i remember zip his user name was arussell. and the thread was je piston tech. august 2008

I also remember the topic, I didnt run them before that either though.

Kod, is there any other engine builders or is this someone you've dealt with for years ?

Yep That's him, if i remember correctly he said that due to the low expansion rate of the SHP 4032 mat'l, they should be run with .0035/.004 clearance piston to wall clearance.
Hey David i ran them once, but never again, in fact i now build with Probe pistons, cheaper than JE, wisco or anyone else and the same 2618 mat'l for a true forged piston.

JMO

Zip.

I think you do remember correctly, I'd always been told before that point to stay away from them. I am bias towards Wiseco, they've helped me out from time to time and stepped up on my new engine a few months back.

This is my first trip to this engine builder Hammer. He has been racing Super Stock cars and building engines for years. He came highly recommeded by some hard core racers in this area. I know guys who have purchased his engines and he has done good work for them. He doesn't have much experience with alcohol engines and suggested I switch to gas. That's why I was wondering how much build difference there was between an alcohol and a gas engine.
And on the dyno, this engine kept 8 inches of crankcase vacuum while running gas and built 24 psi pressure on alcohol.
I run a HV billet oil pump and he figures maybe it's putting out too much oil and flooding the valve train area. He mentioned putting oil restrictors in the block to limit the oil getting to the top end.
Initially he thought we needed to speed up the vacuum pump to get rid of the crankcase pressure, which I havent tried yet as I just received the new drive pulley yesterday.
We don't have as many engine builders to choose from in the Great White North. I am just about ready to get this engine running right on gas, sell it and order a Steve Schmitt engine.

Did you get a chance to leak it or compression it yesterday ?

If you do bail on this engine and go another route, there is better shops to choice from then Schmidt also :wink:

Milky oil
 

I believe SRP pistons are 4032 alloy for small blocks and flat top BBC but are 2068 for high compression BBC. I have 2 sets of 496 pistons here and it says on the box and paper work they are 2068. They are a little heavier than the JE and less compression 12.7 versus 13.5 but other than that they are just $200 cheaper.

Are your gapless rings top land or second land gapless? Top gapless should leak 2%.

Have you talked to a tech guy at TOTAL SEAL about rings? Has your engine builder?

I have built some alcohol engines both naturally aspirated and blown and the rings and cylinder wall prep was only difference per TOTAL SEAL specs.

I have had to file fit gapless rings as they were not in the range of .010"-.040".

I have also had a guy switch back and forth on a carburated engine and saw no differece as far as blowby. His engine did not have gapless rings.

I didn't get a chance to do the lead\k down yesterday. Work got in the way.
I plan on doing it today if I can find enough time.

Re: Milky oil
 

The gapless are top land. I have wondered about the cylinder wall prep, as this may explaing the difference between what I see from the engine on gas as opposed to alcohol. Crankcase pressure on alcohol and vacuum on the gas.

Re: Milky oil
 

Mark, i'm glad you posted that number, i wasn't even aware of the change from the 4032, so i did a lttle research. It appears that the 2068 is not a lot different than the 2618 mat'l, but a lot different than the 4032 mat'l. The 4032 having 11%to 13% silicone compared to 0.7% of the 2068 mat'l, and .025% with the 2618. Chemical composition comparison posted below.

Zip.

2068 alum.

R.R.56 [1]
Melting point 635°C
Density 2.75
Composition
Copper 2.0%
Nickel 1.3%
Magnesium 0.8%
Iron 1.4%
Titanium 0.1%
Silicon 0.7%
Aluminium 93.7%

2618 alum

Chemistry Data : [top]


Aluminum Balance
Copper 1.9 - 2.7
Iron 0.9 - 1.3
Magnesium 1.3 - 1.8
Nickel 0.9 - 1.2
Remainder Each 0.05 max
Remainder Total 0.15 max
Silicon 0.25 max
Titanium 0.04 - 0.1