogged out’ Edelbrock 257 intake that it was decided to also try them out on a manifold that was already at the top of the field.  In this instance and on the ported FM255 intake, performance went backwards.  Here are the numbers.

Crossram: L4224 660 Holley       352 HP@6200, 357 TQ@4500


Click on pictures for larger images.


Stock ECG-4224-D 1957 Ford:

And this manifold completes the dual quad testing.  It’s tested only with two different pair of model 4000 Holleys (Teapots).  Here are the numbers.

L1434 Teapots (1957 2X4 carbs)    326 HP@5500, 355 TQ@4100

L1161-2 Teapots with KM mods     336 HP@6000, 352 TQ@3500


In Summary:

Although I was on the trail of a couple of Edelbrock M254 intakes to also include in the testing, getting either of the intakes here for the test just didn’t happen.  The M254 2X4 intake was designed for the smaller port Ford 239 and Mercury 256 heads so I suspect it would have really been flow restricted on the aluminum heads.  Without actually testing that particular manifold, I can only guess that its performance would have been on par with the Fenton and Edmunds intakes.

One thing that became clear throughout these tests was what worked for carburetor pairs on one intake manifold did not necessarily work for another intake.  While the Lincoln Teapots performed quite well on some of the basic low rise dual quad intakes, they failed miserably on the tunnel ram.  On that particular intake manifold, two different sets of Lincoln carbs were used and both sets simply would not throttle up properly.  It’s a good guess that there was just enough reversion from those short and straight runners to be upsetting the metering in those particular carbs.  The carbs essentially sit right on top of the runners on that particular setup.  But the pair of 1956 Teapots (List #1161-2) with the Karol Miller modifications shined in that particular application.  Still trying to figure that one out but the internal secondary vacuum signal has been altered significantly on the KM modified Teapots which may be compensating for any reversion taking place.  The 660 cfm center squirter Holleys also worked very well on that intake as compared to some of the other carbs tested but that was the application for which they were specifically engineered.  But on the throttle up, all eight barrels were wide open on the 660’s versus only four barrels initially open on the vacuum secondary KM modified Teapots.  Lots to think about.

So there you have it.  Most of the dual quad intakes that were available for the Y have been tested and compared against each other.  Only in the best of circumstances did a dual quad setup exceed those performance baseline values established by a stock unported Mummert single four barrel intake.  Porting definitely works but if running aluminum heads, you do have your work cut out in getting the air flow numbers high enough in the dual quad intakes to match the cylinder head flow.

The next installment of the dual quad testing will cover the results derived from testing the various dual quad air cleaners.  Stay tuned and until next issue, happy Y motoring.  Ted Eaton.

This article was originally published in The Y-Block Magazine, Issue #116, May-June 2013.

Y-Block Ford – Dual Quad Testing on Iron Heads – Part I

With the resurgence of the Ford Y engine making a comeback as a viable replacement power plant for more than just mid-Fifties Fords, there is suddenly a demand for both modern performance and old school looks being in the same package.  And nothing speaks old school as well as performance as a dual four barrel setup.  As I had previously dyno tested the different three deuce intakes, the time was now ripe to do a similar test with the various dual quad intakes.  This dual quad intake test becomes much more complex due to wanting to also test a variety of carburetor pairs to also discern if there was a performance advantage to the carbs themselves.  So with a more definitive test in mind, the call went out for as many different carbs and intakes so that an extensive dual quad test could take place on the 312+ dyno mule.

Click on pictures for larger images.

And the response was overwhelming.  Many intakes were loaned and a multitude of carburetors were either loaned or donated to the cause along with a variety of carb parts and jets.  And a variety of dual quad air cleaners were also provided to do some definitive testing on those.  More on that series of tests further down the road.  And to make the tests go much more smoothly, both Vic Correnti and Tom Drummond stayed for several days to help with the manifold changes and subsequent tuning.  Also showing up during the testing and getting their hands dirty with intake and carb changes were Karol Miller, Randy Gummelt, Joe D. Craine, and Bill Myrand.  Thanks to all for the help as it would have been much more difficult otherwise.

Click on pictures for larger images.

The test engine for this series of tests is Bob Martin’s old 1956 Merc engine that was originally provided as a core for his current engine build.  That core engine was rebuilt and has subsequently been used as a dyno mule for a series of different tests.  This engine is a +060 over 312 with the replacement cast pistons sitting ~.025” in the hole at TDC.  The camshaft is the same cam Bob raced in his ’56 Mercury for thirty plus years.  That cam is a Seventies era Crower Monarch grind sporting 280° adv duration, 238° dur at 0.050”, .450” lift, ground on 110° lobe centers and installed 2° advanced or at 108° intake lobe centerline.  Harland Sharp 1.6:1 roller tipped rockers works the valves.  For this Part I of the 2X4 intake testing article, the heads are a set of mildly ported 113’s and for Part II (scheduled for the next issue of YBM) a set of  Mummert aluminum heads are installed on the engine.  The aluminum heads are thrown into the fray simply to eliminate any questions in intake manifold performance that may be related to a restriction in head flow.  If there is a choke point, it ideally needs to be at the intake so any differences in intake manifold design can be brought to the forefront during the testing.


Karol Miller visit:

Karol Miller had dropped by and when discussing the upcoming dual quad testing and showing him some of the carbs to be used, he pointed out that he had removed most of the choke horn cover from the Teapots that had been used for his record setting Daytona run in 1957.  With that in mind, a pair of 1956 312 L1161-2 Holley Teapots were modified accordingly.  While they do look naked without the choke horns, they do prove to perform better overall than similar carbs with the choke horns in place.  This becomes more evident where the iron heads are changed out to the aluminum units later where head flow restriction becomes less an issue.


