true or false

robs ss said:
I use copper - anneal every time.
Definitely good for sealing washers. Head gaskets? Can't hurt!
BTW - I found out several years ago that it does not matter if you slow cool or quench copper. Unlike steel, which has carbon that can be trapped at grain boundaries by quenching, with copper it does not matter.
Cheers

Edit: copper can, in the extreme, work harden to the extent it will shatter like glass (I have seen it!) - hence, I will always anneal.
Click to expand...
Hot quenching copper will remove the oxidization though.

I found the thread I mentioned earlier. It was started by you Rob. Did you ever go further with it?

robs ss

Thread 'Head Gasket Trimming Idea'

I noticed an article in the April edition of Real Classic on head gaskets (pp 106 - 108).
The gist suggested was to trim the gasket to leave behind only "essential" areas, hence maximising contact pressure in these critical areas - not completely unlike, in effect, Jim Schmidt's idea of glueing 0.005" wire to both sides of the gasket.
The picture below shows before and after shots of a Royal Enfield Super Meteor gasket.
Has anyone tried this with Norton twins copper head gaskets?
If so - any comments on results?
Cheers
Rob
Head Gasket Trimming Idea
 
I have always gone with solid copper, annealed, silk thread around the drain and pushrod areas with Wellseal. Mostly because it was Received
Wisdom. Solid gasket, being less likely to blow out completely, is the real
reason.
I also wear a small bag of cloves around my neck to ward off low oil pressure.
 
I would anneal a copper head gasket, and I would not machine a cylinder head to get more compression. As for balance factor, a rigidly mounted Triumph 650 engine will rev to 8000 RPM smoothly and reliably with a balance factor of 80% and E3134 race cams. A standard Commando cam is similar. When I rebalanced my 850 motor, I screwed a steel plug into the balancing hole which had been bored into the flywheel counterweight. the factor came out at 72% - which is enough. If I race the revs always stay between 5,500RPM and 7,300 RPM and the rigidly mounted motor runs extremely smoothly. When the motor idles, the whole bike moves backwards and forwards, until the motor is revved. It is a really lovely feeling. If I start my motor, I always have the urge to immediately get on the bike and go. I haven't started it for a long time now. But I am about to reassemble the drive train and start it at home. I will probably be booked for riding the bike up my front street. I know I have a sickness - motorcycle road racing is a vice worse than gambling.
 
jseng1 said:
Here's the test results of head gasket sealers.

https://jsmotorsport.com/sealant-comparison/
Click to expand...

Very interesting but it would be helpful to talk about the expected temperatures of at least Norton heads, the application method (cover one side, cover both sides, just around tunnels, around the 5/16" studs. etc.) and how the testing was done.

Also, AN recommends this for sealing the 5/16" front studs: https://andover-norton.co.uk/en/shop-details-2/18674 Have you tested it? I also hear using it covering the copper head gasket on both sides. Any thoughts on that?
 
I have two total head gasket failures on Nortons since 1974! Actually, both in the '70s. Both composite gaskets.

Several times I have stripped a Norton motor for whatever reason, but not blowing head gasket, to find evidence of gas escaping across the copper gasket face.

I do heat the gaskets before fitting, but find it hard to achieve cherry red with a home blowtorch. I don't know if this is effective annealing, but like Jim says, it certainly is effective at cleaning them up.

My crank was balanced high 70s, with JSM extra long rods and pistons. I think it is smooth at high rpm. High rpm is 6000 to whatever it runs to. I don't care what it does under 4000, I don't ride to the shops or cruise....
 
cliffa said:
Hot quenching copper will remove the oxidization though.

I found the thread I mentioned earlier. It was started by you Rob. Did you ever go further with it?

robs ss

Thread 'Head Gasket Trimming Idea'

I noticed an article in the April edition of Real Classic on head gaskets (pp 106 - 108).
The gist suggested was to trim the gasket to leave behind only "essential" areas, hence maximising contact pressure in these critical areas - not completely unlike, in effect, Jim Schmidt's idea of glueing 0.005" wire to both sides of the gasket.
The picture below shows before and after shots of a Royal Enfield Super Meteor gasket.
Has anyone tried this with Norton twins copper head gaskets?
If so - any comments on results?
Cheers
Rob
Head Gasket Trimming Idea
Click to expand...
No Cliffa - It is in my pile of unfinished projects. One day! :rolleyes:
 
marshg246 said:
Very interesting but it would be helpful to talk about the expected temperatures of at least Norton heads, the application method (cover one side, cover both sides, just around tunnels, around the 5/16" studs. etc.) and how the testing was done.

Also, AN recommends this for sealing the 5/16" front studs: https://andover-norton.co.uk/en/shop-details-2/18674 Have you tested it? I also hear using it covering the copper head gasket on both sides. Any thoughts on that?
Click to expand...
Testing was done using a laser temp reader with each sealer applied and allowed to dry on bare alum. The pliobond is fool proof if it bonds to each metal surface. So a thin coat on head, cylinders and each side of the copper gasket. I also use .005" copper wire around the pushrods and oil return hole with the ends crossed. The thin wire crushes into the copper head gasket (not the head). Any excess glue just squishes out flat so you don't need to be neat. You also need loctite on the 5/16" stud into the cylinders (I also use alum washers). I went through all this when I had a peristant oil leak. With the fiberglass reinforced silicone gaskets and oversized O rings the bike stays oil tight year after year.

Head temp is usually about 275 or so normal riding, a little more at freeway speed. Up to 325 after a hard run. 375 and more with extended idling.

