Hey all, I'm relatively new to posting things on the HAMB but I feel that I am out of my depth with my current chevy 350 build. About 2 years ago I dropped a brand new crate 350 in my 1962 impala and this past summer I decided it was about time to install an edelbrock top end kit consisting of new heads, a cam, intake manifold, cam and crankshaft gears, and timing chain giving me 338 hp and 389 tq. Ever since the rebuild (completed 1 month ago), I have been having issues where on a cold start I will need to keep revving the motor until the temperature gets up to about 140 degrees or else the engine will die. Once I get the engine up to a temperature where it can keep itself running, the idle is very low (about 300 RMP's) and the idle continues to rise as the engine gets up to temperature (around 200 degrees). Once the engine gets up to temperature everything sounds good when I rev the throttle, but when I actually get behind the wheel and drive, I start getting a lot of noise out of the exhaust 2500 RPM's and up (It sounds just like a Harley.) I also feel like the car should be more responsive in the higher RPM's. I suspected that it might be a timing issue so I did a lot of tweaking of that but no matter how I have it set, the problem persists. I also thought it could be a result of my old dirty edelbrock 1400 carb, so I rebuilt the carburetor but I did not replace the jets or metering rods. when that didn't fix the problem, I tried putting different sized springs in the pistons of my metering rods but that also failed to solve the problem. I also suspected that my electric choke could be the problem but all signs show it is working properly. Could the problem be that I need to change the jets (which were fairly old and rusty looking) in my carb, or could it be a vacuum leak that I have failed to locate? I also was wondering how likely it could be that my valves are out of adjustment, due to the fact that I have never lashed valves before?
For one thing your automatic electric choke is not working. Cold start idle should be close to 1500 rpm. An engine should never idle at 300 rpm. Also sounds like you have a lean mixture. Bones
Where are you located? Maybe another Hamber can come over and give you a hand. Or you may have to bite the bullet and take it to a shop. You could have late timing, you didn't say whether it was a flat tappet cam which could have some flat lobes by now. You could have a vacuum leak. You could have the valves too tight ,or too loose or a combo of both. You may have to have your carb gone through by someone who knows Edelbrocks. You say the carb was rusty looking inside ? Do you have water in the gas ?
Jack..............honestly, do you know much about 'hopped-up' engines and how to tune them?! NOT being ugly!! If you didn't adjust the valves and think idle speed of 300RPM is OK....you may need to check several thinks before you can get this puppy straightened out. We can walk you thru a lot of it but, if you're not familiar with what we tell you then out side help may be your best hope. Unless a HAMB'er can come give you a hand you might be time & money ahead by finding a shop that knows "hot-rod stuff" 6sally6
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