What is the actual difference between the two heads? Is it worth it to put the 70 head on the 50? What needs to be changed for it to work?

 

Im wonder'n that my self too.But useing the 70 head on the 50 might be too much,and might run poorly.But maby if you use a high compuression piston with the same 49cc displecement and aftermarket pipe it can balence it out some what evenly.But by useing the 70 head on a light bore(49cc-88cc) will hopefully show great improvements, sence more Air and Fule is added,thanks to bigger in/ex valves into the chamber.thats what I think...What about you?

 

the valves on the 70 are almost twice in size. along with the ports. the cumbustion chamber is quite a bit bigger also. too much to run a stock 50 piston (i tryed it). the older head uses a completely different style cam. where the newer ones have a roller bearing cam like the 50. if u are ordering a big bore, it is worth it to get the big bore with the dome piston so u can run a 70 head. ive done it to a couple of em and they run sweet.

 

Yeh I have the 88cc and was definitly planning on a new head, if I can find one cheap I think I may buy one and try it out.

 

The 70 head is definately bigger and able to flow more gas/air. You have to use a piston matched for that head because the 70 head uses a domed shaped piston unlike the flat type design of the 50 head. The 70 cc heads are hard to find used on ebay. If you can find one snap it up.