sports exhaust/extractor manifold

Engine Oily Bits, Ignition, Fuelling, Cooling, Exhaust, etc.
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valencia
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sports exhaust/extractor manifold

#1 Post by valencia » Fri May 07, 2021 9:35 pm

Hello everyone,
after reading the many excellent articles in six appeal recently I was particularly drawn to the re-print of the SAH tuning road test and engine modifications. Considering what can it seems be done to our cars do many of you have any experience with extractor manifolds and a sports exhaust system.
I was particularly wondering what power increase might typically be expected, and does such a system produce a lot of extra noise ? My car is a 2000 mk2, an early car Nov 1969 and all standard. At present it has the original cast iron manifold and a stainless system from double S in Devon which has been on since 1993 and still intact, this system is the small bore tailpipe and two centre silencers type.
It would be great if any of you could share your experiences before I embark these modifications, I imagine I would get the parts from CW.
Thanks for any input.
Michael.

Rod 2500S
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Re: sports exhaust/extractor manifold

#2 Post by Rod 2500S » Sun May 16, 2021 4:35 am

Gday valencia
just checked online, extractor manifolds are running between 450 and 550 quid. Yep for that price I'd want a guarantee of increased performance. FWIW you should get an improvement in gas flow resulting in more Hp. Should!!!!!!!!!!!
Probably better to have the head rebuilt with unleaded seats and perhaps a basic port and polish etc. Some other points:
What carbie/s are you running?
What's the basic condition of the motor? etc
Cheers

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valencia
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Re: sports exhaust/extractor manifold

#3 Post by valencia » Wed May 19, 2021 2:15 pm

Hi, at the moment I'm on the standard stromberg 150 and the engine is all standard, rebuilt about 40k miles ago so compressions about 130-150 range. The exhaust mods seemed easy to swap bits rather than taking off the head for rebuild which I didn't fancy doing. By the time I have a manifold and exhaust plus odds and ends, vat ➕ post not much change from a £1000 so still making up my mind. The car even as is seems fairly lively on a 4.1diff and they're not heavy cars compared to moderns but we all like a bit extra.

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Alec
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Re: sports exhaust/extractor manifold

#4 Post by Alec » Thu May 20, 2021 5:53 am

Hello Valencia,

I don't think just adding an extractor manifold will make a lot of difference, it really needs improvements to the head, a better cam and possibly larger carburetors to get all the benefit.

Alec
0465

MK1.5 2.5 P.I.
Jaguar MK 2 (Long term restoration.)
Hymer 564 Motorhome.

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valencia
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Re: sports exhaust/extractor manifold

#5 Post by valencia » Thu May 20, 2021 12:56 pm

I see, I need to do a full job then to get proper benefits,
just what I needed to know really, for the time being it can stop as it is, thank you for the wise words 👍
Michael.

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