Thread: wont idle right with the lumpy cam

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yep worked for me on a setup kinda the same and i didnt really mean for it to offend neone cept maybe monte man lol i dont like giving ppl advice that is in the opposite direction of what should really be goin on and thanks man you have helped in tha past on this matter if you recall lol thanx alot its the old guys like you that make rodding fun everybody enjoy your rides and all the knowledgable advice in these forums and others like em chow...

btw thyphoon i cant say nething bad about the old mans club it is in my future you know lmao

but yet again im quite certain that dumpin more fuel would only make this guy have even more of a headache and wanted to clear this up before he took it to heart.. he needs more air less fuel in his mixture and theres not a screw on his carb that can make his mixture right hence the holes in tha flys..lol but what do i know check out some of the other post on this and many other forums for your answer...

i'm just waiting for my new intake then i'm gonna start dickin with the carb seriously

i have a HEI spring kit for the advance arms theres 3 different sets... light, medium and heavy spring tension which would be best to use if any..........would this help with no vaccum advance

What I try to do is pick the heaviest springs and the lightest weights. In this way the advance won't happen too soon thereby causing predetonation under heavy load. Also I pick weights and cam curves which will only allow for 12-16 degrees of advance at 3000 plus rpm. in this way if you have the distributor set at 38 degrees @ 3500 rpm, then at idle you will have 22-26 degrees, making for good throttle response.

what exactly are the weights an cam curves

Ok, Jay, when you remove the distributor cap, and then the rotor, you will see two swinging metal pieces which have the form of a “C” with a spring attacked to each one. These are the weights. In the center of these two weights is what is known as the cam which is responsible for how much advance and when it happens during operation of the motor. The weights come in contact with the cam.

Now, you can grind the weights in order to lighten them and you can grind the cam to determine how much timing you will achieve via rpm. The springs are largely responsible for when the advance happens. If you happen to grind one weight a little more than the other, it is no big deal, it really doesn’t matter because both weights work as a team.

It is a bit of a hit and miss tuning that one has to do and it may take you several attempts to achieve the desired performance. But what you are trying to do is ensure that no more than 16 degrees are possible out of your distributor. So after you have done your little dirty deed, start up the engine and see what has happened.

The neat thing is that you do not have to remove the distributor or change the timing when you adjust the weights and cam. For the biggest part, if the timing is set right to begin with, it will stay set during this procedure. In the end, you obviously always have to set the timing dead accurate for optimum performance and also to ensure you do not have too much timing in the stationary setting.

As for the cam, I have found that in some HEI distributors the cam is not removable. In such a case, you will have to manipulate the weights for the desired effect. Oh, watch out for the little c-clips which hold the cam in place. If you lose one, it is almost impossible to find them again. I use a tiny needle nose pliers to hold these little suckers while removing them or installing them.

Good luck. Let me know how you sleep at nights before and after doing this.

hmmmm...would it make a difference just changing the springs.i dont know if i wanna go through all the grinding work...i want mainly bottem end and midrange i dont scream it a whole lot.....my buddy used the weakest spring on his it works alright almost a little gutless though....maybe b/c its a 283...

i just put my car back on the road today it worked pretty good..when the idle is under a bit of load it sounds awsome and when its not its still off.....when i change my intake in a couple days i will put some holes in the butterflies and see how it works..

i noticed that my carb has a flat spot at low rpm taking off.... theres a delay then it jumps in.....its really annoying i had a quad do this before...any idea why???

The carb may need bigger accelerator jets or even a bigger pump. Changing the rate the power valve opens also helps.

well heres an update....i got a new intake a dual plane airgap and a 600 cfm edelbrock....i put it in and it worked good i drove it for about half a day with no prob...i went to take it out that night and if ran like crap it'd idel extremely low then as soon as u touched the gas it'd jump up in a big hurry then idle would change back and fourth....sooooo i thaught maybe the intake gaskets cause every one said it sounded like a vaccum leak so i changed the intake gaskets and was extreamly carefull putting the new ones on... and it didnt much more and was pretty much the same. and i checked with brake clean for leaks.....then i was driving the other day and as far as i know the fuel pump went(mechanical)....so i changed it with another one i had. i tested it and it ran 6-7 psi.....still ran like crap...so i changed hte fuel filter and ran a clear on near the car to see whats going on....when it runs the filter seems to only have a little fuel in it but it stays constant...sometimes its completely full and sometimes very low and sometimes it getts fuller as it sits for a while...when its running u see the odd air bubbles come up in the filter so i tightened all my connections....i'm running outta ideas here i might try an electric fuel to see if it makes a difference......when i get on it its not to bad until the secondarys kick in then it like falls on its face and makes alot of burping noise...i took of the pcv valve it made it runn a little better...any ideas to help me i'm loosing my mind here.....

I didnt read much of this thread but I do remember one engine I had that had a big cam and it ran like crap too and there seemed to be no cure. It rocked and burped at idle and when I took it for a full on speed run it would just fall flat when I really throttled it at higher speeds. If I was easier on the throttle it was alright....thought this to be a vacuum problem or distributor but it wasn't. I swapped out the old heads for some new aftermarket World Products Sportsman IIs and it made a world of difference. The thing purred...as much as a huge cam can purr at idle and ran like a top afterwards. You might just need some more flow in the heads. Keep in mind I didnt read the thread and I don't know what heads you have on it. Port whatever you have or put some better flowing ones on...thats if you don't have them already. Other than that I think everyone else probably answered some questions.

sorry the carb isnt the prob i have a 305 duration cam in the 350 and it idles great with stock heads may need to check for vacuum leaks and invest in an adjustable vacuum advance... and get some bigger jets and if it is a vacuum sec get some lighter springs for the secondarys and set your vacuum advance up with lighter springs so the timing will kick in sooner... the prob with the lumpy cam is that its a low vacuum cam so you have to adjust all the vacuum settings
also dont hook the advance up to your port on your carb hook it directly into your intake for full advance
that should help
you might have to drill some holes in your butterflys to equal out the fuel air mixture .... btw if the prob persist you should check for vacuum leaks around the bottom of the carb intake and the line that runs down to your tranny

Sounds ot be lean....... so, richen the jets by 6 sizes and then test it.