Anyone ever used powerrmax 73.5mm pistons in a forced induction engine?
Turbo Mini Forums

evenings chaps!

Bit of an odd question, has anyone ever used powermax 73.5mm 9cc dished pistons on any sort of forced induction setup?

I know they're not a low comp piston as such, and I've not heard much about them being used before.

Basicly, I'm going to be building a blowthrough supercharger setup later in the year, and ultimately, i intend to build a stonking bottom end capable of withstanding mega power, using 18cc acralites.

I don't really want to test my SC setup on such a costly engine, and was planning on using my current 1380 as a bit of a test bed.

I figured that by using a cometic 120 thou MLS head gasket, i could easily get the CR low enough with an appropriate head, and I just wanted to run the setup at low boost (8psi-standard mpi pulleys) to iron out any initial problems with the charger installation, before trying it on an expensive forged engine build.


So, if anyone has ever tried any sort of boost with powermax 1380 pistons, I'd love to hear how it went!

cheers.

Nick

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

yep got powermax's in the 7 port, dished out to 17cc.

not used it in anger on big boost yet, buit it sees 8 psi on a daily basis

sweet, that's what I wanted to hear! i just really fancy getting a few miles on the charger setup to see what it's like before spending big money on a new bottom end. the current setup will happily take the power, I was just unsure on how the pistons would cope.

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

well mine have seen short 15-20 psi squirts so you shopuld be fine with an sc setup especially if its just for triallying

oh also on my trial lump i just used 2 headgaskets to knock the cr down.

2 head gaskets? that sounds scary! Did it actually survive any boost like that?

I'm going to give one of the cometic MLS gaskets a try, it's what minispeed use in their suck through supercharger kit, so it can't be too bad.

Although it's a trial, I'd rather not destroy the engine, as I'm planning on using the block/crank/rods again when I come to rebuild it with acralites.

So long as the powermax will withstand a bit of testing under boost I'm happy.

The plan is to get it all setup and working perfectly on 8psi, so when I build the forged motor the fuelling and everything will be setup nice and safe for the running in.

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.

yep, 2000 miles on 3psi boost. llokedf fine when i took them off

yes i think a few on here use them pistons with great results :)

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two head gaskets isnt the way to go its a bodge at best!

removing cc in the head combustion chambers is the way to go

I know what you mean benross. my plan is to build a proper low compression engine with 18cc pistons and a decent head. I'm planning on using the cometic MLS gasket just as a temp to get the CR down on my current engine so I can test the charger setup on an 'unimportant' engine so to speak. then, when i know it works, I'll rebuild with 18cc acralites and a head with chambers to the correct volume for my required CR.

Mr. Prawn, the friendly Crustacean- slowly making steps towards forced induction.