M20 head gasket

[tee]

Took apart miniblobs 2.7 today and as suspected the head gasket has gone between cyl 3+4. It is a long time since I had a M20 apart, does this look like a BMW gasket? There are some no.s on it and I am trying to find out the thickness of the gasket so I can put the correct one back in, as the block has been decked.









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[Templ8e30]

Doesn't look genuine to me, genuine Elring gaskets have red seals around the oilways (those are black) and have 2.5/2.7 on the little tab that has FM 498 on that one.

I'd suggest having the head re-faced before refitting it, the block could do with an inspection to make sure it's not damaged between the bores.

Cheers,

Iain T

[tee]

Didnt think it was. Any ideas on manufacture as I need to find the thickness really. Block and head look good on first inspection. Will be cleaning up and inspecting properly tomorrow.

[tee]

Anyone see this head gasket before?

[oguz327]

Doesn't look genuine to me, genuine Elring gaskets have red seals around the oilways (those are black) and have 2.5/2.7 on the little tab that has FM 498 on that one.

I'd suggest having the head re-faced before refitting it, the block could do with an inspection to make sure it's not damaged between the bores.

Cheers,

Iain T

OT that BTB looks naughty with the heat wraps on

[miniblob]

Tee, i've dropped ian (tvrtasmin, guy i bought the car from!) another email to see if he has contact details for the engineering firm he used to deck the block, as he said they supplied the gasket for him!!

Also, anyone know anything about copper gaskets?? Worth using on a n/a everyday car?? Did i make it up, or do people use them (mostly on turbo cars iirc!!)??

[Simon13]

Thats a bad gasket failure! um is the head ok though?!

i'm no help but i spy some high comp pistons

is the thickness of the gasket of alot of importance? silly question i know but?!

[miniblob]

They are indeed high comp pistons!!!!

Apparently the thickness makes a lot of difference, but only going on what i've heard!!!! I know nothing!!!

[miniblob]

Also, anyone know anything about copper gaskets?? Worth using on a n/a everyday car?? Did i make it up, or do people use them (mostly on turbo cars iirc!!)??

Don't worry, answered my own question!!!
http://www.ferriday.co.uk/copper/copper.shtml

[stonesie]

There should be a tab somwhere on the gasket with a number of notches in it, the number of notches equates to the gasket thickness


Other than that get a micrometer and measure the thickness of the fire rings..... it could be an AJUSA gasket from memory but not 100% on that, FAI have red silicone (again IIRC....... most head gaskets i have done recently have been MLS gaskets)

[stuartgallafant]

that'll be why there was no compression on 3 and 4 then tee!!!

[miniblob]

Tee, you have pm......

Ian replied to me, and is his reply included: should be able to work out the required gasket thickness by taking measurements from the block and head and comparing them to the standard specifications, or by working out the compression ratio with the required tools.

Anyone know how to work out the required gasket thickness (anyone know the standard specs?), or the compression ratio?????

[stuartgallafant]

should be fun doing that!!!

[miniblob]

You sound like your looking forward to it Stu!!!!!

[stuartgallafant]

damnit!!!

[cliffybabe]

[tee]

your ok rob. Checked the block and head, all ok. Think we should go for the thickest h/gasket to be on the safe side.

[Speedtouch]

What do you reckon caused it to blow - been caning it alot?

[Barnz]

Didnt think it was. Any ideas on manufacture as I need to find the thickness really. Block and head look good on first inspection. Will be cleaning up and inspecting properly tomorrow.

Tee
Dont know if this helps but gasket manufacturers numbers for M20 are:

Elring - 694.011 Std (1.75) or 567.818 (oversize 2.05mm)
Reinz - 61-27035-30 Std or 61-27035-20 (o/s)
Ajusa - 10032500 (1.9mm)
Goetze - 30-025354-30 (std) or 30-025384-30 (o/s)
Payen - BL680

Hope this helps

[miniblob]

your ok rob. Checked the block and head, all ok. Think we should go for the thickest h/gasket to be on the safe side.

Ok mate, do it!!!

