bebbetufs

Is the spacing for the 16v exhaust ports identical to the 8v. Could one change flanges to use a 16valve header on an 8v head?

rlm328

There are other issues other than valve spacing. The return water course is different for the 2.5 liter heads and the 2.7 / 3 liter heads. I modified a 3 liter block to take the 2.5 liter head so going the other way should be possible. You mat have to make a variety of mods though.

reno808

so you want to use the 2.5 exhaust headers on a 16v head?

bebbetufs

No. I saw a nice equal lenght header for a turbo converted 3l head and though perhaps it could be easily adapted for a 2.5l
http://grabcad.com/library/porsche-9...haust-manifold