Bespoke exh manifolds
I’m after a 4-2-1 bespoke mild steel exhaust manifold for a Mk1 Escort rhd 1600 ohv Kent engine, but I need primaries of 30mm o/d. I’ve tried a couple of the usual manufacturers, one didn’t answer, and the other, Ashley, told me they bend nothing smaller than 34mm.
Does anyone know of a company that can make one?
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Re: Bespoke exh manifolds
Quote:
Originally Posted by
Frenchenstein but I need primaries of 30mm o/d. I’ve tried a couple of the usual manufacturers, one didn’t answer, and the other, Ashley, told me they bend nothing smaller than 34mm.
They're pretty small primaries for a 1600 IMO - any particular reason?
Re: Bespoke exh manifolds
Quote:
Originally Posted by
Forest_rallying JP Exhausts, Congleton.
JP didn’t get back to me.
Re: Bespoke exh manifolds
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Originally Posted by
katana They're pretty small primaries for a 1600 IMO - any particular reason?
I am curious also.
Re: Bespoke exh manifolds
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Originally Posted by
katana They're pretty small primaries for a 1600 IMO - any particular reason?
Interesting info from David Baker from Puma Race Engines from a little while back.
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Thanks for these suggestions I’ll get on to them.
Cheers
Re: Bespoke exh manifolds
Quote:
Originally Posted by
Frenchenstein JP didn’t get back to me.
Did you phone them?
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You can't beat the Dog and Bone.
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Originally Posted by
Forest_rallying You can't beat the Dog and Bone.
Called them; J & R minimum bend size 35mm
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Originally Posted by
Frenchenstein Called them; J & R minimum bend size 35mm
30mm is very small, i think even the original ford GT spec manifolds were bigger than 30mm
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And no mention of whether it's 30mm ID or 30mm OD.
Re: Bespoke exh manifolds
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Originally Posted by
Graham 30mm is very small, i think even the original ford GT spec manifolds were bigger than 30mm
Hi Graham,
I have two exh manifolds from 1600 Mk2 Cortina’s, they have o/d of 31mm, which I’d go for tbf.
Some more companies to call, tho bemused by “bespoke manifold makers” that don’t do bespoke work!
Re: Bespoke exh manifolds
Quote:
Originally Posted by
Frenchenstein Hi Graham,
I have two exh manifolds from 1600 Mk2 Cortina’s, they have o/d of 31mm, which I’d go for tbf.
Some more companies to call, tho bemused by “bespoke manifold makers” that don’t do bespoke work!
Of course they do bespoke work. But 30mm is a very unusual pipe diameter, they may not have bending equipment for it, if they can even source suitable pipe in that size.
Would you be prepared to pay for custom rolled 30mm tube, and single use machined formers for the job ? Which could run into several thousand ?
Goodfabs would be a very capable shop.
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Originally Posted by
stevieturbo Of course they do bespoke work. But 30mm is a very unusual pipe diameter, they may not have bending equipment for it, if they can even source suitable pipe in that size.
Would you be prepared to pay for custom rolled 30mm tube, and single use machined formers for the job ? Which could run into several thousand ?
Goodfabs would be a very capable shop.
Thank you for the suggestion of Goodfabs.
30mm o/d 1.5mm wall steel tube is readily available sir.
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I have read some of David Baker's articles and he seems a very very clever man that seems to know the theory side of things inside out. He appears to be the UK's Vizard, although he has gone Quite of late.
Unless you are wanting that 30mm exhaust manifold to gain some sort of advantage in a one make series then it seems like a lot of expense to go to for an experiment on someone else's advice. As they say though, nothing ventured nothing gained.
Re: Bespoke exh manifolds
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Originally Posted by
stevieturbo And no mention of whether it's 30mm ID or 30mm OD.
Steve - the OP did sayQuote:
I need primaries of 30mm o/d.
:thumb:
Re: Bespoke exh manifolds
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Originally Posted by
Forest_rallying He appears to be the UK's Vizard,
Psssst - David Vizard IS English but has lived mostly in the States since 1969!
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If you word a question nicely, he may respond here....but he hates people taking the piss asking him to spoon feed them !
https://www.facebook.com/groups/1327314560793748
The morons in charge of PH banned him for telling the truth.
Although he has been quiet lately. It's been almost 6 months since I messaged him to see if he was still ok with all that's going on
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Originally Posted by
katana Psssst - David Vizard IS English but has lived mostly in the States since 1969!
Yes I know his origin, I was reading his articles in the early 70's, thanks for the History lesson anyway.
Re: Bespoke exh manifolds
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Originally Posted by
stevieturbo If you word a question nicely, he may respond here....but he hates people taking the piss asking him to spoon feed them !
https://www.facebook.com/groups/1327314560793748 The morons in charge of PH banned him for telling the truth.
Although he has been quiet lately. It's been almost 6 months since I messaged him to see if he was still ok with all that's going on
I used to read the articles written by DB, MT and yourself on that Forum with great interest especially when Mr Baker did his talks on head work. He would often have handbag fights with Peter Burgess which was most amusing. I think being a Mechanical Engineer was DB's second trade as he was either a Solicitor or a Bank Manager previously, that's why he was so bleeding clever. He could tie people in knots if they got into an argument with him.
I rarely visit that forum anymore all though I never posted, I think judging by the response now very few others do either, even Peter B has gone since pop bang, kia diesel etc got banned for the final time.
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I think Kia diesel was one of Dave's names....he created a few names when they kept banning him. Eventually he just got fed up with it though, and that's when he started the facebook page.
