VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 235 vs 216 engine

Please help me. I have a 235 Chevy engine. How does one explain the "oil pump" description vs. a 216 "dipper." I had someone tell me that it is incorrect to say that a 235 has a
"real oil pump" for today's roads, and that the "dipper" was just as good, and that it was only the top of the rods in the motor that were "dipped." (Of course, I know that they both have an "oil pump," otherwise, the engine would burn up.) But, now I am confused. I was under the impression that the 235 had a much better "oil pump" system, especially for today's roads. Your help is appreciated. Thanks,

The dipper type engines, both the 216 and early 235 had an oil pump. The normal oil pressure produced by the pump, hot oil and at 50 MPH was about 15 pounds. The pressure produced was directed through the block to the main and camshaft bearings. Some oil was sent to other locations at a lower pressure but greater volumn. These locations were the rocker arms and pipes that fill the dipper troughs in the pan. At higher engine speeds the pipes directed the stream of oil into the dipper, forcing it into the bearing at very high pressure. The disadvantage is that it fed oil to the rods at only part of the reveloution where as the drilled crank in a pressure fed system feeds oil for the full reveloution. Also at high speeds (above 4000 RPM) the dipper actually cuts the path of the oil so the beaings recieve less. With the full preeure system the hole in the crankshaft at the main bearing feeds oil through the drilled passage in the carnkshaft to the rod bearing.
The full pressure oil pump in the 1953 and 1954 is basically the same as the dipper oil pump but it is designed to produce 40 pounds of pressure at speed and more volumn as it needs to push the oil to more parts. This oiling system is better suited to higher engine speeds- say above 3500 RPM.
The dipper system if fine for the engine speeds of years ago. It is importand that the dipper oil lines are clean and aimed correctly. When new they performed well but too often the lines are plugged up and the oil pump screen as well , that combined with bearing improperly adjusted (too loose) and old worn out babbit caused a bearing failure.
When new we had very little trouble with them.

Hope I answered some of your questions.

Chevgene: Thanks. Sounds good. I appreciate the help.