Head gasket question--535i with M30 motor

[Dash01]

Should the holes for coolant in the head gasket match the holes in the head and block?

The replacement HG sold to me has much smaller and round holes than the corresponding triangular ones on the head and block on the intake side.

On the exhaust side, the HG holes are round and offset, with relatively little overlap of the rectangular holes in the head and block.

Is this proper, or did they sell me the wrong HG?

I'll try and post pics later this evening.

[Martin in Bellevue]

This has been discussed before. The restricted coolant holes keep the coolant volume in the head. This is a good thing, as the head is more evenly temperature regulated. The holes on the exhaust side are for oil return to the pan. You can leave the headgasket uncut for installation.

As an aside, check the old headgasket between cylinders 5 & 6. I caught my headgasket before it let go, in a pre-emptive headgasket replacement with new valve guides & a mild cam regrind. There was significant decay between 5 & 6 on the old head gasket.

[Dash01]

http://i34.photobucket.com/albums/d149/Lbrown01/P1011084.jpg
This shows headgasket vs. block on intake side. Holes are much smaller on HG.


http://i34.photobucket.com/albums/d149/Lbrown01/P1011082.jpg
HG laid in position over head.


http://i34.photobucket.com/albums/d149/Lbrown01/P1011080.jpg
HG vs. head on exhaust side of block.


SO, IS THIS THE PROPER HEAD GASKET FOR THE M30 BLOCK, OR DID THEY SELL ME THE WRONG ONE?

[genphreak]

This has been discussed before. The restricted coolant holes keep the coolant volume in the head. This is a good thing, as the head is more evenly temperature regulated. The holes on the exhaust side are for oil return to the pan. You can leave the headgasket uncut for installation.

As an aside, check the old headgasket between cylinders 5 & 6. I caught my headgasket before it let go, in a pre-emptive headgasket replacement with new valve guides & a mild cam regrind. There was significant decay between 5 & 6 on the old head gasket.How were your coolant holes at the very bac of the block? I think these are the most at risk from blocking with any cludge.

If you can, post some good pics of the block surface before you put your HG on, you could get some very salient advice :)

[genphreak]

WRONG WRONG WRONG. Gasket is all wrong dude.

Geee- pics were posted fast! I wrote a reply and then they were there!

Nice looking head though- who did such a great job on that? Is it new??? Engine is in nice nic too!

Need a decent pic of the head surface (no gasket) and coolant galleries though. Just a nice one for the archives would be good if you can...

[Mr Project]

WRONG WRONG WRONG. Gasket is all wrong dude.


You sure? I think it looks a lot like the one I did on my M30. Couple years ago, though, my memory could be a little fuzzy.

[genphreak]

You sure? I think it looks a lot like the one I did on my M30. Couple years ago, though, my memory could be a little fuzzy.Check out the last pic, the galleries above the exhaust manifolds. I am sure mine was open. Unless it's round the wrong way in that pic, but I don't think it is. Might check my own pics to be sure... hang on

[genphreak]

Check out the last pic, the galleries above the exhaust manifolds. I am sure mine was open. Unless it's round the wrong way in that pic, but I don't think it is. Might check my own pics to be sure... hang onYes it is wrong. But it's confusing-even the right one seemed wrong, in that it seemed to have the wrong sized holes.

Here is a pic of the right one;
http://evansweb.info/files/_images_articles_20030120222157117_1.jpg

[Blitzkrieg Bob]

On the exhaust side, the HG holes are round and offset, with relatively little overlap of the rectangular holes in the head and block.



That's what it looks like. Swiss cheese is cheaper to cut than a full gallery profile

[Dave M]

Great catch guys. I guess this is what the board is for :)

Dave M

[genphreak]

Great catch guys. I guess this is what the board is for :)

Dave MHeh, thanks Dave: We'll teach them 'auto parts ******** artistes' not ot mess with the e34 crew! LOL

It's a right royal PITA getting the wrong part supplied. I try to collect my own part numbers and cross check what I get given- it really helps to avoid trouble. Suppliers don't mind if you can ask why they proffer a different item intelligently- after all they also hate getting parts back :)

Bob, swiss cheese? :D Maybe the gasket was for soemthing else entirely but they got rats in the storeroom.

[Dash01]

I've been told that the round gasket openings (on the exhaust side at the bottom of the third picture) are simply holes for the oil to return to the pan, sorta like a rain gutter. If so, it would not matter much (if any) whether the oil gravity-flows down down via round holes or rectangular. If the oil lingers, it absorbs and disperses more heat?

What troubled me most was the small round holes at the top of the first picture, which have a cross-section only a small fraction the size of the corresponding holes on the head.

The seller was sent these pics and captions last night, and this evening he responded that this gasket kit by Victor Reinz is the same cutout design as one made by Elring, and that it is correct for my M30 engine in a '90 BMW 535i.

My machinist did not inspect this gasket, but says that over the years it was learnt that the original stock flow through engine heads needed to be restricted somewhat, perhaps for better heat absorption, hence the smaller holes in more recent gaskets. He also showed me other heads (non-BMW, af various origin) and blocks in his shop, where the metal holes did not match in shape or size, ostensibly for the same reduced-flow reasons. Who'da thunk?

I'm no expert here, so hope to hear from those who are. Thanks very much for all of your insight and suggestions before I button this engine up.

[aston_jag_tech]

Hey Dash, how did you get that crank nut off?????

[bill g]

What you have been told about the reason for the small holes is generally correct. I am holding a Goetze (German made) M30 head gasket in my hand - the small holes are there just the same.
I have read technical articles about where people have enlarged those holes because they think they look ridiculously small, but that is the wrong thing to do.
It is also correct that the large holes near edge on exhaust side are oil drain back holes - on this gasket they are combined into large roughly rectangular shaped openings. I installed the same gasket on my engine 12 months ago - OK so far.
My old gasket was leaking between no. 6 cyl and the water passage on the exhaust side, a common location for failure on these engines. The slight leak caused the cooling system to be over-pressurised and use a small amount of coolant.

Bill G

[genphreak]

...It is also correct that the large holes near edge on exhaust side are oil drain back holes - on this gasket they are combined into large roughly rectangular shaped openings. I installed the same gasket on my engine 12 months ago - OK so far. My old gasket was leaking between no. 6 cyl and the water passage on the exhaust side, a common location for failure on these engines. The slight leak caused the cooling system to be over-pressurised and use a small amount of coolant. Bill GThat sounds feasible to me... but I think I'd check with BMW or the gasket manufacturer first. I can't see how the smaller holes (in the gallery areas at the lower side) in the new gasket would be dangerous, its not like that much oil would be pumped up there to need larger cavities to return back than what is provided by the new gasket... but I am no expert. I just can't see a reason for making it do this unless it was a documented change done by BMW. If others know better- (heat absorption is certainly an interesting theory), this is good. This is an issue we need to know about. Maybe an email to the gasket manufacturer would be a sensible thing to do before installing the gasket all the same, but regardless, at least an email should be sent so you can let us all know if it is right or wrong. :) Nick

[DanH]

My old M30 gasket and new gasket both had holes like the ones Dash posted. It was manufactured by Elring and came with my M30 upper engine gasket kit. I do not think there is anything wrong with it.

My old one blew between cyl 6 and the exhaust side coolant passage also as Bill G's did. Must be the weakest point in this design.