Getting my motor finally machined and want to know what piston to wall you used. Wiseco says .005" for boosted motors, but the machinest is recommending .006" for 35+ psi Im thinking that sounds like piston slap territory to me. What kind of cylinder temps are there with 10:1 E-85 high boost applications? Opinions?
My basic engine combo consists of:
4G64 2.4LR
ARP main studs
L19 head studs
stock crank
ACL race bearings throughout
Wiseco HD1200 87mm 10.1 CR (running E-85)
Manley turbo tuffs 156mm
Kelford 272's
PTE 6262
FIC1650's & twin 255's
Port matched stock head, intake and TB
Other supporting mods
(not sure yet on head gasket)

 

If I remember correctly they actually call for .0035. Thats what I have mine set at. 700+ with no issues and no scuffing of the cylinder walls.

 

Thanks for sharing.

 

i would go with .005".

 

That's what I remember too. We went higher than that because of plans to run high boost but the motor was still very quiet and was burning much oil...

 

The older paper work will say .0035 and then on the back side it is has an additive for supercharger, turbo, nitrous, or combinations.

5 to 5.5 thou for 700whp. 4.5 is still quiet enough that it sounds like stock and the knock tables can be left alone, Luke & Jeff run 6.5 and its still quieter than an old style JE piston motor at 5. My motor from last year was 5.5, this year is 6.

Aaron

 

good info. i really like when other smart vendors help the community like you Aaron.

 

Thanks man

 

Thanks a ton guys, I appreciate your time in coming in here and giving your personal experiences. I am planning on at least 700+ with this motor so maybe I should go with the larger clearance of .006 as well.

 

Did you mean to say "wasn't" burning much oil?

 

I had a loose dsm ross motor and it was kinda noisy. Could def hear the piston slap. I was in a evo with j.e. pistons on the loose side and omg, thought the thing was coming apart! lol

 

 

5.5 was fine for 831. I went looser since I have an S374 sitting on the shelf next to my desk staring at me. I am sure it will never go on but that and no coolant in the block mean I have to play a little different than others.

 

We have collapsed skirts on Ross and they will do the same thing. They were louder to start with though. Alot of the reason I think is most of the pistons other than Wiseco are full circle and tend to be louder as ths skirt caves. The strutted piston really cant do that as easy.

 

I had 5.5 on j.e.'s, sounded like a diesel.