Advise on carb selection.

440sportfury

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I have a 68 440 hp motor which I had redone. It has 10.1 compression, A lunati voodoo cam Adv duration int/exh 270/280. Duration @.050 int/exh .515/.530. It is a roller cam. There are Edelbrock rpm heads with full int porting,full exh porting (stock gaskets) no chamber work. It has a edelbrock CH4B intake ported The intake was gasket matched. Port plenum, drop divider. The motor has 458 horse at the crank and 500 ft pounds torque. It was done 3 years ago and basically went into the body shop. It had a quick fuel 780 on it. The car is running terrible, flooding,surging and popping. It will not improve with any adjustments I wanted to go with an edelbrock 750 or 800 electric choke vacuum secondaries. There are several models. I was looking for someone who has similar set up for advice. The quick fuel carbs people swear by but I would prefer to go back to single feed and a stock appearance. I am not going to race or beat on car just looking for reliability. The motor is in my 1968 Plymouth sport fury convertible. Thank You sorry for long post.
 
Are you positive that it is the carb?
 
I have a 68 440 hp motor which I had redone. It has 10.1 compression, A lunati voodoo cam Adv duration int/exh 270/280. Duration @.050 int/exh .515/.530. It is a roller cam. There are Edelbrock rpm heads with full int porting,full exh porting (stock gaskets) no chamber work. It has a edelbrock CH4B intake ported The intake was gasket matched. Port plenum, drop divider. The motor has 458 horse at the crank and 500 ft pounds torque. It was done 3 years ago and basically went into the body shop. It had a quick fuel 780 on it. The car is running terrible, flooding,surging and popping. It will not improve with any adjustments I wanted to go with an edelbrock 750 or 800 electric choke vacuum secondaries. There are several models. I was looking for someone who has similar set up for advice. The quick fuel carbs people swear by but I would prefer to go back to single feed and a stock appearance. I am not going to race or beat on car just looking for reliability. The motor is in my 1968 Plymouth sport fury convertible. Thank You sorry for long post.

I have pretty much the same setup and horsepower with my 400 in a 78 NYB. I'm having pretty good results with a Holley Quick Fuel 750 SS carb.

20181013_095944.jpg
 
Are you positive that it is the carb?
When the motor was put in the car the mechanic cracked the base. They replaced the base but It was never the same. The car went into the body shop where it sat for a little over 3 years. They said they where running the car at least once a week which I don't believe them. A few weeks before I got the car back the body shop said it was hard to keep running and they had to adjust it. I picked the car up it ran terrible as it warmed up it ran worse. the car kept popping in the exhaust and surging. I put all the adjustment screws back to factory settings. When the car sits it soaks the plugs. In all honesty I wanted to put an edelbrock on it from the beginning. A friend of mine suggested the quick fuel and would not give up so I reluctantly bought one. People swear by them . I personaly do not like the double fuel feed. Thanks for any suggestions. The car ran perfect on the dyno. with this carb.
 
I have pretty much the same setup and horsepower with my 400 in a 78 NYB. I'm having pretty good results with a Holley Quick Fuel 750 SS carb.

View attachment 259105
Thanks people swear by them. I think the base being replaced. and sitting for so long did not do it any good. I personally prefer the single feed as that and the carb as the car looks like a stock 440 to most. It has stock painted valve covers the heads were rounded off and the edelbrock logo was filled in. To someone with experience they would figure it out but to most it looks stock. I would prefer the edelbrock with the single fuel feed. I just am not sure of an 750 or 800. Your motor looks great thanks for the reply
 
I've got a freshly restored Edelbrock 750 electric choke on the shelf. If you would like to try, I'll send it to you. If you like it, buy it. $290 plus ship
 
What runs well on a dyno might not run quite so well in the car, I suspect. How'd they manage to crack the base plate? Which makes the key question is "Did they get one from QF or Holley?"

A more operative question might be how fresh the fuel in the tank is! Kind of sounds like it might have accumulated some moisture with those years of basically being unused/idle.

Chrysler did have some factory 4160 Holleys, over the years. So the only "non-stock" item would be the cosmetics which QF adds to their products. The Holley 3310 780cfm carb (which was used on many Direct Connection recommended components back then) had the normal dual-inlet situation. With a normal single-inlet Holley, the fuel gets to the rear float bowl via a "balance tube" (sealed by O-rings, which can be a source of fuel leaks if not installed correctly). The Holleys with the "race bowls" that use the dual inlet don't have that balance tube, so the dual inlet set-up is a better way to do things, for Holleys, from what I can tell. Better fills the secondary float bowl in "high fuel demand" situations, which is why it was "invented" years ago.

So, drain the tank and put new fuel in it and see if that helps after the new fuel gets in full circulation.

