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Old 02-10-2016, 11:05 AM   #31
Peterbuilt84
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Here are some pics of what I have.

E21 Block



E21 Head





E21 Injector Hole



E30 Warped Head





Stole this pic but this is what the E30 pistons look like

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Old 02-10-2016, 01:04 PM   #32
TobyB
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Ok, the E30 piston has me confused.

The E21 engine's the later 1.8, and those domes are what I've found in every 1.8i engine
I've opened up.

But what was in the E30 doesn't look familiar at all. And it doesn't look right for the
1.8i head, although it's been a long time since I looked at one carefully.

Huh.

Thanks for the pic! Could you post one of both heads' combustion chambers?

t
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Old 02-10-2016, 02:20 PM   #33
Peterbuilt84
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Here's some pics of the combustion chambers.

E21





E30





Blocked Coolant Passage






Also what is everyone's opinion on getting the head worked on? I called and talked to a local machine shop and he quoted me $6-700 to get the head done, which is almost what I paid for the car. He said it would be cheaper if I took the cam out, etc.
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Old 02-10-2016, 02:40 PM   #34
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You will likely need valve guide seals at a minimum or it will smoke on start-up and when you decelerate. It is a little tricky getting the cam out the first or second time (don't throw it up on a bench and bend the open valves BTW)!

There is a way to get a rough idea if the valves are still seating, but beware - I am not sure if alcohol could wreck your valve guide seals if it gets on there. Get a couple of screwdrivers and prop the head up to protect the valves. Pour a little alcohol into a port associated with a closed valve. If it pours right out, you have a dirty valve/seat at best. Continue process by turning the cam over and checking each valve.

If the valves are not sealing, there is not much use in putting the head back on. The 1.8 is a strong runner, but with only 100 HP roughly, it needs full compression.

What about Bimmerheads - I would check out their site to see if they do the M10

Oh - Yes, the non-circular dome pistons did come in some E30 1.8 engines - I am betting the car or engine is a later production car. Either piston will work with that head. I think the circular domes result in better compression.

Last edited by packratbimmer; 02-10-2016 at 02:47 PM. Reason: I screwed up
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Old 02-11-2016, 07:36 AM   #35
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those confusing pistons. I had a set of those. I think they came in my 85 engine I got from London Ontario. the domed ones I have found in my original 84 and also in an 80 320i engine.
I wound up blowing up and broking those odd pistons. (one anyway)
im sure the domed ones are higher compression
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Old 02-11-2016, 10:42 AM   #36
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Was looking at your pics again on the bad head. Looks like a crack from the blocked coolant passage over to the valve.
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Old 02-11-2016, 09:29 PM   #37
Peterbuilt84
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Quote:
Originally Posted by packratbimmer View Post
Was looking at your pics again on the bad head. Looks like a crack from the blocked coolant passage over to the valve.
Good catch. Didn't even notice. Considering how warped it was I'm not surprised.


So started browsing cl today and might have gotten lucky. Found someone selling a rebuilt E21 M10 head for $150. Guy said he bought it and never ended up using it. Here are some pics.








Should I be worried it's disassembled? I would still have to plug the injection holes but was going to do that either way. So should I jump on it?
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Old 02-12-2016, 03:26 AM   #38
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does he have the parts to reassemle? are they new?

if he did a valve grind. and it looks good (no cracks) sure. but I am thinking 150 canadian dollars.
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Old 02-12-2016, 08:04 AM   #39
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Looks like the exhaust studs were not removed when it was resurfaced. A red flag concerning any other work done on the head. I would proceed cautiously.
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Old 02-12-2016, 08:29 AM   #40
Peterbuilt84
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does he have the parts to reassemle? are they new?

if he did a valve grind. and it looks good (no cracks) sure. but I am thinking 150 canadian dollars.
He said he has the parts. They aren't new though. Thought crossed my mind to put a new cam in but not sure how much that costs.

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Looks like the exhaust studs were not removed when it was resurfaced. A red flag concerning any other work done on the head. I would proceed cautiously.
How can you tell? I only saw the intake side in the pics. When I talked to the guy he didn't seem to know much about it. He had it for a project and ended up not using it and it's just been sitting. Hopefully getting more pics today.
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Old 02-12-2016, 08:56 AM   #41
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Looks like the bottom set of exhaust manifold studs got "kissed" when it was resurfaced. I would need to see a closer pic though to confirm. In order to start out with a flat surface, the bottom studs need to be removed.

It is probably OK - Maybe???

I am just saying that I would question the machinist's other work like resurfacing the valves and getting the seals in properly.

BTW - How does the cam look in your good engine?

Also, look at the rockers on the head that is for purchase. If the rockers are heavily pitted/galled, the valve train would be nosy and hard to adjust. An additional thing to look at is whether there is cupping/pitting on the tops of the valve stems.
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Old 02-12-2016, 10:40 AM   #42
Peterbuilt84
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Thanks for the info! I really don't know much and this is all very helpful!

Here are some more pics I was sent.








Here is the pic of the cam form the good engine. I can get better ones too.

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Old 02-12-2016, 01:35 PM   #43
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When I take a head apart, I keep all of the rockers in order so that it can go back together the way it has worn-in the last 1,23$,#@!,%^ miles (yes, that is well over a trillion). I would roll the dice and use the head that came with your new engine before messing with another one. It looks pretty clean (yours).

Looks like some light rust on your cam lobe there. Clean those up with a scotchbrite pad and some clean oil, then inspect them. If they look pretty good, that is a good indicator of the overall condition of the head.

If you wing it and put it back together, use some engine assembly lube on the cam lobes. Redline or Lubro-Moly come to mind>
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Old 02-12-2016, 03:23 PM   #44
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Originally Posted by packratbimmer View Post
When I take a head apart, I keep all of the rockers in order so that it can go back together the way it has worn-in the last 1,23$,#@!,%^ miles (yes, that is well over a trillion). I would roll the dice and use the head that came with your new engine before messing with another one. It looks pretty clean (yours).

Looks like some light rust on your cam lobe there. Clean those up with a scotchbrite pad and some clean oil, then inspect them. If they look pretty good, that is a good indicator of the overall condition of the head.

If you wing it and put it back together, use some engine assembly lube on the cam lobes. Redline or Lubro-Moly come to mind>
When I took mine to the local machine shop that is what the machinist told me I had to do, number all the rockers, etc. so that it matches back up. He also mentioned the head was in decent shape and by his estimate had about 180k miles.

Thanks for the advice. I was thinking the craigslist head could save me some time but it might be nice to have the peace of mind knowing I did it myself.
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Old 02-12-2016, 10:31 PM   #45
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Yes- thanks for those pix.

At a certain point, you just have to trust your machinist.

I WOULD get him to pressure test it- there is some corrosion, and I had one
once that had a 'porosity' inside- it leaked water into a head bolt sleeve...

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