1968 Riviera 430

An engine with 120 psi of compression is going to turn a lot harder than one with 60 psi of compression.

What you're describing does not sound normal, however. The starter should spin this engine very easily. Realistically, this engine should have 150+ psi of cranking compression.

Are you sure you don't have a starter or wiring problem? Have you tried turning the engine with a socket and breaker bar/long ratchet?

Did you ever verify cam timing as I suggested earler?

 

I agree that this does not sound normal. It seems as though there is some mechanical interference, friction, or something when the car is turning over. Don't know how else to explain other than the vibration and sound that you hear and feel when sitting there starting the car. But I don't claim to have a calibrated rear end so I might just be way off there.

I agree also that 150 psi sounds right for a good engine. When I did the compression testing initially, the engine had between 120 and 150 psi in every cylinder. I would like for it to have been more uniform and perhaps I didn't seal the compression gage into the spark plug hole tight enough or something else that may have caused some variation cylinder to cylinder. I am kind of trying to figure this out as I go along. I haven't done this kind of stuff before.

I am not sure of anything other than I am breathing right now. The engine turned over okay initially but not great as it was dragging a little bit. I charged the battery for a little while which seemed to pep up the starter pretty well.

One of the wires going to the starter is a bit frayed and could be repaired but honestly I suspect it was that way originally before the issue. I might dive under there and see if I can clean it up a bit.

I haven't turned the engine over with a socket and breaker bar / long ratchet. I can try that I suppose to ensure that it is not locked up.

As far as verifying timing, we put two different timing sets on and aligned the dots both times while insuring that we were at tdc on compression stroke for #1 cylinder. I haven't done any more than that at this point.

Someone suggested that the gas may have washed out the oil on the cam bearings and when I heard that, well I figured that I was defeated. I will try to repair the starter wire and also try to turn the engine over with a breaker bar. I will see if I can spot anything else that looks a little wacko. Thanks for the suggestions!

 

HOW did you align "the dots"? Crankshaft gear dot will be "UP", but was cam gear dot UP, or cam gear dot DOWN?

If the cam gear was dot down (typical), you will have to turn crankshaft one revolution before installing distributor with rotor pointing to #1 plug wire terminal. Otherwise timing is 180 degrees off, carb will spit gasoline, engine may or may not backfire, but it WILL NOT run. This does not guarantee that initial timing is close enough to get the engine started, but at least you'd be close--and perhaps lucky.

CHARGE THE BATTERY, fix the starter cable. ASSURE that the engine is at TDC #1 COMPRESSION stroke, and NOT at TDC #1 EXHAUST stroke; and that rotor is pointing toward #1 plug wire terminal.

There are all sorts of possibilities including MIS-MARKED timing sets, you should look for the rockers to have both #1 valves VERY SLIGHTLY open at TDC Exhaust. The distributor rotor will be pointing to #6 at this time. Watch #1 intake valve close, exhaust valve will begin to open. The moment you detect movement of exhaust valve, look at damper/timing pointer--you should be very close to "0 degrees", perhaps a few degrees either side. THEN look at distributor rotor--better be pointing to #6 terminal.

 

I think you can get this motor running. From what I've read here you are narrowing things down well. But it will
run. I don't think the motor is spinning over fast enough to start and your timing/distributor is not set well
enough to fire easily. Pull the distributor and spin the oil pump with a drill and get your oil pressure up.
Install the distributor and verify firing on the compression stroke. Fix the starter wiring to guarantee
full cranking power. Charge the battery to full or use a verified good/new one. Maybe round up a buddy
to give you a hand with the distributor settings. It will run!!!!