e30 swapping 4cylinder for m20 325i

[black bmw 318]

hi guys

i am thinking of attempting this swap myself and was wondering if it could be done in stages?
forgetting about brakes and suspension as i have these sorted, i was wondering if i could change the diff first? what would be a good change to match the m20 and still be driveable until i complete engine and transmission?

would this effect performance of the 4 cyclinder in the meantime?

any help appreciated

[kylebes1]

if you have an 84 or 85 318i, you probably have a 3.91 diff, it will work fine for the m20 b25. And do not worry it will hold up to the straight six

I would not change the diff until after you swap the engine in, the 4 bangers need that low diff to work at all

[Bill 84 318i]

I dunno man...a lot of people asplode those small diffs with 6's pushing them. I'd rock a large case diff. And yeah, you should be able to swap it in ahead of time.

[kylebes1]

Are you sure? I called Euro Depot to buy a large diff and the guy actually had a s50 e30 and ran a small case for three months, and swapped it with no damage.

Similar story with a place from Cali and another right here in ATL at the BMW dealer.

I think it would be ok, if it blows up oh well, they are worthless anyway!

[E30godz]

depends on how you drive, kids

[e30Matt]

I dunno man...a lot of people asplode those small diffs with 6's pushing them. I'd rock a large case diff. And yeah, you should be able to swap it in ahead of time.

:stupid:

Diff swaps are cake.

[kylebes1]

I would not put a taller diff in there if you plan to drive with the m10 much, if that is what you have now.

[Bryson]

Are you sure? I called Euro Depot to buy a large diff and the guy actually had a s50 e30 and ran a small case for three months, and swapped it with no damage.

Similar story with a place from Cali and another right here in ATL at the BMW dealer.

I think it would be ok, if it blows up oh well, they are worthless anyway!

I did an s50 swap which the owner is still running a small case 4.10
I did an m20 swap in my car and the 4.10 seized in a month

[kylebes1]

I did an m20 swap in my car and the 4.10 seized in a month

That is what i am talking about, depends on the diff and the driver. Look at Bryson's Sig, I bet taht added to the breakage!

[black bmw 318]

I did an m20 swap in my car and the 4.10 seized in a month

That is what i am talking about, depends on the diff and the driver. Look at Bryson's Sig, I bet taht added to the breakage!

ha ha