The Stovebolt Site Forums The Shop Area Engine Shop By pass oil filter question

What soap box? What have I stated that is 1. incorrect or 2. 'soap boxy'? This is all in the CHEVVY MANUALS. I guess CHEVVY is all full of themselves to??

The 235s of the 40's 50's were never set up for full oil filtration. Why? Because as Chevvy said it it's manuals you were to throw the oil away at 2000-3000 miles and THAT was how the oil was kept clean. The 235 and early 261s never had the internal passages cast into them to accept a full flow oil filter.

The bypass filters of the time are not 'good' or 'bad' but are, by design, not able to handle the full flow of oil at operating RPM. The reason is that there is no place on the motor to take the oil FROM to filter it BEFORE the bearings without negatively affecting oil pressure to the bearings. Most people equate bypass filters with higher levels of filtration. In the 50's that was not true... The oil filters of the days were 20-30 micron filters. The only bypass filter that I know of that was in the sub 5 micron range was the Frantz type filters.... and they used toilet paper as elements.

In the late 50's and 60's Chevvy made revolutionary changes to the motors... the first one being full flow oil filters and *finally* getting rid of cast babbit bearings. The switch to precision insert bearings, closer engine tolerances and wide availability of detergent oil meant that Chevvy finally had to make changes to the otherwise very successful motor lineup.

I eagerly await any corrections you can make so that I can better understand what I was wrong about.