total timing and idle problem

[jungledave]

I set the total timing on my 460 chevy to 34degrees at 4000 {depending how close the ballancer marks and timing indicator are and now I can't get it to idle very well. It is a vacume 750 holley. I removed the idle speed screw and cut one flight off the spring and reinstalled for more idle adjustment ot get it around 900 RPM; that is where it has always sounded just right. It sure seems to be open quite a bit for just idle. Distributor is a gm Hei, accell version. Idle mixture screws don't make a bit of difference like it is open enough to be off of power circuit. any ideas holley gurus

[ghittner]

Is this a 4 corner idle circuit carb or two screws only? Are the butterflys all the way closed so that it is reading the air bleeds correctly? Try putting the mixture screws @ 1 turn open and closing the butterflies a bit. See what happens.

[jungledave]

Is this a 4 corner idle circuit carb or two screws only? Are the butterflys all the way closed so that it is reading the air bleeds correctly? Try putting the mixture screws @ 1 turn open and closing the butterflies a bit. See what happens.No it is a vacume carb with two primary idle screws. Maybe I was going out too far to begin with. The betterflies are open a little more than usual but I'll have to see in the morning, my neighbors are already pissed at me for the noise. Thanks.

[H20MOFO]

I'm Just Gussin. Vac Leak? Anyone Run A Vacumn Gauge ?

[jungledave]

I'm Just Gussin. Vac Leak? Anyone Run A Vacumn Gauge ?I don't think it is leaking. It ran and idled fine before I changed it; I had it timed at 10 initial but it was at 40 4k. Now I timed it at 34 at 4k and it is only at around 3 initial. I'll mess with it again after the neighbors wake up.

[gbelt]

3 is not enough initial. You can have it recurved although finding a shop to do it might require some footwork these days. You can do it yourself by removing the advance weights and welding or brazing the slots to limit the total travel. Since it's an Accel unit it might be adjustable. Does it have a vacuum advance on it? If it did I'd check the timing at speed with it disconnected.

[jungledave]

3 is not enough initial? You can have it recurved although finding a shop to do it might require some footwork these days. You can do it yourself by removing the advance weights and welding or brazing the slots to limit the total travel. Since it's an Accel unit it might be adjustable. Does it have a vacuum advance on it? If it did I'd check the timing at speed with it disconnected.Thanks, I just remembred that the dist kit did come with three sets of springs so I will try to put on the light set and go from there.

[H20MOFO]

I'm No Expert For Sure,but I Think The Springs Will Only Effect How Fast The Curve Comes In ,not So Much The Total. Just Went Through A Simular Thing(i Was Kickin Out Over 40 Total) With My Pos Mallory. My Dist Guy I Took It To Made It Look Pretty Easy.

[tbanzer]

Dont waist your time untill your timing marks are verified. I have seen them off as much as 12deg.

[jungledave]

Dont waist your time untill your timing marks are verified. I have seen them off as much as 12deg.Good point. I checked them when I was assembling now that I recal and they were off 2 degrees retarded.

[jungledave]

I'm No Expert For Sure,but I Think The Springs Will Only Effect How Fast The Curve Comes In ,not So Much The Total. Just Went Through A Simular Thing(i Was Kickin Out Over 40 Total) With My Pos Mallory. My Dist Guy I Took It To Made It Look Pretty Easy.You are right I believe but I am not having trouble with the total right now just the initial wich they will effect I believe. The spring that were on it were the strongest of the three they come with. I don't know why it would have advanced that far to begin with. Well any way I found the dist shaft was turning about 4 degrees in the cam gear just now, or so I thought. I pulled it and found the roll pin is loose in the distributor gear. I better have jegs send me a different dist than this POS before I try to run it again. I am lucky I didn't have the roll pin fall out all the was out in the middle of the lake or missalign the gear and ruin the cam gear.

[shaun]

the springs will only adjust at what rpm the dist starts to advance and how quickly... I'm not sure about your setup because mine is a MSD dist but it sounds like yours is adjustable and my guess is there would be a place to adjust total advance. On MSD dists there are little bushings you can change and this only allows the dist to advance a specific number of *.
Also i'm not expert but i think you want total advance at 3K not 4K... thats what i was told but i'm sure it's app specific. With my setup 4K was was too high and the motor ran like crap until 4K.
36-38Deg total timing and 10-15 initial... Thats what i was told to use..

[Warp Speed]

I would lock the advance out.
The mechanical advance is very detrimental to spark scatter (cylinder to cylinder variation and total timing variation) throughout the rpm range.
Lock it out, set it at your 34* total and have fun!
Warp Speed ;)