Carb direction?

[Rumble Fish]

Gents,

I am going to try running a Tunnel Ram with two Holley’s on my engine. My question is: do I run them in-line or sideways? I’ve seen both and would like to know the reasons behind each.

Tha

[pishta]

Sideways gives them a smaller footprint on the mount, but inline would be my choice with side hung bowls and jet extensions, the linkage is alot easier too. sideways also uncovers the front jet on acceleration, cant really extend a jet to the side of the bowl. Im sure someone has a setup that could verify or bunk this, but the fluid dynamics are all there. Remember to tie in the vacuum pots on applicable carbs.

[B1owner]

If you have good tunable carbs with the secondary metering blocks, you have to run them sideways. There isnt enough room to butt them end to end if they are longer carbs due to the secondary metering blocks. If you mount them sideways, make sure you use the center hung bowls, and if it REALLY flies, put jet extensions on.

[B1owner]

Originally Posted by pishta

Sideways gives them a smaller footprint on the mount, but inline would be my choice with side hung bowls and jet extensions, the linkage is alot easier too. sideways also uncovers the front jet on acceleration, cant really extend a jet to the side of the bowl. Im sure someone has a setup that could verify or bunk this, but the fluid dynamics are all there. Remember to tie in the vacuum pots on applicable carbs.

Pishta, what do you mean when you say it gives a smaller footprint? The butterflies are symetrical an a standard bore Holley.

[rumblefish360]

Originally Posted by B1owner

Pishta, what do you mean when you say it gives a smaller footprint? The butterflies are symetrical an a standard bore Holley.

It's not the butterflys, it's the mounting holes to the intake.

[B1owner]

Originally Posted by rumblefish360

It's not the butterflys, it's the mounting holes to the intake.

The bolt pattern is symetrical also...

[pishta]

Footprint as in the total area the carbs occupy on a dual quad top. Since there is a distance between the two mounting pads, you need to determine if the carbs are going to have to fit sideways, as in center hung bowls as the bowls are physically larger, or inline if you can because the bowls are flat sided and shorter. Some are large enough to run either way, but that makes for a very long top, most have to run side hung inline or center hung sideways. Look up an Offy dual quad and youll see a note saying "Carter/Edel only, no Holley,even staggered."

[B1owner]

The bad part about running them end to end is it makes jet changing a pain. If you run them sideways then you wont have to remove the carb to re-jet. Thanks Pishta for clearing that up, didnt know what you meant.

[B1owner]

Originally Posted by B1owner

The bad part about running them end to end is it makes jet changing a pain. If you run them sideways then you wont have to remove the carb to re-jet. Thanks Pishta for clearing that up, didnt know what you meant.

Im talking about Holleys here of course!