evo oil pressure measurements

[Xanadu]

been reading web sites claiming to solve HD motor oil pressure problems with a spring set and gauge to monitor the oil pressure...  I have heard many times through the years the evo oil pressure at idle with a warmed up engine is 0 psi.

Well, bought a oil pressure gauge that mounts on the motor case in front of the oil pump...  got the following measurements on a new 120" ultima evo style motor....

ambient temp 105F
start up = 55-60 psi, then quickly drops to about 30 psi.
oil pressure gradually drops as the oil temp warms up...

20 mile ride, oil temp is 240F,

55+ cruise oil pressure is 20 psi.
idle, oil pressure bounces around 0 psi.

Does anybody else have similar results?

Any explanation as to if this is "normal", or yet another anomaly?

Comments welcome..
BTW, I am using the Revtech 25W60 motor oil for HD's.  still breaking in this motor...

[Racepres]

Not willing to get into an "oil" debate...But.
Oil Pressure is a Non Factor, as far as Harley engines are concerned...
Ensure you have "flow" and be done with it...
A simple search will prove this out...or Agonize !!

[Xanadu]

thanks for the update and information!!  racepres.

appreciate that...

[pumpguy68]

My 120" cold has about 35 psi and never goes below 25 on a all day ride at anything above 2000rpm

Hot idle sits around 10 or so.

with racepres flow is more important than pressure on a evo but zero on a new engine/oil pump would concern me personally.

Ray m

[Tommy C]

Oil temps should be lower once the engine is broken in. @ 240 degrees it's gotta be like water.

[mr. pitts]

You will get almost zero oil pressure if you set the idle too low. Setting it low to get the potato-potato sound is a bad idea. Setting the idle to about 1000 rpm is much kinder on the motor & your oil pressure should rise a little. 

[Schex3x]

My 120" cold has about 35 psi and never goes below 25 on a all day ride at anything above 2000rpm

Hot idle sits around 10 or so.

with racepres flow is more important than pressure on a evo but zero on a new engine/oil pump would concern me personally.

Ray m

Have about the same pressures here on the S&S 111,
240* would be roasting nuts for me, 
with the Jagg 10 row cooler, my oil temps stay around 180*, takes a good while to even top 200* in a traffic jam.

[fbn ent]

For sure put a cooler on it. My shovel idles at low pressures also. Common thing for the Evo too. If your lifters start to rattle, you have low oil pressure. Temp and pressure gauges just give me something else to worry about.

I also agree with MrPitts...keep the idle up.

[Xanadu]

idle is up, its not low to get potato potato sound, was set by the mechanic who installed the motor and is offering the warranty.  bike has the spurgin oil cooler on it already.  this cooler dropped my 80" motor oil temp by 20F when the bike was moving, did nothing stopped at a light or stuck in traffic.

in AZ the temps have been over 100F all summer long.  still has not cooled off yet, but I anticipate it will cool off about the time 3 million snow birds arrive in hoards.  maybe 5 more weekends.

What I have noticed is the oil pressure drops at all running conditions as the oil temp heats up.  on a 20 mile ride in 105F temps the oil will be 240F per the dip stick gauge.  I know the bike is jetted fat since I am only getting 27 mpg, and others are claiming at least 32+ mpg on this motor.

its a new motor, new oil pump, etc.   at 200F oil temp it runs 25 to 30 psi at 55+ cruise speed, and about 5 psi at idle.  go to 240F oil temp and it drops to 20 psi at cruise speeds, and about 0 psi on the gauge.

some are recommending straight 60W oil with these temps...  right now I am changing the revtech every 500 miles...

and looking for a better oil cooling solution.

[gryphon]

About 40 years ago I installed a really cool oil pressure gauge on my new shovel motor. Mounted up where I could really keep a good eye on it. It didn't take long before I was always freaked out about my pressure. Took off the gauge and hooked up an idiot light. As long as the light didn't come on I figured everything was fine. I think they come on around 2lbs or so. Still doing it that way and I sleep much better at night.

[Racepres]

About 40 years ago I installed a really cool oil pressure gauge on my new shovel motor. Mounted up where I could really keep a good eye on it. It didn't take long before I was always freaked out about my pressure. Took off the gauge and hooked up an idiot light. As long as the light didn't come on I figured everything was fine. I think they come on around 2lbs or so. Still doing it that way and I sleep much better at night.

Sums up my method perfectly...2 lbs is Plenty!!!!
Is your gauge calibrated good enough for that???
BTW My 1974 has enough miles on it that I maybe should be concerned about something...oil pressure aint it!!!

[Xanadu]

Sure your not concerned about your oil pressure, your oil temp never goes over 200F in your locality I am guessing.  What I have found in 2 days with a oil pressure gauge is the hotter the oil gets the less pressure is registered at the gauge.  its an engine mounted gauge, not an electric one on a dash in a fairing.

currently, the 120" is running 240F oil temps in the 105F AZ heat.  I only ride 20 miles and that is all it takes.  If I could get my oil temp to be 200F or lower my oil pressure gauge would be reading HD spec numbers.

