Have thus far ran twelve different sets of heads on the dyno mule with several sets left to go.  The stock ECZ-C heads in their stock form run surprisingly well although they are pretty well out of wind after 5000 rpms.  All the heads are being tested on the same 312 shortblock with the same intake and carburetor combination as well as the same headers.  On most of the heads tested, two sets of headers were used to discern the difference between small tube and large tube headers on the various heads.  Once all the testing is complete, I’ll post the details.

Lorena, Texas (South of Waco)

Good talking with you today Ted, I like what you had to tell me.   Can't wait to hear the rest.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias

The cylinder head test had a slight set-back yesterday.  The number eight cylinder on the 312 dyno mule has developed a crack in it so I’ve already got the engine completely torn down and getting it ready for a sleeve in that particular cylinder.  Once the engine is reassembled, it will then be run in and base-lined to insure it’s making the same numbers as before.  At that point the cylinder head test will continue on.

 

Here’s a picture of the crack in the cylinder wall.

 

 

I’ll add that there’s a tremendous amount of data being generated.  With what Tim and I discussed regarding his particular heads and the testing protocols, there’s going to be some additional data generated that will confirm exactly what specific increases in compression ratio will have on power output.  Some of this has already been done with the three sets of stock ECZ-C heads that have been run but with Tim’s heads, the testing gets more definitive.  Sorting all this data out so it’s easy to decipher will be a challenge when that time comes.

Lorena, Texas (South of Waco)

Ted: Was there any change in performance or coolant lose noticeable prior to the discovery of the crack?.. and do you have an approximate record of how many Dyno pulls you have done with that engine? It must be well up there!.

Paul

There was no observed coolant loss associated with the crack in the cylinder.  The crack was initially spotted when pulling the 471 heads after dyno pull #350.  I had originally contemplated pulling the engine down at that point but decided to gamble with running it that way with another set of heads.  At that point, the crack was 'small'.  The crack didn’t change much so I just continued to monitor the cylinder each time the heads were being removed.  After running Tim’s modified ECZ-C heads, the crack grew substantially and I figured I’d better stop and repair the cylinder.  It was interesting to watch the crack over the course of several dyno pulls and observe how catastrophic engine failures in the real world start out small before becoming real show stoppers.

 

Once the cylinder wall crack was initially spotted, the engine was being rotated so that the #8 piston was at the bottom of the bore prior to removing the cylinder heads.  This was performed to allow any water that was seeping from the crack to pool on the piston top so any leaking coolant could be observed during the tear down.  There was no water present in the bore and the carbon on the piston top remains the same as on the other pistons so there’s no evidence of any water getting into the cylinder while the engine was running.  Air fuel readings were also being constantly monitored and any water going into the exhaust would have been picked up with the oxygen sensors.  Air fuel readings were clean right to the point of deciding to tear the engine down.  Bearings look incredibly good at this point.  There are now 365 dyno pulls on the engine. 

Lorena, Texas (South of Waco)

Question Ted, John,

I just acquired a 272 with ECG-H heads. Johns site list them as 8.4 comp ratio 56 power pack heads with a 272 and 2bbl. the ECG-C at at 8.5 with a 4bbl and the ECZ-C at 8.0 with a 2bbl in 272 form. 8.4 in 292 and 9.0 comp ratio with 312.

What would the H's be in 292 and 312 ? They appear simmilar to the ecG-c's. Which are you testing the ECZ-C's or the ECZ-C's?

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

OOps, meant to say are you testing the ECZ or ECG-c's.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

Billy.  There are no plans for testing any ECG heads in this cylinder head test.  A variety of ECZ-C heads are being tested though which are similar in valve sizes and basic combustion chamber shape as the ECG-H heads.

 

Assuming the ECG-H heads have 69cc combustion chambers to achieve the 8.4:1 static compression ratio in a 272 with the pistons 0.007” in the hole and 0.025” thick steel shim head gasket, then the SCR using these heads on a stock 292 with the same 0.007” deck and the same steel shim head gasket would be 8.9:1.  And for a stock 312 with 0.007” deck and using steel shim head gaskets, the SCR would be 9.46:1.

Lorena, Texas (South of Waco)

The dyno mule is back up and running.  Installing a sleeve in the number 8 cylinder was a non-event and the engine went back together without issue.  Re-degreed the camshaft just to insure it was sitting in the same place and it was.  Timing chain slack is remaining the same.  The engine was baselined and is repeating the same numbers as before so all is good.  Cylinder head testing is continuing on at this point.  Once that’s complete, then I’ll put the new headers that are on hand through a regime of tests with the dyno mule back in the same ‘exhaust testing’ format that it was in for the other exhaust system tests.

Lorena, Texas (South of Waco)

Great news Ted.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias