"73 1.7. How much roll is typical when the engine first starts up? Maybe 10 degrees or less? Thanks.

Roll?

please clarify

By roll I mean engine rotation around the long or major axis of the car. It's around the crankshaft. Like roll in an airplane. My engine "bucks" a little bit just before starting combustion. You can most easily see it in the surrounding tins side vs. side. The motion is about 1/4" at the tins at the chassis. It only occurs once or twice prior to the first piston kicking in. All motor mounts (suspensions) appear perfect & are tight. Is this normal? The can runs like a champ without any superfluous vibrations or noises.

Sounds normal to me. Is the engine a stock mill?

You've made mention of this starting "kick back" ia couple of times now.

Here's a test for you.

Disconnect the primary side of the coil which should kill spark. Spin the engine.

Is the problem gone?


Another test, this one is mechanically testing the soundness of the motor mounts.

Put the car in 4th gear, engine off.

With a helper push/pull the car back and forth (it won't move far, maybe 6 inches) and get it rocking back and forth between stops. Look at engine while doing this. Is the engine moving too much? Bad mount somewhere. If a mount is completely broken the engine will move quite a bit. 4-6 inches is possible.
Reverse will change the direction of torque and is the next step.

You can sort of do the same thing using engine power and 1st/reverse. Someone's got to watch the engine as you load it both directions.

This works better with automatic transmission cars and "power braking" in both drive and reverse. On some cars one direction the engine will look like it's escaping the engine compartment...

I started my 2.056 on a HF dolly w/o issues. I did have the front engine bar connected so that helped stabilize the engine when running.

I don't understand how a horizontally opposed engine could have any significant "roll" unless a mount is bad?