Tag Archives: YBlk

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.

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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

Cylinder Head Milling for a 1cc Reduction

In the course of milling cylinder heads for a specific decrease in combustion chamber volume, it becomes necessary to know exactly how much a cylinder head must be milled for a 1cc (cubic centimeter) reduction.  While this value is useful for milling heads for a specific compression ratio increase, this value becomes increasingly more important when attempting to equalize combustion chamber cc’s over the length of the head due to a particular head having cylinder chambers that get progressively larger (or smaller depending upon your perspective) from one end of the head to the other.  For a number of cylinder heads out there on the market, there are resources that can be accessed to obtain this information but for the non mainstream engines such as the Ford Y-Block, that information is vague if it’s to be found at all.  To add to the confusion are the different combustion chamber shapes that were available on the Ford Y-Blocks over the course of its production run.  With all this in mind, I’ll share the steps I use to determine how many thousandths of an inch a particular head must be cut to reduce its chamber volume by 1cc.

  1. Measure the distance or length around the edge of the combustion chamber on the head. (inch format)
  2. Take this measurement and divide by pi or 3.1416
  3. This result multiplied by itself or squared.
  4. This result multiplied by 0.7854 (this is the result of pi divided by 4)
  5. This result multiplied by 16.387 (this is the result of 2.54 cubed)
  6. Take the value one (1.0) and divide by the previous answer.  This will be the amount to mill the cylinder head in an inch format to reduce the combustion chamber volume by 1 cc.

Or looks like this in a math formula:   1 /  (((measured distance / 3.1416) squared) X 12.87)   =  inches cut for a 1 cc reduction.

The first order of business is to measure the actual length around the edge of the combustion chamber and this can be performed from at least two different approaches, either being equally effective.  One method is to simply take a piece of wire or string and lay around the edge of the combustion chamber along its perimeter which will provide a measurement of the length around the chamber itself.  Another method is to lay a piece of paper or light cardboard over the combustion chamber and rub the pattern of the combustion chambers edge onto the paper or cardboard.  This chamber imprint can then be measured for its length with a number of different measuring devices of which a map route reader is both inexpensive and effective.

For the following example, a Ford truck 292 ‘CITE’ casting head is being used.  On this particular head, the measurement around the length of the combustion chamber is 10.63”.  Going through the aforementioned calculation steps, the final result is 0.00678” (rounded to 0.007”) and this would be the amount to mill the head for a one cc reduction.

But to take some of the work out of calculating the amount to mill for some of the various Ford Y-Block heads, here’s a chart with some known values.

Cylinder   head casting Combustion chamber perimeter Amount of cut for a 1 cc reduction in combustion   volume
113 11.02” 0.0063”
471 11.38” 0.0059”
B9TE-A 11.02” 0.0063”
COAE-A 10.31” 0.0072”
C1AE-C 10.47” 0.0070”
C1TE-D 10.63” 0.0068”
EBU-A 10.75” 0.0066”
EBV-C 10.83” 0.0065”
EBY-B 11.06” 0.0063”
ECG-D 10.98” 0.0064”
ECG-H 10.79” 0.0066”
ECL-A 11.02” 0.0063”
ECL-B 11.02” 0.0063”
ECR-A 11.02” 0.0063”
ECR-C 11.50” 0.0058”
ECZ-A 11.50” 0.0058”
ECZ-B 11.26” 0.0060”
ECZ-C 11.02” 0.0063”
ECZ-G 10.94” 0.0064”
Mummert aluminum 11.34” 0.0060”

Armed with this information, it’s now possible to mill a pair of heads of different or varying cc’s with a specific amount of cut for each head and ultimately having them equalized or all the combustion chambers at the same cc’s on the first cut.

Special thanks goes out to Tim McMaster and Carl Lynn for providing additional head tracings for some of the various Ford Y-Block head castings that were not on hand.                                Until next time, happy Y motoring.  Ted Eaton

This article was originally published in The Y-Block Magazine, Issue #104, May-Jun 2011, Vol 18, No.3

Milling Heads for a Horsepower Gain

Over the years I have heard a variety of numbers from 2% to 10% for what a point in compression ratio is worth in regards to horsepower output.  The ten percent value obviously sounded a bit exaggerated while the two percent value sounded a bit on the small side.  While dyno testing a variety of cylinder heads on the 312 dyno mule, the opportunity arose to determine exactly to what extent a compression ratio increase would have on the horsepower output.  The dyno mule is the well used, tried and proven +060 over 312 with a Crower Monarch 238@050 camshaft ground on 110° lobe centers,  a Mummert aluminum intake with a carb spacer, and a 750cfm Holley carb.  The bottom end is still pretty much stock with ECZ rods and cast pistons that are sitting 0.025″ in the holes.

