Steve-More RR Info...And A New Question

[Scoobum]

Gonna have him source a new regulator. Joe's a Mopar guy, so I may be able to get one out of Montreal.

Next up. The car shuts off as soon as you let your foot out of it from a WOT blast. The carb was setup in Florida...in hot humid weather.
 
Low 40's here. I'll assume it's not getting enuf fuel at idle? Readjust the idle mix screws...and retry? Where do I source vacuum from to set them?

The 'sight' glass on the two bowls shows fuel at the half...right between the top and bottom of the 'sight' glass. Correct setting?

[nocooler]

Stick a wideband on it Brad!

[Scoobum]

Stick a wideband on it Brad!

If it was MY car I definitely would.

[good2win22]

Brad consider the float level. May be set a bit on the low side and has nothing left after a wide open blast

[Scoobum]

Brad consider the float level. May be set a bit on the low side and has nothing left after a wide open blast

I campaigned a 77 Nova at Cayuga when I was in my late teens to early 20's. I haven't really messed with carbs since then. I'd set the float levels and mixture screws...then make a pass and check the plugs. Never had an issue with a carb going lean when closing the throttle blades quick. The idle 'hunts' on this car...which makes me thinks it's lean at idle. Get on the gas...and it pulls hard.

[reality]

Vacuum guage? or exactly what is the carb and  who played with it??
Iwould think if there was a vacuum leak and somebody tried to tune around it could cause that issue.


a bg or demon?

[Steve Wood]

Brad, I forgot what carb is on it.  Is it a Holley style double pumper?

[Scoobum]

Brad, I forgot what carb is on it.  Is it a Holley style double pumper?

Yeah...checked the vid and it's a 950 Quickfuel.

[reality]

Apparently that problem is not unheard of with that carb. speed talk and yb both have questions on it.

[Steve Wood]

Brad, start with the basics.  Make sure the fuel levels are in the middle of the sight glass and not higher.  Also check the primary throttle blades and see if they are adjusted correctly so that a slight amount of of the transfer slot is showing as it should be.  As you probably know, it is very common to open the primary blades too much which can cause problems because the carb does not switch back to the idle circuits.

Also be sure the fuel pressure is holding thru the run.

[Scoobum]

Thanks Steve. Will check with him if he has an in car fuel pressure gauge this week. Ball park figure what the fuel pressure should be? You can see an AFPR under the hood in the vid...so I can adjust it if need be.

[Steve Wood]

6-7 psi. Not more than 7

[Pyro6]

I know you're asking Steve, my 2 cents. Sight glass aside, if the float level is too high, look down the throat of the carb at idle and make sure there isn't any fuel dripping from the nozzles. The vacuum source you want has to be below the throttle shaft, manifold vacuum. Turn the idle screw in one side at a time, starting on the throttle cable side, as soon as you start losing vacuum, stop. Turn out 1/4 turn. Adjust idle speed again and repeat on the other side. Standard for all carbs, timing must be set 1st tho. Sorry if I'm repeating stuff you already know.

[Scoobum]

I know you're asking Steve, my 2 cents. Sight glass aside, if the float level is too high, look down the throat of the carb at idle and make sure there isn't any fuel dripping from the nozzles. The vacuum source you want has to be below the throttle shaft, manifold vacuum. Turn the idle screw in one side at a time, starting on the throttle cable side, as soon as you start losing vacuum, stop. Turn out 1/4 turn. Adjust idle speed again and repeat on the other side. Standard for all carbs, timing must be set 1st tho. Sorry if I'm repeating stuff you already know.

Carb appears to be brand new...Quickfue l 950. The car is a weapon...and looks to be built professionally ...or by someone that knows their shit. He has a new regulator on the way from Summit...so that SHOULD...finge rs crossed...keep the voltage up to 14...and keep the battery charged. If he gets the car to the track Friday nite...then we'll see what happens when he lets his foot out of it...and if it pulls the same shit again. If it does, I'm bringing along my vacuum gauge and will adjust the carb. If I'm busy with races, then I'll get my buddy Steve with the turbo'd Hayabusa to handle it. He's a licensed mechanic...and prolly still handles this stuff on a regular basis.

Question. I think Holley...or someone...sell s an EFI 'carb'. Could it handle this engine? It's a 440 stroked to 492...and has run a best of 10.5 at 128.

[Steve Wood]

Fast, FITech, Holley, Edelbrock, MSD, etc. all make throttlebody set ups.  Some of these are better known for support than others.

On a car like this, I would probably not choose a throttle body set up because I think Port injection will come closest to extracting power from it close to a good carb and provide better drivability.

When you go FI, you better be prepared to learn to tune for best performance, or be prepared to pay some one to do it for you.  yes, they all self learn but to get serious power across the band, I think you need to fill in the tables and smooth the holes out...