Hitchcocks Forum

Hi

Is anybody successfully running their Bullet without a head gasket?

I was considering lapping the head to the barrell and then using Wellseal.

Tom

Can't see why you would want to.

If you lap the head to the barell and then put a liquid gasket into that joint you will have compromised the joint's integrity, I would have thought ??? Surely a well annealed thin copper gasket with Welseal around the pushrod holes is a lot less hassle ??

I've heard of it being done successfully but I used a homemade .5mm solid copper gasket rather than go the whole hog. I would suggest that you take care not to raise the compression too high as the heads on these machines are not a modern design and they will pink like a bugger if they get too high. I'm ok on 95 octane fuel with the 8:1 piston and the .5 gasket on my 350. Not sure what the viable maximum for a 500 is. On the same topic I'd be really interested to hear how The Bullet Whisperer got on with his squish band heads?

If you can talk to someone with an Ariel Red Hunter with the cylinder head off, you will see how it fits with no gasket or sealant. Just has to be lapped-in lightly with a bit of valve grinding paste; it is a metal-to- metal seal.

John M

ERRR To raise the compression possibly?

Hi

Thanks. Yes I reckon 8.5:1 is quite attainable without a base or head gasket using 8:1 piston.. this would be a useful increase in power to enhance the performance cams.. at 8.5:1 it shouldn't pink much as most modern vehicles are higher comp than this and the awful fuel deals with it OK,. Pinking can be overcome with an accelerator pump carb like a Del-Orto.

Cheers

Tom

I have the head off my sixty5 at mo, due to oil leak from gasket. I had bought a 0.5mm gasket to replace the 1mm one fitted. However, when I checked the height of the barrel spigot, and the head recess, the spigot was about 0.5 higher than the recess, which meant the thinner gasket would probably not be clamped enough. When I put the head on the barrel it sat on top of the spigot with a gap round the gasket face.
So it's back to the 1mm gasket.
It's worth checking the difference between the spigot and recess, as they can be different between bikes.

Ray.

Nettshubby... that would be cured by lapping the head onto the spigot or a bit of milling untill the mating faces meet..

Hi octane fuel will only do so much. Modern combustion chambers tend to have a Squish Band which is a flatish conical beginning to the combustion chamber before it starts to get spherical. This is to stop pre ignition. I saw on The Bullet Whisperer's Facebook page that he was altering a Bullet head to have one. I am keen to know if it was a success or not.