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Discussion Starter #1
Hello. Well making progress but have another issue now. Cant get carb to idle in gear, my friend says it idles fine in neutral but not in gear. Says its dropping from 950 rpm to 550 rpms in gear. Thinks may need a different torque convertor???? I said i will ask the FE gurus and get back to ya! We did upgrade the cam during rebuild, nothing major though. Has a holley 650.... Not sure what other info is needed to help you help me!! Thanks....again!
 

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Discussion Starter #3
GalaxZ, He said he tried that, set it as rich as it would go and still trouble when in gear. He gave holley a call and they said that the carb we are using is for bone stock motor and with all the stuff we did...headers, intake, cam....we needed a different carb. Sound right to you guys? Been looking for a edelbrock, 1405. Anyone have a used one? Real bummer, that was the one thing that had been upgraded when I bought it, so i did not plan on having to fork more money out on a carb! Thanks
 

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Discussion Starter #5
whats done to the motor?

What stall is your convertor?

What gear ratio are you running in the rear?
Complete rebuild, bored .30 over, little hotter cam, not a mechanic...so don't know much more on the details of the motor, but I can sure find out.

No clue on what my stall is, but that is what were thinking it was, and was looking in to replacing that. Called Holley and they told us that the carb just wasn't the right one for our set up with headers and work we did to motor.

9" rear....does that tell you what gear ration I'm running? I got the car last fall and it has been in my friends/mechanics garage almost ever since. Sorry i don't know exact details but I can sure find out if you have any suggestions.
 

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Complete rebuild, bored .30 over, little hotter cam, not a mechanic...so don't know much more on the details of the motor, but I can sure find out.

No clue on what my stall is, but that is what were thinking it was, and was looking in to replacing that. Called Holley and they told us that the carb just wasn't the right one for our set up with headers and work we did to motor.

9" rear....does that tell you what gear ration I'm running? I got the car last fall and it has been in my friends/mechanics garage almost ever since. Sorry i don't know exact details but I can sure find out if you have any suggestions.
Need details on the cam, ( "little hotter cam" ) doesnt exactly mean much. Cam Specs will tell us most of what needs to be known, as far as stall needed IF needed. Carb actually should be ok, not ideal but ok.. Personally I like the Holley's but its your car and your decision on the carb. MHO is not to use the Eddy carb, but its not mine. 9" does nothing for telling gear ratio, guessing would be in the 2:75-3:00 range, should be a tag under one of the bolts telling of ratio, if it hasnt been removed/discarded or changed out. And by richening the mixture as far as he can, what does he mean by that? BTW What did Holley recommend for a carb?
 

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Listen closely. I've tuned motors exactly like this dude's with holley's and I hate holley's, but you need to have him time it ad tune it with a vacuum gauge.

There is a carburetion and or timing issue if it drops 400 rpms just putting it in gear. And the rear gears don't mean anything nor does the stall speed mean anything when the car is at idle.

I think he's running bad timing and he's into the mechanical portion while idling in neutral and the tiny rpm drop when in gear drops off the mechanical timing thus making the car run like crap.

It happens more with holley's than any other carb.
 

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Discussion Starter #8
Ok, here is what he said
"no stall stock converter
motor bored .30 over,rv comp cam with a 268 duration and 496 lift on the cam. edelbrock intake and mad dog full length headers"
didn't get back to me on gear ratio
 

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Discussion Starter #9
Listen closely. I've tuned motors exactly like this dude's with holley's and I hate holley's, but you need to have him time it ad tune it with a vacuum gauge.

There is a carburetion and or timing issue if it drops 400 rpms just putting it in gear. And the rear gears don't mean anything nor does the stall speed mean anything when the car is at idle.

I think he's running bad timing and he's into the mechanical portion while idling in neutral and the tiny rpm drop when in gear drops off the mechanical timing thus making the car run like crap.

It happens more with holley's than any other carb.
Ok, I passed this information on to him. Thanks!
 

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Listen closely. I've tuned motors exactly like this dude's with holley's and I hate holley's, but you need to have him time it ad tune it with a vacuum gauge.

There is a carburetion and or timing issue if it drops 400 rpms just putting it in gear. And the rear gears don't mean anything nor does the stall speed mean anything when the car is at idle.

I think he's running bad timing and he's into the mechanical portion while idling in neutral and the tiny rpm drop when in gear drops off the mechanical timing thus making the car run like crap.

It happens more with holley's than any other carb.
I doubt it's an undersized carb issue at idle.

If the motor bogs that bad in drive, but not in neutral, my guess is that the cam is a bit too lopey for the stall/rear gear combination.

