E21 323i head cracked

[kiwipetrolhead 1]

Hi guys,

My engine is out and being done up. After 280,000Ks it only has 3-thou wear in the bore. Not even one single broken ring! I was going to get it rebored, but told pistons are obsolete and with only 3-thou wear anyway, a re-ring should be fine. It looks like most of the oil burning was due to worn oil scraper rings and valve guides.

But the BIG problem…

The head has the usual crack - between pots 4 and 5. There was no sign of water usage when it was running (not even the slightest hint of condensation), but the crack is there all the same. I phoned Mosen (Hamilton - tel (07) 8462972), but no second hand ones in stock and they are hard to get so I am told. The crack could be welded, but the machinists tell me this is not always successful (I got two independent opinions). According to Mosen, second hand heads sell for about $850, if one was available. To weld the crack and line bore the camshaft housing is about $400, but no guarantee it will last, although some of them do last OK, so I am told.

Any suggestions?

If know of a good second hand head for sale anywhere?

I have no idea of new prices. The engine guy said he was going to ring some Auckland BMW parts outfit about new heads (not a proper BMW dealership), but I'm still waiting to hear back about that.

BTW, I'm in Palmerston North.

Any help appreciated.

Thanks

Paul

[CaM 0]

give european car parts a go....

in auckland, 09 299 1234

otherwise, other m20 head may fit? I may know of one form a mechanically injected 520i, if that may help, being that your car is likely mechanical injection?

[kiwipetrolhead 1]

give european car parts a go....

in auckland, 09 299 1234

otherwise, other m20 head may fit? I may know of one form a mechanically injected 520i, if that may help, being that your car is likely mechanical injection?

Thanks

Yes it is Bosch mechanical injection. Where are you based?

P

[Gus 5]

you need a 731 head. it is from a 320 as well (pre or post facelift models) which is a bit more common, shouldnt be hard to find one

if you get really desparate, i have a 200 head that you could use..however the ports are mighty small compared to the 731 and 325i 885 heads. but it would work

[kiwipetrolhead 1]

you need a 731 head. it is from a 320 as well (pre or post facelift models) which is a bit more common, shouldnt be hard to find one

if you get really desparate, i have a 200 head that you could use..however the ports are mighty small compared to the 731 and 325i 885 heads. but it would work

Thanks Gus. I don't mind if I don't any performance gain (although that would be nice), but of course I certainly don't want to go backwards. How can I tell what the cracked head is, is there some identification on it somewhere?

P

[Gus 5]

on the intake side, around the middle is a part number, im talking about the last 3 digits

[kiwipetrolhead 1]

on the intake side, around the middle is a part number, im talking about the last 3 digits

Excellent, thanks. It's a 200 (full #: 1 264 200).

P

[Gus 5]

really? must be a really early one i suppose

a 731 head would be a nice upgrade.

can you post pics up of the intake ports?

PM me if you want my spare head. if you do, i wouldnt mind your cracked one (dont need any valves etc, just want to use for porting practice)

[conrod 1]

Pretty sure a new head (bare) from BMW is around $1500, but as Gus says, pretty easy to find second hand- just have to make sure they aren't cracked as well! I am helping my friend put his 2.7 race motor back together on Saturday, I'll have a look at what casting they used on that, it was a brand new head, and quite sure it was a 320i casting (although ports were cleaned up a bit) This engine made 250hp with loads or torque from 3-7000rpm, and we have just dropped the CR as it was a bit high, so will be able to put more timing in, which will give it some more power.

[kiwipetrolhead 1]

really? must be a really early one i suppose

a 731 head would be a nice upgrade.

can you post pics up of the intake ports?

PM me if you want my spare head. if you do, i wouldnt mind your cracked one (dont need any valves etc, just want to use for porting practice)

Yip, it is the early body style, in top condition too. When I say it's an '83, the plate under the bonnet says "Built Oct 82".

So a 731 will do the job without any hitches? If so, I will go searching. But yip, I'll have your head if I have no luck getting a 731, or if I hear that other work is required to make it work properly. BTW, how much do you want for it?

I'll take some photos of the intake ports for you tomorrow - too dark outside now (it's in the boot of my Renault Fuego which is in the car park here at work).

I guess you can have the cracked one for practicing your porting.

"PM" - Private (or Personal) Message?

Thnx

P

Pretty sure a new head (bare) from BMW is around $1500, but as Gus says, pretty easy to find second hand- just have to make sure they aren't cracked as well! I am helping my friend put his 2.7 race motor back together on Saturday, I'll have a look at what casting they used on that, it was a brand new head, and quite sure it was a 320i casting (although ports were cleaned up a bit) This engine made 250hp with loads or torque from 3-7000rpm, and we have just dropped the CR as it was a bit high, so will be able to put more timing in, which will give it some more power.

Wow, sounds like lots of fun.

$1,500 is probably a bit steep though, like you say...for a car of this age and value.

