Silicone rocker cover gaskets

robs ss said:

ahem! ... with Yorkshire accent...

"Cardboard? You could afford cardboard? Luxury... luxury!, You tell young people that these days and they won't believe you!"

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I pulled a Norton motor down once and timing cover you could still see the cornflakes box print on one side of the gasket lol, but after 10 years it was leaking and was done by the original owner, never the person asking me to fix a few oil leaks. or people who over use silicone on gaskets and wonder why they have a oil supply problem, some rough nuts around but hey I done a few bodge jobs just to get back home but never on the Norton, honestly.

Ash

I have used K&W Copper Kote on paper and fiber gaskets for many years. Always the brush on variety not the spray. Never hardens and the rocker box covers are easily removed without damaging the OEM style gaskets which can be recoated and reused without leaks.

On a ride just recently, I lost a front tappet cover along with the studs and all. For that reason, I would not use a silicone gasket as mentioned in an earlier replay, you cant tighten them too much or they will bulge out. This was the first time I had a problem. Previously, and now, I don't have a problem with the original gaskets, done up correctly.

ashman said:

I pulled a Norton motor down once and timing cover you could still see the cornflakes box print on one side of the gasket lol, but after 10 years it was leaking and was done by the original owner, never the person asking me to fix a few oil leaks. or people who over use silicone on gaskets and wonder why they have a oil supply problem, some rough nuts around but hey I done a few bodge jobs just to get back home but never on the Norton, honestly.

Ash

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Was part of the pit crew of a 7R AJS at the IOM Manx two years ago. The motor had been assembled by a name builder but some person had changed out the magneto and taken off several covers and spread black RTV everywhere. I recomended to the owner the motor be stripped but he decided no.

Lasted 1.5 laps of practice and stopped with a seized big end. Stripping of the motor revealed the big end feed, cam feed and piston cooling feed all blocked with RTV.

You can use it. But carefully. I only use it on chaincases really where it can't do any damage. Hi temp rtv on Norton exhaust rings is brilliant.

I use JSs gaskets on my Commando. The whole motor and gearbox don't leak a drop..Only leak is from the swinging arm.

RTV is good for bathrooms and laundries

Fast Eddie said:

A shotgun cartridge isn’t likely to have quite the same effect is it ?!

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You mean the old waxed paper ones?

For those who haven't noticed my previous post - the JS fiberglass reinforced silicone gaskets can be tightened down the same as paper gaskets. But Silicone gaskets without the fiberglass reinforcement cannot. See the image. If you can't see the white threads on the edges of the gaskets then they don't have the fiberglass reinforcement. To my knowledge I am the only one offering these.

Not to be the wet rag dropped on the top of an unfinished recently sanded wooden table, but JS fiberglass reinforced rocker spindle cover gaskets do squeeze out some and show a frilly edge when tightened down so they do not leak on my 750 engine. However unlike silicon gaskets without the fiberglass reinforcement they do not split, fall apart, or slide around. I reuse the heck out of them, which could be why they look like they do. That and there is oil pressure behind that rocker spindle cover. JS valve/rocker cover gaskets don't need to be torqued down as much as paper gaskets to stay dry.

Example...


Don't get me wrong. I like the JS gaskets. I know I have a funny way of showing it.

jseng1 said:

Schwany Yours must be super tight. I haven't done that. Mine are years old, normal tight and look like this:

I recommend aluminum washers throughout. See them on my rocker cover.
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Well maybe, but they have been off and back on several times which might contribute to the frilly edges situation. Not a big deal to me. The rocker spindle covers leak a little if not as tight as they are. Like I said they have been off and back on many times. I'm using your rocker spindle covers washers and bolts. The gaskets looked better when I used them the first time, but they have been on and off and compressed more than 10 times. If I bought new gaskets and never took the rocker spindle covers off again, I'm sure they would look as good as they ever do regardless of who tightened them up. I don't believe I have ever use washers under the valve cover crown nuts. The crown nuts are not super tight, since the covers tend to warp if the nuts are real tight. Learned that the hard way over 50 years ago. The valve cover gaskets don't have the frilly edges, but the fiberglass reinforcement makes the surface look a little bumpy at the angle the camera was at when I took the pic.

There is one more improvement I could make with the fiberglass reinforced silicone gaskets. Presently the silicone is 70 hard (common hardness). But 90 hardness is available in unreinforced silicone on special order. I've asked for reinforced silicone in 90 hardness but haven't been able to get it yet. I'll keep trying.

Even if I felt like I needed "better" gaskets, the appearance of installed silicone gaskets in the pics convinces me never to buy them!

With the red colour silicone gaskets makes it easier to see if they are leaking lol, but I been running them for years now and have had no problems at all, but then its been a long time since I adjusted my valves, I know when they need doing.

jseng1 said:

There is one more improvement I could make with the fiberglass reinforced silicone gaskets. Presently the silicone is 70 hard (common hardness). But 90 hardness is available in unreinforced silicone on special order. I've asked for reinforced silicone in 90 hardness but haven't been able to get it yet. I'll keep trying.

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They work with the fiberglass reinforcement thickness and hardness you are using. Might as well stick with what works.

I just wanted to show an extreme reuse situation. Multiple cams, and multiple lash setting tests means the covers come off many times. Plus I was fooling around with the rocker spindles and covers more than typical Norton motorcycle owners would. Can't help myself when I get an idea that probably in the end won't make a butterfly fart of a difference in how the engine works.