Summary check list
1. Start with distributor cap off. Does distributor rotor turn? If not gear or other part connecting distributor are out (gears can jam or break on a 50+ year old anything). If it does turn, does it turn in the right direction?
2. NEW ITEM NOT PREVIOUSLY MENTIONED. Have you checked the small piece of braided wire on the distributor plate? Corrosion and normal engine vibration will break the wire at one (or both) of the connection points or inside the insullation. It looks normal but no electricity gets through. If wire has not been replaced, recommend you do so on general principles.
3. NEW ITEM NOT PREVIOUSLY MENTIONED: If the distributor is Delco-Remy, check for the stiffness of the bent contact on the rotor. High voltage cannot jump the distance if (as happens over time) the bent contact is worn due to age and does not stay up to contact the piece on the bottom of the cap. If distributor is Auto-Lite, check to see if the spring on the contact in the cap still "bounces" over time these will rust and corrode freezing the contact in place. As it touches the rotor it will wear and if the spring cannot let it drop, again high voltage cannot jump the distance. If in doubt, replace cap with a good new one.
4. Check points and condenser for proper operation. If they have not been replaced in the last 4 years, they should be replaced on general principles. Make sure points are properly gapped. Be sure to check the contact point where the points hit the rotor to open and close. Plastic contacts in particular will wear to the point where the rotor no longer hits and points do not work.
5. Check coil and verify it is properly connected (correct ground) and that you get spark to distributor.
6. REMEMBER THAT WITH TODAY'S GASOLINES, YOUR FUEL SYSTEM ROTS OUT IN ONLY A FEW YEARS! ALL PLASTIC OR NEOPREME SEALS AND COMPONENTS IN THE CARB AND RUBBER FUEL LINES ROT OUT UNLESS MADE TO PROPER SAE SPECIFICATIONS. If you have not had major fuel system components and fuel lines checked/replaced in the last 4 years, they should be checked for fuel-related damage (your EPA at work changing gas formulas almost annually to the point where late model vehicles are suffering as well).
7. If spark plugs are suspected, have them checked at a garage; replace with heat range type A-5 plugs and adjust timing based on 1951 Kaiser-Frazer Shop Manual settings. Helps reduce engine operating temperature which helps deflect vapor lock a bit.
8. Check timing chain for proper operation and tightness. Chains will stretch a bit over time, causing the engine to not hold timing.
9. If the car has at least 9,000 miles on it since last valve adjustment, adjust valves as needed.
10. Pull head to check condition of valve heads and seats; you are looking for valves that appear burnt or otherwise not seating properly. Prolounged use of unleaded gasoline without hardened valves and valve seats will cause valve seat recession and improper seating of valves.
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