Bench marks:

The first order of business was setting some bench marks or base lines for the testing.  This was accomplished by running the engine in a single four barrel format.  And in doing this, it was decided that three bench marks would be established with one being with the 1956 ECZ-A intake, the second being the 1957 ECZ-B intake, and the third being a Mummert aluminum intake.  All the intake manifolds are stock and unmodified while the carburetor used on all three for bench marking purposes is a tried and proven 750 cfm Holley with vacuum secondaries.

An adapter was used to allow the use of the 750 Holley on the Teapot flanged ECZ-A intake and that particular intake was also tested with three different carbs;  a Lincoln Teapot Holley, a 600 cfm Holley, and the aforementioned 750 cfm Holley.  While each larger sized carb did increase the power output, the difference in horsepower between the Lincoln Teapot carb (~500 cfm) and the 750 Holley was only 3 HP which indicates a serious flow restriction in the ECZ-A manifold.  Ford engineering was definitely at the top of its game with the introduction of the ECZ-B manifold for the 1957 models as it was a very noticeable improvement over the previous year’s intake manifold design.

Why three benchmarks?  These would represent three different performance levels depending upon the time frame or era that the dual quad intake testing could be referenced back to.  The ECZ-A intake would represent what the typical performance build would have represented in 1956 while the ECZ-B intake would represent a performance build starting in 1957 and what would be the standard for the next forty plus years.  And the Mummert intake would set the standard for what a dual quad intake would at least need to equal to for matching modern day performance.

And here are those bench marks:

ECZ-A Intake with 750 Holley           240HP / 324TQ

ECZ-B Intake with 750 Holley           276HP / 324TQ

Mummert intake with 750 Holley     311HP / 342TQ


1957 ECG-D 2X4 Intake:

First on the list of intakes was an original 1957 ECG-D dual quad intake with the factory supplied L1434 dual quad model 4000 Holleys (Teapots).  With the factory jetting in place (45P/55S), the peak numbers are 285HP@5200 and 336TQ@3600.  Changing the carbs out to the pair of KM modified 1956 312 L1162-2 Holley Teapots netted 288HP@5200 and 322TQ@3400.  Next was a pair of Mike Suter reproduction dual quad Teapots and the numbers for those after rejetting was 273HP@5200 and 319TQ@3400.  And the final carb change for this intake would be a pair of L1094-1 Lincoln Teapots with the numbers peaking at 296HP@5200 and 338@3700.  The Lincoln Teapots required the secondaries being worked mechanically due to the vacuum secondaries not pulling in quickly enough.  Some tinkering with the secondary springs would have likely cured that but there was a chance in the damaging the aged diaphragms so it was not attempted.

The picture on top is the 1956 EDB-C intake.  The lower picture is the 1957 ECG-D manifold.

Click on the pictures for larger images.


Edelbrock #257 Intake (hogged out):

Next on the list was a highly modified Edelbrock p/n 257 dual quad intake.  The plenum dividers had been completely removed and the only divider material that remained was in the runners themselves.  Because the low end torque values were so dismal, this intake was tested only with the Lincoln L1094-1 Holley Teapots.  The peak numbers ended up being 272HP@5200 and 305TQ@3800.  This intake had extreme difficulty in loading the engine on the dyno at 2500 rpms.

Click on pictures for larger images.

Edelbrock #257 Intake (stock):

This was a stock unmolested intake and the testing started with the Lincoln L1094-1 Teapots.  The peak numbers for those were 296HP@5300 and 341TQ@3500.  The next pair of carbs was the KM modified L1162-2 Teapots and they peaked at 303HP@5200 and 332TQ@4200.  Carb adapters were then installed and a pair of 625 cfm Steet Demon carbs were bolted in place.  After jetting and other adjustments, these two carbs peaked at 309HP@5400 and 343@4300.

Top picture: Edelbrock 257 intake on top and Edelbrock 255 intake on the bottom.  Note the difference in the carburetor spacing.  The lower picture is a ported Edelbrock 255 intake manifold.

Click on pictures for larger images.

Edelbrock #257 Intake (ported):

Another intake change and this time to the Joe Craine ported Edelbrock #257 with carb adapters and 2” HVH tapered carb spacers.  The first pair of carbs to be tried would be the Street Demon carbs with the 55P & 72S jetting and the peak numbers would be 320HP@5200 and 342TQ@4400.  Next to try was a pair of Edelbrock 500cfm carbs.  With just the carb adapters and 2” HVH carb spacers, these carbs peaked at 310HP@5300 and 335TQ@4400.  Using the same carbs but removing the 2” carb spacers netted the following peak numbers: 304HP@5300 and 335TQ@4400.  And here are the peak numbers with the Lincoln L1094-1 Teapots w/o the 2” carb spacers: 309HP@5300 and 347TQ@4100.

Click on pictures for larger images.

Iron Head Summary:

With 311 HP being the best single four bench mark number, the Edelbrock #257 intake ported by Joe Craine was able to surpass that.  The remainder of the dual quad intakes tested on the iron heads still proves that adding dual quads to your mid-Fifties era modified Y-Block was a great power adder back in the day though.  And if you were replacing a single four Holley Teapot setup, you were taking giant leaps forward.


And coming up:

The next installment of the Y 2X4 intake testing has the iron 113 heads off the engine and replaced with a set of Mummert aluminum heads.  And this is where the testing gets even more interesting.  While the same intakes that were tested on the iron heads get retested on the aluminum heads, the Fenton, Edmunds, Hogans, the 1956 Ford and Mercury factory dual quads (yes, they are different manifolds), and Edelbrock FM255’s also get throwed into the fray.

Stay tuned and until next issue, Happy Y Motoring.  Ted Eaton.

This article was originally published in The Y-Block Magazine, Issue #115, Mar-Apr 2013