Cylinder base plate seal

RUSHTON · Post by **RUSHTON** » Tue Feb 15, 2011 5:01 pm

On my 350 G3L I Am refitting the cylinder compression plate to the crankcase and the gasket set I have has only one paper seal. When I removed the compression plate there were jointing seals on both sides.
The manual says take paper seal and to smear jointing compound on one side only and fit to crankcase.
This would leave the cylinder and compression plate without an oil tight seal surely?
What is the recommended method?
I would have been inclined to make another seal and put seals on both sides of the compression plate.
Any help would be appreciated. RR

itma · Post by **itma** » Tue Feb 15, 2011 5:38 pm

recommended method is the factory advice surely?

but then again I always wipe each side of both gaskets with wellseal.
If I feeling righteous I just use grease.

wilko · Post by **wilko** » Tue Feb 15, 2011 8:43 pm

Why not throw the plate and get rid of that sidevalve power!

legg · Post by **legg** » Tue Feb 15, 2011 10:52 pm

I can remember putting a gasket on both sides of the compression plate when I owned a '51 G80. Didn't realise (at the time) that you could leave the plate out!

wilko · Post by **wilko** » Tue Feb 15, 2011 11:10 pm

All that power you're missing out of! It does make a difference.

iandusud · Post by **iandusud** » Wed Feb 16, 2011 7:10 am

Don't remove the compression plate if there is the slightest ridge at the top of the barrel. Also as there was a gasket on either side of the plate when you dismantled it you should reassemble it with two gaskets for the above reason. If however you've got no lip whatsoever then I would follow Wilco's advice, assuming the plate is not particularly thick and that the bottom end is in good condition.

Ian

MikeM. · Post by **MikeM.** » Wed Feb 16, 2011 10:53 am

Should you decide to remove thebase plate you will also have to take into account the pushrod tube rubber gaskets on the top of the tubes.
These will need to be shortened by the same thickness of the plate (approximately 1/16" I think) otherwise the tops of the tube will collapse inwards due to the rubber gaskets being over compressed.

RUSHTON · Post by **RUSHTON** » Wed Feb 16, 2011 12:11 pm

Thanks for all your advice fellas:-
I know you can leave the plate out, but I am not inclined to do that, even though there is no bore wear. The manual is explicit in what parts to remove if you leave out the plate. So I have decided to make another paper seal and let Hylomar take care of the leaks - being new to working on motorcycle engines I just wanted to see if in the light of 68 years since it was made there have been any advances on what the 1941 manual says - apparently not!!