ix block stroker combinations?

[imwhyteyo]

To keep it short and simple a customer has come to me with the idea that he wants to make his turbo IX with a factory 2.5 engine into a 2.7"stroker". Now i know the blocks are different from awd to rwd so thats out of the question. But mainly im curious what the best combination of internals would be for a sprinty turbo IX.

WE have access to:
A spare IX m20b25
An early m20b27 bottom end
And a m20b27 SETA Bottom end

Can someone inform me which combination of parts would be ideal for this setup?
Is it better to use the ETA crank rods and pistons in the ix block?
Would it be more desireable to use the SETA crank piston and rods?


A side note i should add is that i have a spare m52b28 and an s52b32 sitting for parts as well if there are any notes on that worth mentioning.

I am only interested in stock bmw part combinations. No custom pistons and all that everyone keeps reccomending.

Also when this will be created, arp rod hardware will be used, but ill need information or perhaps links in which piston rings to use, which rod bearings to use, and if anything like wrist pins etc should be replaced. All engines are under 110k.waffles
The setup will see megasquirt with a variation of boost between 12psi to 22psi, using a dual pattern 270cam from bimmerheads (turbo cam)

[downforce22]

To me, if you are going to be pulling the block for a stroker rebuild you should get the most displacement possible. The larger cranks may require custom pistons depending on your combination, so that may be out for you.

You could throw the m20b27 internals in the ix block and that would probably be the cheapest option. But it may not be the best option.

I'm pretty sure the SETA is just an eta with an 885 head anyway. If you use this combination it will lower compression below 8 IIRC which is a good proven combination for turbo m20s. Does he really want to pull apart the whole engine and reuse pistons/rods from an eta for only 0.2 L more displacement?

It seems like a lot of work for minimal gains?

[imwhyteyo]

The 2.7 engines are already apart and shelved which has sparked this idea. Im interested in doing a replica turbo setup that ive done on my 2.5ix and see how exactly they will compare using the exact same parts and management to somewhat put a proven record behind these ideas. Its really not that much work either.

[digger]

seta bottom end and b25 topend

[imwhyteyo]

Seta going to create that tiny nick more power than the regular flet top pistons?

[MR 325]

I'd also go with the Super Eta bottom end and the M20B25 top end. The Super Eta does use the same 885 head as the 2.5L but it has a weaker cam and single valve springs. I am running this combo in my turbo E30 at 9psi and it's tons of fun! I would recommend using Goetze piston rings and Glyco rod/main bearings.