I just installed my rebuilt engine in my '71 superbug with 87mm Mahle pistons. I can feel the extra power and I was wondering if a 2bbl carb would improve it even more? I don't want to do wheelies, but like the extra oomph. ;D
John,
Which one?
A weber 2 bbl "progressive" or a 36/40 Dell or 36/40 IDF? I've read a lot of posts these past few years and it would appear that one of the main drawbacks to either of these setup's is the need for the best manifold heating/transfer possible. The next hurdle, particularly with the progressive, is tuning the thing. Most performance setups use the carbs mounted close to the heads, unlike a single 2bbl set-up where the distance is extended. This also relates to how good your manifold is!
There is also the EMPI 40mm single setups as well. Note how little pre-heat there is and the fact it's mounted on a skyscraper manifold.
Speaking of manifolds again for the Dell/IDF combo, they are made to fit 44-48mm size carb throat size so there is that factor to consider as well.
Your next task (should you choose to accept this mission ;D) is tapping for manifold vacuum and for the CV feed.
A well respected carby guy mentioned he has hot rodded a 34 Pict 3 up to about 127 cfm IIRC but that is a lot of work such as thinning the throttle shaft and boring the venturi and probably smoothing the flow over every surface imaginable.
I've got a single 40 Dell and AC.net manifold in the shed awaiting various modifications so don't feel it's impossible, just needs careful thought on how to get it all done.
Any of the above applies to duals in whatever flavour you choose with the added complication of all our hosework and CV location thrown in.
Have you changed your jetting in your present carb? That'd be the place to start!
Regards
Volkenstein
I would rather go to twin carburetors
as Sean says, the Manifold does Freeze up and does cause Big problems
during cooler weather...
I have heard that with Twin carburetors. besides getting More horsepower
Your Gas mileage can also get better...
I believe this is hard to do with a single or twin barrel carburetor with long inlet manifolds
I should have gone to twin Kadrons as My Son had them
but I chose to keep My single carburetor and single port inlet Manifold and heads...
I think its related to age.... lol.. ;D :D
Lee
[welcome back from Holidays Sean]