Hi.. I know some of you racers have had experience with running 2.0 3ngines and need some advice.
I have noticed that my engine, 1973 2.0 factory stock, about 4 degrees cam advance, rebuilt factory FoMoCo bosch distributor dual advance cams, pertronix ignitor i, stock oem 1.5 ohm coil resistor wire from ignition to coil. stock rebuilt holly weber progressive 2 bbl 4 speed manual trans seems to have a rough spot at 4000 rpm.
The engine pulls strong from about 2000 rpm to about 4000 rpm and then from 4000 to 5000 runs rough.
I have tried connecting the vacuum advance to the carb port and the manifold port and even run it without the vacuum. Without the vacuum the centrifugal advance seems to have about 20 degrees.
The best low end torque seems to be with initial timing set at 12 degrees, at 1000 rpm, no vacuum advance for total advance of about 33 degrees but runs rough at 4000, with initial timing set at 10 degrees, total at about 28-30 it runs smooth at 4000 but bogs at 2300 rpm and lacks low end torque.
Any vacuum connection seems to exaggurate the problem.
I am considerating a couple ot solutions
1. Replacing oem coil with 3 ohm pertronix coil and wiring the coil to 12 v around the resistor.
2. Recurving the distributor by adjusting the limit tabs in the distributor to limit the centrifugal advance to about 16 degrees so i can set initial at 12-14 and have the total limited to about 28-30.
Also when using a timing light, the light flashes as expected up to 4000 rpm th3n tends to flicker as if either it cant keep up or the coul cant keep up. I am pretty sure the problem is with the ignition rather than a vibration.
I understand these engines had some vibration problems at this range...is this normal?
Has anyone had any experience or suggestions.