Silicon didn't prevent the HG from leaking in hot Calif temps of 100+ deg

Wierd thing is that Ron Wood told me about Pliobond back in the mid 1980s. I don't know how he figured it out. Turns out to be the best I've found - especially when things overheat in hot climates.
 
jseng1 said:
Testing was done using a laser temp reader with each sealer applied and allowed to dry on bare alum. The pliobond is fool proof if it bonds to each metal surface. So a thin coat on head, cylinders and each side of the copper gasket. I also use .005" copper wire around the pushrods and oil return hole with the ends crossed. The thin wire crushes into the copper head gasket (not the head). Any excess glue just squishes out flat so you don't need to be neat. You also need loctite on the 5/16" stud into the cylinders (I also use alum washers). I went through all this when I had a peristant oil leak. With the fiberglass reinforced silicone gaskets and oversized O rings the bike stays oil tight year after year.

Head temp is usually about 275 or so normal riding, a little more at freeway speed. Up to 325 after a hard run. 375 and more with extended idling.

Silicon didn't prevent the HG from leaking in hot Calif temps of 100+ deg

Wierd thing is that Ron Wood told me about Pliobond back in the mid 1980s. I don't know how he figured it out. Turns out to be the best I've found - especially when things overheat in hot climates.
Click to expand...
Definitely not saying your wrong but it seems weird to me to coat everything with glue to keep a copper head gasket from leaking! Makes me wonder if you could do the same except forget the head gasket!

How hard is it to get a head off after doing that?

BTW, slightly off topic, but I believe I've learned that the "re-torque composite head gaskets after x miles" is wrong. Heat cycles may have something to do with it, but I think time means a lot more. Build an engine, don't get around to finishing the bike for a few months, and check the head torque - loose!
 
I've not done it, yet. Others have said that they use a gas grill to heat the copperhead gaskets.
 
marshg246 said:
Definitely not saying your wrong but it seems weird to me to coat everything with glue to keep a copper head gasket from leaking! Makes me wonder if you could do the same except forget the head gasket!

How hard is it to get a head off after doing that?

BTW, slightly off topic, but I believe I've learned that the "re-torque composite head gaskets after x miles" is wrong. Heat cycles may have something to do with it, but I think time means a lot more. Build an engine, don't get around to finishing the bike for a few months, and check the head torque - loose!
Click to expand...
You want the pliobond to bond to the metal - not just be applied to the gasket and then pressed against the metal head and cylinders etc. I do offer a .003" thick head gasket ring and you use only the .005" wire around the pushrod tunnels and oil return. No I havent' tried pliobond only without anything else. Thats one more experiment waiting to happen.

My head came loose no problem when I checked it but if its reluctant you can always tap upward on the exhaust nut with a wooden block and hammer. Kicking it over with the bolts loose should also work (ignition off).
 
franko said:
I've not done it, yet. Others have said that they use a gas grill to heat the copperhead gaskets.
Click to expand...
I'd be surprised if a gas grill got it hot enough. I've put it on my kitchen gas range's big burner which means that the fire actually touches it and they don't get hot enough - just a light pink. So, I do a combination of the range and also a propane torch section by section and that works well.
 
I used the Pliobond once. It certainly works. But I found it harder to remove the head than I was comfortable with. Maybe I used too much.

I settled on Wellseal after that, and I'm content with it.
 
SteveA said:
I used the Pliobond once. It certainly works. But I found it harder to remove the head than I was comfortable with. Maybe I used too much.

I settled on Wellseal after that, and I'm content with it.
Click to expand...
Mine came off easy with the pliobond. I only heard of a couple plus yourself who had to tap them with the woodblock & hammer or kick it over with the bolts loosened. Well seal may work for some but I'm not sure its enough in hot weather.

Another method I used in racing is shown below. This was before I used Pliobond and nothing was keeping my head from leaking with composite or copper gaskets no matter what I did - until I used the groove and copper wire only. The wire would crush and need retorquing but once settled it was done. I was also looking for max compression.

true or false


This was in the monoshock frame with the first experimental lightweight Wiseso pistons as shown below (1985). One fin cut off the shortened cylinders.

true or false
 
Last edited:
I have never had the problem of a head gasket leaking. However I have not ever machined material off the mating face of a cylinder head, or used bolts which were not original equipment and might stretch more when tensioned. One of the things which causes problems is heat. A bike which runs on petrol gets hotter than a bike which is run on methanol. I would not glue the head gasket - heat causes reactive chemical compounds to cure stronger. The contact faces of the head and barrel are quite large in area.
 
Pliobond definitely works. Requires the patience of a monk scribe to apply. I had to use a wood block to get the head off. It was a little scary, but I didn't break off any fins. In addition, it is very difficult to mix Pliobond in a squeeze tube so that it has the proper application consistency. I know Pliobond is good stuff and I respect your opinion and experience Jim but before I would use it again, I would try copper coat spray and save myself a lot of frustration during application and head removal. If I was building a very high compression engine with a bunch of very expensive parts, I would probably try it again though, because it holds things in place really well.

Getting back to aftermarket alloy cylinder with iron liners that sit a little above the deck... Has anyone taken two .020 copper gaskets and cut one to fit around the liner, fit it, then pliobonded the other gasket uncut over the top of the first one? Probably end up with a .041 thickness gasket. I figure it might actually work or blow out between the two gaskets like butter in a stack of pancakes.
 
Oh Yeah - I just remembered another repeated saying that slipped my mind - bringing down the compression will reduce vibration. I've never found anything to reduce vibration but lower reciprocating weight.
 

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