Re: Don’s 1937 (120) 138CD Deluxe Touring Limo

Posted by Bob J On 2024/5/5 18:38:46

On the distribution tube: feel inside the opening, there is a hole in the inner wall of it, take a wire like a coat hanger and bend a tight hook in it, insert it in the hole and tug the tube out. It is tapered so as soon as it starts to slide it will come free and the rest of the travel is quite easy. Mine looked like yours, so it too should slide out fairly easily. Mine was empty for years with no frost plugs so was glued in with mouse house yet still came out fine.
I used Permatex (thinly!) as a sealant throughout the rebuild.

Your compression results look like work needs to be done. You are getting a drop in compression due to either worn valves/seats, or worn rings/cylinders or likely both. A valve job is fairly straightforward on these anvil heads. I have heard a check on rings can be done by adding some oil (STP?) to the cylinder through the sparkplug hole to temporarily seal them. By doing a test again after the STP type additive it may show whether it is rings or valves. (If compression goes up, the rings are worn, if it is the same, it's the valves)

You may be able to test the valve's seating by removing the sparkplugs and the valve covers, turn the motor over until both valves are closed, spray a penetrating oil at the valves through the sparkplug hole and look for leaks. May show up any bad seats.

You and I know that an 87 year old engine would be best to have the engine rebuilt at some point. If the compression is showing wear, it would not be isolated to the combustion chamber. Con Rods, Mains, Oil Pump, Cam/bearings are also VERY likely in need of rework. It will never be cheaper than right now, and it does not get any easier as we get older either! Also, the parts to do it right will not be around for ever either.

Makes going out touring more fun when you are not worried about the engine.
It's all very well to have a beautiful kitchen in your house, but if the foundation's cracked and the roof is leaking...?
Bob J.