This is a long story about my (1958-1962) 235 engine that no longer runs; so take a seat.
the engine is set up as follows:
Fenton intake and headers
Two Rochester BC carbs, balanced with a Uni-Sync tool
Original series coil, distributor, wires; plugs are three posts which center over the tip of the spark plug.
Dual, 2 inch exhaust pipes, with LOUD mufflers
the lifters are solid and valve lash is adjusted by the book
I set the timing by using a vacuum gauge; I advanced it until the improvement in the gauge stopped and then returned to the high point.
the engine is hard to start and, initially at 1500 - 2000 rpms, does not run smoothly. Once the engine warms up (3-4 minutes) the engine runs smoothly at 1,000 rpms and is immediately responsive to the throttle
I can not get the engine to run under load; when not under load the engine responds immediately . When not under load it idles from 1,000 rpm to 4,000 + rpm immediately and snaps back immediately every time. suction is identical in both carbs.
When i pulled my 235 engine powered 1951 Chevy truck into the garage it would not idle below 1,800 rpm but otherwise accelerated great up through 4,000 rpm. I fixed the high idle problem and installed a used 261 cam and later a new 261 cam.
With both camshafts I could not get the engine to run over 2,000 rpm, every time I shift from 1st to 2nd it's like the fuel is turned off; the engine coughs, sputters and has zero power/acceleration.
What I don't understand is the truck easily [u]ran[/u] above 1,500 rpm even with then broken the rocker shaft and now it doesn't.
the vacuum gauge shows 14 pounds (?) of suction, close to the end of the red stating "advance distributor timing" and just before the green area stating the engine is running correctly. When running, the needle on the vacuum gauge is rock solid, NO movement.
I absolutely assure you the timing mark is in the right place, before installing the fan onto the water pulley I made an adapter to bolt onto the vibration damper so i could rotate the engine slowing and carefully while setting the valve lash. The settings were done with the pistons exactly on TDC.
Part of me wants to remove the carbs and re-set them up again. i hesitate because they run great now and did before i changed camshafts.
The other approach seems to be looking closer at timing and that's probably where i'll start on Friday.
Any and all help appreciated. Thanks, Ted
