port and polish

[bondsman]

is it worth doing a port and polish on my 472 ive installed 2.19(i) and
1.90(e) valves in 76cc heads to breath and i know my cfm would be
better with a p&p but my caddy is on airboat with max rpm of 3000.
any opinions?

[Don]

Let her get more air. You might want to talk with Maddog on the CB7 site. He has one Bad A$$ Airboat that I had a chance to ride on and drive last summer. He has done it all and would be glad to offer advice.

[J-rod]

I agree - let her get more air. You'll get better volumetric efficiency.

[Andy V]

Don't know if you've already installed these valves, but IMO a 1.90 exhaust valve is too big for low end torque production.

a 1.77 or 1.84 is plenty big. 1.90 if that is what you have will hurt low end, where you are running.

Lightly port and polish the exhaust if you have time.
Lightly port the intake and take out any casting flash etc., I wouldn't polish the intake smooth though. Keep it rough as cut w/ carbide burr.