helping flow

[luvsit]

guys!!herd about intake and exhaust manifolds getting some how blasted down the ports to inprove flow,just like to know whats it called, thankyou very much!!

[72' Stang 351 H/O]

Port and Polish? That's for the head's though. I don't know what your talking about.

[CFM25]

The process is called extrude hone. An abrasive compound, mud like, is pushed through the openings in the manifold at high pressure and fairly high velocity. The compound is recirculated until the manifold is suitably conditioned. Definitely not something you can do at home.

Manifolds on nearly every stock engine out there are serious flow restrictors. That is not enough to know.

Simply gouging out and/or polishing the intake manifold will probably not help the engines output. As a matter of fact it may diminish performance and it often does unless done by a very knowlegeable person who has elaborate equipment such as a flow bench and dynomometer.

An aftermarket exhaust header may help a little but even that has some potential problems. Changing the intake or exhaust configuration will definitely affect your fuel distribution curve. If your ride has EFI the cpu may make adequate adjustments by itself, and that is a maybe. If you are carbureted, you'll almost surely have to tinker with jetting.

I hope this helps. Please know that there is a lot of bad information out there. Some of it is foisted off on the car enthusiast in a clever effort to separate people from their money.

I claim some knowledge in this area because I have been long involved, on a professional level, in The performance racing industry. I do head and manifold work as a specialty. Have done so for 40 years and I am distressed by the absence of knowledgeable information that is put forth in advertising and, indeed, on forums such as this.

There are no secrets about portwork. Most of us will tell you anything you want to know about the process. The ones who will not tell you are the ones who are not sure of themselves. None of us are in danger of losing our livelyhoods by telling what we know. Quite simply if you decide to do your own port job, without serious prior study, you will almost surely lose some horsepower. I know I will get some real flak for remarks like that last one. That is because the home boys with a $60 porting kit must justify the mistakes that they will be so hesitant to acknowledge or to even discover. Did you know that port and polish is a dirty word pair for professionals. Polish is sometimes very detrimental to performance. Pretty; yes, effective; probably not.

I'll get off my soap box now.