Ok Don Coatney

[John Burke]

I picked up a couple of oil pressure gauges and will afix them to the two oil passage fittings on the block. I will then crank the motor over...In your opinion.....what should I be looking for? If anyone else has an idea....dive right in...We're trying to decide which line goes into the filter cannister....John

[Don Coatney]

I picked up a couple of oil pressure gauges and will afix them to the two oil passage fittings on the block. I will then crank the motor over...In your opinion.....what should I be looking for? If anyone else has an idea....dive right in...We're trying to decide which line goes into the filter cannister....John

John;

If the internal plug is not in place I would think the pressures would be equal.

If the plug is in place I would think the lower hole would be much higher in pressure. I await your results.

[John Burke]

Both gauges read 60# of oil pressure...what is your diagnostik Dr Don????...jb

[Don Coatney]

John;

I am not exactly a doctor. I did have an amateur gynecology practice in my younger years but I gave it up a few years back. If your pressures are equal I do not believe the internal plug is in place. I am not sure of the best way to connect your by-pass filter. I would think there must be a port somewhere that drops directly to the oil pan or a place in the system where there is lower pressure for the return line to connect. I have never used anything but the full flow system on my Desoto engine. Hopefully someone may have an answer.

[Reg Evans]

John,

If this full flow filter will work it's yours for the cost of shipping. However.......There is one string attached.

If I ever make it to your neck of the woods I'll expect a ride.

[55 Fargo]

Silly question, how do ya tell if you have the full flow or by-pass type filter. My engine is a 1951 Canadian built Dodge D 40 218 ci. Thanx Fred

[John Burke]

Thats a good question Fred, I'd like to know also...It seems that all of the pic's I have seen of by-pass filters show the input line going to the top of the cannister and dumping in?????? My aftermarket filter has the inlet at the bottom of the can..... Since i have equal pressure at both fittings on the block. The only decision I need to make is whether to run the 1/4 or the 5/16 line to the inlet. For a return I am going to use a brass T where the dipstick goes in and run the return line to the leg of the T. I think all of the other block ports for oil are pressurized????Right???? John

[Don Coatney]

Silly question, how do ya tell if you have the full flow or by-pass type filter. My engine is a 1951 Canadian built Dodge D 40 218 ci. Thanx Fred

If you have the full flow filter it will look like the one in the picture Reg posted.

[Don Coatney]

For a return I am going to use a brass T where the dipstick goes in and run the return line to the leg of the T. John

I believe that will work John.

[55 Fargo]

Thanx Don, I happen to have a full flow on my parts engine, the one I sent you the dizzy from. Can a full flow be installed on an engine originally equipped with by-pass. If yes, is it a difficult swap......Thanx Fred

[Don Coatney]

Thanx Don, I happen to have a full flow on my parts engine, the one I sent you the dizzy from. Can a full flow be installed on an engine originally equipped with by-pass. If yes, is it a difficult swap......Thanx Fred

Fred;

In order to make the full flow filter work this plug must be in place.

[55 Fargo]

Thanx Don, now if I am the type that changes the oil and filter often, is there an advantage to making this swap. My engine has got miles on her, how many I am not sure, it has 40 lbs of oil pressure at an idle when running at full temp,the compression when last checked was 100 to 110 on all cyls, with the exception of cyl # 5, it had 95 or so...........Fred

[Merle Coggins]

John,

If you have pressure on the lower port, it must be a full flow setup. And it sounds like the filter you have is a by-pass type. The by-pass type filter isn't designed to take large amounts of flow. And if the pressure is the same on both gauges how is oil suppose to flow through it? The return line for a by-pass filter needs to dump back to the pan.

If I were you, I'd take Reg up on his offer and use the proper filter for your engine.

Merle

[John Burke]

As it happens.....I have a full flow filter assembly...but don't worry Reg...If you show up here somday...Heck, I'll let you drive it...but with very little gas in it...I don't want it to end up in Califernia...hahaha

Actually, I am still not clear on the issue...I may just plug the holes, like they were before, and run it like I did last year...change the oil often...John Burke

[grey beard]

Another way for anyone to tell of a block is set up for full flow or bybpass filtration is to look inside the pressure regulator hole. You can just screw this plug out on any operational engine, but catch the spring and don't loose the copper washer around the plug.

Pull the regulator valve out with a small magnet and feel inside the hole at the bottom of the bore. With bypass systems, there are two exhaust holes inside the pressure regulator bore that return oil to the pan. These two holes are about 3/8-inch apart. The inboard hole exhausts excess oil pressure when the regulator plug moves outward against its spring. The outer hole controls the return flow in the bypass filter system, shutting it off uder certain pressure conditions.

The oil pressure line fitting on the outside of the block ABOVE the pressure regulaor is the pressure feed into the bypass filter. Doesn't seem to matter if the pressure goes in the top or bottom of these filters - I've seen them plumbed both ways from the factory, and the filter purely doesn't care how the oil flows.

Soooo, not only do by-pass systems filter PART of the oil at any time, they only do that much when the pressure regulator allows it. This is TWO reasons why full-flow systems are far superior to part-quantity, part-time bypass filter systems. JMHO:)

Wish my block was set up for full flow. I envy you guys who don't have to plumb a work-around to get full flow, and to my knowledge all the 218/230 blocks are bypass only. Dratttt . . . . . .

[John Burke]

Thats interresting to know, what you said. I'll try that out...In the meantime since you said 218's & 230'S were bypass only...how about 251 Desoto's? was full flow and option? or did they all come one way or the other from the factory....

[james curl]

On my car you have to remove both starter bolts and rotate the starter and lift the front end of the starter up higher than the plug for the oil pressure valve. I have been trying to get my oil pressure where it should be because the relief valve spring had the last two coils broken. I have moved that starter more than a dozen times to cut a peice of a coil off until it will hold 46 psi hot at 60 mph and only go to 60 psi cold at 60 mph. I could not find a new spring anywhere so I went to Fastenall and found a spring with the right wire dia. and the right coil dia. and spacing as my old one then estimated the unbroken length and cut it off to that length for starters, too much oil pressure. Cut the coils a little at a time. This was not fun because the starter covers the oil pressure relief valve plug.

[grey beard]

James,

Be tempting to park that rascal on top of a long hill, pull the starter, and clutch-start it on and off till I got the spring sized correctly - if your starter is as much fun to get off as mine. I literally cannot get to the top inner bolt with my big hands, all of which brings up the little-known fact that I have found an excellent use for a six year old grandson . . .

Too bad ya' can't bottle some'a that extra oil pressure and dispense it on this forum. A few of us could (ahemmm) use some . . .

[james curl]

All that it takes is a longer or stouter spring and you can have more than you want, like 80 psi a idle. I also pulled the piston out and placed a tight drill bit inside of it so I could rebevel the champher on the leading edge and polish the end on a fine sharpening stone using an electric drill, that helped hold oil pressure with engine hot.