M52TU Swap

[bennno2005]

Hi guys

First post here, so go easy on me!

I've not long bought a 325i coupe. The M20 isn't very well so I'd like to swap an M52 in.

Have found one from a 728i but doesn't come with the ECU. Would I be safe to assume I can buy another MS42 ECU and when I have the EWS removed it will work?

Cheers Ben

[flybynite]

Can't see a problem, any MS42 should work of the correct vintage once ews is deleted, however...

There is not much that can be wrong with a sick M20 that cannot be fixed, and probably for less than a swap and loss of originality.

What exactly is wrong with the M20?

[bennno2005]

Can't see a problem, any MS42 should work of the correct vintage once ews is deleted, however...

There is not much that can be wrong with a sick M20 that cannot be fixed, and probably for less than a swap and loss of originality.

What exactly is wrong with the M20?

Thanks for the feedback, good to know.

The car's done 212k, its not the original engine so I've no idea of the history. Doesn't start well, does run ( a bit lumpy but no knocking etc) but has a bad oil leak (i think from the crank seal), as its history / mileage is unknown I'd want to rebuild it if keeping but I'd rather an M52 engined car anyway, lighter engine, more powerful, simple ignition system, OBD 2 etc.

I've had a few M54 engined 330 clubsports in the past and really liked the engine but these are a bit more complex to go in an E30 as far as I can tell.

Its a shame as the car is very original coupe at the moment but its not a sport and with the high mileage, complete lack of history and non-original engine I don't think its the end of the world, plus there are a few other changes I'd like to make.

As a side do you have an idea of what the M20 engine would be worth as this could be sold to fund some bits needed for the swap.

[flybynite]

I get the thinking and I am doing an M54b30 swap myself but I have an E30 with no engine and a spare known 330i that is past its best.

I am betting you could get the M20 running fine for less than the cost of the sump and arms for the M52. Faster is a bit academic as any modern hot hatch will leave either behind. IMHO it is all about the experience at legal speeds these days and the M20 wins hands down at that.

Also keep in mind all M5x engines are old now and many are past their best and in need of rebuild too for some it is out of the frying pan into the fire. The later Motronic M20 is about as simple as it gets

Most swapped E30s have been done on the cheap and the better ones get tarred with the same brush so it will always be worth less than an M20 325 even with a non original engine.

An M20B25 with loom ancillaries and gearbox was posted in one of the groups recently for £1000 no offers. It did not sell and eventually went for £800 so I think that is a good guide. I might even buy it myself if you are close

[bennno2005]

I get the thinking and I am doing an M54b30 swap myself but I have an E30 with no engine and a spare known 330i that is past its best.

I am betting you could get the M20 running fine for less than the cost of the sump and arms for the M52. Faster is a bit academic as any modern hot hatch will leave either behind. IMHO it is all about the experience at legal speeds these days and the M20 wins hands down at that.

Also keep in mind all M5x engines are old now and many are past their best and in need of rebuild too for some it is out of the frying pan into the fire. The later Motronic M20 is about as simple as it gets

Most swapped E30s have been done on the cheap and the better ones get tarred with the same brush so it will always be worth less than an M20 325 even with a non original engine.

An M20B25 with loom ancillaries and gearbox was posted in one of the groups recently for £1000 no offers. It did not sell and eventually went for £800 so I think that is a good guide. I might even buy it myself if you are close

Thanks for that and understood.

I think I've sourced an E38 M52 so no need for expensive sump etc. Appreciate there will be other costs (manifolds, radiator etc etc)

I'm not doing the car up to make money, I'm doing it for me although it would be nice not to waste it.

Mind me asking what makes the M20 better at legal speeds and do you not think at 35 years old with an unknown history, running or not by M20 will be in need of a rebuild?

I'm based in Shrewsbury so if you are local and do want it you're welcome to come for a look....

[flybynite]

I'm a fair way away but couple of times a year I do swing round the bypass but normally around xmas.

IMHO the M20 just sounds so much better, the world is full of 4-valve engines, the 8-valve sound in either the M20 or M30 is a rare thing today. I remember how unimpressed I was with the E36 328 when it came out, so much I eventually bought a good E30 325i.

M5x can be effective if done right, which I why I am looking at it for one of mine but I already have an M20 car. If I only had one it would be M20 all the way. Which is probably why the M54 is still in the 330i and I keep looking at bits for a 2.9 stroker M20

[bennno2005]

I'm a fair way away but couple of times a year I do swing round the bypass but normally around xmas.

IMHO the M20 just sounds so much better, the world is full of 4-valve engines, the 8-valve sound in either the M20 or M30 is a rare thing today. I remember how unimpressed I was with the E36 328 when it came out, so much I eventually bought a good E30 325i.

M5x can be effective if done right, which I why I am looking at it for one of mine but I already have an M20 car. If I only had one it would be M20 all the way. Which is probably why the M54 is still in the 330i and I keep looking at bits for a 2.9 stroker M20

To be honest, I've looked into it more and have decided to keep the M20. You are right, I don't need more power that's not the point of it and am now planning to keep the car original(ish) it is a 325i after all, even if its done moon miles and isnt a sport.

At some point I'll get the engine out and rebuild it.

Will get a build thread up here to keep motivated with it, have just finished my V6 converted MR2 which will be going for a respray soon so should hopefully have more time to get stuck into it then

[bennno2005]

Did fire it up when I first got it, nearly died from fumes but it did sound epic

[Speedtouch]

A little over 200,000 miles is nothing for these engines - a Mobil 1 test car did over 1,000,000 miles and was still running well !

Maybe yours just needs a good service...