[Sirrotica]

Originally Posted by Tom Vaught

Brad, not wanting this to get out of context here, I see nothing wrong with the Bypass Filter philosophy, in general. We had to balance oil flow to a turbo that was run at max engine rpm +10% for several hours at a time. That portion of the testing was not done once but many times over a 300 hour dynometer test. Several hours of rpm at max torque rpm, several hours at max torque rpm = 10%, several hours at high load low rpm, you get the idea.

Also the manufactures typically specify hydrodynamic bearings for lots of applications. Hydrodynamic bearings pass through boundary and mixed-film modes during start-up, and shut down, or when faced with transient upset conditions. This means that material selection is an important design consideration for all sleeve bearings, no matter what their operating mode. The general attributes of a good bearing material are:

A low coefficient of friction versus hard shaft materials,
Good wear behavior against steel journals (scoring resistance),
The ability to absorb and discard small contaminant particles (embedibility),
The ability to adapt and adjust to the shaft roughness and misalignment (conformability),
High compressive strength,
High fatigue strength,
Corrosion resistance,
Low shear strength (at the bearing-to shaft interface),
Structural uniformity, and
Reasonable cost and ready availability.

So the very small micron particles you are referencing (being removed by the by-pass filter) are somewhat incorporated into the bearing design. The "embedibility" feature.
The bearing material basically absorbs the very small particles.

If you run a hard race bearing (on the street) then maybe the by-pass filter might help the bearing life. Most race engines get inspected much more often (as you know) vs accumulating 250,000 miles before a rebuild. Hobby cars might see 3K miles or less in a year.

Tom V.

Tom, I'm familiar with embedibility, been around since poured babbit bearings. With less than pure lubricants in those day embedibility was needed and still has it's place in certain applications today. I doubt many people today even know what a poured babbit bearing is or how they were scraped to fit the shaft that was to ride on it.

I didn't target race engines or hobby cars here, although I feel has better than average oil filtration has a place in either engine. Most of the cars I talked about were 7,500-10,000 + miles per year cars. In a car that is stored more than driven and is in a climate where there is more than 10% humidity would benefit in a filter that can remove condensation from the oil. TP style filters are the only filters i know of that can hold up to 6 ounces of water. Any car that has the pudding deposits on the dipstick has a condensation problem.

In this Kleen Oil demo around 1:43 they pour water into the system and soon after it is removed by their filter, same as a Frantz will do up to 6 ounces. No full flow filter will remove water from oil. Another advantage to the by pass system. https://www.youtube.com/watch?v=AaBuV9pOcrU
The whole demo is worth watching, but at 1:43 is where they put water in the oil to be filtered out.

Mick Batson,member here on PY has a buddy of his that runs I believe it was a BBC in a 10 second car and uses a Frantz oil filter. I'm sure he has his reasons for using it, it surely won't hurt anything.

Dirt race cars get dust in the crankcase no matter how well the outside of the engine and intake tract are sealed. No reason a dirt car couldn't benefit from a by pass filter too.

I believe that somewhere in your resume you mentioned off road racing. The early VW based off roaders were having durability issues and started using Frantz filters to supplement the VW screen in the sump. It made a huge difference in their durability and solved their oil contamination issues.

While we're on the subject of by pass filtering, a few years ago I read in an industry publication that ford was going to implement a by pass filter system on their E series, that never happened. Any inside info if it was ever on their agenda, or just a blurb that meant nothing and should be taken with a grain of salt?