I'm going to be porting my throttle body, UIM, and LIM here pretty soon, and I was gonna see if anybody had any input. My plan was to smooth out the corners in the metal on the TB to make it flow better into the TB. For the UIM to LIM I was going to scribe out the lines for the gasket, and open the ports up the same size. I can't port far into the manifolds, as I only have a little die grinder, but I'm supposing that just matching the port openings makes a difference. Any advice is always welcome.

 

I want to do this too, I don't want to screw up as i don't have a backup.

 

the tbody part sounds good, but on the intakes i think you want to remove the imperfections, more than porting it. kinda like if you got a perfect casting



mike

 

If you matched the intake exactly to the engine would you not have more intake charge reversion? Thus cancelling any gains you make?



J

 

see thats one reason i would just remove casting imperfections. the factory guys know more than i do



mike

 

I heard that is a bad idea. Can't remember why tho.

 

I really don't know how it all works. I just thought that you wanted all the runners to line up perfectly.

 

Not always, and it's because of charge reversion - this is more important in the exhaust system, where you never want the header to flow continously out of the exhaust port, you want a step up in diameter to help keep the exhaust from "backing up" and contaminating your intake charge during the overlap period. On piston engines some people use the same principle in the intake manifold but since the rotary flow characteristics are rather different I'm not sure which approach would be better for the intake.



J

 

Where's the judge when you need him?

 

considering NA intake manifolds are easily found, it can't hurt to experiment if you're willing to waste the time, documenting the results would be useful for others.