Thread: polish and port

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That intake manifold is most likely ok . It's if your head ports look like this . Then they need the intake gasket match porting .

Check out a book from SA Design, titled "how to build max performance chevy smallblocks on a budget". It's written by David Vizard, and has some good info on porting & polishing.

I got mine at a book store, but it's also available at cartechbooks.com.

Adam

Here's a couple pictures of basic port work. The intake and heads were matched to the gasket and the ports smoothed out some (but not polished) back into the manifold and head ports.

I also polished the outside of my intake and will never do that again. Buying one factory polished is a great investment IMO.

Kitz

beautiful jon thanks so much for the pics.

double post

heres a start....They also sale porting kits to get you started , Summit and Jegs do also.


Mondello Performance Products-Head Porting At Home

Mondello Performance Products-Porting at Home

I barrowed the first pick from above to show basicly what I started with and the finish product. They are both stock cast iron heads. Do plenty of reading before doing this you can ruin a good thing real quick. Another thing is that its real time consuming. If you are still planing on just port matching your intake it should be no problem.

The first thing I will say is stay out of the valve seats.
To many people have given me heads that require a few new valve seats because someone has gotten to wild with the die grinder.
For cast iron you will need to invest in some carbide cutters.
They are a little expensive but should last you forever.
Then you will need a porting kit.
I would try Goodson for your porting supplies.
I would first remove all the parting lines and knock off any casting flash if there is any present.
Think radius/smooth.
No sharp turns of rough edges.
In a street car I would try and keep the finish in the 120/180 on the intake side to try and keep all the air/gas atomized.
The exhaust should be made very smooth.

thanks denny

You could check out your tools on some junk heads before going after the good stuff.

Hi JYG, So far nobody has said "why". You want to match the ports to the manifold on the intake side and leave the intake ports in the head a little rough to maintain enough turbulence to keep the fuel droplets homogenized. The ports on the exhaust manifold should actually be a little larger than the exhaust ports of the head to provide a little ledge around the exhaust port to prevent "reversion" which is a slight tendency for exhaust gas to go back into the chamber. The exhaust ports in the head are where you want a smooth surface because the hot gases expand and need as much help getting out of there as possible. I know the theory, but paid $200 to have the exhaust ports smoothed out on my 350 "882" heads because it takes SKILL to do it right without holing through to the water chambers. I know the theory but don't have the skill so I paid a pro!

Best Wishes,
Don Shillady
Retired Scientist/teen rodder

Did you start on your port/polish job?
Here's a decent overview article I ran across.

DIY - Basic Cylinder Head Porting -Standard Abrasives Motor Sports