Tubular manifolds?

[mole42]

Looking at the ones offered for Stag, I notice there's little or no attempt to make each header the same length. When I was designing tubular headers for Triumph 6-cylinder engines we always used to make each header pipe the same length -it seriously messes with the tuning of each cylinder if they are different. I wonder why the Stag manifolds have unequal length headers? to quote from a US guru: "When it comes to <snip> headers with seriously mismatched tube lengths, Reher-Morrison points out these unequal tube lengths actually create a different tune for each cylinder. Hooker Headers adds there can be as much as a 50 horsepower difference between 5,500 and 6,500 rpm when compared to a set of pipes with more or less equal lengths."

Is it simply that there's isn't room in the Stag engine bay?

[jbuckl]

Yes, not enough room to do it neatly or compromised access to other items / packaging.
Bespoke 4 into 2 into 1 may be possible to make equal… but spendy. ( join 2 under body …. Requiring bespoke silencers)
The original iron ones work but look ugly.
They look better with vitreous enamel but that is spendy now too.
The stag isn’t that in need of extra horsepower , just my 2p though.

[flying farmer]

4 into 2 into 1s with more or less equal lengths certainly are possible going down and back rather than forwards because I have a pair fitted to my Mk1

Certainly not easy to fit or fabricate.

I went that way with my Stag simply because I had good results on the Stag engine in my TR where there simply isn't room for 4 into 1 headers.

Its an itch that needs to be scratched when I get round to fitting a serious engine to my MK2, simply to see how the power and torque curves differ to the 4:2:1. That's assuming there's room of course, without compromising ground clearance. Don't want to go forward as fitting 2" pipes under the crossmember isn't going to end well when I get off road when I'm going paragliding.

Neil

[mole42]

Yes, not enough room to do it neatly or compromised access to other items / packaging.
<snip>
The original iron ones work but look ugly.
<snip>
The stag isn’t that in need of extra horsepower , just my 2p though.

To me the appearance isn't important, I only open the bonnet to check the oil and water :-) I suspect the iron isn't that bad, my respect for the engineering at Triumph remains high, they did some fabulous stuff.

I don't think I'd go for tubular manifolds anyway, because the Stag wasn't homologated back then I'm quite sure I'd have trouble getting new manifolds past the scrutineers.....

[mole42]

fitting 2" pipes under the crossmember isn't going to end well when I get off road when I'm going paragliding.

Neil

Or, in may case, off road on a classic rally forest stage. My standard left-hand downpipe gets pretty badly knocked about anyway, I dread to think what would happen to a pair of 2" pipes.

[jbuckl]

Or, in may case, off road on a classic rally forest stage. My standard left-hand downpipe gets pretty badly knocked about anyway, I dread to think what would happen to a pair of 2" pipes.

Didn’t know you rallied with your stag!

[Phil S]

I have 2" pipes from the tubular manifolds they follow the same route as the standard pipes , but only road use.