Just some thoughts,
CBODY67
 
What runs well on a dyno might not run quite so well in the car, I suspect. How'd they manage to crack the base plate? Which makes the key question is "Did they get one from QF or Holley?"

A more operative question might be how fresh the fuel in the tank is! Kind of sounds like it might have accumulated some moisture with those years of basically being unused/idle.

Chrysler did have some factory 4160 Holleys, over the years. So the only "non-stock" item would be the cosmetics which QF adds to their products. The Holley 3310 780cfm carb (which was used on many Direct Connection recommended components back then) had the normal dual-inlet situation. With a normal single-inlet Holley, the fuel gets to the rear float bowl via a "balance tube" (sealed by O-rings, which can be a source of fuel leaks if not installed correctly). The Holleys with the "race bowls" that use the dual inlet don't have that balance tube, so the dual inlet set-up is a better way to do things, for Holleys, from what I can tell. Better fills the secondary float bowl in "high fuel demand" situations, which is why it was "invented" years ago.

So, drain the tank and put new fuel in it and see if that helps after the new fuel gets in full circulation.

Just some thoughts,
CBODY67
HI Thanks
 
HI Thanks
Hi Thank you. The base was cracked when they dropped the carb. The owner said it was overtightened either way it broke . They used a direct replacement from quikfuel.When I got it out of the shopit was very unpredictable it would run well then next minute it ran terrible.I ket getting the small backfires in the mufflers. The body shop took the car for there supposed 6 month job which turned out to be over 3 years. They said they started it at least once a week. I doubt it I went down drained the fuel and put new in. It ran but not well. About two weeks time they were moving it back and forth and they said they had to adjust carb it was running terrible. I picked it up it did not drive bad at first but then stated pulsingand popping in the mufflers. when the car is shut off over night it drain all the gas out and floods the engine. I backed off the screws and put them back to factory settings but it still runs like hell.
 
Possibly, with that (generally) rich base mixture calibration of the QF carb and the cam specs, possibly the engine didn't run long enough for things to get fully cleaned/warmed-up out after a cold start? End result, some fouled spark plugs, possibly. Maybe some condensation inside the distributor cap, even?

If you've already got the fuel system with refreshed fuel, then a more-normal carb might be something to try.
 
Possibly, with that (generally) rich base mixture calibration of the QF carb and the cam specs, possibly the engine didn't run long enough for things to get fully cleaned/warmed-up out after a cold start? End result, some fouled spark plugs, possibly. Maybe some condensation inside the distributor The car ran agood half hour and was always kept I a heat and humidity controlled building . I just wante to kow if I could go with the edelbrock 758 or th edelbrock 750
 
I am a BIG fan of the Edelbrock carbs with electronic chokes. Some friends have had great luck with the Demon carbs.
 
Sounds like a float problem.
Should be easy to tell, quick fuels have sight glass in the side of the float bowl.
 
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Sounds like a float problem.
Should be easy to tell, quick fuels have sight glass in the side of the float bowl.
Hi I adjusted the level to the line on the sight glass and it stays at that level. When I start the car it is so flooded I am amazed that it even runs. once it clears up it seems to run fairly ok. if you step on it a little it will stumble and get a lot of popping in the mufflers and the exhaust will burn your eyes from being so rich. I have set it lower than the mark and still the same. I know they have a great reputation but I was thinking if I have to replace it The edelbrock would be a better choice. I was wondering which model would be recommend I was leaning towards the 750 electric choke vacuum secondaries. Thank You
 
If you look down the carburetor when it is idling does it drip fuel out of the boosters? It may have a internal vacuum leak. I know old Holley's would due this die to warping. With what yours has been through I wonder if something has gone wrong.
Overtightening is a problem.
Just some thoughts.
Another problem could be the air bleeds are clogged sitting in a body shop, God knows they always have crap flying around in the air.
 
If you look down the carburetor when it is idling does it drip fuel out of the boosters? It may have a internal vacuum leak. I know old Holley's would due this die to warping. With what yours has been through I wonder if something has gone wrong.
Overtightening is a problem.
Just some thoughts.
Another problem could be the air bleeds are clogged sitting in a body shop, God knows they always have crap flying around in the air.
Thanks for the response. when I take the air cleaner off and look inside I don't see anything dripping but I get a very strong fuel smell. I agree with all the dust flying around also. This carb has gone through an awful lot. I'm going to give the Edelbrock 750 vacuum secondaries electric choke a try. Thank you for your advise
 
FWIW, I have had good luck with the Thunder Series from Edelbrock.
Thunder series is a good carb. Like the AVS with tuning spring loaded air door, better than the AVS in that it has real Venturi and boosters in secondaries. It would be my choice if I was buying a new street carburetor.
 
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