Hitchcocks Forum

Hi Folks

Still working on Rusty, my 350 Superstar. I've recently bought one of Mine Host's ally barrels and I'm getting to the fitting stage. I trial fitted the head (suitably breathed on by BW - thanks again Paul!) on top of the barrel off the engine and am a little concerned about the gasket space, which seems a bit too thick. Without the gasket, there's about 0.050" gap, and the gasket (composite type) measures about 0.045". Should I get something like 0.020" machined off the top of the barrel spigot to ensure there's sufficient room to compress the gasket?

Thanks, Stephen

I would say you will have to get it reduced, the only other alternative is to use 2 gaskets, not a good idea!
I had a similar problem, though not as bad on my Sixty5, I put a 0.5mm copper gasket in and it leaked oil. When I checked the gap as you did it was near as damnit 0.5mm, so wasn`t clamping the gasket enough. I replaced it with a 1mm copper gasket and sealant and no more leaks.

Thanks for that, skimmed a small amount off the spigot to allow for about .010" compression of the gasket. Nice gasket-goo seepage after torquing the head down this afternoon.

Stephen

Hi Stephen, can I ask what gasket goo do you use for the head gasket?

Thanks

Hi Lennie, I use Hylomar Blue but understand this will probably prompt a flurry of responses saying something else is better! I've used 'Blue' for several years as it is robust, is easy to use and stays flexible. I probably put on more than is recommended, then scrape off any 'ooze' a couple of days later when it doesn't stick to my screwdriver as much!

Stephen

I have now lost count of the damaged engines I have seen where people have used excessive amounts of silicon type sealant which not only squeezes out of the joint on the outside but also squeezes inside it eventually falls off and blocks an oilway.use it very sparingly.

I am a bit surprised that people are using sealant on a head gasket at all, (especially because of the oilway blocking problem.) Make sure everything is scrupulously clean and flat, check nothing is fouling, torque up in several stages and check after 500 miles.

(I have in the distant past assembled a 250cc Villiers engine with no gaskets at all with any subsequent problems.)

Our hosts recommend sealant when using copper gaskets. I used it on my Sixty5 because I got a weep from the pushrod tunnel area of the head. I have found on my past Bullets that the head face especially is not always dead flat. The composite gaskets I suppose are able to "form" to the uneven face better without sealant. I intend to fit a 535 alloy barrel conversion when I get the cash together, and I will skim a couple of thou of the head face to make sure it's flat!