M50 - but 2.8

[E30BeemerLad]

Did I read correctly somewhere that you can fit an M52 2.8 crank straight into an M50?

Would I need the rods aswell?

Anything else?

[maxfield]

12345kevin (?) is doing this at the minute, maybe worth a PM.

Or a PM to 1an about it.

[E30BeemerLad]

not sure if it's in the M50 sticky thread somewhere, but it has gotten so damn long it's a pain in the arse to find anything and my laptop seems to be running so slow at the moment

[Jhonno]

no its not in there..

i believe making an m50b28 is the same principle as making an m20b27...

[DanThe]

Im doing one, Non Vanos, schrick cams, raised comp, everything balanced blah de blah

Just waiting for the piston rings *Cough* Ant! *Cough* and it can all be put together

[E30BeemerLad]

well i have a non-vanos M50.

To just cobble together a 2.8 setup without going all out on cams etc would I just need crank & rods from the M52? Are there variations in the cranks on M52's at all?

[ste]

If you're going to those lengths it may be worthwhile you fitting the M54B30 crank for 3.0l ?

Assuming you haven't just got a b28 crank and rods already sat in your garage with no home.

[E30BeemerLad]

Just an idea at the moment really.

To be honest, I really just need to get my finger out and get a hoist sorted and get the lump swapped in and get it all up & running before i start tarting around with depraved ideas of capacity increases or forced induction.

Interested in the M52 hybrid idead though as presumably all the benefits of the 2.8 without bore wear problems or restrictive inlet, suppose the down side is the weight of the M50 compared to the 52.

[maxfield]

Also I think there were problems with threads for the head bolts stripping and the block being scrap?

I would of thought Iron would be better for F/I due to it being stronger.

I think Ste's idea is the best

[DanThe]

I think there were problems with threads for the head bolts stripping and the block being scrap?

F*cking tell me about it! The amount of alloy blocks ive had with pulled threads is ridiculous, and also frustrating, the muppets will spend £70 on a genuine head gasket but will skimp on the £20 for new head bolts with special coating! Any technical data ive ever read about M52 engines states NEW BOLTS MUST BE USED

Oh, and dont forget the Nikasil problems, not to mention the 'mobile liners'

Its enough to make you think the engines were doomed from the begining

[1an]

I think there were problems with threads for the head bolts stripping and the block being scrap?

F*cking tell me about it! The amount of alloy blocks ive had with pulled threads is ridiculous, and also frustrating, the muppets will spend £70 on a genuine head gasket but will skimp on the £20 for new head bolts with special coating! Any technical data ive ever read about M52 engines states NEW BOLTS MUST BE USED

Oh, and dont forget the Nikasil problems, not to mention the 'mobile liners'

Its enough to make you think the engines were doomed from the begining

Dan your doing exaclty the same as wat my dad is about to have done to his.

[dasparkybad]

Its not the head bolts on the m52 engine that cause the problem i have used new head bolts on these engines and still pulled the threads out this happens when the engine has been seriously overheated
the answer is to have the whole set of bolt holes helicoiled by a reputable engineering firm
my one puts two sets of helicoils in each hole the cost is around £100 but i have not had any problems with this and i am running one of the engines that had this done in my own e30 cabby
we also have another engine in an e39 528 with the same work done and no problems
i would say that this work in an m52 engine rebuild is a must
from what we can gather from the work we have done with this engine when the engine overheats the alloy around the threads goes soft and if you pull out one thread others will be damaged too
the machining work if done correctly will cure the problem
get searching for those scrap m52's
they are repairable and if being sold for scrap value very cheap
Dan is right though new bolts must be used every time as they are stretch bolts and once they have been stretched they cannot be used again

[DaveD]

come up to the milk bar on friday and tell us all about it...the more the merrier

[dasparkybad]

where is the milk bar & what time are you meeting there

[E30BeemerLad]

Friday @ 7pm

www.squires-cafe.co.uk

[dasparkybad]

Nice one will try and make it

[DanThe]

Not just the stretch but they have a special lubricating coating that disintegrates over time. I have an alloy M52 block here with only one thread pulled, but no doubt if the others were torqued down they would also pull as the old bolts were re-used and it was pressurising like a bas*ard.
Pointless though as it has the dreaded Nickasil disease. Its only slight wear but what would be the point in rebuilding when I can use an iron block which is as good as the day it was run in 14 years ago.
I had a 1996 dated steel liner engine which had blown the head gasket also. The liners had clearly moved as I could feel the difference between cylinders with my finger nail.
I would like to use an alloy block for an engine build purely to save weight, but the last 6 ive had have all been scrap!

