Motor guard filter for oil?

[Sumpy]

G'day all,
I managed to find a place down here in Australia that sell the motor guard M30 air filter.
I bought one & would like to know how you blokes up there modify it for oil.
I was going to machine up on my lathe (to the identical dimensions) the internal "collars" that are made of plastic out of alum & probably machine an o ring groove into the bottom collar so as to get a good seal at the inlet presure side.
I assume the inlet is the centre one that ports the oil to the top of the filter? What is the recomended restrictor size as I will be tapping oil from the pressure side & returning to the sump.
Is the restrictor fitted to the pressure or return side of the filter?
Is the 'T' handle seal & body halves square seal OK for oil?

All I need now is some US dunny rolls as ours down here are only 4" high, which is far too short for the motor guard.

Cheers

 

[Gary Allan]

Not to worry, mate. Is this a gas application? If so, toss your collars in a pot of boiling water and see if they soften up. Mine don't. Now an oil burner might reach high enough oil temp to wilt the little buggers a bit ..but not likely in a gas rig. If they were PVC ..they would be soft @ 212F/100C. If they're nylon ..then they're good to go up to around 500F.

..but while you're in the machinin' mood ...make the collars (or wun-o-em, N-E-ways) take up the 'ahfinch' o slack in your bum wipers. Way too much cost n importing 'em.

Most put the restrictor on the outlet.

I'm unsure of the need for the o-ring machining on the collar. The O-ring is fine for oil.

 

[Sumpy]

Thanks for the info Gary.
I went and did a silly thing today & READ THE INSTRUCTIONS that came with the filter which states that the plastic collars are made out of POLYPROYLENE.
This has a melting temp of 170C/338F and working temp around 135C/275F.
Should have looked at this first as it probably would be OK even for a diesel as in my case, but I have already turned up the collars (at least they look alot nicer than the plastic ones).
I machined & put the o ring at the base of the bottom collar as the plastic collar is a tight fit into the lower body & would seal well however metal to metal was not such a good seal.
The large seal is made of Buna-N (nitrile) & 'T' handle thrust/seal washer is of Nylon so both are good for oil.

Why is it most common to put the restrictor in the outlet? is there any advantage?

 

[Gary Allan]

Quote:

---

I went and did a silly thing today & READ THE INSTRUCTIONS that came with the filter

---

That's the American way of coping with technology. Only when all else fails does one consult the instructions. You've been on the 'net too much.

Some of the larger bypass filters have restrictors on the inlet. They have such high capacity that they'll rob too much of the flow before producing backpressure to lube the engine. I don't see any reason not to do it on the inlet. In the case of our spin-on Amsoil units, we use a 0.030 restrictor. The alleged reason for the outlet side is probably multi-dimensional. It was probably easier to restrict the center threaded part of the mount, and the restrictor is so small that they probably didn't want it getting clogged by the stray large particle or varnishing eventually shut.

Ralph (who sells his modified MG's on this site) may know other advantages of the outlet side restrictor (others too, maybe).

 

[RalphPWood]

I signed up as a Motor Guard dealer when all they had were all aluminum and designed for the common 1 1/2" TP in 1966. I didn't have much luck with the polypropylene parts. They don't melt but will swell in oil and come off the mounts. I use a 6061 aluminum alloy tube with a little copper and stainless steel. I have to figure that someone might be tied up in traffic with the air conditioner on with a gasoline engine running 250 degrees F. I have seen 300 degrees rated hose get so brittle they break like a twig. I have seen so called 200 degree hose that can take more heat than the so called 300 degree hose. I don't think it matters where you put the orifice, putting it at the outlet solved the problem of large chunks clogging the orifice. Orifice clogging would be rare in todays engines. What I am doing on the new ones is I put the orifice at the inlet but thread both ports so that the orifice can be removed with an Allen wrench and installed in the outlet. Or it can be removed for fuel or when used with a sandwich adapter. I am going to check the filter to make sure it is getting hot. the normal size for the orifice is 1/16". I know that I have customers that have thrown away the Nylatron internal parts because they stayed inside the dirty TP. I use a hydraulic press and snap ring pliers to assemble the metal parts. Its time consuming. The origional Motor Guard filtered from the bottom up then down thru the core and thru the orifice. There were advantages to that. We tilted the filter so that the big stuff would not go back down to the engine at shut down. Kind of like a gold pan. the old Beetle engines were bad about generating a lot of large chunks of metal, put any kind of filter on a Beetle and you could triple the engine life. I have never heard of anyone complain about no filter on the engine. I would use the 4" paper just push the roll down in the bottom half, that's where the seal is. Save your empty TP cores, split them and slide them inside the 1 5/8" core TP.