323i Head Cracks, what's your experience?

[e21Keith]

Progress has picked up with the acquisition of some new fuel tanks, hoping to have these installed within a couple of weeks, refurbed front suspension ready to go in now.

My attention is about to turn to the engine and both of the engines I have suffered from "head gasket failure" or at least water and oil mixing. One engine had the head removed and skimmed, it came in the boot of the car but was never fitted, the other still awaits dismantling so is an unknown. Looking on the Dutch forum head cracks are not unknown and when the cars were current they were legendary for cracking heads although I hoped the later models didn't suffer, I've had 10s of e30 and e34 M20s and never had a head crack, never even heard of it!.

So what is peoples experience of 323i head cracking, where do they crack?

[Jeroen]

M20 head cracks are pretty common, and yes especially on the early ones say up to 1984. Mostly its near one of the camshaft bearings in the centre. If they're dismantled anyway I'd have them pressure tested to be sure.

[e21Keith]

OK, thanks for the advice.

I need to find someone who can crack test the heads for me, ideally someone local. I'm in the UK not that far from Aldershot, Basingstoke, Farnborough, Guildford, West London.

Does anyone know which e30 head is the best to use and what mods would be required please? I have a spare 888 dead kicking around!

[e21Keith]

Correction the spare head I have is an 885.
Does anyone know the benefits/issues with fitting this to my 323i bottom end, which cam should I use? I'm keeping the original Jetronic as I want a standard looking engine bay.

[Duracel79]

I've had an 885 head crack, picks in the thread below page 8 (if they still work damn PB):
http://www.bmwe21.net/forum/viewtopic.p ... &start=105

From what I remember the gasket failed then the resultant overheating cracked the head, took 2/3 laps of Snetterton to do it.

[bmw e12 e21]

I had a crack at cylinder 5,,,
http://www.bmwe21.net/forum/viewtopic.p ... 15#p293606

[e21Keith]

Yep, saw that on the Dutch forum, google translate is awesome!
Looked really closely and can't see anything that looks like a crack but have ordered a kit for detecting cracks in welds so maybe that will show something? Also checked around for people in the UK for crack testing but none of them could be bothered to reply to my email,
Has anyone used an 885 head on an e21?

[gerrit323]

Correction the spare head I have is an 885.
Does anyone know the benefits/issues with fitting this to my 323i bottom end, which cam should I use? I'm keeping the original Jetronic as I want a standard looking engine bay.

You can't use this 885 head on the original 323i bottom end .. your compression will be to low.

If you want to use this head you will have to source a e30 b25 bottom end.

With that setup you can still keep the stock k-jet tronic and the engine will be putting out 160hp.

If you want to keep the b23 bottom end you will have to use the 200 head but preferably the later 731 e30 type head as the flow is a bit better.

Hope this helps

I never experienced head cracks on any of my cars .. both the e21 hartge and the e30 2.7 stroker were driven hard without and issues .. think luck has to be on your side

And warming them up gently and long enough can help also

Rgds
Gerrit

[e21Keith]

I have a complete M20 B25 engine for rebuild + the 324d Forged crank, rods and schrick cam to build a proper 2.5 or 2.7 but I really want to stay stock, so it's fingers crossed on the 200 head, otherwise I need a 731 head I think.

[bmw e12 e21]

I put thisone on my 323i afther the crack.
https://www.ebay.de/itm/BMW-E30-320i-32 ... SwtudajZRR
I´ve been told they are stronger than the original BMW heads. They have more ´´meat´´ so they don´t crack so easily.
They have also the 2,5 version.
https://www.ebay.de/itm/BMW-E30-E34-325 ... SwRgJXg~sG

[e21Keith]

I have seen those heads, unfortunately I missed a brand new unused one on eBay just last month.