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Webber chevy manifold
Posted: Wed Sep 02, 2009 7:20 pm
by kiwicar
Hi all
anyone know how well these inletmanifolds flow
http://cgi.ebay.co.uk/NEW-350-400-CHEV- ... 286.c0.m14
Working on the basis they can be opened up to 48mm (minimum) I would be fitting throttle bodies not webbers. They look like a nice straight shot at the port, however there is a bit of a "pinch" where they cross over, any one seen any articles? Has anyone used a set? anyone know anyone who has used a set?
I'm looking at them because they are half the price they were a year ago and that makes them very tempting.
Best regards
Mike
Posted: Wed Sep 02, 2009 8:45 pm
by Eliot
I assume you would intend to put the injectors in the throttle bodies - because I dont think you have room to machine them into the manifold.
Posted: Thu Sep 03, 2009 9:42 am
by kiwicar
Hi Elliot,
I was thinking of putting bosses behind the carb mounting flange where the runner turns down from horizontal, it should be possable to aim right at the back of the valve
Mike
Posted: Thu Sep 03, 2009 10:00 am
by Eliot
I see what you mean - that should work..
All you need is someone local with a tig & lathe then....

Posted: Thu Sep 03, 2009 1:59 pm
by kiwicar
"All you need is someone local with a tig & lathe then...."
I might well be in touch!
Just need to find out If they flow enough air to do the job. They will be sticking out in the fresh air so although the exhaust will be immediatly below they shouldn't cook
Mike
Posted: Thu Sep 03, 2009 2:56 pm
by Eliot
Even if they flow 1CFM - its more than your engine & car is consuming right now?
Posted: Thu Sep 03, 2009 3:22 pm
by kiwicar
OK you have a point !
I have a big issue with funds at the moment (infact for the last few months), something that has come up today may put all spending on hold for a while
Mike
Posted: Sat Sep 05, 2009 10:17 am
by crayefish
Looks like quite a nice set of manifolds.... like the welded steel cross-overs that were made for rovers but with out any vibrational problems on the welds....
So would you want to turn them directly into throttle bodies? Where would you mount the throttle flaps - in a set of throttle bodies bolted on? Why not buy some weber-body style throttle bodies with the injector already on there and just and mount them? If that was the case you would be better off buying the vertical ones that were designed for drlas and idfs etc as they are shorter and also keep the throttle body away from the exhaust which would save you making all kinds of exhaust shields etc.
Posted: Sat Sep 05, 2009 3:46 pm
by bigaldart
I would be very wary of that one mate. Pro-comp parts are of very dubious quality. They are normally a good bit cheaper than other performance parts but the quality reflects the price. Most US forums have thread upon thread of bad experiences with parts from Procomp.
Alan
Posted: Sat Sep 05, 2009 3:52 pm
by crayefish
Is that Pro-Comp as in the people who make the shocks? Their shocks aint too bad for the price.
Just had another look at the item and have to say it does look like a well designed manifold (if you exclude the casting imperfections in the port openings!!!!!!!!).
However did notice one prob... if using the taller style rocker covers (perhaps even the shorter ones?) it looks like the carbs would interfere with them... (looking that the pic with the manifold on the engine).
Posted: Sat Sep 05, 2009 5:31 pm
by Mark
Pro comp stuff is made in China and sold on as if it was made in Australia.
Mark
Posted: Sat Sep 05, 2009 5:47 pm
by crayefish
Mark wrote:Pro comp stuff is made in China and sold on as if it was made in Australia.
Mark
Ah ok, then I assume its nothing to do with the american manufacturer of shocks, springs, lights etc that i mentioned before... full name Explorer Pro Comp
Posted: Sun Sep 06, 2009 11:58 am
by CastleMGBV8
Mike,
I did a quick search on Procomp and came up with an aussie forum, and nobody had a good word for them in respect of the quality of the castings of any of their products. They seem to just be an e-bay trader.
FWIW.
Kevin.
Posted: Sun Sep 06, 2009 5:35 pm
by kiwicar
Hi
I'm aware of Pro comp's route to market, originating made in China, Whole sale to trade through this Australian company (who also retail direct) then through about 4 or 5 US retail sites (they are all the same Pro-comp) at least one US retailer takes the castings out the box repackages them and makes out they are US manufacture. A manifold however has no moving parts and will have to be matched to the heads anyway, when I posted I thought it worth a punt at the price.
I here what is being said here and what is being said.
There are also big problems with the 3 or 4 types of down draught manifolds at least one just joins up the holes with an open "void", although I would rather go for a down draught manifold the cost is high (£2300 from webber without carbs) and they all have issues with tight bends into the port.
As I said above an issue has come up as of Thursday has made it all a bit irelevent.
Thanks for the replies.
Best regards
Mike
Posted: Sun Sep 06, 2009 7:02 pm
by CastleMGBV8
Mike,
Hope it's not too dramatic.
Regards,
Kevin.