Join Date: Mar 2014
Location: Los Angeles, CA
Timing and carburetor adjustments
68 camaro, 4 speed stick shift. Don't know much about the heads and what's under the covers as I acquired the car only few months ago and it's a work in progress. Carburetor is a Demon Road 625, Intake manifold Edelbrock Performer, Valve covers are Moroso and the following is what I got form the guy that sold me the car, I just copy everything as he wrote it: professionally rebuilt engine, decked and line bored, balanced, teflon coated skirt, flat top 10:1 pistons, cam, SS comp roller rockers & timing chain, ARP bolts, high volume oil pump.
Now the following is my issue. I've no idea where should the timing be on this one and the carburetor adjustment is another issue.
I idle between 600-700rpm, but the most I could get out of the vacuum is 15. The only time I get around 20 is when the idle is at 1000rpm. With the timing set at TDC. If I advance the timing, RPMs go up, I lower them and the vacuum goes back down. I checked for leaks on both hoses - one from carburetor to valve cover and the other one from the intake manifold to the brake booster. No leaks. Also checked the carburetor on the intake manifold, no leak there, only thing I didn't check thoroughly for leaks are the valve covers, but they look great and from what I can see there are no leaks there.
I know one has to see the car to figure out what's going on as every classic car is different. Do you guys know any mechanic that really knows our cars and how to successfully adjust the timing and the carburetor? I'd really appreciate it. I live in the san fernando valley.