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I am getting ready to install a remote oil filter in my 235/6 should i use a full flow filter or a by pass? ron

Full flow will do a quicker job of filtering but if you don't live in the dusty desert a by pass will work. If you decide on a by pass check the link below for the best by pass I have ever owned.

I guess I don't understand. I thought the difference isn't in the filter but the engine it's connected to. A splash engine would be a "bypass" and a full pressure would be a "fullflow". While some filter better than others a filter is basically a filter. It's the connections that decide if oil bypasses it or not. Is that not correct? I have a modern (full flow?) filter connected to my bypass 216. Would that make it a "fullpass" or maybe a "byflow" setup?

You might want to do a search on oil filter, full flow, etc. There are few terms that can be confusing. Here's a start on definitions:

low-pressure internal oil lubrication system - used on all pre-1954 216/235 Chevrolet truck engines

high-pressure internal oil lubrication system - used on all 1954-1962 Chevrolet 235/261 truck engines (and on all 228/248/270/302 GMC engines).

by-pass oil filtration system - optional canister oil filtration system available for all 216/235 truck engines and 1954-57 261 truck engines (and all the GMC truck engines). In a by-pass system, only a small % of the flow of oil is filtered as the oil flows through the lubrication system. Think of it as a line that splits into two lines and one side flows through a filter and the other side goes back into the oil system. The side that is filtered also goes back into the oil system.

full-flow canister oil filtration system - a GM canister-based system for 1958-1962 261 truck engines. The oil flows through filter as if the filter is a "line" in the oil system.

full-flow spin-on oil filtration system - the oil flows through filter as if the filter is a "line" in the oil system. Now it gets more confusing:
1. This is an easy adaptation for 58-62 261 truck engines (that already have full flow filtration).
2. Supposedly, this is a possible adaptation on all other engines, as long as you use a restrictor washer in the inflow line (thus, it is still a by-pass system).
3. This can be used on any 216/235/262(54-57) (and any of the GMC blocks) that has been adapted (through drilling for a fitting, and plugging an existing internal oil journal) to work as a full-flow, spin-on oil filtration system. There are tech tips for this, I think.

This is most like too much information (and, if any of it is wrong or unclear, maybe someone will help out).

Finally, some of the above information needs to be slightly adjusted in reference to USA and Canadian passenger car versions of some of these engines.

Tim

Full flow, as I understand it, flows under pressure (oil pressure), by pass filter flows oil through a filter located on the outside of the engine. I have been using an oil cleaner as a by pass filter since 1963. It's a Franz oil cleaner and uses a roll of toilet paper as a filter.
Back in the 60's the Franz Oil Cleaner was sold through individual distributors. Kind of like Tupperware. The filter was very controversial. A lot people thought the toilet paper would come apart and clog up the engine. The fact was, the filter was ingenious. It was designed on the premise that oil never wears out -- it just gets contaminated. It wasn't designed to replace the engine's oil filter.

The unit was mounted usually in a place under the hood that was easily accessible. Usually on one of the tire wells or firewall. It had a chrome cover the size of a roll of toilet paper. You placed a roll of toilet paper inside the cover and slid the cover over a metal tube about the size of the toilet paper core. It attached to a base using a ring-type clamp. It had a rubber o-ring gasket at the base, and when you set the clamp, you got an oil-tight seal. It had two small pipe-fitting connections on the bottom. Using the connectors that came with the unit, you would attach a rubber hose to the opening marked "inlet" on the Franz and the other end to a fitting on the engine that had oil pressure. It came with a fitting that would allow you to unscrew the oil pressure gauge fitting and install the Franz fitting, which had two outlets. You could then reinstall the oil pressure fitting and a fitting that would allow you to connect the Franz Oil Cleaner. The other opening on the Franz was discharge outlet. You usually punched a hole in the oil pan and screwed in a fitting that came with the unit. You then connected a hose back to the outlet on the unit.

The Franz didn't replace the oil filter that came on the car for two main reasons. First, you didn't want to void the car's warranty and second, you couldn't replace the filter, because a car's filter was designed not to restrict the oil pressure or flow to the engine parts. A cars oil filter doesn't clean oil, it just filters small microscopic metal parts from the oil.

Now this is where the Franz Cleaner was ingenious. About 10% of the car's oil would flow through the Franz. It went from the bottom and up through the tightly packed toilet paper into the center tube and back down in to the engine pan.

