Doug's D627 Opinions

[emorrison96]

Hey guys - I'd like opinions on a set of headers, specifically Doug's D627 header.  I would like to use these in a mustang.  It is my understanding that in a flat plane crankshaft the exhaust pulses are equal from side to side, giving a european V8 sound.  In a crossplane V8 such as the FE, there are are times when the exhaust pulses double on each side, giving the classic American rumble.  If these headers move the exhaust form the off cylinder to the opposite side and even the pulses between banks, does this mean that these headers will cause the engine to lose it's American rumble sound?  I believe the Thunderbolt used something like these, but I don't want to use them if it means giving up a distinctive personality trait of the classic American V8.

[TomP]

It won't sound any different, it isn't like 180 degree at all. It has 5 and 4 firing next to each other into the left collector instead of 7 and 8 which also fire next to each other.

[emorrison96]

Interesting.  If that's the case, do you know what benefit there is to the pipes crossing under the engine like that?

[cammerfe]

They started as a way to get closer to equal length primary pipes within the close confines of the engine compartments in '60s drag Fords. One of the guys who worked at Dearborn Steel Tube, 'Bondo' Larsen, was well known for innovation in exhaust systems. We had a set of his tubes on a TP-equipped Thunderbolt run by the Corrunker Brothers. They came apart into about a dozen pieces and had TWO pipes from each side that crossed-under. And then a pair of megaphones attached to the collectors.

Brother Lon put a set of cross-unders such as you show but made by Larsen on his TP/427 engined '67 Mustang.

KS

[emorrison96]

Exactly the info I was looking for and a history lesson to boot.  Thank you TomP and Cammerfe for educating me!

[bn69stang]

Another header option is  REF headers , they re in Az  1-928-692-0111 , you may want to check them out .. Bud

[emorrison96]

If I use these ,space in the engine bay will not be an issue.  However, I'm wondering how much ground clearance these things have when installed.  Does anybody know if these are "speed bump" friendly?

[fe66comet]

I have a set, unused at this point. Nice set of headers but wish they came in stainless, the tube length is not equal and tower modifications are going to be neccessary regardless of what vehicle they go into.