Hello,

Recently completed top half rebuild on small block.

B&M / Holley Powercharger 144 blower.
Holley Supercharger carb. 700 cfm.
Holley Hi-flow 110 gph mechanical fuel pump.
Dart 72cc iron heads.
Comp Cams Nitrous HP cam.
MSD 6AL ignition kit for HEI.
etc...

The car runs good, but it seems to fall on it's face in the long run.

What I mean is that if I get on it in 1st gear or 2nd it pulls very hard but when I shift into the next gear it seems to pull less and when I go into yet another gear it pulls even less hard.

Does this sound like a fuel problem? I've got a new fat line from the pump to the carb, but still the stock original pickup and line from the tank to the pump.

or...

I thought I might be running out of gear out back, but the car isn't over revving ?

Any ideas?

Please advise.

Thanks

[This message has been edited by Whipple (edited September 19, 2002).]

Of course, ya gotta think that no car is going to pull as hard in 3rd and 4th as it does in 1st and 2nd. My car pulls real good in 1st, ok in 2nd, but not much happening in 3rd. The overall gearing keeps going down and you lose mechanical leverage. Now if the engine itself is showing signs of power loss, its another story. Is it missing or bogging or does it just give up pulling? What is the max boost on the 144, 8-10psi?

Well, there is no bogging or missing.

What you said makes sense...however, my condition seems to be more related to how long I've been on the pedal more than what gear I'm in.

What I mean is that when I get on it in 1st it pulls hard then less with each shift.

likewise... when I get on it in 2nd it pulls hard but then less again with each shift.

As far as the boost, The engine only been together a short time and I don't really know how much boost it's putting out.

According to the pulley diameters I've chosen it should be right around 6 pounds.

I'm using cast pistons and It was suggested to me not to exceed 7 pounds of boost without forged pistons.

Put a boost & fuel pressure gauge on it so you can see just what is doing when you are driving.

I don't think your stock pump is keeping up with the new demand for more fuel.

Disregard the part about the fuel pump. I just reread your post.

I've installed a boost gauge, but have only ran it a few times since.

I'm currently waiting for my MSD box to be repaired and returned.

I did see that it was making boost while I was on the throttle ( under load ). I couldn't tell how much, I just saw the needle had moved from the vacuum side to the boost side.

Kinda hard to read while shifting etc..

I have not installed a fuel pressure gauge yet.

Soon.

Any more ideas ?

Thanks

It's about time to start thinking about spring.

Haven't touched the car for quite a while.

Any other ideas?

Thanks

As for the running out of power ... I don't think its normal due to gears etc, the guy I was racing thought I shut down early. This is how drastic the change in power seems when your driving it.

[This message has been edited by Whipple (edited January 04, 2003).]

Valvesprings?

Replace the fuel lines from the tank to the carbs, install an electric fuel pump & filter at the rear of the car, sump the tank if you can, and make it like a drag/racing car. That way you'll have PLENTY of fuel....and if you wanted to run a small shot of nitrous (after the forged slugs)..it might be good for a 100 shot...