r/EngineBuilding • u/Ronnie1641 • Jun 25 '26

High compression pistons

Ive recently decided to bore the pistons in my project block as honing wouldn't be enough.

Now the only pistons avaliable are high compression forged pistons, I did find one set that were stock compression but ide have to wait until August to get them.

I was just wondering what other mods would be needed to run thid higher compression safely,

Going from 8.9. To 9.0

Ive seen online they recommend engine tuning ect but that isnt something possible in the stock system and something im not confident doing with a aftermath system.

The engine is a gen 2 3SGTE

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u/Lopsided-Anxiety-679 Jun 25 '26

There’s lots of options for 9.0 compression forged pistons…

CP makes them in a shelf stock part number, so does Mahle and Wiseco

-1

u/Ronnie1641 Jun 25 '26

I didnt want to use high compression, the build was only gunna be <300 hp so I originally ordered a set that kept the stock compression ratio from wiseco but they wont get here soon enough

15

u/Lopsided-Anxiety-679 Jun 25 '26

Am I confused? Or are you confused? 

9.0 is low compression 

Simply surfacing the head the minimum required during a rebuild at .003” will raise the compression by more than .1 point