At 07:18 PM 3/22/2000 , you wrote:
>----SNIP----
>I am now thinking of doing some porting and polishing work on
>my intake manifold and heads. I have some experience porting
>and polishing but by no means an expert. I also have some tools
>such as air grinders and polishing wheels to use.
>Question:
>1. Can I port and polish my intake manifold with good results
>in my garage or do I need a machine shop to do it?
>2. Same question but for the heads. (this one I am leaning towards
>machine shop
>I saw Mopar sells some jigs for final shaping of ports)
>My goals in the port and polish is to simply increase air flow for
>better
>HP, torque and MPG. Nothing to radical.
>
>Ja
Well, for starters, check out this link
http://www.sa-motorsports.com/diyport.htm for porting info to get an idea
of the process. The Standard Abrasives kit can be had for 40 bucks through
Summit, bought plenty of them through them.
Porting is an art and an acquired skill. A little change here and there
can make a big change in engine air flow in the good and bad
direction. When I first started learning to port years ago I went to the
junk yard and stocked up on worn out 302 heads and ground several to the
water jackets and wasted plenty of burrs, stones and cartridge rolls before
I got to the point where I feel confident in what changes I make and what
the affects of the changes are. Lots of seat of the pants time and when I
could afford it, flowbench and dyno time.
On dry intake fuel injection, not much has to be done to the intake
manifolds. Simple gasket matching, cleaning up casting flaws, and using
cartridge rolls to smooth the runners is enough. If your after serious
power, that's another story. The heads are tricky. I'd recommend a racing
shop for that, depending on your desired performance level. Lozano
Brothers Porting in San Antonio Texas is high on my list for having
excellent work done, but the price is on the high side - you get what you
pay for. For improved efficiency, gasket matching the intake to the heads
and exhaust manifolds/headers to the heads, remove casting flaws in the
runners, improving short side radius flow, and chamber polishing - without
any serious cutting of metal. Just that simple task improves power, the
amount depends on what's in the engine and the cam.
What gains are you after with your porting and polishing?
Mike
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