Over carbureted?

[Paul G]

What are the symptoms of having a too big of carb for the engine?

[68X426]

Poor throttle response and "bogging".

Good introductory info on carb cfm from holley: http://www.holley.com/data/TechService/Technical/Selecting%20A%20Carburetor.pdf

[Paul G]

I just rebuilt the 750 dual feed on my 360. It was flooding out badly. Needed new needle and seat assembly's. Put a whole kit on it. Came with a new 65 power valve also.   

I am noticing a distinct bog and lack of power when the throttle is mashed from a stop or a slow roll. Seems to take a while for the engine to "catch up". Cant spin the tires at all from a stop. Hold the brake and build rpm's and it will roast em. When accelerating normally everything is great, no bog or stumble at all when the throttle is opened slowly. Cruises very well. Just that big fat stumble when I mash the gas from a stop. No backfiring, just sounds like the engine is trying to suck air, and no power for about 25 feet, then it rips. 

[elacruze]

750 on a single plane with a big cam/moderate compression may do that...

Mechanical secondaries?
Auto Trans?
Manifold?
Cam specs?
Compression?

[Paul G]

750 on a single plane with a big cam/moderate compression may do that...

Mechanical secondaries?
Auto Trans?
Manifold?
Cam specs?
Compression?

Holley 4160 vacuum secondary's

727 auto, stahl? Not sure the torque converter is healthy.

Edelbrock small block dual plane intake that accepts spred bore or square bore carb.

Cam and compression unknown. Vacuum gauge does not read steady. Needle vibrates back and forth 2 psi at idle. I read that is a sign of a lot of cam overlap?

[lisiecki1]

easy way to check your stall.....start the car, put it in gear, stand on the brakes and give the engine throttle until the tach "hits a wall"....that will give you a pretty good idea where your stall speed is.

[Cooter]

It is possible to "flood" an engine with too much air and not enough fuel too.(lean Bog)...Sounds like your carb doesn't have enough squirter shot....Too muchj air, then the Venturies take over and everythings cool...Therefore, the "bog"...I'd try stepping the squirters up about two sizes and extended..

Also, try different Accel. pump cams to "time" the shot...

[Paul G]

easy way to check your stall.....start the car, put it in gear, stand on the brakes and give the engine throttle until the tach "hits a wall"....that will give you a pretty good idea where your stall speed is.

Standing on the brakes the car starts to pull hard at 900 RPM, tires start to spin at 1400 ish. I got this engine/tranny vibration at 3000 I cant find and a rattle that is coming from nowhere. Add that to the bog I am trying to figure out, I wonder if my converter has gone south?

It is possible to "flood" an engine with too much air and not enough fuel too.(lean Bog)...Sounds like your carb doesn't have enough squirter shot....Too muchj air, then the Venturies take over and everythings cool...Therefore, the "bog"...I'd try stepping the squirters up about two sizes and extended..

Also, try different Accel. pump cams to "time" the shot...

I didnt have this bog problem till recently, along with the vibration and rattling. I rebuilt the carb due to bad needle/seat flooding. Today I tied back the secondary's and ran on the primary's only. Still got that flat spot. I am wondering if it aint the carb at all??

[lisiecki1]

I can't say for sure the convertor is your problem, but with everything I've read about your car and how it's built (badass, by the way) I think you should have at least a 23-2500 stall in it....

I'm fairly sure the factory stall is around 1500, maybe someone more knowledgeable will chime in.

[firefighter3931]

I didnt have this bog problem till recently, along with the vibration and rattling. I rebuilt the carb due to bad needle/seat flooding. Today I tied back the secondary's and ran on the primary's only. Still got that flat spot. I am wondering if it aint the carb at all??

That answers my question on your other thread Paul. Based on what you're describing the TQ conveter has gone south and it's pulling the motor down and causing the BOG. 



Ron

[Paul G]

Any recommendation for a converter?

[FLG]

What size gears are you running? Motor specs? 

[Paul G]

3:91 gears, 71 360 warmed up a bit, guessing around 350+ HP. I was told by the previous owner, who had the engine built, that it has hogged out iron heads, around 10.5 compression, aggressive cam (no specs or cam card), has crane gold rockers under the valve covers, 750 CFM 4160 on an Edelbrock dual plane. She runs good, or used to.   

[lisiecki1]

I would say 2800-3000 to keep it streetable.  Kind of depends on what and how often you use the car.

[firefighter3931]

3:91 gears, 71 360 warmed up a bit, guessing around 350+ HP. I was told by the previous owner, who had the engine built, that it has hogged out iron heads, around 10.5 compression, aggressive cam (no specs or cam card), has crane gold rockers under the valve covers, 750 CFM 4160 on an Edelbrock dual plane. She runs good, or used to.   

I like the Dynamic 10in street/strip unit for that application....very efficient at lower engine speeds. 


Ron

[Paul G]

How are TCI converters?

I went and talked to the guy who does the maintenance on our company vehicles today. He agrees that the converter is not healthy. He is a Mopar gear head to boot. He has a used TCI "Street Fighter I think" 10" converter that he bought about 8 years ago for a race car he used to have. It was used in a big block, but was too low of a stahl so he only used it for a few passes at the track and took it out. He will sell it to me for $100 + install labor if I want it. He said it is an externally balanced converter.

Is it worth it or should I pass and get a Dynamic.

[firefighter3931]

How are TCI converters?

Hit or miss from what i've seen over the years 

.
Is it worth it or should I pass and get a Dynamic.

If it were mine I'd be purchasing the Dynamic 



Ron

[c00nhunterjoe]

whatever you buy make sure you have a nice sized trans cooler to keep teh temps down. higher stall converters get tranny fluid hot quick around town