SETA Pistons

[Andy348]

I know I'm going to get flamed for this, but I've searched for three hours now and can't come up with a 100% definitive answer. I'm 90% sure this is correct, but I'll ask anyways.

I can use an 86 eta bottom end, SETA pistons, 885 head w/all I electronics, accessories and wiring to make a '327i' and end up with a CR of 8:5:1?

Thanks.

[MR 325]

Yes, you are correct! Super Eta engines use the same crank and rods as a regular Eta engine.

[CorvallisBMW]

Not to threadjack, but...

Changing to 'i' rods ups the CR to, what 9.5:1? Anyone know of the power difference between the 2 options?

[nando]

Not to threadjack, but...

Changing to 'i' rods ups the CR to, what 9.5:1? Anyone know of the power difference between the 2 options?

That doesnt work, the pistons would protrude 5mm too far. So your cr would be approx 9999:1 ;)

[CorvallisBMW]

That doesnt work, the pistons would protrude 5mm too far. So your cr would be approx 9999:1 ;)

Good to know lol

[KenC]

What about stock eta crank, eta rods, euro eta pistons, with 885 head?

[der affe]

The 885 head will drop the pistons compression ratio down by 1 point. IE, 10.5:1 will become 9.5:1. At least that is what I figured out win my euro eta pistons.

[CorvallisBMW]

hmmm, so if euro eta motors were 11:1 then an 885 head would result in 10:1... perfect :twisted:

[der affe]

The squish of the piston is a bit of a mismatch for the 885 head, there have been some discussions about it and where the down fall lies or how much HP may actually be lost because of this. I have never seen anything concrete as far as an answer though.

Good luck finding early eta euro pistons in decent shape anymore though. It took me a while to find mine.