Header Theory by Vince Roman from Burns @ PRI

[hoffman900]

That and as Calvin has pointed out, for packaging reasons, 180* are out of favor due to the primaries being way too long. For a lower rpm deal, they can make sense. Maybe if the exhaust ports were in the interior of the valley, they could work.

Here is a set of Elston headers for a SBF and a first gen Mustang chassis. 1.623” off the head and they make over 600bhp.



Formula One teams have known the difference between the single cylinder engine and mutlicylinder on the exhaust side for a long while. I’ve cited the Honda white paper numerous times discussing this.

[MadBill]

Merkur Motor Se'18 002.JPG

By way of contrast/comparison, here's an owner-built* (*first and he swears only, ever!) set for a tube frame 1986 Roush-designed Mercury Merkur IMSA road racer, specced by me via PipeMax. 380", 700 HP @ 8,000, 1.75" off the heads, reverse megs inside collectors.
The benefits of not having to weave the system through a stock chassis are obvious.

[Carnut1]

Exhaust art mixed with physics. I love it and thanks for the pics.

[hoffman900]

Something Calvin does, and can be observed if you look at his (and other high end headers) is seperate flange for each port. That way you can install the header in a sequence and are able to fit tubes into an area that you couldn’t with a common flange.

[MadBill]

Yes, that's the case with the system in my pic; the primaries all install separately, then the one piece secondaries/collectors are slip-fitted.

[plovett]

Something Calvin does, and can be observed if you look at his (and other high end headers) is seperate flange for each port. That way you can install the header in a sequence and are able to fit tubes into an area that you couldn’t with a common flange.

Me, too! And my headers were only like $400.

paulie

[GARY C]

Yes, that's the case with the system in my pic; the primaries all install separately, then the one piece secondaries/collectors are slip-fitted.

Now if only header manufactures could grasp this... It amazes many how many headers don't fit the chassis they were designed for.

[hoffman900]

Yes, that's the case with the system in my pic; the primaries all install separately, then the one piece secondaries/collectors are slip-fitted.

The reverse meg inside the collector is the way to go, IMO. Acts like a A/R collector

[Newold1]

Most header manufacturers are paying attention to three or four things when they build and sell header systems.
1. How much will the customers pay for that set of headers? (Marketing)
2. How can they be produced as inexpensively as possible and still offer some measure of value? (Cost Controls)
3. What materials and particular sizes, components and construction methods are required? (Manufacturing factors)
4. What shape do they need to be to fit the customers engine and chassis.( Application costs)

Unless the header user is willing to purchase his headers optimized in all areas and maximized performance and not be bound by chassis and frame restrictions and have cost as a non-factor most headers built and supplied to most aftermarket performance uses are not going to be the ultimate size, shape , materials or performance characteristics.

Seems as though the answer is you determine a budget and cost range and then select the best possible compromise from a standpoint of optimized tube length, bends, pipe and collector lengths, shapes and sizes and materials that will fit the frame and chassis and hopefully deliver the best power and torque outputs they can provide to the engine. It's kind of like Horseshoes, you can hopefully get close to the best ultimate header, but most of the time it's hopefully going to end up close but not perfect!

Alas, sounds alot like the hopeful best in life in general!