true or false

I keep hearing people repeating what I myself used to believe but have found it just to be repeated opinion.

You should anneal a copper head gasket - yes it softens but doesn't seal any better. Copper Commando head gaskets do not crush AT ALL when torqued down (measure one yourself). It does make sense if you want to heat a used one red hot to clean it.

Higher balance factors are smoother at higher RPM - I tried various balance factors and higher balance factors shake less vertically and shake more horizontally - the opposite is true with lower balance factors. The ideal compromise is somewhere in the mid 60s wet. A 65% wet balance factor comes out to 72% dry. A solid frame twin balanced to 80% still shakes horribly at high RPM (with heavy stock pistons).

Is there a right answer?

There is more to making an engine run smoothly at high RPM than the crank and pistons. That said using the long rods light weight pistons and a lighter weight crank and clutch makes for a Norton engine that accelerates extremely well and doesn't feel like it will fly apart at high RPM. Question is what's high RPM?

For some reason this subject makes me think about something Hotbot said. Ms Peal or whatever he called his Norton would do 90mph in 2nd gear. That has got to be high RPM and possibly a steaming pile of BS.

Yeah I don't think copper head gaskets compress.

I use too anneal all my copper head gaskets but the last time I removed my head (a very long time ago) and forgot to anneal my new copper head gasket and remembered after torquing it all down so left it alone, well that was over 15 years ago now and have only retorqued the head once at 500 miles and a few years ago when a slight seepage started (2 large head bolts were lose), so far the un annealed copper head gasket hasn't leaked, 15+ years (been that long can't remember when I did it lol).
As for balance factor when I converted my 850 motor to the Featherbed frame back in 198/82 and hard mount engine plates, my crank was balanced at 72%, I wasn't there when the old English gentleman done it, but my Commando/Featherbed is smooth as but at some points of the rev range it does get some vibration but only in 2 spots of the rev range and for only a few second when revving through those 2 points, it always smooths back out past those 2 spots, my motor is leaned forward same as the Commando, I did the conversion from 1980 to 82 and had been an everyday ride till 2013 when I brought a new Triumph Thruxton, but the Norton is ridden regularly and is my hotrod and fun bike.
If it was bad with vibrations I would have sold it a long time ago but it's not, its a very comfortable bike and can be ridden all day and has done many of long travels and nothing shake off it and exhaust flanges stay tight without any mods to the flanges.
My motor is built for the Featherbed running a 2S cam profile, major port work, still running the original valves, bigger carb jets and 40thu oversize Hepilite flat top pistons that had very tight final hone to bore to piston clearance when done as well the crank balance at 72% and a stock 19 tooth drive sprocket.
This set up has worked well for me and I was lucky I was put on to a crank balancer who knew what he was doing and knew all about what I was wanting to do with my Commando/Featherbed set up, this was all done over 44+ years ago now and is still going strong.

Ashley

Schwany said:

For some reason this subject makes me think about something Hotbot said. Ms Peal or whatever he called his Norton would do 90mph in 2nd gear. That has got to be high RPM and possibly a steaming pile of BS.

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"possibly"?

Oh, my...

unless he only had second gear, used it for "1st", and fourth gear used as "2nd", then, yes.

Schwany said:

Is there a right answer?

There is more to making an engine run smoothly at high RPM than the crank and pistons. That said using the long rods light weight pistons and a lighter weight crank and clutch makes for a Norton engine that accelerates extremely well and doesn't feel like it will fly apart at high RPM. Question is what's high RPM?

For some reason this subject makes me think about something Hotbot said. Ms Peal or whatever he called his Norton would do 90mph in 2nd gear. That has got to be high RPM and possibly a steaming pile of BS.

Yeah I don't think copper head gaskets compress.

Click to expand...

My original stock 74 850 Commando use to valve bounce at 6500 RPM and not rev any further, but after building my motor for the Featherbed frame with the work I done my motor will rev freely past 8000 RPMs but would you let it go that far is another thing, you wouldn't hold it on those high RPMs for very long unless I like to blow holes through my cases, my motor is a fast revving motor that will run very freely but I do know its limits and how far to push it, my days of flogging my Norton are over, but it's good to know it's there when needed, I still ride my Norton hard but I do know when to back off as well, I have never blown any of my motors up in 50+ years of riding hard, you learn just how far you can go with your own motors and when to back off and these days I have nothing to prove to no one.
How fast will my Norton or any of my bikes go, who cares, how fast is it on the 1/4 miles, who cares, I just enjoy riding my hotrod Norton and get me up in the tight twisties is where I have my fun, for an old bike it's still shows up a lot of others in the twisties for what it was built for.

Ashley

Old men talking shit. Gimme a break..

lazyeye6 said:

Old men talking shit. Gimme a break..

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Arm or leg?

jseng1 said:

I keep hearing people repeating what I myself used to believe but have found it just to be repeated opinion.

You should anneal a copper head gasket - yes it softens but doesn't seal any better. Copper Commando head gaskets do not crush AT ALL when torqued down (measure one yourself). It does make sense if you want to heat a used one red hot to clean it.

Click to expand...

Here's what I don't understand. I've always used copper head gaskets on Triumphs and BSA and they were always annealed before I got them. I've never re-torqued and they have never leaked. When I started using them on Commandos, they leaked. I talked to AN about them and they said that they were not annealed before sale. OK, the next few I annealed, and they still leaked. Then I read something at AN talking about sealer on copper head gaskets - that was the end of me using them for me on Commandos. They still are all I use on Triumph and BSA but I do check to see if they are soft before installing and they normally are.