Although as with any such thing it can be difficult to get off the ground, with relevant input etc. I know one user did take the piss and started sending him private messages asking details about build etc, which pissed him off no end. He will assist and give great advice, but he isn't there for handouts or for free consultancies ! He wants people to learn and do a lot of the research themselves.
Re: Bespoke exh manifolds
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Originally Posted by
Forest_rallying I have read some of David Baker's articles and he seems a very very clever man that seems to know the theory side of things inside out. He appears to be the UK's Vizard, although he has gone Quite of late.
Unless you are wanting that 30mm exhaust manifold to gain some sort of advantage in a one make series then it seems like a lot of expense to go to for an experiment on someone else's advice. As they say though, nothing ventured nothing gained.
Ok then, here is the reason:
I have a 1968 Mk1 Escort with a 1600 711M engine, +20 standard pistons, “stage three” burton head, 234 cam, adjustable cam sprocket, twin 40’s; basically a formula engine, meaning if you fit this you get that etc. It goes well enough and I’m happy with it. It makes 220psi, 119bhp @ 5600rpm, can’t remember the torque (typical; power sells cars etc). Good power to weight ratio, the car weighs 840kg wet.
In 1979 my brother in law and I realised that the Heron type pistons were a jolly heavy unit which got me thinking that I could build a quicker revving engine with flat top pistons, using a 1600 Transit chambered head.
Three marriages and six bambino’s, several houses, and associated outgoings later I’m going to build that engine.
Now I have the block and head back from my engineers. I have a Newman Phase 2 cam with 108deg LSA. I will have circa 10.3:1 compression ratio.
Ign. timing will be an adventure.
The engine will be down on power in comparison to the one presently in the car but that isn’t the object of the exercise. With other much lighter items fitted to the new engine it will accelerate through it’s rev range a good deal quicker, and that’s where the fun is.
Now if Mr Baker says that I need smaller primaries to extract those gasses from my “down on power” engine so I can have the most fun from said engine, tell me why on earth would I ignore that info from a man that I have the utmost respect for?
Just saying.
Answers on a postcard please.
Apologies for spelling mistakes, apparent “less than forgiving tone of reply”, it’s my HFA condition and I can’t help it, (that’s my excuse anyway :)).
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Why not get someone that's good with a gas welder to modify one of your Cortina GT manifolds to see if the exercise's going to work or not. That way you aren't laying a fortune out on a bespoke manifold until you are certain things are moving in the right direction. Failing that you could always try a bog std 1100 xf cast manifold, just a thought.
Re: Bespoke exh manifolds
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Originally Posted by
Forest_rallying Why not get someone that's good with a gas welder to modify one of your Cortina GT manifolds to see if the exercise's going to work or not. That way you aren't laying a fortune out on a bespoke manifold until you are certain things are moving in the right direction. Failing that you could always try a bog std 1100 xf cast manifold, just a thought.
Good idea with the Cortina manifold. I could gas it myself (or MIG it).
I was thinking of sleeving the initial few mm of the Escort manifold but I don’t think it will be long enough to make a difference.
(I’ll pass on the cast iron idea. Though I do have a Mk2 Cortina cast iron piece if anyone needs a door stop/boat anchor etc.
Re: Bespoke exh manifolds
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Originally Posted by
Frenchenstein Now if Mr Baker says that I need smaller primaries to extract those gasses from my “down on power” engine so I can have the most fun from said engine, tell me why on earth would I ignore that info from a man that I have the utmost respect for?
Ahhh ! That might explain it. Maybe the terminology was a bit misquoted? When Mr B 'said 'smaller primaries' I don't believe he meant smaller diameter but shorter Length! A shorter length primary will move power up the rev range. Smaller diameter pipes will improve torque up to a point where they become restrictive which 30mm ID will certainly be with a 1600 engine. I'd use 35mm ID or even 38mm ID to let the engine breathe and shorten the primary length!
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I'd just turbocharge it lol....then small primaries would be great.
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Originally Posted by
stevieturbo I'd just turbocharge it lol....then small primaries would be great.
Noooooo lol
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Originally Posted by
katana Ahhh ! That might explain it. Maybe the terminology was a bit misquoted? When Mr B 'said 'smaller primaries' I don't believe he meant smaller diameter but shorter Length! A shorter length primary will move power up the rev range. Smaller diameter pipes will improve torque up to a point where they become restrictive which 30mm ID will certainly be with a 1600 engine. I'd use 35mm ID or even 38mm ID to let the engine breathe and shorten the primary length!
I’ve tried for about two hours (that I’ll never get back) to upload DB’s exhaust primaries table, it comes with an explanation of imperial and metric tube Wall thicknesses and it clearly states O/D’s of pipes, nowt about lengths. I can send the screen shot via WhatsApp if you like, but I’m fucked if I can upload it here. Lol
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And a bit of an argument with some info and other links
https://www.pistonheads.com/gassing/...&t=1393659&i=0
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Re: Bespoke exh manifolds
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Originally Posted by
stevieturbo
That’s the one I can’t upload.
Cheers.
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Originally Posted by
stevieturbo
yeah i just read that, no love lost there!
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Originally Posted by
stevieturbo
to my mind there is one major flaw in that table, its too simplistic, it doenst even take engine size let alone anything else into account
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Engine size doesn't really matter though, ultimately airflow is airflow....and a certain amount of air, will allow a certain amount of power...give or take a few variables.
So whether it's a 500cc engine making 100hp, or a 5,000cc engine...it's still 100hp worth of air moving. Some characteristics may change just.
But as we all know, it should never be just about making a single number in terms of power. We want a good spread of power/torque.