Re: Why are the engines called 66cc/80cc need info
I think the designation 80cc may have started solely by marketing forces-
I'm not sure when the larger engine actually came into widespread use- I think it's only been the last ten years- but before that was the 50 cc bike motor as a standard-
then when that changed I think the sellers wanted to stress that it had more power and they simply exagerated- until people started checking the actual stats- and found the displacement 66cc
if you think about it though- a 66 displacement is actually almost 32 percent larger-
adding twice 16 cc difference to the 50 factor-
so maybe there was confusion about 30 percent and people added 30 to 50 to get 80cc.
anyway- the stud sizes are not an accurate guage to determine the size- because at first and for some time- 66's were made with 6mm studs- mine is, that I first bought in 2009- the 8 mm came out shortly thereafter, but the suppliers stores being what they are, there have been 6 mm stud 66's around for awhile- but I think there are probably all now 8mm studs new- you can still probably find 6mm motors, and surely jugs and heads to fit the bottom ends with 6mm studs, but beyond having the other set-up already- why?
I'm stil not sure what actual advantage 8mm studs may be, except heavier in weight- and the oil companies that run all corporations always like that, because it sells more gasoline.