no head gasket

I have a grubee GT-2B 48CC.
Replaced head gasket with pop can as gasket material.
I also run the SBP expansion chamber and a home made boost bottle.
Custom made my 36t sprocket.
All in all i run 35 / 40 mph all day long.
Many miles and it still runs good.
Most of the time I run 2 oz octane booster per tank.
Either NOS offroad or Lucas.
I'm thinking i will be changing my bearings to higher quality tougher rated ones.
No head gasket got me as much boost as the expansion chamber.
But high octane runs better.

NO HEAD GASKET 2 THUMBS UP

Are you saying the squish is non existant because its a dome head with a very wide combustion chamber, or because the squish has a very tight clearence?


Also are you talking center fire head or the slant head?

I guarantee your bike will run better on regular unleaded do not put octain booster in your fuel. think about it? 6:1 comp!

Do it up right and buy new gaskets, they are cheap. To verify to have a bad base or head gasket, with the engine running spray some quick start around base and head. do not let it breath into the carb. If the rpm's change you have a leak.

ok...allot of drag cars will run with no head gasket...the machining tolorances on these are VERY small...sorry but how much did this motor cost???i garruntee you the tolorances are way more...your local machine shop probably cant make these tolorances and if they can you would probably be better off buying ten motors and chancing that there might be a combo that would work(probably still wouldnt find one)...dude all any gasket does is fill these little gaps...thats why they exist...dont try silicone...wont work for very long...tried and true metal,paper,cork,rubber...all have there place and all are according to heat and materials in contact with them...put a headgasket in there for the love of god

agreed very thin copper sheet sheer it to rough it and mini die grinder clean it up case match it done 1/2 hr copper sheet comes in all thicknesses i put little dowel pins in when i case matched mine and it will help to keep cylinder from walking if it trys its just a peave i have LOL!!! peace

Mine does 45 MPH. I got a 34 tooth MANIC MECHANIC rear sprocket assy. Where I got my biggest gains was when I put on a 18mm Mikuni and a straight intake from Jim at MANIC MECHANIC..but when you use a 18mm Mikuni you have to open up the intake hole on the straight intake manifold..It's way to small to get optimal power out of a bigger carb..I have other performance mods too....It isn't easy to get to 40+ MPH...MPH NOT KPH

Definately run with a head gasket and a pure copper one is the best - go to a hobby store or a card making craft store and buy a piece of sheet copper there it is cheap and thin enough you can use a hobby knife to cut it. Before you use it heat it with a torch and throw it into a bucket of water so it softens up and will seal the head. Next best head gasket material is a Coke can but do not bother to try to anneal it because it will evaporate. A Coke can will last a while but a copper one will last and last - each time you open your engine to play with it just heat the copper gasket again and throw it into water to soften up the surface again.
Use paper on the base - even butcher paper is good from the deli as long as it is butcher paper and not waxed paper. Just make sure your piston is not taller then the floor of the ports AND the skirt of the piston does not go higher then the bottom of the exhause port.
Do not use silicone (rtv) on an engine anywhere it is not fuel resistant enough - even the high temperature stuff will turn to gel and mess up stuff.
If you are milling your head with the paper on glass (or miror) method the best way to get it flat is the figure 8 way to move the head. Also I would suggest using a BIG black or blue marker and colour the surface of the head and do a single pass and check that the marks are being removed evenly from the surface - that way you know you are flat on the paper covered mirror or glass.

BTW - drag racing engine can get away with no head gasket because you rebuild a winning motor after each event AND your sponsors will pay for it.