Inliners International Forums General Discussion Blown and Injected blowthru 250 clifford holley 2bbl orientation

When installing the carb on my 250 with a clifford intake, does it make much difference if the throttle shaft (and thereby the position of the throttle blades) are parallel with the engine or perpendicular? The carb adapter will let it mount either way.

In searching, I could find pics of the carb mounted both ways. Clifford site didn't indicate a preference.

Seems like perpendicular might affect the fuel distribution with one bore so close to the 3 and 4 intake opening and then it seems that installing the carb parallel might affect how the carb itself functions (floats and bowl slosh) during acceleration.

What are your thoughts?

The project is a 67 c-10 with a 250 six blowthru

As long as you have it tuned and jetted correctly, it really doesn't matter. Carbs are used in both orientations with no real gain or lose either way. On the 292 dyno tests that tlowe did recently, the carbs were on the intake with the shafts perpendicular to the engine because the dyno throttle controls work front to back , but when placed in the vehicle, they will need to be turned parallel to the engine because of throttle cable routing. So its probably preference more than anything.

There is always the possibility of running a bellcrank if youn want to mount the carb in a diffeent orientation. But as CNC said, there's no real advantage.

Most will mount with the shafts parallel, because it makes a bit of sense for fuel distribution. But, if you're blowing through, I don't think it'll make much of a difference.

Also, good to see you over from the 67-72chevytrucks.com board.

-Sam.

Personally, I prefer to place the secondaries or primaries outboard. It theoretically gives a better fuel mixture to all cylinders.

The internal shape of the hat has a strong effect on mixture distribution (at least, on a 4 bbl.). Some of the "looks cool, must work well" hats favor front or rear barrels, and not only make for weird plug readings and knock sensor reports, but less power. This is evidently not easy to predict, since the number of commercial hats that don't do well is fairly large.
Here's one that supposedly works, notice the larger radius above the air-horn, and the separator.

Panic, do you have much intel on good blower hats vs not so good? I am in the market for one and would appreciate the advice.

The one pictured is a nice one.
The ones to stay away from are the low profile ones,but if you have no hood clearance,what can you do?
Cut a hole in your hood?
I have a Shaker Pontiac Trans Am scoop off to the side of the hood on my Camaro.

Most people that see it,,thinks I dont know where the center of the hood is .LOL.


MBHD

Now that's funny.