I am partially concerned because I just had to replace a 80" HD motor with 69K miles on it due to metal in the oil....  I have a 1 year warranty on this motor, so I wont sweat it until that is up...

if you live in the midwest where your oil temp never even reaches 200F ever, then your oil viscosity will be thick enough and your oil pump will give you good spec numbers. but like someone mentioned at 240F the oil is like water...

[Racepres]

Maters Not if the oil is like water...long as it still flows....Nothing "floating" in yer Harley like a Car motor...more like a Briggs Lawn Mower....Flow is everything...and at Low RPM's there is Not really very much flow...and of course your oil cooler is not much use if oil ain't flowing Thru It!!!
Again...Over 2 Lbs is OK...We need to worry more about GPM!!!!!!

[gryphon]

Xanadu, I agree that there is not much comparision between your riding area in Arizona and mine here on the Oregon Coast. Over the years I have lived in some areas where the weather did get pretty hot but I never had a 120ci motor before. It does sound like your motor is getting warmer than some others who have responded and who also live in the Southwest. Because yours sat in the shop for so long I'm guessing you haven't had a chance to get it properly broken in yet. Hopefully your temps will cool down once things loosen up a bit. Have you tested your gauge for accuracy yet. Test it in some boiling water. If it reads over 212 degrees or so (depending on elevation) it may just be the gauge giving high readings. You should have some cooler weather heading your way soon. Hopefully that will bring you some relief. Pretty soon our daily highs will drop into the 40's and very low 50's. Then I will be envying you.

[Schex3x]

I looked at the Spurgin site, I see it has a built-in auto thermostat that just starts to open at 190*, makes me wonder if your actually flowing through the cooler, or if it's mostly bypassing.

I didn't want a chance of that happening when I installed the Jagg cooler on my bike, I wanted all the oil passing through.
I cover the cooler if the oil temp runs too cool in the winter.

Maybe go into the adapter and try to remove or disable the thermostat, or run a different adapter with no thermostat, looks like running too cool won't be a problem for you.

[Xanadu]

I am still working on the break in, and have less than 2K miles on this new motor.  I am commuting every day with the bike now.  20 miles each way, mornings its low 80F ambient temps, oil pressure gauge looks about right at high 20's low 30's psi when crusing and about 3 to 5 psi at idle, oil temp per my gauge is 200F.  going home its 106F ambient, the same ride oil temp is 230 to 240F when I get home, and oil pressure at idle reads 0 psi on the gauge, and about 20 psi when crusing 70 mph.

I am using the revtech 25W60 non synthetic oil, and am changing it every 500 miles.

currently getting 27/28 mph.

the oil cooler, has an adapter with a built in "thermostat" which consists of a spring loop.  However when I installed the thing the spring was just flopping around in there.  I could not figure out how it was supposed to work.  I suspect it does nothing and the cooler is open all the time.  I do notice during winter months my oil temp (on last 80" motor) was lower than usual which confirms my theory the built in "thermostat" is not working properly.

it appears AZ gunner is experiencing similar conditions with his S&S 124" motor.  His oil temp numbers are like mine.

Last night I pulled the oil dipstick with the gauge in it, and put in an AC thermometer with a long shaft directly into the oil, it extended into the oil a lot deeper than my dip stick gauge.  I was able to confirm 230F temp.  I will have to do the boiling water test to see how close my gauge is to that reference point.

If my gauge is off, its not off by much I am thinking.  my oil pressures also correlate to less pressure across the board as the oil heats up.

I am still looking for a solution. 

the power of the motor is awesome BTW.  every harley should have this kind of power!

[gryphon]

My Jagg oil cooler also came with an auto thermostat which never worked from day one. Was always open. Even when placed in boiling water the little piston never closed. Always bypassed the cooler.

[Xanadu]

I checked my dip stick gauge in boiling water tonight, it read 207F.  so I think its probably within a few degrees of accurate.

I drain my oil cooler with the drain plug in the bottom its full of oil.  and when I am riding its hot to the touch.  I suppose its possible the oil is just bypassing the oil cooler since I never was able to figure out how that flopping spring loop in the housing was supposed to work to regulate oil through the cooler? 

[Xanadu]

I got an oil bud oil cooler adapter from buddy clark.  I installed that last week.  his oil adapter comes in two halves that bolt together with a thermostat that sticks out the top.  on my 93 fatboy the voltage regulator gets in the way, so the thermostat on the oil bud adapter blocks the front pipe 02 bung.  I just have plugs in them for now.  when I removed the spurgin adapter I inspected the "thermostat" in the adapter.   It consists of a flat coil that when heated uncoils and blocks a hole that shuttles oil to the oil filter.  When that hole is closed the oil is forced to the oil cooler.  the seal there is not a very positive one.  its just a flat piece of metal that covers a hole.  At least I understand how the spurgin unit works now.  plugging that hole would make all the oil go through the cooler.

the oil bud unit comes on at 180F and is fully open at 200F.  its cooler here in AZ now so early morning commute oil temp is only 200F with the oil bud adapter.  going home when the ambient is 85F I am getting just over 200F as long as the bike is moving. 

I may have an issue with the spurgin thermostat device effectively shuttling the oil up through the oil cooler, however I need to ride the bike more to get more data on that.