The toilet paper not only cleaned the oil, it removed water from it. You never had to change the oil, only the roll of toilet paper. One of the reasons I think it didn't catch on was that by the 70s most of the cars were using oils with additives. The additives would automatically under heat change the color of the oil from fresh clear-looking oil to black dirty-looking oil, even though it was as clean as the day you poured it out of the can. In conducting an experiment using oil without any additives, the oil never changed color. It remained as clear as the day it came out of the can.

The Franz had a metal wire that was in the cleaner top that was placed there before you inserted the toilet paper so when it came time to change, you unfastened the clip at the bottom, removed the top, then you could use the metal wire to pull the paper out of the holder. Yes, if you weren't real careful and didn't know what you were doing it could be messy. If you did know what you were doing, it was great.

Just think about it. When it came time to change the oil & filter all you did was pop the hood, replace the toilet paper in the Franz, add 1 quart of oil to the engine, and you were ready for another 3,000 or 5,000 miles. You never needed to change the car's regular oil filter because no sludge ever built up in the engine to clog it up. You didn't need to drain and change the car's engine oil because it remained clean and free from contaminants. Your cost for an oil and filter change? One quart of oil and one roll of toilet paper.

Franz cleaners were not only used to clean a car's engine oil, they also were used to keep the radiator water clean and the transmission fluid clean. They also made one that held 3 rolls of toilet paper and was used for large diesel trucks or or any large gasoline- or diesel-driven equipment or machinery.
They are still manufactured today. The website is:
http://www.wefilterit.com/

That's all well and good guys but the difference between a bypass and full flow is that the bypass system allows some of the oil to bypass the filter and full flow does not. If I'm correct in that, I guess I don't understand Ron's question. If his engine is set up to use a non bypass filter where all the oil gets filtered every time through the engine, why would you consider using a bypass filter?

Tiny,

The only way that a 235 would be "set up" for a non by-pass filter (a full-flow filter) is if someone had modified the block.

The first response, while not necessarily incorrect, might have resulted in an incorrect application of a full-flow filtration system.

Some people use a "full flow" spin-on filter with a restrictor in the inflow line and it seems to work OK. This has confused discussions in the past - a full-flow spin-on filter used as a by-pass spin-on filter.

If WE b OLD wants to play it safe (and play it the way GM intended), a by-pass filter (of any brand/design) will work on a non-modified 235.

Tim

If you get a bucket of dirt in the engine every few minutes, you've got a major problem. Dirt doesn't accumulate in a relatively well sealed engine very fast. Most of the dirt that gets into a normal engine also doesn't do damage very fast, so a bypass oil filter SHOULD keep your oli clean enough to allow your engine to last longer than you do, especially if you change the oil and filter at reasonable intervals.

"Full-flow" oil filtration means that all the oil that leaves the oil pan and is pressurized by the oil pump flows through a filter before it reaches the engine bearings. In this type of system, the filter medium must be of sufficiently open-weave construction to prevent signifigcant loss of pressure. Most modern full-flow filtration systems have a spring-loaded bypass valve that opens and routes oil around the filter element if pressure drop across the filter exceeds about 4 PSI. The problem to having such a free-flowing filter is the fact that it will allow moderate-sized contaminants to flow right through the filter. A full flow filter traps "rocks, marbles, and medium-sized grains of sand", in the words of an instructor I had in a General Motors training center class I once attended. This type of filter exists to trap pieces of dirt big enough to wedge themselves between rotating parts such as the crankshaft and rod or main bearings, and other close-tolerance areas.

A bypass filter taps off a small volume of oil from a pressurized oil gallery, runs it through a very fine-mesh filter medium, and dumps it back into the oil pan. It is not intended to filter all the oil going to the bearings, as it would virtually cut off oil flow to them due to its tight construction. The advantage to the bypass system is that it traps even very tiny particles of dirt. I used to sell the Frantz system for Diesel trucks, one that used the standard LuberFiner 750 canister about 10" in diameter and over 1 foot tall. It held 3 gallons of oil when the filter element was changed, on an engine oil system of 12 to 15 gallons. The Frantz filter would trap particles down to 2/10 micron, (.0002") That's the thickness of a strand of hair split into 10 equal slices.

Ideally, an engine should have both systems, a full-flow filter to catch the big chunks, and a bypass system to actually clean the oil. The only place I've ever seen that setup is on industrial engines and some 18-wheelers.
Jerry

To make a long story "VERY" short, a by-pass filter, filters some of the oil some of the time but, not all of the oil all of the time.

Amsoil makes a full flow/bypass remote filter setup like you are describing. They do have one that is sized for smaller engines. I am considering doing this on a full flow 261 since I want to install a spin on remote mount filter anyway.
http://www.amsoil.com/storefront/bf.aspx

Well put. Not exactly 100% filtration.