When you guys port the runners do you only cut the rough or you enlarge it ? If you enlarge it, by how much ?? It's for a turbo application.



Thanks!



Alex

it depends on what you want. for the engine i'm doing right now we want a smooth idle and decent (300-320rwhp), so i just cleaned up the casting flash and smoothed any rough/sharp edges, or in other words i want to make the stock ports work a bit better

For now I will run on the stock cosmo twins, but I would like to prepare the engine for a big single eventually.



Thanks

Somebody has other input on runner porting with my application ?

They should have ~ the area of the port, maybe a few % more to increase velocity at the port.

I vote for cleaning the casting off the port runners and scissor the short radii at the port runner to outlet. Works very well. The port runners don't have to be humongoid to make alot of power.



B

That's what I did yesterday. I didn't remember that runners on RE were that big compare to a 13BT. So I decided to just clean them.