JE piston to wall clearance 2.4 turbo

[Force Fed Mopar]

From what I could find, JE seems to say no more than .004". This sound right? They are going in a 2.4 turbo build that I plan on running a lot of boost on, 450whp is the goal.

[GLHNSLHT2]

FM always states .0035 to .004 on the JE's I've bought from them. I ran .0035 on my 2.5 and haven't had an issue at 20psi. I run .004 on my 2.2 they're ok but a bit noisy on startup. The one's I'm putting in my 2.5 Masi will be set to .0035.

[4 l-bodies]

Rob,
I would say .004. This is what happened to Rocky Johnson's motor in ten minutes of total run time. The guy who put this motor together was supposed "Nascar" engine builder that knew too much to bother sticking to piston manufacturer's guidelines. I tore down motor to find out what went wrong. Piston to wall was tip of iceberg. Not saying that was all from too tight piston to wall butt...We were able to save the aluminum rods out of motor. The rest was scrap!
Todd

[GLHNSLHT2]

scary Todd. What's "tip of the iceberg"? I sold the 2.5 8v JE's out of my daytona that had been run for years at .0035 with some very lean a/f's dealing with "tuners" at times and 20lbs of boost once I started tuning and they looked pretty much brand new.

[shackwrrr]

Rob,
I would say .004. This is what happened to Rocky Johnson's motor in ten minutes of total run time. The guy who put this motor together was supposed "Nascar" engine builder that knew too much to bother sticking to piston manufacturer's guidelines. I tore down motor to find out what went wrong. Piston to wall was tip of iceberg. Not saying that was all from too tight piston to wall butt...We were able to save the aluminum rods out of motor. The rest was scrap!
Todd

My weiscos looked like that after overheating. I reused them but they are really noisy.

[Force Fed Mopar]

Yeah I told the shop to go with .004".

---------- Post added at 12:35 AM ---------- Previous post was at 12:32 AM ----------


My weiscos looked like that after overheating. I reused them but they are really noisy.

I replace 2 Wisecos in the 2.5 in the Lebaron when Tony still owned it that looked like that, also due to overheating.

[turbovanman²]

.0035-.004".

That's all I run, quiet until I melt things, :(

[shackwrrr]

Two of the 4 looked like this lol. Still runs and runs good. Just makes lots of embarrassing noise.42963

[Force Fed Mopar]

Mine is quiet :)

[Rampage16V]

I've always run 3.5-4 though with je's on 2.5 and 2.4's been good.

[trannybuster]

0.0035-0.004........ΔΔ3.5 might be too much :)

[contraption22]

Rob,
I would say .004. This is what happened to Rocky Johnson's motor in ten minutes of total run time. The guy who put this motor together was supposed "Nascar" engine builder that knew too much to bother sticking to piston manufacturer's guidelines. I tore down motor to find out what went wrong. Piston to wall was tip of iceberg. Not saying that was all from too tight piston to wall butt...We were able to save the aluminum rods out of motor. The rest was scrap!
Todd

I had the same exact thing happen when I had an engine built by Ray Barton Racing Engines. (Yes the Hemi guys).

[turbovanman²]

0.0035-0.004........ΔΔ3.5 might be too much :)

Don't you mean too little, :D

Crap, just realized you wrote 3.5, lol.

[GLHS60]

Doesen't Simon have a shop that expands or knurles over clearanced, or collapsed forged pistons?
Simon please elaborate, I have been meaning to ask you explain your post, of probably a couple of months ago.

Thanks

Randy
.




Two of the 4 looked like this lol. Still runs and runs good. Just makes lots of embarrassing noise.42963

[turbovanman²]

Doesen't Simon have a shop that expands or knurles over clearanced, or collapsed forged pistons?
Simon please elaborate, I have been meaning to ask you explain your post, of probably a couple of months ago.

Thanks

Randy
.

Yes, when I toasted my engine a few years ago due to a bad injector, my head porter knew a guy who lived under a bridge, kidding, seriously, he has a machine to expand pistons, so he did mine, worked awesome, went from noisey to quiet, :thumb:

[Force Fed Mopar]

Yeah knurling is an old trick, can be used for rod bearing bores, etc.

[turbovanman²]

Yeah knurling is an old trick, can be used for rod bearing bores, etc.

Yes, it is but he didn't knurl them, he expanded them. Get out your glass's old man, :D

[wallace]

Yes, it is but he didn't knurl them, he expanded them. Get out your glass's old man, :D

How does that work?

[turbovanman²]

How does that work?

He has a hydraulic press unit I guess, goes inside and blows the piston out, he said they can only do it once or twice and only a few thou. It worked on mine, I can't complain.

[wallace]

He has a hydraulic press unit I guess, goes inside and blows the piston out, he said they can only do it once or twice and only a few thou. It worked on mine, I can't complain.

Thanks, I didn't even know it could be done that way, I had heard of the knurling.