Gasket question

MikeG

MikeG

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Should I use any kind of sealant on a new properly annealed copper gasket? For the record its on a BSA A10 rocker box, an area that I have never been able seal for very long. Lots of torsional stress the e due to the top engine mount.
 
A really old trick for sealing copper head gaskets is to put a silk thread around the surface surrounding the push rod tunnels. Glue it down with gasket sealer.
 
Mike, is there any place where we can add either dowel pins, or taper pins? That would take away the shaking-like-a-whore-in-church action of the head steady on the box.
 
MikeG said:
Should I use any kind of sealant on a new properly annealed copper gasket? For the record its on a BSA A10 rocker box, an area that I have never been able seal for very long. Lots of torsional stress the e due to the top engine mount.
Click to expand...
If you search you will find work that Jim Schmidt (@jseng1 ) did on finding the best compound for copper head gaskets - the winner was Pliobond (didn't cook hard) plus using a loop of 0.005" copper wire around pushrod tunnels and rear oil drain, similar to what @ILLF8ED suggested but a little more specific.
Cheers
 
robs ss said:
If you search you will find work that Jim Schmidt (@jseng1 ) did on finding the best compound for copper head gaskets - the winner was Pliobond (didn't cook hard) plus using a loop of 0.005" copper wire around pushrod tunnels and rear oil drain, similar to what @ILLF8ED suggested but a little more specific.
Cheers
Click to expand...
I think that the OP was trying to seal the rocker box to head joint with a copper gasket. The narrow mating faces would probably prevent the use of copper wire, but Pliobond on the gasket looks like a good suggestion.
 
oldschool said:
I think that the OP was trying to seal the rocker box to head joint with a copper gasket. The narrow mating faces would probably prevent the use of copper wire, but Pliobond on the gasket looks like a good suggestion.
Click to expand...
Sorry - I thought head gasket. 👍 👍
 
concours said:
Mike, is there any place where we can add either dowel pins, or taper pins? That would take away the shaking-like-a-whore-in-church action of the head steady on the box.
Click to expand...
I want to re-engineer the upper mount to incorporate something like a shock absorber bushing. Sealing flanges are far too thin for any type of pin.
 
MikeG said:
I want to re-engineer the upper mount to incorporate something like a shock absorber bushing. Sealing flanges are far too thin for any type of pin.
Click to expand...
I would council strongly against that. Much knowledge gleened from a Beezer chopper custom head steady evolution.

JMWO
 
Where is your oil leak? I have been trying to stop a rocker box Leak on my A10 since I built it in around 1986 !!!!
Mine leaks at left side exhaust valve area of the box
Drives me mad ,I hate oil leaks and I've tried allsorts to stop it
It currently has an SRM Composit gasket and that has made it a bit better
I have tried a rocker cover breather etc etc
 
baz said:
Where is your oil leak? I have been trying to stop a rocker box Leak on my A10 since I built it in around 1986 !!!!
Mine leaks at left side exhaust valve area of the box
Drives me mad ,I hate oil leaks and I've tried allsorts to stop it
It currently has an SRM Composit gasket and that has made it a bit better
I have tried a rocker cover breather etc etc
Click to expand...
I had a quick search around for composition gaskets for this post and came up will nil...
A friend of mine used anneal the copper gasket ..then thinly evenly coat it in a hi temp silicone and once it was full cured fit and torque it done as usual...it actually worked...for how long I'm not sure..but it was certainly oil tight a few months after he did the job...actually he was a ex Army Engineer ....
 
KiwiShane said:
I had a quick search around for composition gaskets for this post and came up will nil...
A friend of mine used anneal the copper gasket ..then thinly evenly coat it in a hi temp silicone and once it was full cured fit and torque it done as usual...it actually worked...for how long I'm not sure..but it was certainly oil tight a few months after he did the job...actually he was a ex Army Engineer ....
Click to expand...
Generally the rocker box base gaskets available are rubbish and don't fit well
I've not tried the copper ones as yet
But may do in the near future
 
baz said:
Generally the rocker box base gaskets available are rubbish and don't fit well
I've not tried the copper ones as yet
But may do in the near future
Click to expand...
Oh so it needs some glue :)
Sorry I was stuck on head gaskets..lol
My Army mate had a 920 and had the weep issue from the front of the head
 
Gasket question
Gasket question

Fretting of gasket caused by the top motor mount working on the joint?
 
MikeG said:
Fretting of gasket caused by the top motor mount working on the joint?
Click to expand...
Yes probably, but also the design (as on a Triumph) means the valve springs are acting against the joint too.

If you think about the pressure on those springs, and the amount of reciprocal movement at decent rpm, there’s potential for a lot of stress and fretting.

That’s why copper gaskets are good in this application.

But you need to be careful, I fitted some to a Triumph once, the pushrod holes weren’t quite right and the copper rubbed on the pushrod, it made such a horrid noise, like it was haunted / possessed :eek:
 
My solution to the ridged top engine mount. Maybe now it won't fret the gaskets quite as much? Almost an isolastic mount.
 

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