[Phil Waterman]

Hi Bob


Just started working on the throttle linkage for the 235 and Pattern 12. I originally put a 1953 216 in the Pattern 12 and the water pump and thermostat housing were enough different that the original throttle cross over shaft would not fit period. I fabricated a totally new cross over shaft assembly.

The 235 is still running in on the test stand, I’m addressing several little issues. I’ve got 10+ hours on the clock now on this engine and just as with the one other rope rear main seal engines after running for some real time it has started to weep just a little. Just enough that with a clean piece of paper on the drip pan on the test stand I can see a fine line of oil drops after the engine has run for an hour. So I’ve got to do some real checking to see what is causing the leak, though they ground the crank and fitted all new bearings during the rebuild machine work, I forgot to tell them to grind the rear main seal surface. If that is the cause then the fix is simple speed-sleeve over the seal area. That was the fix on the 1953 216 and it has worked well. What is strange is that there is more oil on the left side of the bell housing than on the right, this might mean two things that I can think of one that the oil passage plug on that side is leaking or that the oil is leaking bye on only one side of the rear main, I can not remember if I shimmed the rear main. If the rear main surface is smooth and clean then I’ll just replace the rope and be extra careful of fitting of the seal. I really don’t think the replacement gasket is as good as the original.

I’m going to replace the exhaust valve rotators to see if I can get rid of a click. Did a compression test on the 235 this afternoon with the engine fully warmed up about 190 degrees all of the cylinders are right at 130 psi +/- 2.

I’ve got to clean the radiator on my test stand because it just can not get rid of the heat with the engine at 1500 rpm it comes up to 190 even with auxiliary cooling on the heater connections, I have to heater cores with a blower hooked up. I think my problem is that my main radiator fan just is not moving enough air. I’m getting a 15 degree drop across the main radiator and I’m getting a 20 degree across the heater cores. The 235 is running 180 thermostat.

I want to do these engine swap once each truck then I just want to drive the trucks for 30 years without touching the engines.

The reason I pick 30 years is that is how long I’ve driven my HUP without ever tearing the engine down. The 216 engine in the HUP has never been apart in all the time I’ve owned it. Engine leaks oil but it runs so nice that I hate to take it apart.

The 261 engine is just about complete, (missing of all things the oil drain plug) I’m going to run it in on the test stand with the correct 261 water pump. Then I’ll move over to the adapter type, really wish I had a flow meter that would tell us do they move the same amount of water.

Think your idea of adding an oil cooler may be a really good idea.

The guys I know who have re-engine there US military stuff with 261 have cheated and used 12 volt electric radiator fans and not bothered with all the conversion of the water pump. I’ve got to go take some pictures of how they did it.