1930 Fordor low compression

[gitudor1930]

Bought a 30 Fordor that did not start, but knew there were some valves sticking. Freed those valves and engine rotates, but very low compression on all cylinders (<10lbs) . Engine rotates with crank easily with no resistance from compression compared to my 30 tudor that runs. Valves open and close as they should now. Head has one crack in water jacket between cylinders 2-3. Tried another head and same results. Distributor shaft rotates. Any thoughts? Some pics of valves and cylinders. Oil in cylinders does not increase compression.

[John]

Time for a valve job.

[40 Deluxe]

Try pull starting it. Tow it about 20-30 MPH in high gear. This will spin the engine fast enough to limber things up and get enough compression to start. Let it warm up as you watch for blow-by and leaks. Obviously, the car must be roadworthy to do this (brakes, steering, tires, etc.).

[Mike V. Florida]

Replace the spark plug with an air chuck and listen for air leaks in the exhaust, intake, oil fill. This will also point to a leak.

Put some oil in the cylinders and see if the compression goes up. If yes your rings are stuck or broken. If no the valves are still a problem.

[michael a]

I'm for give it a pull. It is amazing what heat and oil will do for stuck rings!

[Patrick L.]

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I too would recommend a simple leakage test, doesn't take much air pressure. It looks to me as though there are some valve face/seat issues. I'd pour some ATF in the cylinders and let it soak for awhile.

[Synchro909]

Check your tappet clearances.

[Sunnybrook Farm]

I had a similar problem and had to lap the valves with the suction cup tool and grinding compound. It was a job since some of the valve guides wouldn't come out even with the KW tool so I just did them with the springs off rather than mess up something. I used a standard head gasket with copper spray and finally got good compression. I also put marvel mystery oil in the cylinders while the head was off and let it sit awhile before the start. My motor hadn't been run for over 20 years so all of the problem came from just sitting plus the soft valves they used back in the 50s and 60s. It needs new valves but the next guy can do that.