Hitchcocks Forum

When fitting the composite head gasket, would best practice be to use a light smearing of Wellseal or not? (Joint faces are excellent, with a 20 thou gasket gap). What you reckon? Thanks.

Barry, don't know which one you've got but if you look in the Accessory Catalogue under cylinder head the gasket listed there seems to be ok without sealant.
REgards, Mark

If the head is torqued down correctly and the mating surfaces between the head and barrel are flat and parallel, then you should not need any sealant on the head gasket. None of my bikes have any including my Commando with its Combat engine.

2nd what Mark said. Friend of mine who owns my previous Bullet, fitted comp gasket, no sealant and no leak. Makes it a lot esier to take the head off next time. cheers Trevor

Hi Guys--------- If your gasket is thicker than that 0.020" then yes, as per the guys above. Have just done a top-end re-build this winter (Classic 500) using one of our hosts American Composite Head gaskets fitted DRY and am pleased to report that no probs. at all during the various club rides so far this year. Also -- am still on STD. gearing so have been v. careful not to over rev. especially when chasing a fast "Wolf" on a well set-up BeesA single (My late Uncle was a keen B33 rider in his day !). However would tend to use the Wellseal with a Copper gasket-- if only because of the pushrod tunnels tendancy to leak given half a chance.

Thanks Gents. I'm not a great lover of jointing compound where it's not neeeded, so agree with your views. A very thin smear around the dreaded push rod holes would have been my only consideration. Couldn't imagine any harm doing that as a "belt and braces" though?

I have just done a 1943 Gaz 67b cylinder head and 2001 500 Bullet cyclinder head. On the Gaz it said don't use sealant, because there was already a sealant compound on the gasket and any added stuff might break it down. I did use hermetite type sealant (the red stuff) on the composite Bullet gasket and torqued down to the right figure.

I hear other views, but my C A E BOOKER manual does say "smear with jointing compound" for the 1943 WDCO and copper gasket.

GAZ 67b - not a motor bike I'm afraid - see my web site at: http://www.gaz67b.1trewithen.co.uk/index.htm