Anyone know if it helps to polish (deburr) the air casing to increase air flow?

Polishing it, or changing the overall shape of it will change a lot of variables to the engine's performance dynamics.

But just smoothing it out will hurt airflow, as the best surface to promote airflow is dimpled. Unless you have another principal that you are working on... I.E. reversion wave refraction.

I agree with Chris.

With one caveat.

I have seen TYPE IV heads that had some of the fin area between the combustion chambers blocked with casting flash.

I DO remove that flash to get a better shot at keeping the heads cool.

Udder than that.. I don't touch em externally.

Clayton

This is another Polish joke, right? The Cap'n

I'm gunna go home and polish my thingy...

Thanks for da reminder..........

C

I just notice that when cleaning the casing that it was very rough, I will stop playing with my self ;-)

Rough means more surface area


On intake runners you want slightly rough too, but thats a different scenario than polishing the exterior of your heads.

If you are talking about the cast aluminum enclosure for the engine cooling blower, and it's ductwork, the answer is a big fat YES, flow will increase. It will decrease the system resistance to flow. As long as you don't go relocating any of the major interior contours or metering/steering vanes, the proportional distribution of the air flow will remain the same, but the volume will increase. Same is true for the blower impeller itself. Clean it up and deburr/polish away to your heart's content.

It is only when the discussion turns to the intake manifold and heads when roughness and air tumbling are important NOT to polish away. The direction of air flow as well as quantity and speed are all very important in combustion.

For the cooling system, all you will be affecting is the velocity (speeding it up).. so it only helps the situation.

I've got 15 years of air cooling system design to back up what I say so questions are very welcome.

that is what I thought, I guess I was misunderstood?

Thanks Brian,
Dan