Page 1 of 1

orig E21 diff with M52B28 engine?

Posted: Thu Jun 01, 2017 2:16 pm
by pihlen
Hi all,
I´ve heard some different thoughts about using the original diff and the whole rear parts (drive shafts, A-arms etc) from the E21 (1981 M10 318i) when swapping engine to a M52B28 (suspension, brakes and strutbars will be upgraded no matter what). Some say it´s strong enough and some say it´s not! I´ve also heard "the original diff is strong enough for road use with M52B28". (i´ll do road use 99% of the time)

So would it work to use the original parts up until the gearbox and "only" changing the engine and the gearbox to a 6 cyl M52B28? I will keep the engine stock so it's a 193 hp engine. Does the gearbox differ from a E39 M52 and a E36 M52? I mean the 5 speed manual. The cardan shaft will have to be modded too ofc and I´ll solve the speedometer somehow.

I also understand it as i need to change the brake booster (to what, would you suggest?) and change the oilpan (or oil sump or what is it called in english?) to an E34 M50 pan/sump as its shallower and allows more ground clearance? About the cooler it should fit with the original one but its "prefered" to use another (smaller/more effective per size) i guess? Electrical fan?

I´m working on some sort of (for now) personal wiki about this engine swap and i need to gather as much info as possible before starting the work as i have to be quite time-efficient when starting it. Hopefully this wiki will turn out good and i´ll ofc share it here later as (one of many) how-to's :) it´s a long journey though but im super excited and have never done an engine swap before.

Thanks a bunch

Re: orig E21 diff with M52B28 engine?

Posted: Thu Jun 01, 2017 6:09 pm
by nas80
I've done several swaps with m52b28.

6 of them have been on stock diffs, albeit all had LSD.

Stock diff can take the pain during road use.

Unless your name is Dom and try to race my rx7 cos you'll break a spider gear (lol)

Or you a ham fisted reprobate and go on track days and jump the rubbing strips. (Jamie)

Other then that you'll be fine

Re: orig E21 diff with M52B28 engine?

Posted: Thu Jun 01, 2017 9:22 pm
by mcjjordan
Im still running stock 4:11 open diff from 316....
I just dont launch it or it will break as it is nearly 40 years old.