1939 Ford Deluxe Coupe, 85 hp. V8. Holley 94 rebuilt carburetor, 59000 miles showing, but odometer is not working. Non ethanol gas is used.
Heads were removed for inspection. Engine appears to have never been overhauled based on inspection of pistons and valves. Pistons and valves heavy with dry carbon. Nothing wet around piston/valves. All pistons stamped STD and do not wiggle, do not appear to be loose. No wear sign around cylinder walls, no ridge at top of cylinder. There is evidence the intake manifold has been removed at one time. ??? Compression test run from 77 to 89. Engine does not knock, sounds like a Singer at idle.
Car starts and idles well enough but does not run well particularly under load. As I shift through the gears it runs progressively worse as speed/rpm’s increase. When I accelerate in first gear about the time to shift to 2nd it’s rough, shift into second and it runs pretty good until it’s time to shift to third when its rough again. At steady speed is porpoises badly. With footfeed on floorboard it begins to stall and gets progressively worse until it would stall out. It does not backfire. Carburetor leaks a little. Not sure where the body is leaking.
The electrical system has been overhauled: new plugs (two sets of H12) gapped at .025, new plug wires, rebuilt coil from Skip, new condenser, new points, new rotor (Ford Script) new distributor caps, gaskets, new ignition switch, etc. Plugs torqued to 25 lbs. Head nuts torqued to 50lbs.
The carburetor has been taken down twice in an effort to solve the problem. New kits were used both times and great diligence was used to clean and properly adjust the carb based on sound and experience. Vacuum line is clear. Fuel line is clear from tank to carb and properly filtered.
I am receiving conflicting information from people I respect who have a good degree of mechanical knowledge about old cars. Their experiences range from Porsches to Packards, and one has lifetime experience with Early Ford V8’s. We all are nearly as old as the car for what that’s worth!
One suggest “the engine should be overhauled. It’s old, its background is unknown. Most cars from this era are due for overhaul at 60 to 70,000 miles. There probably is a ring problem and/or bad valves. Everything else has been tried and not solved the problem. It’s time for overhaul.”
Others suggest “it is a lack of air. There is not enough air to properly burn the fuel being delivered. Most likely is the carburetor, more specifically the Venturi. Could even be a rag left in the intake, but there is an air restriction. The marginal compression readings are not bad enough to cause the degree to which the car runs so poorly.”
What is your take on the situation? Thanks for your response.
BF
Heads were removed for inspection. Engine appears to have never been overhauled based on inspection of pistons and valves. Pistons and valves heavy with dry carbon. Nothing wet around piston/valves. All pistons stamped STD and do not wiggle, do not appear to be loose. No wear sign around cylinder walls, no ridge at top of cylinder. There is evidence the intake manifold has been removed at one time. ??? Compression test run from 77 to 89. Engine does not knock, sounds like a Singer at idle.
Car starts and idles well enough but does not run well particularly under load. As I shift through the gears it runs progressively worse as speed/rpm’s increase. When I accelerate in first gear about the time to shift to 2nd it’s rough, shift into second and it runs pretty good until it’s time to shift to third when its rough again. At steady speed is porpoises badly. With footfeed on floorboard it begins to stall and gets progressively worse until it would stall out. It does not backfire. Carburetor leaks a little. Not sure where the body is leaking.
The electrical system has been overhauled: new plugs (two sets of H12) gapped at .025, new plug wires, rebuilt coil from Skip, new condenser, new points, new rotor (Ford Script) new distributor caps, gaskets, new ignition switch, etc. Plugs torqued to 25 lbs. Head nuts torqued to 50lbs.
The carburetor has been taken down twice in an effort to solve the problem. New kits were used both times and great diligence was used to clean and properly adjust the carb based on sound and experience. Vacuum line is clear. Fuel line is clear from tank to carb and properly filtered.
I am receiving conflicting information from people I respect who have a good degree of mechanical knowledge about old cars. Their experiences range from Porsches to Packards, and one has lifetime experience with Early Ford V8’s. We all are nearly as old as the car for what that’s worth!
One suggest “the engine should be overhauled. It’s old, its background is unknown. Most cars from this era are due for overhaul at 60 to 70,000 miles. There probably is a ring problem and/or bad valves. Everything else has been tried and not solved the problem. It’s time for overhaul.”
Others suggest “it is a lack of air. There is not enough air to properly burn the fuel being delivered. Most likely is the carburetor, more specifically the Venturi. Could even be a rag left in the intake, but there is an air restriction. The marginal compression readings are not bad enough to cause the degree to which the car runs so poorly.”
What is your take on the situation? Thanks for your response.
BF
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