X pipe, H pipe or bundle of snakes

[JP Verweij]

I consider doing it differend, Going an upside down header option allows me to ad extra mufflers.

My KVA B type, 3.5 Rover came with those headers. They are turned upside down like powerboat headers. So I was thinking, would invest in a bundle of snakes realy benefit or just go forn an X or H pipe instead and have the same benefits or who knows even better.
Its a mildy tuned RV8, but thats how I see it....

True, bundle of snakes look good, but are a pain in the ass for the mechanic who has to deal with it.
As I am building a replica it realy doesn't matter to get that close to original.

So from a modern point of vieuw, Bundle of snakes worth the effort or is it just a period thing of that era and would X or H pipe doing the same or better

Oh that pic is another bundle of snakes just for the eye. Somebody might recognise it..

 

[JP Verweij]

My project engine, headers as the car came with. Guess mk3 KVA.

 

[Ian Anderson]

JP
i saw an original MK3 with very similar headers. 2004 Le Mans Classic. It had a connector pipe straight across, immediately behind the engine And then they turned down for silencing etc.and behind that cross pipe the original MK3 luggage system.

So not something that has never been done on GT40 before.

ian

 

[Ian Anderson]

GT40 MKIII Engine Bay Pictures

Hello, Does anyone have any photos or know where I can find them showing the detail of the MKIII engine bay? I am stripping and detailing my engine bay at the moment and want to try and keep it as close to the original as possible. Thanks, Ed

www.gt40s.com

will show a picture!

 

[Chris Kouba]

True, bundle of snakes look good, but are a pain in the ass for the mechanic who has to deal with it.

As I am building a replica it realy doesn't matter to get that close to original.

So from a modern point of view, Bundle of snakes worth the effort or is it just a period thing of that era and would X or H pipe doing the same or better?

There is no question in my mind you should go through the trouble of fitting a true, 180° crossover bundle of snakes. Listen to the soundtrack of a GT. There is no mistaking the very distinctive sound of the flat-plane crank emulation.

It might be a pain to fabricate, but you will hear that exhaust system every time you start the car. I'm no rivet counter but I honestly wouldn't build the car without doing that aspect properly. It's symphonic.

 

[Jac Mac]

X-pipe only works properly flow wise if the primary pipe lengths are equal. H- pipe is more about keeping things quiet. Go with the 180 deg headers. If I had my way they would all be 8 into 1, that makes the 180 deg setup a walk in the park.

 

[Randy V]

I consider doing it differend, Going an upside down header option allows me to ad extra mufflers.

My KVA B type, 3.5 Rover came with those headers. They are turned upside down like powerboat headers. So I was thinking, would invest in a bundle of snakes realy benefit or just go forn an X or H pipe instead and have the same benefits or who knows even better.
Its a mildy tuned RV8, but thats how I see it....

True, bundle of snakes look good, but are a pain in the ass for the mechanic who has to deal with it.
As I am building a replica it realy doesn't matter to get that close to original.

So from a modern point of vieuw, Bundle of snakes worth the effort or is it just a period thing of that era and would X or H pipe doing the same or better

Oh that pic is another bundle of snakes just for the eye. Somebody might recognise it..


View attachment 109988

65-66 Ford Indy Car?

 

[Mike Pass]

Crossover to get the "GT40 sound"
A few example pics here.
Cheers
Mike

 

[JP Verweij]

So bundle of snakes has to be differend on a Rover V8 as the fire order differs as do cilinder numbers.

@ Ian, these headers had a crossover like the mk3 in the pics. As my crossover was fake and not connected at all I removed it to think it over again.

That pic for the eye, Ferrari 312.

 

[Tom]

If fabrication of bundle is too onerous, is there room to do a Tri-Y? Thinking about it, probably not.

 

[JP Verweij]

Its not the fabrication thats an issue.
Looking from a mechanic point of vieuw they are crap to deal with, to assembly and dismantle. Ive worked on a French mens GT40 at Spa Sixhours a few years ago. Had to dismantle the system to get the sparkplugs out...

So is it worth it to go bundle of snakes, or is it just the looks and specific sound.

 

[Bill Kearley]

Have a look at post #2 on my build, quite conventional. Valve cover and plugs are no problem. I would try and keep the overall surface area of the pipes and muffler to a minimum and reduce heat radiation under the clam.

