Headers, Port-Matching

[CFreed11]

How important is port-matching for new headers? The exhaust ports on the car are more square-ish where the OBX headers I have, and the new Pacesetters I bought both have circular ports. I took the time when I installed the OBX headers to grind them to more of a square port to match as close to perfect as I could get, but is it really necessary?

[ssms5411]

Re: Headers, Port-Matching

Not really necessary but I would think it would flow better if their matched.

[bigbrian442]

Re: Headers, Port-Matching

As long as the header is larger than the port your fine.

[3.4grapeofwrath]

Re: Headers, Port-Matching

The purpose of the header is to allow better flow on the exhaust side of the engine. If you have a restriction right at the point of exit what would be the point of installing the headers in the first place? I would get the die grinder out and hog those ports out.

[bigbrian442]

Re: Headers, Port-Matching

The purpose of the header is to allow better flow on the exhaust side of the engine. If you have a restriction right at the point of exit what would be the point of installing the headers in the first place? I would get the die grinder out and hog those ports out.

ON the head or the header?

[MegaHertz]

Re: Headers, Port-Matching

I'm guessing the heads. I don't think there is much material to remove on headers unless the opening on the flange is smaller than the header pipe.

[bigbrian442]

Re: Headers, Port-Matching

Once again, You want the port in the head smaller then the header. You do not want them the same size.

[CFreed11]

Re: Headers, Port-Matching

My situation was the port on the OBX headers were probably pretty darn close to the same size as the port on the heads, but they were round whereas the heads are a rectangular shape. Since the header ports were round, I squared them off basically so that they were the same shape as the port on the heads, but funneled into the round shape of the header pipes. It's hard/confusing to describe with no pictures, but I think you guys get the jist of it..

[3.4grapeofwrath]

Re: Headers, Port-Matching

ON the head or the header?

On the header. I agree the header port should be slightly smaller then the exhaust port. Use your gaskets as a template to hog out the header ports but leave some material.

[whitdog54]

Re: Headers, Port-Matching

Once again, You want the port in the head smaller then the header. You do not want them the same size.

:poke: wut?

[3.4grapeofwrath]

Re: Headers, Port-Matching

On the header. I agree the header port should be slightly smaller then the exhaust port. Use your gaskets as a template to hog out the header ports but leave some material.

Sorry, I had that backwards. The head port should be smaller. Like the man said.