If it seems to lose any power, we'll do it again another time with a slightly thinner gasket maybe

[tee]

Didnt think it was. Any ideas on manufacture as I need to find the thickness really. Block and head look good on first inspection. Will be cleaning up and inspecting properly tomorrow.

Tee
Dont know if this helps but gasket manufacturers numbers for M20 are:

Elring - 694.011 Std (1.75) or 567.818 (oversize 2.05mm)
Reinz - 61-27035-30 Std or 61-27035-20 (o/s)
Ajusa - 10032500 (1.9mm)
Goetze - 30-025354-30 (std) or 30-025384-30 (o/s)
Payen - BL680

Hope this helps

Cheers for that barnz, does not really tell me much about this gasket but will be usefull in the future.

[tee]

What do you reckon caused it to blow - been caning it alot?

Poor quality h/gasket and Rob's driving style........ rev limiter?? what rev limiter?

[tee]

your ok rob. Checked the block and head, all ok. Think we should go for the thickest h/gasket to be on the safe side.

Ok mate, do it!!!

If it seems to lose any power, we'll do it again another time with a slightly thinner gasket maybe

Rob.... you a fookin nightmare!

[miniblob]

Ha ha, not my fault i've got such a big right foot!!!!!!

Yeah, wasn't aware of over revving it at any point, but i didn't know there was no limiter on it - so i suppose i could've got over excited at some point

Only drove it for a week!!

[Templ8e30]

Doesn't look genuine to me, genuine Elring gaskets have red seals around the oilways (those are black) and have 2.5/2.7 on the little tab that has FM 498 on that one.

I'd suggest having the head re-faced before refitting it, the block could do with an inspection to make sure it's not damaged between the bores.

Cheers,

Iain T

OT that BTB looks naughty with the heat wraps on

She's a beasty alright

Cheers,

Iain T

[e30_Turbo]

Lennies blew in the same place, can't remember what he put it down too tho. Too much too soon, just like me.

I'd also say that the gasket looks like a oem one, having been through a few myself latley

Elring looked good although the firing rings were pressed in, didn't like 21psi tho ended up with a oem one which just looked the best, one piece firing rings and a metal mesh pressed into the gasket itself, felt heavier also and obvioulsy plenty more money

The thickness of the head gasket will effect the compression ratio and it's quite suprising how little a change can effect the C/R overall.

[miniblob]

Found some american website that reckoned it was almost common for them to blow between 3 & 4!!!!!

Weak spot maybe?? Don't see how.

Guess i just have a heavy right foot!!!!

[adamS]

What symptoms did the car have before you pulled it to bits?

Thats a nasty crack!

[Speedtouch]

Can't you get solid copper head gaskets any more, rather than the laminated sandwich type?

[miniblob]

What symptoms did the car have before you pulled it to bits?

Thats a nasty crack!

None!! One minute, all was spot on. Next minute, cruising on the m'way, it just lost power - and that was it!!


Not sure about the copper gaskets - read a bit on them and thought maybe a bit extreme at the mo. If it goes again and i can't find a reason for it, i might consider one!!

[Andy335Touring]

Was it pinking at all ?

I'm sure i had some pinking on mine when i used full throttle in 5th from 80mph to 100mph ?

But mine does need mapping really because i've upped the C/R and not touched the ignition map

[miniblob]

Nope, no pinking at all - until the gasket suddenly 'went'!!!!! Quite strange i thought!!

[JaMMi]

What do the heat wraps do? I can hazard a guess but a decent explanation would help alot Haven't put my 6 branch on yet ysee (Old style) -- pm might be easier (rather than hijack) cos i may not see this one again!

PS - Fingers crossed the fixing goes well ;)

[tee]

Engine should be back together on wednesday Rob, so we can start to arrange getting the next E30 over!!

[miniblob]

Coolio

I'll give you a bell!!!!!!

I've filled the car with parts and i'm writing you a list

JaMMi - i presume you were reading my other thread in the tech section?? There's more of an explanation on there, but basically, keeps the heat in the manifold/exhaust - hotter gasses flow better/faster. Also reduces the underbonnet temp so your intake may benefit from cooler air.