The source thread for this one was the second of a series of typical list oil wars -- this one was a pretty good one as it was enthusiastic but polite and unusually factually based (good research done by most everyone)

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1231439524


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What is the Savage's oil pressure at 1,000 rpm idle speed (fully warmed up) and what is it at the low speeds you would achieve in say a parking lot.

There is a method to this odd question's madness.

When you  set up a bypass oil filter system (remote filter) you need to put anti-backflow check valves in place to keep the "storage oil" that sits inside the relatively large bypass filter housing oil from flooding back into your sump while the bike is sitting on the sidestand.  Since these filters can hold as much oil as our sump does, you understand the need to keep it all out of the sump.

Since you gotta have them little check valves on both "to" and "from" lines, you have the opportunity to do a little serendipity magic.

The little cheap check valves that you would use for this sort of work are built to a fixed opening or "crack open" pressure setting.  These crack open pressures can range from a fraction of a psi up to about 12 psi (generally in 2 psi increments).

I want to set the crack open pressure slightly up over the fully hot 1,000 rpm idle oil pressure setting so that at a stop light ALL of the oil goes through the standard passages up to the plain head bearings unreduced and unimpeded by the bypass filter system.

This is a good thing ...

So, I will get no negative pressure affects on the internal oil system at all until the motor rpm gets high enough to exceed the crack open  pressure, enough to supply both the existing oil pressure needs and have enough pressure left over to trickle oil through the sub micron bypass and then dump it --- into the head pool bucket of all places!

Then I slightly deepen the head pool bucket by raising a little epoxy lip on the exit side that intentionally directs the slightly higher oil pool to empty --- on the cam chain as it goes down the front side to the bottom sprocket (force lubing both the chain and the wear stressed front chain guide).

So, you guys with them oil pressure gauges do tell, what is the Savage's oil pressure at 1,000 rpm idle speed (fully warmed up) and what is it at the low speeds you would achieve in say a parking lot.

No, not really.   Search turns up low figures of 2-4 psi for thin 10w40 dino oil on a hot day and 5-7 for 20w50 dino oil on a hot day with a hot engine at idle speed.  

Lotsa data span here, too much not to question it a bit.

Very cold engines always seem to give high (50 psi) pressures no matter what, so that might be a reflection of a sludgy dino product not flowing well when cold.

Most of this pressure info is VERY OLD and the points being discussed back then might have flavored the topic a bit.  Way back then we were just learning we HAD to run a 1,000 rpm idle or pay the head bearing piper for too low oil an pressure due to a hot slow idle.

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Looking for somebody with a current accurate oil pressure gauge to give me some current real numbers.

if you mount the filter low enuff and pointed down while on side stand would you still need a check valve?

T-Mack, what sort of pressures do you see when riding?  

Our riding RPMs are around 3,000-4,000 rpm so oil pump volume output will be at whatever maximum ounces per minute that the pump generates and the pressure will be being vented by whatever internal overpressure valve the Savage uses.

Important to have the check valve to the large bypass filter be a lower crack pressure than the Savage's internal dump valve pressure or it won't be functional at all.

Just some more data to back up T Macks' observations. My oil pressure gage, using Mobil 1 V-Twiin 20-50w,  reads around 10-14PSIG at speeds in the 45-65 range. If I push the revs up above 4500 I might see readings as high as 15-18PSIG. Never seen anything over 20 except at startup on a cold day.

All warmed up at 1100 rpm idle, the gage shows about 2 psi, as the picture below shows. The oil gage is the one on the lower left.

Oldfeller--FSO wrote on 01/23/09 at 01:26:59:

Once it goes thru that check valve the pressure will be lower.  Hense will you have enough pressure to run the filter if the pressure is 30 -6 psi?  or 18 - 6psi?

Charon is asking me if my proposed wimsy is actually cheating a bit.
Yep, in several ways.           (I likes to cheat a bit, I do)

The extra quart or more of oil does increase mileage capacity of the oil load because I will be filtering half again to twice as much oil as originally equipped on a Savage.  

Next, I will be putting the tank horizontally on the sissy bar right over the brake light.  This appeals to me as being "out of the way" and not cluttering up the lines of the motor part of the bike.   Plus it will look interesting sitting back there and everyone coming up behind me will wonder what the heck it is.  

Heck, I may put me a name brand nitrous bottle sticker on it just for the giggles of it.

Next, the long quarter inch copper lines running to it and back will act as as an oil cooler.  Cooled, cleaned oil being dumped back in the head will help cool that hot zone in a somewhat minor manner.   Cam bearings, cam lobes and tappet flats will see some minor advantage from a steady bath of much cooler very clean oil.

Damming up the head pool such that it has an intentional extended oil exit chute to dump the running oil on the cam chain at the front guide junction can only help those two pieces to live longer.

Remember, I'm copying at 1/2 scale a bypass oil filter that is commonly used on 30 quart oil capacity 16 wheelers that run it for 10,000 miles between Bounty filter material changes.  

Let's ASSUME that I could filter 15 quarts of oil for a similar distance  (using 1/2 scale factor -- just for discussions sake -- I know you won't really agree to assume anything, but that's OK)  so factor in the idea we are only dealing with 3-4 quarts of oil and a 650 cc motor cycle engine instead of a 14,000 cc diesel engine pumping 30 quarts of oil we might assume to get some sort of 15x (less trash produced) life mulitiplier might theoretically apply to some sort of degree.

Too many Blackstone oil analysis done by too many truckers and BOBSTHEOILGUY combatants say the Bounty oil filter material works to get fine trash out of oil.  Mind you, I have already removed all the ferrous materials with the supermagnet sitting on the main filter, all we are feeding this secondary bypass filter is the fine non-ferrous trash.

And yes, you will lose pressure going through the check valves and all that long tubing.  I have an drain tap on the drum that I will use to vent air out of the system that can also be used to do a "incoming" volume check on the oil reaching the system back at the sissy bar.  Unhooking the head piping can do a final "output" delivery check as well.

As long as the volume is appreciable as far as lubing the cam chain goes then the system "works well enough".  Any light drool through the system would process the total system's 3-4 quarts of oil fairly quickly.

And the good news is that if it plugs itself up totally, why then I'm back to just using the stock Suzuki lubrication system,  jest like da rest of youse guys.



And if I only change the oil once a year when I change the main oil filter element (still the weakest part of the overall system) then I can see if there is any difference in the non-ferrous trash build up on the filter element.  Also, if cam chain wear out is eventually documented enough to create an averaged value then I could see if I get an noticable increase in cam chain life that could maybe might be a possible indicator of increased motor wear life.


Like the orange cat sez, "You gotta keep things in the proper kitty perspective"

Perhaps I was unclear in my question. Granting that the filter works as planned, and gets out more and finer particles, how are you going to decide whether it actually makes a difference in engine life?