I am an old car newbie and I need some guidance on troubleshooting an issue with a 1951 Chrysler Flathead 6. I was driving the car at low speed (less than 20 mph) when it shut off on me and would not start back up. It turns over, but will not start. I checked for spark, no spark at the plugs, and traced the issue back to the distributor. I first replaced the points, rotor, etc., still no spark. I realized the rotor was not turning and proceeded to pull the distributor and replace it with a tested NOS distributor, still no spark and rotor was still not turning. I did some research and thought that it might be a broken timing chain. I dug into the engine, removed the chain cover and the chain and gears/sprockets are in great shape. I cranked the engine over using the keys and the cam and crank sprockets turn, I seem to be getting compression on the cylinders, and there are no odd sounds when the engine turns. What's my issue?
Was the old distributor stiff to turn (turning the shaft in the dist. body) when you pulled it out? also have you done a compression test? more importantly if you're looking for a timing belt you're not going to find one (they are chain driven not belt).
The gear on the camshaft that runs the distributor is broken or stripped. It looks like that gear is an integral part of the camshaft, so you will need to get another one (just a guess, I'm not very familiar with that motor). I would pull the distributor our and look down the hole at the camshaft while cranking the motor over. Posted using the Full Custom H.A.M.B. App!
I'd rather bet on the driven gear that is on either the distributer or oil pump shaft rather than the gear on the cam, however, in either case the motor will be easier to work on if removed from the car, as it needs to come apart, or at least pull the pan, to find out why the pin that locked the gear to the shaft sheared off : something stopped the shaft from turning, & that something is usually inside the oil pump. This is an engine-saver, as the motor stopped ; if it hadn't lack of oil would have damaged the bearings &/or crank/rod assembly.
The distributor drive on those is on the top of the oil pump. The oil pump shaft has the driven gear on it. If you pull your oil pump (you don't need to drop the pan, it comes out from the side of the engine), you will find your answer. Could be the drive tang on the bottom of the distributor has snapped off,or it may be a stripped drive gear on the pump (easy fix, get a new pump) , or stripped drive gear on your camshaft (not so much fun, camshaft has to come out). If you find that the trouble was caused by a locked/jammed oil pump, open it up and check what it was. It may have swallowed a nut or washer from somewhere else in the engine.
The oil pump seized. Seen it on Chrysler sixes a few times, also Ford 300 sixes and Y-blocks.. As stated above, the pump on your engine is external, comes off easy. I don't know how something running in oil can seize, but it happens more often than you would think.
Every MoPar I ever saw had a intermediate shaft with the gear on it and that drove the distributor and oil pump. BUT, I never had a flathead six apart. '32 Bangers, yes. Dodge and Chrysler hemis, yes. B block wedge. Same deal. But maybe the six has the gear on the oil pump. It's got to be somewhere. Maybe the cam broke. Something in there is no longer driving the distributor. When you look at it I think you will know it.
On the flat head six the distributor tang drops into a slot in the oil pump drive gear. The oil pump is driven by the camshaft. You stated that the timing gears and chain turn so that leaves the oil pump gear or the cam shaft gear that has sheared some of its teeth. I once had a distributor top ball bearing come apart and locked the distributor shaft and striped the gear on the camshaft. I would have thought that the distributor shaft tang would have sheared but it did not and the cam gear did. I had driven the car to a doctors appointment and parked and went inside. When I went to start the car it hit and quite trying to start. Pulled the distributor cap and turned the engine over with the starter and had no movement in the distributor, the gear must have sheared when I tried to start it.
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