stroker parts list

[CorvallisBMW]

I thought there was a sticky thread here somewhere for a DIY stroker, but i can't seem to find it. My engine now has 208K on it and i think it's time for a rebuild this summer. I want to get an early start! While i'm at it, i might as well do a 2.7 or 2.8, its hardly more effort, right? I've never rebuilt an engine but i should have some good help doing it. My question is, what parts do i need to do the stroker? M20B27 crank? or the M50B25 crank? con rods? customs pistons from whom and what specs? and does the block need to be clearanced in any spots? how about a new cam or injectors? should i get the manifold or head port/polished or extrude honed? any tips or links are greatly appreciated. thanks for the help guys!

Darin

[CorvallisBMW]

Oh and btw, does anyone make a "rebuild kit" for this engine, with all the miscelaneous gaskets and seals and whatnot?

[JJGBMW323]

MM will sell you a complete 2.9 stroker, or greater but they are very expensive.


As for what to get. Start with a 90 325i engine.
The head is 885 and is superior to any other m20 head.

You can use the "I" rods.
You can use an eta crank.
The eta crank is cast where the 524td crank is forged.
They are both 81mm.
I have knife edged my 524 td crank, but some have used an eta crank
and that ok as well.
Then you need forged pistons.


Also MM, and Pete McHenry have used the e36 M3 cranks. The 95 e36 s50 crank is roughly an 86mm crank, and the later 96 s52 crank is even greater.
These can be used in the M20 but it requires more work, custom pistons, and custom rods. These are the 3.0 liter and greater M20s that Metric Mechanic advertises for lots of money.
They put out in the neighboorhood of 230 or more hp.

[CorvallisBMW]

As for what to get. Start with a 90 325i engine.
The head is 885 and is superior to any other m20 head.

Why is that? is it any different than the head of my '88 325iS?

[silversleeper]

^iws... when did the head design changeover? i have an 89, is that sufficient? is that an 885? where can i find out more on this?

also, how much did the knife edging cost ya? can most local machine shops do this?

[SpecM]

-All 325i, 325is, 325iX, 325iC have a 885 head. 885 head = b25i head.

-You may want to use s50/52 rods. They are the same size (130mm, yes?) as a m20b25i rod but weigh a lot less.

[NC325iC]

Also MM, and Pete McHenry have used the e36 M3 cranks. The 95 e36 s50 crank is roughly an 86mm crank, and the later 96 s52 crank is even greater.
These can be used in the M20 but it requires more work, custom pistons, and custom rods. These are the 3.0 liter and greater M20s that Metric Mechanic advertises for lots of money.
They put out in the neighboorhood of 230 or more hp.

yeah baby :evil: :evil: