I posted this in the exhaust forum, but got no replies.

Has anyone ever heard of custom "Y" type headers that connect cyls that are opposites; fireing order-wise?

By that I mean "Y" cyls 1 to 6, 8 to 5, 4 to 7, and 3 to 2.

Then, a little further down, "Y" together the 1/6 pipe to the 4/7 pipe, and "Y" together the 2/3 pipe to the 5/8 pipe.

Seems like that set-up would provide the smoothest, most efficient flow since the exhaust pulses would all be evenly spaced and would tend to assist each other at scavanging exhaust.

 

Yes, on paper it would seem so.

Draw the physical layout of those on a sheet of paper, and let us know if you can get them to fit in your car without going underneath the oil pan.

I have never heard of any headers that do that, due no doubt to the obvious physical constraints.

There are however intakes that do it; unfortunately in the process something else gets sacroficed, usually equal length runners. To make a 180° intake (the usual term applied to such a thing) with equal length runners, you'd end up with something that might possibly be as RPM-hostile as TPI. And of course if you did that, it wouldn't matter how "smoothly" it flowed, because it wouldn't make any HP anyway.

 

I found a vague reference to them being used in NASCAR.

http://www.thorleyheaders.com/tech_basics_triy.html

I've made custom headers before when I worked in a muffler shop, but that was along time ago, and I never tried anything like this.

I've seen a lot of full length headers that were lower than the oil pan. Shouldn't be that big a deal unless car has been lowered.

 

Yeah, some of the NASCAR guys did used to do something like that; in particular Runt Pittman, the engine guy for the 4 car, used to do something similar for the plate tracks. That might be one of the reasons why that car used to win Daytona & Talladega races so much back when Ernie Irvan and Sterling Marlin were driving it. You could tell sitting in the stands that it had a different exhaust, just by the sound.

Of course, those cars also have a dry sump oil pan, a tube frame, etc. etc. .... a far easier environment.

Have you gone out and looked under your car to see where it would have to go, yet? Or figured out how you'd install it (bolt up to 2 heads and make 3 or 4 connections somewhere under the car)? It's one of those things that's possibly beneficial, and probably possible, but probably not very practical in the real world.

I've owned a few headers that hung down below the oil pan, and the frame..... ended up ripping every single one of them off of the car on some road hazard or other. One (a Chevelle) was particularly funny, a railroad track sliced one of them's primary open like a can opener. Another friend of mine had a 2nd gen Camaro; bought headers and a complete new dual exhaust and had it run on his car, which as anyone who's had a 70-81 F car knows, the headers are lower than the frame and pan; the very first time he tried to drive into his own driveway, about 10 minutes after he had all this done, he smashed the pipes flat and bent his exhaust to where it all rattled against the car like his old garbage did. $600 down the drain instantly. Neither my Chevelle nor his Camaro were lowered BTW.

Personally, I will never again put an exhaust lower than the oil pan or the frame on my car.

 

If I was the practical type, I wouldn't be installing a stroked/poked/full roller/h-beamed/balanced (high rpm capable) engine, with all the high-dollar aftermarket (low-rpm) TPI goodies, in a 21 year old car!

It looked so good on paper.

I bet it would sound killer with true duals..