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A new cylinder head is £180 but i must resist and keep it original.
- Thread starter Welderpaul
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brightspark
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skimmed and crack tested sorts that
mike os
just a little insane.....
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Think you will get that for 180? (OK chance the replacement is also goosed)skimmed and crack tested sorts that
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Thank you for your assistance chaps, I'll get it off to be ground next week and take it from there.
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Head pressure tested ok and skimmed.
I've cleaned up the original combustion caps and have two options for gaskets. I have copper seals which i will look to anneal to be on the safe side, and the gasket pack came with fibre gaskets for the combustion caps. Which am i best using to seal it once and for all?
I'm tempted to use Hylotight blue as i've never had a leak with this before but i don't know if it would stand the heat of combustion.
Even the chap at the engine rebuild place said trying to get combustion caps to seal is always a nightmare.
Thoughts o wise ones?
I've cleaned up the original combustion caps and have two options for gaskets. I have copper seals which i will look to anneal to be on the safe side, and the gasket pack came with fibre gaskets for the combustion caps. Which am i best using to seal it once and for all?
I'm tempted to use Hylotight blue as i've never had a leak with this before but i don't know if it would stand the heat of combustion.
Even the chap at the engine rebuild place said trying to get combustion caps to seal is always a nightmare.
Thoughts o wise ones?
Last edited:
8ob
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As I mentioned before Paul some of the P3.P4 and P6 engines use a copper sealing ring like this https://www.ebay.co.uk/itm/38400699...55-0&campid=5338722076&customid=&toolid=10050
If the caps are a loose fit in the head it will be using the copper rings and the fibre gaskets (if at all) , if the combustion caps are a tight fit in the head as in need tapping in they will use the copper gasket, if the copper gasket is not compressing it definitely needs the copper rings.
Bob
If the caps are a loose fit in the head it will be using the copper rings and the fibre gaskets (if at all) , if the combustion caps are a tight fit in the head as in need tapping in they will use the copper gasket, if the copper gasket is not compressing it definitely needs the copper rings.
Bob
Brad93
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Perkins P4 Seal Washer Joint Combustion Chamber Cap 0490115 Original 1957 Part | eBay
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Gareth J
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Have had those sealing nightmares on those pre-combustion chamber caps myself. The fibre ones were the last used and did seal. Wouldn't like to say if it were luck or that fibre beats copper though.
brightspark
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the fibre may compact better than solid copper even if its been anealed . high compression racing engine head gaskets run on fibre copper ones not solid copper
Gareth J
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the fibre may compact better than solid copper even if its been anealed . high compression racing engine head gaskets run on fibre copper ones not solid copper
Possibly more tolerant of differential heating rates too, which I suspect come in to play here.
plewlandsbob
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Too late now, but maybe getting rebuild place , to take a light skim.off the side of , the head, would have given you a flat face too deal against.
You could lap the caps to the ports, with grinding paste, just like grinding the valves.
You could lap the caps to the ports, with grinding paste, just like grinding the valves.
brightspark
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a fibre copper gasket would take up any minor consistency
Ubique
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I'd be inclined to use rings rather than the flat gasket, the seal is only needed around the periphery of the boss that projects into the head. If you have a large area of copper, the torque is spread over it, reducing the overall pressure so there is a chance that a pressure seal won't be made effectively. using a smaller but thicker ring (providing the mating surfaces are clean and smooth) will give you a more effective seal as the pressure will be on the gasket where the seal needs to be made, there is no point having a large flat gasket that has all the pressure disippated over it, it only takes one small high (or low) spot, speck of contaminant or dirty thread for the seal to be breached. What I would do, is cut the centre of the copper gasket out, slightly larger than the thicker sealing ring to give you a limit on each side to prevent the cap being torqued down too much on one side, it will also indicate if the cap is level by virtue of no gaps.
