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M21 Block, M20 Head?
Posted: Wed Oct 25, 2017 8:36 pm
by miki_cba
Hi there, I’m Nicolas from Argentina, I have a question, I’m about to buy an E30 324d (with the head and camshaft broken) but here in my country the swaps are VERY difficult (you need to do a lot of papers, money, government...)
The original idea is swap for a M50 or M52 engine and a Big turbo...
BUT, only to be curios, anyone know or has done something like M21 block with M20 or another petrol head? Of course with proper pistons, and all that kind of stuff...
Sorry for my English!
Thanks!
Re: M21 Block, M20 Head?
Posted: Thu Oct 26, 2017 9:43 am
by Speedtouch
Welcome to the Zone!
I gather the 324d uses the same bore (80mm) and stroke (81mm) as the M20B27 eta (325e) engine, so I suppose you could fit an eta head and pistons, or a 320i (731) head.
Re: M21 Block, M20 Head?
Posted: Thu Oct 26, 2017 10:11 am
by steve_k
if you are going to all the effort of swapping pistons etc then wouldn't make more sense to swap the crank into a m20 block & built a stroker?? you already have the most important part (the 324d crank).
Re: M21 Block, M20 Head?
Posted: Thu Oct 26, 2017 12:47 pm
by Speedtouch
I think the M21 block is the same as the M20 on which it is based.
So, probably just a matter of changing the pistons and cylinder head to suit petrol.
Re: M21 Block, M20 Head?
Posted: Thu Oct 26, 2017 6:57 pm
by steve_k
Speedtouch wrote:I think the M21 block is the same as the M20 on which it is based.
So, probably just a matter of changing the pistons and cylinder head to suit petrol.
very true, nice cheap(ish) stroker

Re: M21 Block, M20 Head?
Posted: Fri Oct 27, 2017 8:02 pm
by miki_cba
steve_k wrote:if you are going to all the effort of swapping pistons etc then wouldn't make more sense to swap the crank into a m20 block & built a stroker?? you already have the most important part (the 324d crank).
the problem here in Argentina is that swaping and even finding a M20 Block is veeery dificult and expensive, and you have to go to the police with the new engine and the old one, explain why are you swaping, have all the papers, go to the govermen after the police and explain everithing again and pay a lot of money to do all the new papers of the car..... and for example a M50 engine only without accesories can cost 2800 USD
thats why haha

Re: M21 Block, M20 Head?
Posted: Sat Oct 28, 2017 9:52 am
by Speedtouch
Can't you repair the 324d head and fit a replacement camshaft?
Re: M21 Block, M20 Head?
Posted: Mon Oct 30, 2017 12:34 am
by miki_cba
Speedtouch wrote:Can't you repair the 324d head and fit a replacement camshaft?
yes but i want a lot of HP and torque, rollcage and race a little haha

Posted: Wed Nov 01, 2017 2:39 pm
by miki_cba
good news for me and someone who wants to do something like me
the block is almost the same
