[KEN CROCIE]

For those "on the fence" regarding the bypass, I recommended doubling the bypass spring in the filter housing.

[Sirrotica]

Originally Posted by KEN CROCIE

For those "on the fence" regarding the bypass, I recommended doubling the bypass spring in the filter housing.

This is what I've been doing in oval track engines after the Lee filter went away in the 70s, in street engines I kept the original spring.

With an 80 lb pump and a doubled up bypass spring, I have pushed oil out of the filter O rung on a cold startup. After that experience I always let the engine idle until the oil thinned out a little bit, that was also running 40 Wt racing oil.

Pontiac isn't the only engine brand where this dispute takes place, chevy guys dispute blocking the bypass valve also.

I have seen the filter elements implode a few times on different brands of filters causing lower end bearing damage. I never felt it was worth the chance to completely block off the bypass over worrying about a bit of dirt reaching the bearings. On the off chance a dozen small bits would reach the bearings it will embed in the bearing material and no major damage will result. If the oil has that much abrasive bits in it that it will totally ruin the lower end, you already have a bigger problem than blocking the bypass valve.

Having run a ton of Pontiacs on dirt, you absolutely will not keep all the grit out of the engine no matter what you do, it gets in there somehow. The air filter would ideally keep out anything larger than 10 microns in theory, but upon disassembly of one of these engines you might be surprised how much ends up inside of a formerly clean engine over time.

I adopted the Frantz by pass oil filters after I quit dirt track racing, If I were to build another dirt engine, or even a good street engine, I would currently use a Frantz, (as Troy, Dragncar, has already said he does) to keep the really small abrasive out of the bearings rings etc. All the oil in the engine gets run through a by pass filter every 3-5 minutes, so every drop is filtered to a sub 5 micron level frequently. if your adding abrasive at a rate faster than that, nothing is going to save that engine anyway, been there, done that.

There are IC engines that have no oil filtering systems used in racing (Briggs and Stratton, and Honda clone engines) that run in go karts on dirt and asphalt that run a long time with no oil filters on them, just frequent oil changes keep them alive. In 1961-63 Pontiac offered a block off plate option on the 194 tempest engine to eliminate the oil filter completely, I've posted pictures of that OEM part previously, so Pontiac engineers obviously felt at one point that if you changed oil frequently enough, the filter could be eliminated, and the engine would still be covered under factory warranty. I've also heard the theory that this option was for those that wanted to install a by pass filter system after they took delivery of the car, by pass filters were pretty popular aftermarket add on in this time period.

The air cooled small engines run in a fairly hostile environment when used in lawn care, and construction, and survive pretty well with just changing oil frequently. and no filter system, something to keep in mind when considering how important a filter system is, or isn't. ROI is a consideration, as is the upfront cost of the engine being protected by a filter system. Mainrtenance downtime is also a factor.

Likely the filter systems modified with no bypass valve are doing little in the grand scheme of things to keep the engine alive. I believe that the people that have adopted no bypass valves feel that they have accomplished something that really doesn't amount to to a hill of beans, but probably is comforting to them, and it likely won't hurt their engine unless the filter media collapses/ruptures, and dumps all the abrasives caught, directly into the bearings all at once.

Keeping the oil analytically clean by use of a by pass oil filter will filter much more dirt out of the engine oil than blocking the bypass valve valve of a standard OEM style filter anyway, (40 microns full flow, 5 microns bypass). You also gain at least 1 quart of capacity as well as there is going to be marginal heat loss from the oil as it passes through the extra plumbing and canister of a by pass filter. it's just a better system to use to supplement the OEM style full flow system already engineered into the engine.

Mu current thought would be use the OEM bypass system unaltered from original, supplemented with a by pass oil filter. Never worry about an implosion of the full flow element, and filter your oil to a standard much higher than any OEM system is capable of.

[HWYSTR455]

Originally Posted by KEN CROCIE

For those "on the fence" regarding the bypass, I recommended doubling the bypass spring in the filter housing.

Where would one source such a spring?

I 'used to' bend the spring retainer inward, but over time realized that was not a proper approach. I've never found the fiber disc dislodged, but guess that could happen.



.

[Sirrotica]

Originally Posted by HWYSTR455

Where would one source such a spring?

I 'used to' bend the spring retainer inward, but over time realized that was not a proper approach. I've never found the fiber disc dislodged, but guess that could happen.



.

I removed a used spring from an extra oil filter adapter, then wound the 2 springs together, reinstalled both into the adapter I intended to use.