Over 10,000 Posts
DTT BOTM WINNER
I remember there was an SAE paper or similar way back when. Or at least I think I do....
teazer said:26mm CV carb flows much less air that the equivalent round slide and that one is probably closer to 22-24 of effective area, so that's not an issue. It isn't imp[ossible to get the bike to run OK with a pod and those carbs, it's just harder to them right that a slide carb.
teazer said:The airbox is not part of the intake length. Pressure waves "see" that as an open space. Where it makes a difference is that the air in their is still and not blowing and turbulent.
To put the whole inlet tract length thing into perspective, it's worth probably 2% power at the peak compared to a similar intake of the wrong length, and loses almost as much off peak and getting jetting wrong can cost 10-20%.
If you really want more power, then a larger bike is probably the easiest route, but failing that, higher compression, larger piston, 24mm carb with velocity stack inside a large capacity filter are things to consider.
Tijmen said:How do I determine the intake duration of the camshaft?
crazypj said:Piston mods are specific, you may have to machine parts for clearance. You can't use two stroke pistons in fourstroke motors (unless you want an oil burner ;D )
There are very few direct swaps when doing big bore conversions.
You should be able to go to around 145cc though, it's major work to go much bigger.
You will need better valve springs to cope with higher rpm, they float, touch something, break off heads and destroy motor
Cheers!teazer said:The key to the "filter over stack" approach is to ensure that the open end of the stack can get enough clean air from the sides to clean up flow.