Someone please explain this to me!

Motorman 407 · Post by **Motorman 407** » Tue Jul 12, 2005 2:50 pm

With a singel carb one fuel bowl need to feed 500 hp and with dual carbs one fuel bowl only need to feed 250 hp.
More pump capacity is needed to keep up with the fuel draw out of that singel set up. The BG 280 pump will not supply enough fuel for your application the 400 pump will be a better choice.

Rick360 · Post by **Rick360** » Tue Jul 12, 2005 4:35 pm

The same volume of fuel is required in both applications to make the same HP. If the needle/seats and regulator(s) are sized properly then in most cases the same pump would work in either case. If the needle/seat are too small then the regulated pressure to the bowls would need to be higher on a 1x4 application to flow the needed volume of fuel thru only 2 needle/seats, which could require a higher pressure pump.

If anything the regulator would need to be bigger on a 1x4 to make sure the pressure stays constant with the sudden flow of fuel at WOT.

my $0.02
Rick

Joe Mendelis · Post by **Joe Mendelis** » Tue Jul 12, 2005 6:09 pm

Two carbs means less restriction. You would think that would lower your BSFC. Maybe it doesn't. Atomization not as good...? Either way, I don't understand why you couldn't easily get in the ballpark of what you need.

bill jones · Post by **bill jones** » Tue Jul 12, 2005 10:59 pm

-the way I see it is it's all about having to get 250 HP (say 125PPH) worth of fuel thru one needle and seat or do we have two to work with.
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-It is damn hard to get 250PPH of UNAERATED fuel into each bowl on a single four barrel where if you have two carburetors with 4 needles and seats it's a piece of cake because you only have to get 125PPH per needle and seat.

sheppard00 · Post by **sheppard00** » Wed Jul 13, 2005 7:29 am

I'm not a carb guy at all but is seems to me that the pressure drop that the regulator has to compensate for would be more gradual in the 2x4 set up so the pump would have more time to get the momentum of the flowing fuel up to the carb's demand... now on the single carb it will be sudden regulator will open fast and the pump will have to get the entire lenghts wort of fuel system flowing to speed a lot faster so it may have a better chance of going lean on sudden launches than the 2x4 set up..

does this make sence to anyone else?