I bought a dc sports header and I noticed that the ports are 1 cm smaller in diameter than the stock manifold... Is this to create more backpressure and work with the tri-y design of the header???

Also is the collector typically 2 inches in diameter? I've seen several headers that are 2 inch collectors so I guess thats typical?

 

Anybody?

 

I could really use some help peeps I need to know before I install or return... Thanks Everybody!

 

 

By ports, do you mean the openings at the flange that look similar to this:

[ O : O : O : O ]

or do you mean the tubing diameter itself? Your question will be easier to address once this is clarified, because I'm having a hard time understanding why DC made the ports smaller than stock (though I've never measured a DC header from your application, so anything's possible).


[Modified by Padawan, 1:40 AM 3/19/2003]

 

Sorry yes the inner diameter of the port opening itself :

 

I am wondering if maybe I got a header for a 1.6L motor or something

 

And since they are oval, I assume you are measuring at the widest point (i.e. width, not height)? Have you measured the exhaust ports on the head as well? How do the two compare? As long as the actual exhaust ports are the same size as those on the header, there shouldn't be a problem. As for the collector, the size you stated (~2") is pretty much standard, since the headers are meant to bolt to the stock cat.

 

I am wondering if maybe I got a header for a 1.6L motor or something

 

Yes I measured at the headers widest point of the port and also the head exhaust port...

The head port is 1.7in and the header port is 1.6in so... the header port is smaller than the head port...

 

That does indeed sound like a problem. Since I don't have much experience with that application, I can't really say how the tubing on those headers is typically sized, but I can't think of any reason why one would want smaller-than-stock ports. If you determine that the header you have is the correct one for your application, you may want to consider something from a different manufacturer, such as Greddy, which is priced similarly. If it turns out that the tubing is equally small (which I doubt), then at least you will know that it is something common to these headers, and you can then make the decision to keep the Greddy or explore other options.