I switched to an x cam ( yeah yeah, I like the idle.) and 3.50s, with a stock stall, as soon as the car was in drive, it'd fall on it's face. Vacuum was good in park or neutral.

upped the stall to 2,500 and viola! perfect idle, doesn't bog and leaps off the line.


for reference, I'd not a holley fan.
 

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Discussion Starter #11
ok, he spoke to holley and this is what they said
'the 80452 holley carb was designed for an oem engine with no cam, the idle circuits are not big enough for the engine with the upgrades. its not the common holley 600 carb, its a Cali emmission"
and to FE
he said that "it drops 400 rpms when i put it in to gear, not when idling. And, the timing is at 8 before top dead center and that its idling in park at 950 rpms and when in gear it drops 450 rpms"

.....sure wish I knew what all this meant!! haa
 

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That cam is not radical enough to be causing your troubles. The effective duration is 218* so you will have a "noticeable idle", as Comp calls it, but that RPM drop is excessive...indicating the engine is not making enough torque to pull against the converter. You need to get the idle down to 750-800 RPM by advancing the timing while backing off the idle screw...and/or obtaining a carb you can really work with, as Holley suggests.

You need initial timing into the mid teens, but also have to more than likely recurve the dizzy to keep it from advancing too far when the mechanical is all in. I think FE's point may be right...you might be getting unwanted advance from the centrigal system because of the too high idle RPM. I would expect around 11-12" of idle vacuum with that cam...maybe more...so concentrate on that.
 

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Discussion Starter #13 (Edited)
That cam is not radical enough to be causing your troubles. The effective duration is 218* so you will have a "noticeable idle", as Comp calls it, but that RPM drop is excessive...indicating the engine is not making enough torque to pull against the converter. You need to get the idle down to 750-800 RPM by advancing the timing while backing off the idle screw...and/or obtaining a carb you can really work with, as Holley suggests.

You need initial timing into the mid teens, but also have to more than likely recurve the dizzy to keep it from advancing too far when the mechanical is all in. I think FE's point may be right...you might be getting unwanted advance from the centrigal system because of the too high idle RPM. I would expect around 11-12" of idle vacuum with that cam...maybe more...so concentrate on that.
Ok, thank you. I'm sure my friend knows, but what does "recurve the dizzy" mean? I am looking for a new stall convertor and carb. Any suggestions on those, what CFM, going to go with an edelbrock, just not sure which one?
 

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Discussion Starter #14
I doubt it's an undersized carb issue at idle.

If the motor bogs that bad in drive, but not in neutral, my guess is that the cam is a bit too lopey for the stall/rear gear combination.



upped the stall to 2,500 and viola! perfect idle, doesn't bog and leaps off the line.
Thanks, which stall did you get?
 

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With "only" about 355 cubes, I'd go with a 600 CFM carb...but others might suggest a 750. The smaller carb should give you a little snappier response from idle, but possibly giving up a little at the very top of the RPM range(which the engine will hardly ever reach...in MOST cases).

A dizzy re-curve is what you do to compensate for advancing the static timing by 10* from stock because the engine will now have 10* too much advance at the limit. You may also want to increase the rate at which the advance comes in. Different springs are available to quicken the advance and different dizzy advance "arms" are available to limit the total advance. Search the FE forum or other places for lotsa info on how all this works but basically, you may already have the proper "arm" down in the current dizzy but it may not be "in play". You've got some reading to do...
 

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Thanks, which stall did you get?

He stated, 2500 stall....

That said tho, your cam is fine with the factory TQ. Not enough duration, nor is there going to be enough overlap to need a "high stall converter"
 

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Discussion Starter #17
He stated, 2500 stall....

That said tho, your cam is fine with the factory TQ. Not enough duration, nor is there going to be enough overlap to need a "high stall converter"
I saw the 2500....I guess I should have been more specific. Was asking which brand to look for, which are good and what to avoid.
 

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Discussion Starter #18
With "only" about 355 cubes, I'd go with a 600 CFM carb...but others might suggest a 750. The smaller carb should give you a little snappier response from idle, but possibly giving up a little at the very top of the RPM range(which the engine will hardly ever reach...in MOST cases).

A dizzy re-curve is what you do to compensate for advancing the static timing by 10* from stock because the engine will now have 10* too much advance at the limit. You may also want to increase the rate at which the advance comes in. Different springs are available to quicken the advance and different dizzy advance "arms" are available to limit the total advance. Search the FE forum or other places for lotsa info on how all this works but basically, you may already have the proper "arm" down in the current dizzy but it may not be "in play". You've got some reading to do...
Yike..ok! Thouroughly confused now! Haa, I will get to researching and reading up on this topic. Thanks
 
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