[G.M.]

Henry when we started testing we took the temperature at the top of the heads where the hoses are or on the water outlet on the 36 type pumps plus the top of the radiator the center of the radiator and the bottom tank also the center of the heads and the rear of the heads. At some point we took the temperatures on the the head on each cylinder just below where it dips down for the spark plugs. We ran all tests for 30 minutes with a large fan against the radiator, this simulates driving down the road and I would say engine speed was in the 45 to 50 MPH range. Once the temperature stabilizes for 10 or 15 minutes meaning it gets to say 175 degrees and don't go any higher it will run all day at that speed at this temperature. The temperature in the center of the radiator was lower then the top and even lower at the bottom tank. If I recall the bottom was on the 145 range. After a 100 or more tests we came to the conclusion the only temperature that is important is at the head outlet and that both sides are within a few degrees of each other. The other temperature of importance is in the very center of the heads between 2 and 3 and 6 and 7 which gets hotter then the back of the heads. Almost all diesel engines have a problem with pin holes in the cylinders IF AN ADDITIVE LIKE Purple Ice is not used. Infact the warrantee is void if not used. Go to a Ford truck forum and find the results. What happens is in certain internal areas the surface gets small air bubbles attached to the surface. This insulates the surface from the water creating hot spot and the oxygen in the bubbles causes the pin holes from what I read. Purple Ice coats the surface and eliminates or greatly reduces the hot spots. When I first thought the problem looked like the same as what I read about diesels I bought 2 bottles of PI. We had run 10 or 12 tests on the 33 and after 20 minutes with fan at the grill it would get to 229 and spit over a gallon water out everytime driving it the same thing happened that's why we got into the testing. After lunch I put the 2 bottles of PI in and started it up, it went up to 216 then 217 and I thought "SH##" that was a waste of $18.00. It didn't keep going up as it did on all the other tests it sat a 217 for about 5 or 10 minutes then started to slowly drop to 207. I was watching close with the laser pointed thermometer as it came down. After that when we ran it it would stay at 207. That's when we made the first pump and it came down in the normal range on one side and still up near 207 on the other side. Swapped pumps and the cold and hot side changed as stated in another post. G.M.