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e30sequel 02-08-2012 02:13 AM

320i - any experience/success with performance NOT swap
just acquired 320i - need to do a head job so want to replace with 2.5 head redone and conclude with a small turbo - anyone done this with success, not much love for the 2.0 but it still revs smoother/higher - wanted to capitalize on this - any help appreciated - thanks

Bimmer Heaven 02-08-2012 02:23 AM

24V swap>all...

egye30 02-08-2012 04:24 AM


Originally Posted by Eurostyle (Post 1547764)
24V swap>all...

you heard the man

MaxBell 02-08-2012 10:35 AM


Originally Posted by egye30 (Post 1547770)
you heard the man

As I am finishing up my M50B25TU swap, I am feeling that this was well worth the time.

msinger 02-08-2012 11:44 AM

M30 swap.

egye30 02-09-2012 02:26 AM


Originally Posted by msinger (Post 1547806)
M30 Turbo swap.


El Gato Liso 02-09-2012 03:36 AM


Originally Posted by MaxBell (Post 1547789)
As I am finishing up my M50B25TU swap, I am feeling that this was well worth the time.

i dont think it is...if i can redo, i'd go straight to M52

joking! M50 TU Swap was def worth it...if its cheap! $ Pulls harder from 0km, and once the RPMs are up, especially with VANOS engaged, dumping the gas pedal into WOT, it gooooes!

my fave... 2nd gear @ 4500rpm. and 3rd gear and 5000rpm ! Just make sure your shocks are proper cuz the 24V is heavier than M20!!!! and you will blow your shocks.

MaxBell 02-09-2012 10:43 AM


Originally Posted by El Gato Liso (Post 1547976)
Just make sure your shocks are proper cuz the 24V is heavier than M20!!!! and you will blow your shocks.

I've got Bilstien Sports up front, will those live?

e30sequel 02-09-2012 07:43 PM

the swap option is extremely tempting and more trouble free sounding but I will retain the bottom end - I am sincerely interested in the high revv nature of the smaller displacement - and would like to capitalize on this via some boost almost........ 7000rpm limit is more tempting
the swaps will be for future e30s ..... will have a harem of all kinds eventually ..... will post progress as it happens

craz azn 02-09-2012 08:12 PM

There is no replacement for displacement! :D

But realistically, you won't find any difference in regards to the 'nature' of one M20s willingness to rev over another. Sure you may think smaller displacement would want to rev higher, but BMW engineers threw that theory out the window with the S54... Similar design (as far as cylinder spacing and whatnot goes) and yet, with a retardedly long stroke compared to the M20, it manages to spit out a displacement of 3246cc, and it revs to 8k all day.

The biggest limiting factor with revving any original/stock M20 is the top end (ie rocker arms, and to a certain extent, the rest of the valvetrain)...

FWIW, I'm gonna wager a guess that the 320i has a lighter flywheel and maybe that's why you think its more 'willing' to rev. *wave*

Bullet Ride 02-09-2012 09:22 PM

It's funny how the title of the thread specifically says NOT swap and yet the first 6 posts all say swap lol.

If you put an 885 head on your motor it will lower the compression ratio slightly because the combustion chamber on the 885 head is a few cc larger than on the 731. However if you're planning on going turbo then it's not a big deal as you're going to want to lower the compression anyway.

The stroke on the B20 is so short, I wonder what the limiting factor would be in the bottom end. I'd imagine that if you were to have everything balanced very well, with a set of beefy rockers and stiffer springs you could rev that motor to 8000rpm

e30sequel 02-10-2012 07:50 PM

But folks the stock power is produced at 6k with a 6800rpm cutoff - I was on to the idea of 2.5 head because there is one rebuilt/refurb on kijiji that I had in sight........ BUT I am now wondering what the issue will be with regard to head gasket (ie the hg is designed for the 2.5 pistons so will there be a fitment problem??? ..... this is why I was looking for someone who may have done this and addressed this issue or found the answer)
- I was really ready to pull the trigger on the rebuilt head but it came to a screaching halt when these questions started coming up .....I do not want to find out when I have started the job already I will try to research some uk sites to see whats up/feasibility etc ...... and yes if all fails then swappity swap

SamE30e 02-11-2012 03:11 PM


e30sequel 02-11-2012 09:07 PM

yea, was just looking at the frank macalusa write up on e30 but if I went that route it would be because I got a blueprinted one but more likely would go for the e36 323is alum bottom w/single vanos and obd1 top = about 200hp even would be good enough
BUT still interested in retaining 2.0 - there is a bit of info on the b20 and am in the process of digesting ....

msinger 02-11-2012 10:06 PM

M30 swap - torque is unreal. easy transplant and easily turbo-able after. no brainer.

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