Hey guys, when i ordered my cam (218\218 @.050, .494\.494) the catalog said a daily driver with a noticable idle, but was talking about everything from a 289 sb to a 460 bb. i figured that in my 429 it would be a relatively smooth idle. i havnt been able to get it to idle straight however. it runs fine but i cant get a smooth idle out of it no matter how much i play with the timing. which is another thing....i cant use my light to adjust that because the marks are off...but i cant tell from sound when i get it right because i can turn the distributor a good ten degrees without noticing any change whatsoever in the smoothness of idle, however if i advance too far it will start shaking and if i retard too much it will start glugging out...anywhere inbetween (i would guess there is at least 20 degrees of distributor rotation there) is a mystery though... do i have a problem here or is this normal for that size cam?

 

this is a very hard problem to deal with. If you have a holley, try adjusting the idle mixture screws. The power valve could be blown, or like you mentioned, the timing could be off a bit. I use a 224/234 .574/.580 cam in my 460 and I got it to idle fine. It sounds "almost" stock (you can hear just a faint lope), so I know that your cam should idle like a stocker, if it's all tuned properly.

 

Im running a 218/228 at .509/.509, and mine idles rather smoothly. You can hear a lil lope through the exhause when I run it open, but you should be near, if not at, stock idle quality.
Try this.. advance your dist until it starts to chop out, then retard it about a quarter way to when you notice it retards. That will put your timing about right on.
Have you checked for a bad plug wire or plug? if it's on the right cylinder, it will sound like it's lopey, but in a 460, you'll still think it runs strong cause there's soooo much power there you wont notice it much.
If you have a holley, there will be 2 air bleed screws on the sides of the front metering block(very small) try turning them counter clockwise (richer). The ideal mixture should be around 1 1/2 or 2 turns out. If the idle smooths out, groovy. if not, pull your front fuel bowl and check your power valve.
If you have a carter/edel, there will be the 2 air bleeds up front. Ideal mixture here ranges from 1 1/2 to 3 full turns out. No power valves on the carter/edel.
These are pretty much the only causes of a missing/lopey engine.. The carb, the dist, or the wires. Check them all, Cause your engine should NOT be running real rough with that cam. Good luck!

J/.c

1965 Ford Galaxie 500 (okay, so not quite a truck)
460/C6 transplant @ 389hp/491 lb.ft.
14.29@103.8, 13-14 mpg heheheheheh

 

Thanks a lot guys, its good to know that i shoudl be able to get a near perfect idle with that cam...now i just need to find the problem. thats a good point that one cylinder could be not firing and it will still have so much power that you would think its a slight miss...been there done that its wierd though, ive adjusted the carb to as good as i can get it, and even tested it out on another truck and it ran BEAUTIFULLY! so its not a fuel problem, it also has a new distributor, new cap\rotor\plug wires\ and plugs...so id like to think ive covered any ignition problems. i have a donor truck parked next to it, maybe ill try a different coil? also, although im sure the timing is off right now, there's just no way to straighten out the idle by messing with it. hmmm, worse case scenario...internal mechanical problem? its wierd though because it sounds so much like an erratic ignition miss. thanks for the help guys, any other thoughts?

 

how bout a vacuum leak? that'll cause a rough idle as well.

 

Given the additional info, it sounds like a definite ign. prob. Maybe you cracked a plug when installing, or tore a wire inside, where you cant see it.. Maybe you got a bad set of wires.. Good Idea to try that coil. Very rarely does a coil go out, but... You never know!! Good luck!

J/.c

1965 Ford Galaxie 500 (okay, so not quite a truck)
460/C6 transplant @ 389hp/491 lb.ft.
14.29@103.8, 13-14 mpg heheheheheh