Here's my issue. Just completed ground up restoration of a 48 Power Wagon. Everything was rebuilt or replaced. I sent the 230 ci motor to a local mechanic to rebuild. I had every confidence in his ability, he was a helicopter maintenance crew chief in the military during Vietnam repairing helicopters. His son told me if he didn't sign off it didn't fly. Anyway, I gave him the motor with a complete rebuild kit. He bored out the cylinders to .060 over, resurfaced the head, new everything inside including an Isky performance cam. Sadly, three weeks after he delivered the motor he was killed in a car accident.
On the first start up of the motor it ran fine but would backfire through the carburetor at high rpm. We figured a timing issue since I was still running the original distributor. I replaced the distributor, electronic coil, wires and plugs. It runs better but after playing with the timing and carb settings the most rpm I can get is 2800. When I take the truck on a level highway it only gets up to about 38 mph, any more throttle after that and the engine just drops off. I should note, the peak performance I have been able to achieve is 2800 rpm with the idle timing at 34 degrees Before TDC.
I checked compression down the head: 130#, 130#, 125#, 125#, 110# and 130#
It's been suggested that the cam might be off a tooth since I am having to advance the timing so much. That possibly the valves aren't seating at the right time and therefore not getting enough compression when it counts. Also, three of the plugs have electrodes that are white on one side and black on the other. Granted, these trucks new only produced about 4,000 rpm max with top speed of 45 mph but I'm not getting anywhere near that.
