Engine Porting - Gases out, Fuel Air in

[Egor]

Mike those engines were bullet proof, I had one a million years ago. They would produce that kind of power, but it was most because of the fuel. With alcohol there is almost no way that you can have too much fuel. With gasoline the mixture has to be just rite or it makes no power. All those carbs were feeding through reed valves, so if the engine did not need them nothing happened the reeds would just stay closed and that carb would just sit there and wait for the engine to need that carb if ever. The material used in the manufacture of this engine would be in two different States after that much alcohol, LOL. Look and see if you could find some of those carb's, I can't remember the name. If you could find one it would work nice on one of these engines. Have fun, Dave

 

[motorbikemike45]

Dave,

I'm afraid I have no idea what carbs they were. My brother was killed in an auto accident and I went off to fight in Vietnam about then. His widow got rid of all his toys before I got back so I lost track of it all. All I know is they were small, mounted in pairs on two manifolds at about 45 degrees from verticle, and they had really cool velocity stacks about 2-2 1/2 inche long. He intended to put a second engine on the cart, add centrifugal clutches to both engines, and run it on the drag strip for laughs. He figured they'd put him in C fuel dragster class and he'd eat the other dragsters lunch for the first 100-150 yards, then watch them hurtle past as he continued on at his top speed.

He ran a '60 Chevy at the strip in modified production class with a heavily modified 348 that would turn 8,500-9,000 rpm and live. I wish I had half his hot rod knowledge.

 

[Rconce01]

I just need to know if you increase an intake port by lowering it 1/4" if your supposed to also cut the skirt off the piston too?

I did both and the bike bogs out really bad but idles fine. To get it up to speed i have to slowly give it throttle little by little and it will get up to top speed. there is a major lack of torque almost throughout the entire rpm range.

I think its either cutting the port lower or cutting off the skirt because obviously the combination of the two yielded really bad results.

Can i flip the piston so that the skirt cut is on the exhaust side, will that make things worse or better?


Thanks

 

[superbee]

hey, on mine i just ground the port on the block, left the piston alone. It runs GREAT!

 

[Rconce01]

I think grinding the lower port plus notching the piston threw the timing of the intake way way offf.

The thing runs horrible! I might as well pedal.

 

[superbee]

That sucks man, looks like you might have to find you a new jug.


Maybe you can sweet talk somone on here for one real cheap.




Speaking of which, ive ridden my bike maybe 5 min total this whole year, i really need to RIDE!

 

[Rconce01]

i dont think i need a new jug the port job was done properly according to the instructions. by the way they sell for like 13 bucks brand new at pirate cycles.

I am gonna get me a new piston and see what happens. there goes another $15.

 

[superbee]

oh sorry, piston is what i meant to say, lol i was just posting real fast while watching a movie and said the wrong word.

 

[oologah]

Make sure Pirate cycle has the right piston for your engine. I have a Grubee and had to get mine from gasbike. Pirate said theirs wouldn't fit the Grubee.. Good luck...

 

[Rconce01]

Why does everyone give all these motors different names and cc ratings. HT, happy time, grubee, china motor, 50cc,49cc, 80cc....These things are all the same built in china with a piston diameter thats a little over 1-5/16".

Why does it not fit the "grubee" engine?

Make sure Pirate cycle has the right piston for your engine. I have a Grubee and had to get mine from gasbike. Pirate said theirs wouldn't fit the Grubee.. Good luck...