P

(envious)

[Gus 5]

i cant see the 731 head being a problem at all. however dont have much experience with the v early m20's. 323's are normally 731 headed...they must have been 200 in the very first which 82 is. i imagine it would perform a lot better! looking at the size of the ports on the 200 i have it should do.

PM is just personal [email protected] does well too

$150 or so is fine..just need to sort out some sort of shipping it down to ya

[CaM 0]

Thanks

Yes it is Bosch mechanical injection. Where are you based?

P

Feilding.

was off a tired e28, killed by the old rust no doubt. alledgedly the guy had not long spent a few pennies on getting this one sorted, and put on his smokey old bottom end (original head died the same death as yours). He reckons there's a water gallery which has benn added by a reputable engine builder, which is often not on the head, but is present on the block, creating a hotspot right in the middle, which could be the reason these ones crack. Will try and find out over the next day or two, I'm pretty sure I saw the car atop a stack of wrecks at the dump when I was getting rid of a parts car around a month ago, he may have salvaged the head though!

Another option, aside from gus' head, should you need it.

will post back here. Wont get word until sunday at the earliest I shouldn't think

[kiwipetrolhead 1]

Feilding.

was off a tired e28, killed by the old rust no doubt. alledgedly the guy had not long spent a few pennies on getting this one sorted, and put on his smokey old bottom end (original head died the same death as yours). He reckons there's a water gallery which has benn added by a reputable engine builder, which is often not on the head, but is present on the block, creating a hotspot right in the middle, which could be the reason these ones crack. Will try and find out over the next day or two, I'm pretty sure I saw the car atop a stack of wrecks at the dump when I was getting rid of a parts car around a month ago, he may have salvaged the head though!

Another option, aside from gus' head, should you need it.

will post back here. Wont get word until sunday at the earliest I shouldn't think

Thanks CaM. Sunday is fine - in fact, you can call me at work on Monday if you like - 356-9099x2445. I assume this one is a 731 head too?

Cheers

Paul

i cant see the 731 head being a problem at all. however dont have much experience with the v early m20's. 323's are normally 731 headed...they must have been 200 in the very first which 82 is. i imagine it would perform a lot better! looking at the size of the ports on the 200 i have it should do.

PM is just personal [email protected] does well too

$150 or so is fine..just need to sort out some sort of shipping it down to ya

Thanks Gus. I'll wait and see what CaM can come up with - being close by and all. If the head he's talking about is available and with the added water gallery, that sounds like the way to go. The Engine Builders tell me these heads do have a strong tendency to crack. When I took it in to him (still assembled) he asked if it was cracked. I said, "No, not that I know of... no symptoms at least." But low and behold, it was.

I'll pop out and take that photo for you this morning.

P

[CaM 0]

I assume this one is a 731 head too?

I can't be too sure. Wiill definitely find out on sunday for you, so long as the guy is home.

I shouldn't imagine he'll want silly money for it, will try and get ahold of it for aorund the same money as gus is offering. the guy's reasonably switched on to parts values at times, although not in it to tuck people!

Will contact you asap

[kiwipetrolhead 1]

I can't be too sure. Wiill definitely find out on sunday for you, so long as the guy is home.

I shouldn't imagine he'll want silly money for it, will try and get ahold of it for aorund the same money as gus is offering. the guy's reasonably switched on to parts values at times, although not in it to tuck people!

Will contact you asap

OK, great, thanks.

[kiwipetrolhead 1]

i cant see the 731 head being a problem at all. however dont have much experience with the v early m20's. 323's are normally 731 headed...they must have been 200 in the very first which 82 is. i imagine it would perform a lot better! looking at the size of the ports on the 200 i have it should do.

PM is just personal [email protected] does well too

$150 or so is fine..just need to sort out some sort of shipping it down to ya

Hi Gus,

Here's one 600x450res pic for you - intake is about 32mm dia at right angle to the part where the injector sits. I'll email you direct with a larger version of this (not too big tho, unless you want big photos) plus 3 more photos so you can get a good idea of the ports and so on.

P

[kiwipetrolhead 1]

BTW guys, I've been told from elsewhere this morning that the intake manifold would need porting out to match a 731 head with it's bigger intake ports. The intake manifold cannot be changed to match because of the different injection system. Makes sense. Otherwise, no other issues.

P

[Gus 5]

the manifold stuff makes sense..could prob run without it though, or get hold of a pre FL 320/323 manifold from one that had a 731 head (if indeed they did..they might all have had 200 heads..although im sure the 323s had 731..could be wrong however)

up to you! intake ports are tiny! defo the same as my one..let me know what ya want to do

[Palazzo 477]

Hey Gus, you are thinking E21, not E30? According to the 2.7 build sticky, the ports are considerably larger on the 731 vs 200 head, which they say is effectively the same as the head on the 525e. Maybe a 525e head would be a relatively easy find from someone who'd pulled apart a 2.7 for other uses. . . .

[kiwipetrolhead 1]

Hey Gus,

I will buy your 200 head for $150 if that is OK.

Thanks

Paul