[Andyboy]

I had a 1996 dated steel liner engine which had blown the head gasket also. The liners had clearly moved as I could feel the difference between cylinders with my finger nail.

It's not the liners that move, but the alloy sinks between them. M52 stuff is just horrible as far as I'm concerned, I wouldn't touch any of it. It's fine when it's running but just throwaway when it goes wrong. I've seen Helicoils pull out of the block as well, even the Timeserts. An iron block does weigh more (about 17 kilos), but they're practically unbreakable and cost peanuts.
Any M52 2.8 crank will fit an M50 block but if using a 3.0 M54 crank you'll need to relieve the base of the bores so the rods don't touch.

As for head bolts; too many clowns use cheapo Euro Car Prats bolt sets which are actually M50 ones. These don't engage fully with the threads in the block and pull the top ones out whether they've been cooked or not. Only the proper bolts should be used.

BTW M52TU and M54 heads won't fit an earlier block in case you've spotted a cheap one on Ebay. Also the TU heads are made from compressed alloy balls as opposed to sand casting and they crack like a bastard.

[ste]

It's all interesting stuff this M52 bashing.

Are you not overexaggerating the problem though? There are still thousands of E36s running about with these engines in them with no issues whatsoever. The Nikasil issue is no longer a problem. If an engine was going to fail due to Nikasil coating wearing prematurely due to bad fuel it would have done so by now. The other issues you're all now bringing up (liners moving, headstuds pulling etc) are due to stupid mechanics or inferior pattern parts.

Lots of other manufacturers use alloy blocks with no problems, Porsche 911s use Nikasil blocks too, Peugeot XU engines use liners etc. None of these 'problems' are real problems if proper procedures and parts are used.

If mine fails I'll either rebuild it properly or just buy a new engine for the circa £300 going rate. In the meantime I'll enjoy watching iron block engined cars in my mirrors.

[brian325i]

nice post ste
even if they are exagerating the badpoints at least we can learn what all the bad points are,even if the above probs happen to 2% of all m52s

[DanThe]

When did this allusil coating come in that the e36ers are always banging on about?

[Andy325i]

It's all interesting stuff this M52 bashing.
.... In the meantime I'll enjoy watching iron block engined cars in my mirrors.

[Andyboy]

The other issues you're all now bringing up (liners moving, headstuds pulling etc) are due to stupid mechanics or inferior pattern parts.

That is utterly wrong Ste. Yes, there are still thousands of them about but you only cook an M52 once and it's scrap. You can use bolts which have been gold plated and blessed by Allah, the block threads WILL strip on the final tighten and sometimes even on engines that haven't blown a head gasket.

Take for example a 1999 523i M52TU that did a water pump, as is fairly common. 'BONG' comes the coolant level warning, needle up into the red. Result is a scrap engine with a coolant leak from the head gasket on the exhaust side where the head bolts have pulled out - that's before anyone took it apart. The car was bought for £500 and another engine built using a good TU block I gave them.

As for the liners, they do not sink or move in any way. Rather the alloy sinks between them as is common on engines where there isn't quite enough meat between the cylinders. That's why it never happens on the 2 litre alloy block. As yet it's not known whether this is caused by a blown head gasket or is the actual cause.

The M52 is a good engine when it's running `and the Nikasil thing doesn't scare me at all - I'd rather have a good running Nikasil engine than the steel liner unit. I'm just aware that they won't tolerate a single overheating 'moment'.

[Andyboy]

It's hard to see, but this is a scrap block where the alloy has sunk between the liners. You can see where the gasket fire rings sit - if you can feel the slightest ridge with your fingernail, it's party over:


And a pulled block thread:


As for other cars and Nikasil - 911's use barrels so it's not the same due to the higher temperatures they run at, but 944's and 928's do too. The difference is in the quality of the alloy used and BMW stuff isn't that great.
I'll be sticking with iron blocks knowing that it won't shit itself and is at least fixable.
M52 2.8's for £300? That's a nice little business opportunity - FAB are still getting £1000 + VAT for those.

[Andyboy]

When did this allusil coating come in that the e36ers are always banging on about?

It didn't. Alusil was only used on the V12 and M62 V8's, NEVER on the M52. Yet they keep banging on about Alusil blocks.

[ste]

That is utterly wrong Ste. Yes, there are still thousands of them about but you only cook an M52 once and it's scrap....

Some good points mate. I don't plan on cooking mine though.

Like I say, if I do I'll get another one easy enough. If we were talking the money S50 blocks still go for I'd be worried. FAB may be asking a bag for M52s but we all know they're available much cheaper.

[Andyboy]

True - but 300 sheets is silly cheap!

[Jhonno]

m50's are £200 when ive asked round.. Almost rude to do an m20 swap at all nowadays