ChevyRacer

I have a set of virgin 083's no miles yada yada.

I started cleaning them up and "porting" them yesterday.

What exactly do I do to the runners? To I take material out or am I just smoothing it all so the air can flow better.

My tools are basic but they get the job done quite well. I have an Electronic Speed Controlled Dremel, Diamond Grinder Bits, Stone Grinding Bits, and other things. They work quite well for this purpose never been able to use them for anything else except when I cleaned up my TES headers.

On the intake sides my Short Side radius feels rather smooth stock, but I kept smoothing it out anyhow. The exhaust side you can feel the lip there, and I smoothed it out, and trying to make a mirror finish for the exhaust. Still trying to figure out what needs to be done to the in take bowls. It’s got to be me but feeling my other sets of heads (882's and 601's) I cam to a conclusion my 083's have been messed with before, their ports seemed way too smooth for stock castings. But I kept cleaning them up.

I should have pics later of what I have accomplished. MY expensive Digital Camera Batteries Were lost so I am forced to buy new ones. Have using disposables because they cost so much, but these expensive rechargeable are getting ridiculous too. I'll stop ranting.

vrtc350

iTrader: (1)

Air, especially carrying any kind of liquid (gas) hates to turn, sharply for that matter. So you want to make the trip to the valve as gentle and straight as possible. If there is any sharp turns ledges etc, remove that material then keep getting smoother with smoother transitions. The goal is to open them up as wide as you can for flow.

My dad has 083's on his and he ported the hell out of em. So there is lots that can be removed.

Sitting Bull

You don't want to "open them up as wide as you can for flow", rather you want to open things up in the correct places.

Follow the link at the end of my sig.

vrtc350

iTrader: (1)

Sorry, got a little carried away. Of course you don't want to hog every inch of metal out. You want to keep the transitions as smooth as possible. But in 083's, there is a lot that can be taken out to greatly improve flow.

batchik2

its something you gotta be careful with. you can make them "look" like they flow better but in some cases you can actually create more of a restriction.

F-BIRD'88

There is practically nothing you can do as far as porting a 305 or 350 TPI head that will make it worse off, except maybe carving out the floor of the port. You do need to not be afraid to get in there are carve out some metal. (about 10cc's of metal needs to be removed from each port.) Don't be shy. You will not do it with a "Dremel" You'll need a real electic die grinder that takes 1/4" shaft, bits.

Spend $10 on David Vizards book on Building a small block chev on a budget. All the head porting info in it is relevent to these heads.