compression on a auto m20 engine

[nova_130bhp]

hello there i have a 325i auto that has been coverted to manual im wonder wat the compression ratio is as i am thinking of turboing it.the engine code is m20 i think,cheers

[blingsta]

what year mate? if its a late engine, it will be the lower comp which is fine to turbo

[hongkongfuey]

look on the block passenger side, right hand side, b25k low comp , b25e high comp

[stonesie]

It will be just infront of where the Dipstick tube goes into the block, that little flat area covered in crud/rust

[nova_130bhp]

its november 89. my friend has a 91 sport and mine seem to pull harder especailly when it get to 4000 rpm the engine note seems to change.i was starting to think that there is a cam or something in it.it is lumpy on tick over

[jaistanley]

It's probably the years it spent having a lazy life in front of an auto box. I got myself a 60k mile M20B25 auto and converted that to manual and it was a rocket ship!

Yours should be the late engine if it's from an '89 so fine to turbo.

[hongkongfuey]

if its high comp it takes off over 4k

[nova_130bhp]

yea mine seems to take of over 4k engine note changes and it pulls like a train