No power under load

[1929ModelAFord]

1929 Tudor. Recently did valve job with guides and springs. Replaced leaking water pump with leakless model. Rebuilt Zenith Carb. Engine idles but has no power. Compression is 60 in all four. Looks like number one and two are not firing. Changed cap, condenser, points, etc. Vacuum good. Installed new ignition switch. WOndering if valves need readjustment. Will be looking for exhaust blockage. Gas flow looks good. Is it possible rings are 'bad' even if I show 60? Looking for any suggestions. Thanks

 

[steve s]

Simplest possibility is that the timing is all messed up. Any other symptoms? runs hot, backfires, starts hard?

BUT, if you know that half your plugs aren't firing, that's definitely the place to start. Does the idle change when you short out the plugs to the head with a large screw driver? If so, that plug is functioning; if not, that plug/cylinder is not pulling its share of the load.

Steve

 

[Purdy Swoft]

You may be getting slow valve action caused by not enough clearance between the valve stem and guide. the one piece guides usually need to be reamed. The foreign two piece guides are mostly junk, I have found one out of three to be useable. If its not too bad you might get by useing Marvel mystery oil in the gas and crankcase. The spark plugs that are not firing may be caused by an out of round upper distributor shaft, there has been a lot of bad ones on the market. I would check the points gap on all four lobes of the distributor cam. I would set the points gap at .022 if the upper shaft or cam is just a little off, this setting will help. I would also check the gap between the rotor tip and the four contacts in the distributor cap body. The Andrews book recommends a gap of .025 and this will work ok but a gap of .035 has worket good for me and I feel the larger gap gives a hotter spark at the spark plugs. If the dist. shaft is really bad, you won't be able to have the same gap on all lobes of the cam or all contacts in the dist. cap and this will cause weak or no spark at some of the spark plugs. Good luck.

 

[Mike V. Florida]

1929 Tudor. Recently did valve job with guides and springs. Replaced leaking water pump with leakless model. Rebuilt Zenith Carb. Engine idles but has no power. Compression is 60 in all four. Looks like number one and two are not firing. Changed cap, condenser, points, etc. Vacuum good. Installed new ignition switch. WOndering if valves need readjustment. Will be looking for exhaust blockage. Gas flow looks good. Is it possible rings are 'bad' even if I show 60? Looking for any suggestions. Thanks

I told you this was the place to post your problem. I'm sure it will get fixed!

 

[Mike V. Florida]

1929 Tudor. Recently did valve job with guides and springs. Replaced leaking water pump with leakless model. Rebuilt Zenith Carb. Engine idles but has no power. Compression is 60 in all four. Looks like number one and two are not firing. Changed cap, condenser, points, etc. Vacuum good. Installed new ignition switch. WOndering if valves need readjustment. Will be looking for exhaust blockage. Gas flow looks good. Is it possible rings are 'bad' even if I show 60? Looking for any suggestions. Thanks

Two things come to mind, poor fuel flow and plug gap.

How good in the flow out of the tank? Is is a good steady stream of about 3, 4 inches? Have you checked the internal screen in the carb?

What do you have the gap set to on the plugs?

Remove the wires from the plugs on on and two leaving a gap of about an 1/8 on an inch. Run the engine and see if you have spark.

Report back you results.