Bubbles dahling

[Convert]

Well, finally found the reason for my cooling system pressurisation, got bubbles in the expansion tank, and a sniff test confirms combustion gas.

So, what do we reckon, tin or composite gaskets?

If composite, which brand?

Also how much do heads need skimming to maintain compression ratio?

The engine (350i) has done around 70k, and runs very well. No oil in coolant or vice versa.

Is it worth changing the cam / followers whilst it's stripped down?

If so what cam for a little more 'oomph'

Finally, what would the going rates be for a specialist to do the work?

[pk500]

I done my boys 350 it had a few burnt valves I used Payne gaskets and composite head gasket get the heads pressure tested with all valves out and a skim

[Convert]

Cheers Paul

[pk500]

Convert said:

Cheers Paul

he has been to wedge fest and Boston and drives like it stolen and it's been great

[Number 7]

Elring composite head gaskets. If its the original cam, worth changing, with lifters and timing chain set. Not sure about cam choice - when I did my 350 15 years+ ago used an RC87, but they're no longer available. I reckon you would get charged around £1K for that lot.

[Convert]

Again, cheers Paul (s)

What about headbolts, I don't think that they're stretch bolts so they can be reused ?

[pk500]

Convert said:

Again, cheers Paul (s)

What about headbolts, I don't think that they're stretch bolts so they can be reused ?

Headbolt and re use

[adam quantrill]

+1 for Elring, the 400SX eat up a couple of composites before I found these, now nice and sweet - no coolant loss.

If they can put up with atmospheric + 50% compressed and ignited, then they'll be bulletproof in a normally aspirated engine.

Also I used ARP studs, the main (big) set only, and left off the extra row, probably not strictly necessary to use them and some people find them a pain in the arris. But they, too, can be re-used.

Head skimming is probably a waste of time unless they are very badly twisted - the bolts pull them true anyways. But yes - if you want to match the CR take off the difference in thickness, and the cam preload will be maintained better too.

Edited by adam quantrill on Wednesday 22 February 21:26

[Convert]

Cheers Adam, I reckon the Elring are the way to go, but sounds like I can reuse the bolts.

[adam quantrill]

Yeah - reused mine on the 350i, no problems there. Just get them in a jar of petrol as soon as you pull them out, and wire brush the crud off but keep them in the petrol.

Also go round the whole lot 1/4 turn max to crack open before proceeding to extract.

[TVRleigh_BBWR]

another vote for Elring, not worth using anything cheaper, as your loose in the long run with all the labour if you need to do them again

[adam quantrill]

Actually, you'll be hard pressed to find anything cheaper anyways:

1 x Head Gasket 3.9/4.0/4.2/4.6 10 Bolt Head (Elring) ERR7217G LVB500030G (LVB500030G) = £7.50

from Island 4x4.

You probably want a different part number for a 350 though - smaller bores.

Also order some pushrods at the same time - 4 off Britpart ones for 4 quid - in case you have any a little bent.