So, more insight please! I would rather use copper head gaskets on Commandos, but it's a PITA to switch them out for composite when they leak! Of course, re-torquing is a PITA for composite!

marshg246 said:

Here's what I don't understand. I've always used copper head gaskets on Triumphs and BSA and they were always annealed before I got them. I've never re-torqued and they have never leaked. When I started using them on Commandos, they leaked. I talked to AN about them and they said that they were not annealed before sale. OK, the next few I annealed, and they still leaked. Then I read something at AN talking about sealer on copper head gaskets - that was the end of me using them for me on Commandos. They still are all I use on Triumph and BSA but I do check to see if they are soft before installing and they normally are.

So, more insight please! I would rather use copper head gaskets on Commandos, but it's a PITA to switch them out for composite when they leak! Of course, re-torquing is a PITA for composite!

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When you used them on Commandos was the head and barrel resurfaced or not?

seattle##gs said:

When you used them on Commandos was the head and barrel resurfaced or not?

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Last time, head yes, barrel no.

Schwany said:

this subject makes me think about something Hotbot said. Ms Peal or whatever he called his Norton would do 90mph in 2nd gear. That has got to be high RPM and possibly a steaming pile of BS.

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It’s feasible.

A 23 tooth sprocket at 8,000rpm = 91.4mph.

On Triumph twins all the copper head gasket is doing is sealing the head gasket joint. And most of (the late ones at least) barrels have a groove machined around the bore to allow the gasket to deform into the groove slightly and help sealing.

On Nortons the head gasket is also expected to perform an oil tight seal around the oil return hole and the pushrod tunnels.

It’s the tunnel sealing that’s the biggest issue for oil leaks IMO. The bolts around it do not look well placed for maximum clamping to me (total layman’s observation) and I believe the composite gasket performs better in this aspect.

On the last two engines I’ve built with the leak prone combo of copper gaskets and alloy barrels, I used sealant around the pushrod tunnels. Wellseal on one, high temp silicone on t’other. Both are oil tight so far. Both had the gasket annealed.

On Maney barrels the liner protrudes very slightly above the barrel face, this is deliberate and is intended to ensure a good head gasket seal. I believe that annealing the gaskets to ensure they’re soft IS beneficial in this case as it helps the protruding liner bite into the gasket fully.

All only IMHO of course.

I thought the purpose of annealing was to make it more pliable so that it follows any slight deviations?
I read an interesting article once where a guy with (I think) a Square 4 was suffering repeated blowing copper head gaskets. He eventually trimmed the gasket so that there was quite a lot less surface area, and the problem was resolved. I think I remember @ludwig saying he does the same on his Commando. I’ll see if I can find the post.

Annealing does make the copper softer so it complies more easily to imperfections, but a used gasket put back into the same place with the same mating surfaces will have already shaped itself to that placement. I would always reanneal though and not leave it to chance it would work unannealed.

Excuse my ignorance on this but I would like to know what is the advantage of using a copper head gasket over a composite? I have always used the composite with my shaved head and went through the ritual of re-torque during the first 2,000 miles along with waist cut head bolts. I do check the torque about every 6,000 miles and never had one that was loose.What am I missing?
Thanks,
Mike

It's a pity that multi layer steel head gaskets aren't available for Norton twins. I've used them on several triples & they don't leak. Having said that, they aren't sealing the pushrod tunnels in that application.

YING said:

Excuse my ignorance on this but I would like to know what is the advantage of using a copper head gasket over a composite? I have always used the composite with my shaved head and went through the ritual of re-torque during the first 2,000 miles along with waist cut head bolts. I do check the torque about every 6,000 miles and never had one that was loose.What am I missing?
Thanks,
Mike

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There’s a few benefits / reasons folk use copper head gaskets, but they’re not important to everyone:

1) More stable thickness, helpful if trying to set an accurate squish band gap, ascertain CR, etc.
2) Available in various thicknesses, further aiding fine tuning of the above.
3) Whilst they may leak oil easier than composite, they’ll still function when compromised whereas a composite will be far more liable to blow out completely, rendering you stranded.
4) No (or at least much less) faffing around with the re torquing procedure.
5) Composite is not available for 920 / 1007 motors. So kinda makes the debate a moot point for those folks !


Benefits for composite head gaskets include:

1) Better sealing around the oil return and pushrod tunnels.
2) Less heat transfer from head to barrel (in theory at least, I’ve no idea how realistic this is).

Had one composite gasket blow out on a triumph head, long 4Km push home. Copper gasket on that ever since with no issues/leaks but 2 re-torque cycles. Did not anneal. BSA gaskets have the same pushrod sealing duties as Norton heads, but they don't seem to have the same issues with leaking there. They also have an o-ring arrangement at the oil drain holes up front, where they are prone to leak, but I used x-rings here and it's been all good with no re-torque yet. On the 750 I'm now building I plan to open up the oil drain hole in the gasket and use a x-ring there, it would be interesting to see if a similar solution can be devised for the pushrod tunnels

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.

To keep copper head gaskets from leaking use Pliobond high temp contact cement and .005" thin copper wire around the pushrod tunnels and oil drain return. Problem solved.

Comstock is the one who clued me in to annealing being pointless. He has a post about that somewhere in this forum. Annealed copper does not conform to the high and low imperfictions - measure it accurately and you will see. I too used to believe in annealing till I read Comstocks post and made accurate measurments.

If you reshape a copper Commando head gasket so it is very thin then you may be able to get it to crush here and there - but then you risk deforming the head as can happen with a composite head gasket.

I have Maney cylinders with the protruding liners and they always leaked around the pushrod tunnles until I used the pliobond and fine .005" copper wire.

Composite gaskets can fail over time. I've experienced it.