my new engine i converted to carb is running after it is shut off or dieseling, i was told this could be from to low of a compression and to big of a cam. i have s/r torquer heads and a lunati cam that has a duration at .05 of 227/233, lift is .489/.504, 670 street avenger, dual plane manifold, low compression, around 8.5/1, stock temp. ac delco plugs?

 

At what RPM does the car idle at?

How many degrees of timing?

If the car is idling too high and has too much timing at idle it would cause the car to run on after you shut it off.

You will have to find the right combination that works.

 

it idles around 700-750 with 8 degrees of advance

 

That's a familiar cam, the voodoo 60103, I had one a little while ago.

Your throttle blades are open WAYYYY too far. Bump up timing to around 18* base, and close down your throttle blades i'd say.

That's too low of a compression ratio for that cam for sure.

Check the mixture at idle, and check the plugs. You may need to go to a colder plug, but with that low of a CR, I doubt it.

 

i had the same problem when i drove my new engine for the first day, need to lean out mixture, and work with timing, see what work best for you.

 

thanks for the advice, my other question is would it be easier to to up the crompression by getting the heads shaved, they are 76cc cambers or just get some differnet pistons for it, by the way if i do go with new pistons, can i use the old rings, engine has less than 5000 miles on it.

 

if you get new pistons, you should be able to reuse your rings. Most people will say no, but I would do it if it were me. (and I have...)

It's a toss up, new pistons would require a full on rebuild, shaving the heads wouldn't. You can't get all that much by shaving the heads though, lest you have to shave the intake to match. Do the math and see what you come up with vs what you want the final CR to be.

 

what would be the minimum compression recommended for this cam 9.5/1?

 

I had this problem because of too much timing was heating up everything in the combustion chamber, and i also had 9.5-1 compression on 87* till i changed it, i would say 9.5 would be very beneficial to this cam.

 

Yea, 9.5:1 would be pretty good. I had 10:1, it worked awesome, really brought back my bottom end.

 

my other question was how are the flow rate on s/r torquer heads w/2.02 and1.60 valves compared to some stock vortecs, i was thinking about switching over since the smaller chambers in the vortecs would up my compression?

 

That's a good idea. I'm not sure what those torquers flow, but i'd be willing to bet the vortecs flow better. Remember you'd need a new intake manifold though.