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tips, technology, tools and techniques related to vehicle driveline components

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roverman
Art Gertz
Winchester, CA.
(2841 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Two IDF's, Offy manifold for RV8 ?
Posted by: roverman
Date: January 06, 2017 12:40PM

I'm trying to convince Offy to mod their casting, to accept IDF Webbers. This should be more desirable than antique, Rochester 2bbl's ? Any interest out there ? Thanks, art.


Moderator
Curtis Jacobson
Portland Oregon
(4274 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: Two IDF's, Offy manifold for RV8 ?
Posted by: Moderator
Date: January 06, 2017 06:43PM

Nearly anything is more desirable than Rochester 2bbls.

The younger crowd don't care about Webers. Instead, they buy used motorcycle carbs on eBay.

But the future isn't carbs, it's throttle bodies (for EFI).


joe_padavano
Joseph Padavano
Northern Virginia
(105 posts)

Registered:
02/15/2010 03:49PM

Main British Car:
1962 F-85 Deluxe wagon 215 Olds

Re: Two IDF's, Offy manifold for RV8 ?
Posted by: joe_padavano
Date: January 10, 2017 12:41PM

The dual 2bbl Offy is NOT your first choice for performance. It is for looks only. Nearly anyone who uses that intake wants the look of two Rochesters or (better yet) Strombergs. There will be no market for that intake machined for newer carbs. You probably stand a better chance of getting Offy to sell you one that doesn't have the carb flanges machined.


mgb260
Jim Nichols
Sequim,WA
(1716 posts)

Registered:
02/29/2008 08:29PM

Main British Car:
1973 MGB roadster 260 Ford V8

Re: Two IDF's, Offy manifold for RV8 ?
Posted by: mgb260
Date: January 10, 2017 01:59PM

Art, I have a picture of one with Weber's:
webber%2048%20IDF.jpg



Edited 1 time(s). Last edit at 01/10/2017 02:30PM by mgb260.


roverman
Art Gertz
Winchester, CA.
(2841 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Two IDF's, Offy manifold for RV8 ?
Posted by: roverman
Date: January 10, 2017 06:45PM

Big surprise, Offy sells more 215/RV8 manifolds to England and Europe, than here. Will "they" want Rochesters and Strombergs ?


DiDueColpi
Fred Key
West coast - Canada
(1173 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
What if the Hokey Pokey really is what it's all about?

authors avatar
Re: Two IDF's, Offy manifold for RV8 ?
Posted by: DiDueColpi
Date: January 10, 2017 11:17PM

To me Art, the only reason to run a 2x2 or even a 3x2 manifold is for the looks.
They will under perform a well done 4bbl manifold every time.
Throttle response, fuel economy and power will suffer.
But you will gain the endless joy of continuous carb and linkage adjustments accompanied by backfiring and fuel standoff.
If you must run a multi carb manifold, give the Moon eyes setup a look. They use stromberg replica carbs plumbed for fuel injection.
You get the looks, close to 4bbl performance and no fuel leaks or "gas in your hair " if you have a convertible.
They are based on the SDS fuel injection which is ridiculously easy to use.
Save the webers for a 1 barrel per cylinder application. That's what they were designed for and excel at.
If I were going to run a "multi carb look" manifold. I'd use the Offy, gut a pair of 2GC marine carbs to use as throttle bodies, hide a fuel injection spider from a GM Vortec under the manifold and run an ECU of your choice.
It wouldn't be easy, but it's simple and reliable, probably better power and throttle response than the 4bbl, with the old timey good looks.

And that's all me and my evening scotchy scotch have to say!

Cheers
Fred


roverman
Art Gertz
Winchester, CA.
(2841 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Two IDF's, Offy manifold for RV8 ?
Posted by: roverman
Date: January 12, 2017 01:15PM

Wow Fred ,a lot of good info. ! Wish you spotted my "OEM injection or ? " post. Centrifugal supercharger at 8-12 psi. manifold pres.on E85. Target hp. is 50 hp. per 30 cu. in. cyl., total (6) air cooled. Fairly likely, I will make billet aluminum/nicklsil barrels, with 92 mm Mahle/VW pistons. Thanks, art.



DiDueColpi
Fred Key
West coast - Canada
(1173 posts)

Registered:
05/14/2010 03:06AM

Main British Car:
What if the Hokey Pokey really is what it's all about?

authors avatar
Re: Two IDF's, Offy manifold for RV8 ?
Posted by: DiDueColpi
Date: January 12, 2017 05:50PM

That's only 100hp per litre Art, totally doable.
Are you messing with a Corvair by chance?

Live like you mean it.
Fred


roverman
Art Gertz
Winchester, CA.
(2841 posts)

Registered:
04/24/2009 11:02AM

Main British Car:
74' Jensen Healy, 79 Huff. GT 1, 74 MGB Lotus 907,2L

Re: Two IDF's, Offy manifold for RV8 ?
Posted by: roverman
Date: January 16, 2017 11:12AM

Fred, yes, in a 914,(Chalon). Pretty lost on best injection for E 85 street use. Thought is to mount TB. right at the cent. blower inlet. Intercooler likely unneeded. Hyd. roller cam, reverse rotation. Info on doing this seems mystical ? Thanks, art.


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