Drilling cooling fins

[sinfull]

Drilling cooling fins on cylinder, been reading some articles and looking at alot of old race bikes, read some articles about how it increases surface area, there is math involved and from what I understand is the hole should not exceed double the thickness of the cooling fins or you lose surface area. Any one tried this before or any insight.

Getting ready for next build after summer and have already ordered my gy6 b cases. Have had heat issues with 205 and 232 running higher Temps on longer runs. So trying to think of different ways to manage Temps on the big engines. Any insight or information would be appreciated

[aeroxbud]

I no nothing about the drilling of fins. But on most Chinese bikes, an oil cooler is considered a must do when using the big bored cylinder kits.
It's commonly used on the big bore Grom builds too. It might be worth considering.

[90GTVert]

It makes sense based solely on the surface area. Not sure how much effect the holes would have on airflow overall. Could be that it causes more turbulence and I don't know if that would be good or bad in this case. Some say fins with holes release heat near the engine and it's best to have the heat transferring out further away from the engine at the ends of the fins. Kinda seems like one of those things you'd have to test to find out.


An oil cooler definitely helped to reduce CHT as well as oil temp on my old GY6.
49ccscoot.proboards.com/thread/16180/139qmb-cooler-information-installation-help

Liquid cooled cylinders are out there.

[sinfull]

Most definitely try the oil cooler 1st before I take out the drill.