JE Pistons

[jltcat]

Ive heard some people hate JE pisotns why is this? I have put them in several of my engines and never had a problem?

 

[92redman]

I think it's because most people don't like piston slap on their street car, but don't quote me on that.

 

[Wobble]

the way they are composed, you MUST let the engine COMPLETELY warm up before ANY driving, or you risk piston slap.. this can be quite annoying in a daily driver.. especially in the winter..

im sure most people dont like to sit in their car for 5 10 or 15 min just letting it idle up to temp before backing out of the driveway..

 

[allwheelTSI]

theres alot of conflicting opinions on this matter,truth is,you can get piston slap with any forged pistons. i think most of the problems are due to bad machining.

 

[Groomz]

Its all about tolerences and how its machined. Small four cylinders like the 4G63 produce more power per given displacement ( duh ) so there is more heat for a smaller area compared to a 200hp 3.0V6 for example. The pistons are going to absorb more heat and expand more, so the pistons are machined to have more gap between them and the cylinder walls. Some companies have had trouble w/ piston manufactures that call for very tight piston ring to cylinder wall gap which can cause friction issues on higher horsepower engines. Magnus Motorsports switched to Ross only pistons after having trouble w/ some other manufacturer recommend tolerences too tight. Big horsepower = big heat = more need for extra room for metal to expand. JEs are top quality, but there only for those of us who are producing extreme power. AllwheelTsi is correct also, forged pistons are more likely to cause piston slap on cold starts. The price we pay for power.

 

[jltcat]

I thermal coat the tops of the pistons this should reduce the extreme heat environment that cause expansion to some degree allowing for a slightly closer clearence. This may explain why Ive never had any problems. Thanks for the speedy replies.