Carb Orientation?

Right now I'm running my 600 cfm Holley 4 Bbl so the bowls are facing front and back because if you run the carb so the bowl faces side to side it will hit the shock tower.

Would there be any performance increasce if you did orient the carb so it sits side to side?




I want to know theory and real world experience, not it should run better because I say so....

I'm considering notching the shock tower to make it fit. I'm also an experienced Bodyman/frame tech/painter so I've worked on hundreds of unibodies so I know how to notch a shock tower PROPERLY and SAFELY so dont concern yourself with that prospect of it....

Also what about the fact of the fuel rushing to the side of the bowl on launch vs the way it sits right now as far as the jets are concerned?

I realize that there are other less drastic ways of making the carb fit like making a new adapter plate and shaving the intake but I can pull the carb, cut the tower, reweld it and paint it in 2 or 3 hours so thats the most expedient way for me too do it.

Thanks,

Doug

Don't have my Holley book with me at work, but if the primaries and secondaries are equal size, shouldn't make any difference at WOT if the secondaries open all the way. Had my Holley mounted both ways on my 300 six and didn't notice a difference. From the design of the manifold it looks like it would get better fuel distribution if the primaries were mounted closest to the shock tower. One barrel to feed 3 and one to feed the other 3. The way you have it now, the primaries would have preference to the front 3. Just my two zinc pennies worth. Alex.

Back in 1986 , I had a customer come in and show me his combo , nice Inline combo, 68 Nova 250 six , but he complained of hesitations and different plug readings. This was a street car NOT an all out race setup , he had the cab oriented like a V-8, like most of what Ive seen here, this is not a jab just an obeservation ans asteticly it looks great , BUT , if you look at 2.3 Fords ( an example ) the primary is usually situated toward the Valve cover, , anyway we did that exact thing on the Nova and got great results , now I have never Flow benched the combo , but I also built a 225 slant six and it also worked best with primarys facing the valve cover ( 14.50 at 94 mph ). ( these were Vac secondary carbs ) on a race car and with mechanical secondarys I believe there would be less difference because of the lack of time spent at part throttle.

Thats what I'm starting to get now that I've had my plugs in for awhile so I can read them. The front 4 look slightly lean and the rear 2 look rich.

I know I can jet it up further yet by looking at my front 4 plugs but if I do then I fear the back 2 will be running too rich.

I'm always looking to pick up another 10th or so in the qtr so I was thinking this might do it.

Last Friday night it went a 14.58 @ 92 with a 2.05 60' on BFG T/A street tires.

What do you guys think about the fuel flowing away (or to the side) of the bowl away from the jets? Is this gonna be a problem. 1.99 or 2.0 60' times will not be a problem once I get some drag radials on it.

A lot of tunnel ram cars run thier carbs sideways, do they do anything differant with the jets or bowls?

Thanks,

Doug

Is the carb inclined slightly forward? The machinist who modified my log made my adapter with a 4* inclination to compensate for float bowl fuel slosh on acceleration. I have no idea whether that would have any effect on uneven distribution once the mix has left the carb, though. Just a thought (and a question, since I'm curious about the new head design details).

Doug,
If you do decide to mount the carb sideways, get some Braswell Circle track floats. They have bevels on them so when the fuel sloshes toward the rear of the car, the bevel will allow the float to drop so you won't starve the motor.

Personally I don't think turning the carb would make any performance or even driveability difference. I haven't tried it though so who knows!

Later,
Will

Will, Doug has the side mounted float bowls.

I know they make many different floats for the center mounted float bowls.
The only side mount floats are for jet extensions.

http://www.braswell.com/products/floats_1.htm

Braswell has some fantastic holley parts.

There floats are far superior to holley floats, be it duracon, brass & nitrophyl. Bill

wsa111":jdvir7ge said:

Will, Doug has the side mounted float bowls.

Click to expand...

Ummm....I guess I should've looked at the pic a little more!

Then there shouldn't be much of a problem with this then.

Will

Doug, check out the link to my post on this. There are pics showing the clearances at the tower and the adaptor plate.

http://fordsix.com/forum/viewtopic.php?t=49364&highlight=

Granted you would have to fab a different adaptor plate and your spread bore dimensions are a tad larger but this may work for you if you want to mount 90 degrees to the crank.

I'm affraid I can't comment with the performance issue. I don't run the quarter mile at all.

I also have the drawing for the adaptor if you need it. Good luck, Ric.

I just checked my Holley book and most of the 600's had 1 1/4" primary venturies and 1 5/16" secondary venturies with 1 9/16" throttle bores for both. Alex.

Is the carb inclined slightly forward?

Click to expand...

My carb sits reclined back slightly.

If you do decide to mount the carb sideways, get some Braswell Circle track floats.

Click to expand...

What Bill said

Ric,

Just checked it out. I can do the cutting and welding faster than the machine work can be done

I just checked my Holley book and most of the 600's had 1 1/4" primary venturies and 1 5/16" secondary venturies with 1 9/16" throttle bores for both. Alex.

Click to expand...

Thanks for the info!

I guess I'll just have to do it this fall and report on the results back in the spring.

Thanks for the input!

Later,

Doug

Doug, if you turn the carb sideways you might try using a turtle, which may help direct the airflow. I'm going to see about having some made so I can test them on a flow bench and dyno. If it helps, I may try to design one for a modified (Holley/Autolite) log intake as well.