 

[Ian Anderson]

So bundle of snakes has to be differend on a Rover V8 as the fire order differs as do cilinder numbers.

@ Ian, these headers had a crossover like the mk3 in the pics. As my crossover was fake and not connected at all I removed it to think it over again.

That pic for the eye, Ferrari 312.

JP
No you still take the middle 2 cylinders from each side and cross over to mate with the front and rear of the other side.

ian

 

[Chris Kouba]

I can swap my valve covers/all of my plugs without issue. Sounds like the layout you worked on wasn't ideal.

It's possible to have effective access with a bundle, and if you don't have a bundle, it's possible you'll still have those same issues if it's not well laid out.

I would agree with Bill to try to get the heat out as quickly as possible. Ceramic coat or wrap would be a great idea.

 

[Jac Mac]

So bundle of snakes has to be differend on a Rover V8 as the fire order differs as do cilinder numbers.

@ Ian, these headers had a crossover like the mk3 in the pics. As my crossover was fake and not connected at all I removed it to think it over again.

That pic for the eye, Ferrari 312.
[/QUO

So bundle of snakes has to be differend on a Rover V8 as the fire order differs as do cilinder numbers.

@ Ian, these headers had a crossover like the mk3 in the pics. As my crossover was fake and not connected at all I removed it to think it over again.

That pic for the eye, Ferrari 312.

TE]
Early SBF & Rover are the same, just #1 is shifted to front of opposite bank, Remember the engine does not know which cylinder is given #1 by the human race.

 

[Paul Hendrickx]

HI,
This is a picture of original MK3 exhaust manifolds
on one bank cyl 1 is connected with cyl 3
and the other side is cyl 1 & 2 and cyl 3 & 4
and a cross-over pipe of decent diameter

Paul

 

[JP Verweij]

HI,
This is a picture of original MK3 exhaust manifolds
on one bank cyl 1 is connected with cyl 3
and the other side is cyl 1 & 2 and cyl 3 & 4
and a cross-over pipe of decent diameter

Paul

What you describe is what Rover used on all their SD1 V8 engines but without the H pipe, and exactly what we are running with our Rover V8 powered Capri including the H pipe. It probably explanes why our Capri never sounded as a cross plane crank V8.

Present situ in our project.. The 4 into 1 headers it came with.

For those who wonder, its a KVA "B" chassis build around Jaguar XJ parts. They only made 3 of them. Citroën gearbox converted by HML.
GTForte mk2 kit as it came with. Car came from Mick Ridley.

Took the Capri V8 out for a spin today. 3.5 RV8, Merlin heads, Magnacharger 110 roots blower. SD1 cast 4 into 2 manifolds as GT40 mk3, 2 into one down pipe, 2½" dual exhaust with H pipe halfway behind the gearbox. Hooker Aerochamber mufflers.
On WOT exhaust sound gets shadowed by the Gilmer drive of the roots blower.

 

[JP Verweij]

Reason of this topic, present headers allow me to put extra mufflers to meet sound regulations for registration.

If I go straight down to both the side corners and use Corvette C5 mufflers overthere, go back up and with a 180 turn above the bell house back down to OEM GT40 exit with a pair of round mufflers I can create a system with 4 mufflers and a decent amount of tube lenght needed to get some DB's out and meet regulations.

Car has a UK registration, but not solid they take it in Holland anymore as rules have changed and Brexit aint going to make things easyer.

 

[Tom]

HI,
This is a picture of original MK3 exhaust manifolds
on one bank cyl 1 is connected with cyl 3
and the other side is cyl 1 & 2 and cyl 3 & 4
and a cross-over pipe of decent diameter

Paul

that looks pretty close to a Tri-Y, so I guess it does fit.

 

[Jasper]

Reason of this topic, present headers allow me to put extra mufflers to meet sound regulations for registration.

If I go straight down to both the side corners and use Corvette C5 mufflers overthere, go back up and with a 180 turn above the bell house back down to OEM GT40 exit with a pair of round mufflers I can create a system with 4 mufflers and a decent amount of tube lenght needed to get some DB's out and meet regulations.

Car has a UK registration, but not solid they take it in Holland anymore as rules have changed and Brexit aint going to make things easyer.

What kind of dB's are you having to pass? Isn't it 95? Thought that was doable with a big muffler each side only.