Carb offset on intake manifold?

[Alex]

I've been contemplating having a custom carb intake manifold made (by an expert such as Beck or Marcellas)

One thing I've tossed around is if it's possible to offset the carb on the intake manifold, such that instead of being in the centre of it, it's more towards the rear of the engine (to help with clearance issues).

Assuming that the runners and overall design is built to compensate for this, is this a bad idea? Obviously it'd be a bad idea to take an OEM one, start chopping it and move the carb pad backwards, but if one is designing one from scratch.........

 

[Randy V]

Not necessarily a bad idea as long as the plenum design has relatively equal length runners to each of the cylinders. Even then, the runners just need to be close. Reference the design differences between a single plane and dual plane intake manifold..
I have seen (many years ago) Offenhauser Carb offset elbows. They also raised the carb about 3" from what I recall...

((Can't believe I found it))

Offenhauser Part Number 5497 - shown here;
Offenhauser 5497 - Offenhauser Carburetor Adapters - Overview - SummitRacing.com

I would think that the additional plenum volume might not work well at higher RPMs and that there may be some fuel pooling issues in the lower RPM (subject to cam profile and other things) - but as long as it was tuned properly on the dyno, it should work for you..

 

[Alex]

Another idea to add to the thought pool I guess.

Btw, that carb elbow is just plain WEIRD!

 

[Doc Kaler]

Alex,

What is this thing you call a "carb"? :drunk:

 

[Alex]

Alex,

What is this thing you call a "carb"? :drunk:

I'll draw one onto a stone tablet and send it to you

 

[Terry Oxandale]

The ford engine has always had the runners of basically two different lengths on the same manifold (single plane type) with great results, so I cannot see where an offset would be detrimental. My best intake I ever ran was the old Edelbrock Torquer (the first iteration) with the rotated carb (15º or so).

 

[Mike Huddart]

Another idea to add to the thought pool I guess.

Btw, that carb elbow is just plain WEIRD!

Alex,
those offset "elbows" were sold in pairs to convert in line duall four barrel manifolds to the "cross ram" set ups that were all the rage in the late '60s. Like the Chevy Z/28 302 and sundry Chrysler models.
OK, they weren't that efficient but at least you got "the look" !!

Mike

 

[Ron Earp]

That is cool. A pair of them would look bad azz on the T70, sticking out and over the rear bodywork. And I'm sure would be the root cause of many problems.