Printable Version of Topic

Posted by: Literati914 Sep 7 2019, 10:59 PM

I know people use 1.7/1.8 exhausts on 2.0L /4s and vise versa all the time - but someone I thought knew what he was talking about, made the following statement to me the other day and I thought 'woa, bullcrap!, don't think so'... but it's had me thinking ever since.

"I know on the 2.0 litter exhaust ports heads are more of a rectangular squared shape vs. the 1.7,1.8 are a true oval shape port"

So, is that actually the case, or not?

Posted by: Tbrown4x4 Sep 7 2019, 11:59 PM

2.0L vanagon heads had a squarer shape after 1978(?). I don't think his statement applies to the 2.0 Porsche heads on the 914.

Posted by: porschetub Sep 8 2019, 01:02 AM

Please read on , later than our motors ,thank god as exhaust options are very limited ,and I seem to remember very small valves….

Posted by: rick 918-S Sep 8 2019, 05:29 AM

Crappy bus 2.0 heads have square ports

Posted by: ClayPerrine Sep 8 2019, 05:37 AM

All 914 heat exchangers will fit all 914 heads. Square ports were never used on 914 heads at all.

But.. you want to use the 2.0 heat exchangers for best performance.

Posted by: rick 918-S Sep 8 2019, 05:42 AM

Clay, aren't the inside tube diameters the same? The only difference is the up lift at the rear of the tubes on the 1.7 set.

Posted by: ClayPerrine Sep 8 2019, 06:08 AM

I think the 2.0 tubes are bigger, at least from looking at the muffler gaskets. The 1.7 exchangers use a steel casting to connect to the head, the 1.8 and 2.0 use loops welded to the tubes. The steel casting doesn't flow as well as the tubes. And the 2.0 exchangers flow better due to the straight tubes at the rear.

Posted by: Olympic 914 Sep 8 2019, 08:51 AM

On the SS Heat exchangers the tubes are the same for the 1.7/1.8 and 2.0 with the only difference being the bends on the end where the muffler mounts.

On the original steel units, the 1.7 tubes are smaller than the 2.0