Area of 3500 ex. port?

[rsisbetter]

Does anybody happen to know the area of a 3500 Exhaust port? I can calculate a circle, or a square, but im not too sure about a D? haha Just curious, for header sizing is all.

Thanks
Cody

[bszopi]

Scan a port in (with a ruler next to the port), and I can draw it in AutoCAD and determine the area that way. Done it several times for Ben on different areas...

[SappySE107]

You don't size a header based on the exhaust port. You can base the flange and a short stub to fit if necessary but the rest of the tube should be sized for power output.

[rsisbetter]

i'll try and get a measurement

Ben, thats a good point i'm glad you said about power output, I thought that was also the case. One ofmy dad's friends found a program on building headers, i cant remember the name of it off hand, i'll h ave to find it and post it up, its supposed to be really good. punch in the numbers, and expected power output, and it will size accordingly.

I though 1.5" would have worked for the primaries, because i had some 1.5" combo bends already. But, compared to a 3500 port, you would have to manipulate and somwhat bend up a 1.5" tube to even cover the port area of a 3500 head. I would assume naturally that anything smaller than the port itself would probably do more harm that good, and restrict it. which was why i thought i should bump it to 1 5/8".

Thanks for input
Cody

[SappySE107]

1 5/8 is good for where most of us would fall under for hp output. You also have collector size to deal with. I have the headersbyed sheets that explain header design but there is software that also gives a good idea. Its better to be on the small side for the collector but its RPM/Output based as well. I think 2.25 collector outputs are where its at for most. Without knowing your specific goals/application, it is hard to be specific.

[rsisbetter]

^^ you are the man, as always

Thanks, i'll try and track down the n ame of that program i had, it was supposed to be really good. very extensive.

cody