By lieu of the number of heads being tested, two different test scenarios presented themselves.  One set of tests involved several pairs of heads with the same casting numbers that were simply milled different amounts.  The other test was taking two sets of heads and dyno testing them in a before and after milling scenario to determine exactly how much compression ratio increases were worth on these particular pairs of heads.  This later opportunity was obviously a more controlled test in that variations within the head castings themselves would be eliminated.

In collaboration with Tim McMaster who had already shipped several sets of heads as part of an extensive cylinder head test, it was decided to take two sets of those heads and dyno test these in a before and after milling test.  The heads selected for this test are a pair of ECZ-C’s and a pair of C1TE-D’s.  Both sets of heads were initially run on the test engine in their ‘as delivered’ state of mill.  The heads were then milled and re-ran with everything else on the engine remaining the same.  The headers being used are the Engine Masters Challenge headers with 1.75” tubes stepping up to 1.875” before going into a 3” merge collector.  Mufflers are being used.

The C1TE-D heads have no port work on the intake sides but the exhaust sides have been ground on and opened up.  The valves have been upgraded to 1.805” for the intakes and 1.600” for the exhausts.  Initial combustion chamber volumes averaged 74.2cc providing an 8.41:1 static compression ratio.  Peak horsepower in this format was 294.5 at 5400 rpm while peak torque was 334.6 lbs/ft at 3800 rpm.  The heads are then cut ~0.045” which nets an average of 68.2cc for an 8.95:1 compression ratio.  The peak horsepower jumps to 297.1 at 5100 rpm and the torque increases to 337.4 lbs/ft at 4400 rpm.  That’s a 2.6 HP increase for a 0.54:1 increase in compression ratio or a 1.63% increase per compression point.  The calculated horsepower increase for a full point of compression in this case would be 4.8HP.

The ECZ-C heads have had 1.900” intake and 1.600” exhaust valves installed.  The intake and exhaust ports are still stock and have not been ground on.  The combustion chamber volumes in the ‘before’ test are 74.0cc producing an 8.43:1 SCR (static compression ratio).  The peak dyno numbers for these heads before milling are 289.5HP at 5400 rpm and the torque is 333.8 lbs/ft at 3900 rpm.  The heads are then milled ~0.050” which gets the combustion chambers down to 67.3cc for a 9.04:1 SCR.  The horsepower in this format jumps up to 295.4 at 5300 rpm while the torque increases to 338.5 lbs/ft at 3900 rpm.  That’s a 5.9 HP increase for a compression ratio increase of 0.61:1 or 3.34% increase per point of compression.  The calculated HP increase for a full compression point in this case would have been 9.7HP.

But now we get to discuss the other testing scenario.  There are three sets of stock ECZ-C heads being run on the dyno mule and while the ports and valve sizes were stock, the pairs of heads had been milled differently.  The compression ratios were 8.12, 8.6, & 9.0:1 with the HP values being 273, 280, & 288 respectively.  As expected, there was a HP increase with each increase in compression ratio.   In calculating the increase from 8.12:1 to 8.6:1, there is a 5.34% increase in HP per compression point.  It’s found that the increase in CR from 8.6:1 to 9.0:1 produced a 7.14% HP increase per compression point.  And in examining the overall increase from 8.12:1 to 9.0:1, there is a 6.24% HP increase per compression point.  As mentioned earlier and because this was three different sets of heads being tested, there are still some other variables being introduced but the fact still remains that each compression ratio increase did net an increase in the horsepower output.

In the definitive milling test, there is an average of 2.6% HP increase per point of compression.  In the less definitive test where three sets of heads with different combustion chamber volumes were tested, there is a 6.24% HP increase per point of compression.  Regardless of which value you’d like to use, compression ratio increase is still the easiest and least expensive method in which to up the power output of your engine.

As always, this is food for thought.  Until next time, happy Y motoring.  Ted Eaton.

 

Click on pictures for a larger image

Originally published in Y-Block Magazine, Issue #106, Sep-Oct 2011, Vol. 18, No. 5