HP Oil Pump from Mike's

My radar is always up on this issue. My knowledge of oils, and break-in oils, is far too old-school.

But, one factor I'm keeping in mind with all these new oil publications is that they're mostly oriented toward liquid-cooled engines, where typical oil temps rarely go over 220°F. Several members here, using thermometer dipsticks in hot summer, have reported oil temps in their air-cooled XS650s going up to the 280°F range.

Please excuse this over-simplified approach, there's a mountain of data on this.

At this higher temperature, the kinematic viscosity of the oil approaches that of Jim Beam whisky, and the oil's life expectancy (for non-synthetics) is severely reduced. What I'm concerned about is the oil's hydrodynamic cushioning properties, to control clatter.

If you study this chart for a moment, see where the equivalent viscosities occur for various grades and temperatures. Note that the oil's kinematic viscosity in a liquid-cooled engine is in the range of 8-20+, whereas it drops to the 3-8 zone around 280°F.

 

If you use 5W-30 oil in these engines, you'll have noisey top end clatter. So, no that grade of oil is not appropriate for the XS650. Even 15W-40 diesel oil causes the tappets to clatter. Stay with 20W-50 for these engines.

 

As any Guzzi has a separate gearbox, and a dry clutch, I guess they are less limited with regards to what oils they can use. When using the same oil for the actual engine, gear box and a wet clutch, the modern low friction oils may not be the best choice...

 

A lil' thread update.

I recently installed a high volume oil pump.


It appears to be very well made.


I like the two alignment pins in the shaft, compared to the original woodruff key. However, the outermost pin on my unit was 0.010" too long, and had to be ground down to allow fitment of the gears.

The rotors measured right at 0.472" (12mm), 50% increase over the 8mm pump. Found the cavity depth to be 0.4765", a 0.0045" side clearance, confirmed with feeler gauge.


I wanted a 0.0015" side clearance.

Spend quality time zeroing up the pump body in the lathe.


Skimmed off 0.003"


My side clearance is now 0.0015", confirmed with feeler gauge...

 

A critical installation note:
Remove the shaft and rotors, leaving just the pump body and the 2 alignment pins. Now, dry fit the pump body (and pins) to the pump base in the sidecover. It should easily plop right in, and fully seat. Double check that it seats fully using a flashlight and inspection mirror.

If it doesn't fit easily, or sit completely flat and seated (as in my experience), DO NOT continue with the installation. The pump rotors will surely bind.

Check for interference around the periphery of the oversized pump body. In my case, there was early-model casting flash near the lower screw hole, and this area had to be clearanced before the pump body would seat properly.

 

Ride report:
I run a "top end" oil pressure gauge, as shown in this thread:

http://www.xs650.com/threads/xs650-top-end-oil-pressure-gauge.45317/

This video shows the "top end" oil pressures I got from the original 8mm stock oilpump, on a typical hot Texas summer.



The High Volume oil pump produced roughly 30% greater oil pressures.

At the high oil temperatures of 225°F:

Idle: Before: 1/2 psi, After: 1psi
Highway speed: Before: 3psi, After 4 psi.

Not an alarming increase in pressures, but my top end clattering at idle is greatly reduced...

 

Just curious, what was the thinking behind wanting less side clearance...

 

The manuals show rotor side clearance specs, 0.0012" - 0.0031"



Also, member 650Skull collected and posted mods done by member XSjohn (rip) into this thread. Post #4 shows his oilpump side clearance fix.

http://www.xs650.com/threads/a-collection-of-xsjohns-mods.2426/


So, I figured, why not...

 

Do you think the side clearance is a major contributor to the performance that you got? any idea how it would have performed with the out of the box 0.0045" side clearance...

Seems to show a decent improvement, but just wondering if the side clearance mod is a "must" in order to get those numbers...

 

Well, that extra 0.003", over the bridge between the inlet and outlet ports, would be similar to a 0.050" hole in the pressure side. Insignificant by some, intolerable by others (like me).

Since I'm running paper filtration, I figured that it could be closed up, not worrying about particulates.

Just me being me...

 

The mention of a Husqvarna with no oil pump was a bit wrong. The 510 4/cycle engine used crankcase pressure to force oil up to the top end through a one way valve. Clever and interesting!

 

The low RPM clattering is why I have been interested in increasing oil flow. I have long noticed that the clattering quiets down as RPM's increase and speculated that this was the result of increased oil flow. Your experimentation appears to confirm this.

Have you seen any down sides associated with the high volume pump?

 

So how did this end? did he ever get the HP pump in? Did it fit OK or was it as bad as other pumps people had bought?
The bottom end of the 650 seem nearly bullet proof and seems the lower section is nearly self lubing (thinking the old Chevy Babbitt bearings)
Another question related to the chart with the different oils and temps, are any better or worse as far as "foaming up"?
I know that was the fate of many of the TX750s from the counter balance weights. causing the main bearing failure.. Sorry but I still have a soft spot in my heart for those old Hand Grenades waiting to happen.. But I honestly had dang good luck with them, up to the 40k area. I sold mine and bought a new Honda Shadow back then but it was still running fine.. Sure had a sound of their own! Kinda swishy.. Or as others have told me klunkklunkklunkBANG! followed with the rear tire screaming from being locked up.... lol

 

None. I've been doing a lot of riding (testing other experiments) since the install, watching the pressures, listening for clatter at idle (which is less now). I'll be pulling my paper filter after awhile to see how it holds up.

If you're speaking of the OP, spockwerks, dunno.
He'll have to answer that.

Good question on the foaming. All our motorcycle oils are supposed to have anti-foam agents. But, shortly after I finished the install, ran it for a short while, then pulled the dipstick to check level, and noticed foaming of the fresh Yamalube 20w50 on the stick. Probably should check that again.

Otherwise, I haven't seen any "foaming" charts...

 

It isn't the things in the charts I worry about....it is the things I DON'T see!

 

Got about 300 miles on the high-volume oil pump now, time to check my Budget Oil Filter (BOF), see how it's handling the higher volume.


It's holding up just fine.


Open it up, look for particles.
Those shiny specs would've passed right on thru to the engine.
Plenty more filters available.

 

Now you're teasing us more, lol. What's this "budget oil filter"? Looks interesting and easy to implement. That's just a paper sleeve on a stock filter, right?

 

Haha, 5Twins. Caught ya off-guard did we?

In the "Oil filter" thread, post #205, from about 2-1/2 years ago:

http://www.xs650.com/threads/oil-filter.72/page-11#post-340944

Post #244 may also interest you. Relieving of the sidefilter chamber's ports.

Yeah, this sidefilter thing is another passion. Been playing around with variations, wanting a 'stealth', unobtrusive filter.

 

Hey, Spockwerks, glad you're back. Yes, this thread took on a life of its own. And, the discussions are spanning two threads. The other one:

http://www.xs650.com/threads/xs650-top-end-oil-pressure-gauge.45317/

That's odd. My tach drive gear and tach driven worm screw fit-up just like original. My pump driven gear has the recess so that it'll fit low over the pump body. I have a later pump, with a later driven gear that's just flat, no recess. Maybe that's why. I never thought to check that.

There's some good data. I'm guesstimating that my paper cover is about 150% of the screen's area. It's working fine for now, but always room for improvement...