High Volume Oil Pump?

mo650chopper · Posted: January 2, 2006, 3:56 pm Post subject: High Volume Oil Pump?

Just curious if there is a need or advantage to installing the "High Volume Oil Pump", Part # 05-0044 in Mike's XS Catalog? I have an extra Right side cover that I plan to grind the Yamaha off of, Install a spin on oil filter adapter from 650 Central and polish or chrome. Would I even be able to change the oil pump with the right cover off? I've every other of the bike apart, or so it seems anyway, except the engine so I've never seen the inside yet.

xs650mike · Posted: January 2, 2006, 4:13 pm Post subject: Re: High Volume Oil Pump?

I've been curious about the need for this mod too since IIRC the bypass valve limits oil pressure to 16 lbs. no matter what.

mo650chopper · Posted: January 2, 2006, 7:37 pm Post subject: Re: High Volume Oil Pump?

I assumed with it being a "High Volume Pump" that it flowed more oil not neccesarily more pressure.

xs650mike · Posted: January 4, 2006, 12:23 am Post subject: Re: High Volume Oil Pump?

Since liquids are not compressable I'm having a hard time picturing how you could have more volume flowing through the same size oil passages without the pressure increasing. If the pressure is limited to a constant 16 lbs. no matter what, how is the flow able to increase? Maybe at idle it could and that would help the engine. I'm going to have to study the diagram of the XS650 lubrication sytem and read up on fluid dynamics a bit.

Jack · Full Member Joined: Mar 15, 2005 Posts: 411

My concerns of running a High Volume oil pump on the XS engine,is of it's low oil capacity now and running at higher RPM's COULD suck the lower sump try by pumping all the fluids upstairs and the return drainback may be an issue............Jack

mo650chopper · Posted: January 4, 2006, 12:46 pm Post subject: Re: High Volume Oil Pump?

Maybe someone out in cyberspace has ran one and could enlighten us.

kitw1977xs650 · New Member Joined: Feb 16, 2006 Posts: 3 Location: Norway

mo650chopper wrote:

Maybe someone out in cyberspace has ran one and could enlighten us.

First of all, I do not have experience with this motor (I bought mine about a month ago), so my considerations are based on experience with hydraulics in general.

I find very unlikely that the High volume pump will pump all oil up to cyl head, as there normally are well sized channels for return.

If pump rate exceed the capacity of the inlet line, cavitation may occur, but I find this very unlikely to happen (I guess the pump does not have that much overcapacity).

The other possible negative consequens of to high pump displacement could be overpressure, if the pressure relief valv not can handle the flow, (high RPM with cold oil). I find this also very unlikely to happen.

I guess the oil pump you described is developed and tested on similar moter. If you are uncertain, it is possible to connect a gauge and measure the pressure.

So some question to you:

Why do you feel for increasing the oil flow? Is it related to better cooling, or do you get to little pressure at low RPM?
Do you know the minimum required oil pressure at idle speed? You say maximum 16psi, which is quite low. On my bike the oil pressure lamp is flashing at low idle hot motor. The pressure switch is marked 0,3 bar ( which is 4,5 psi) Seller told me that the switch is from a HD, which potentially may have higher oil pressure. I have not found any spec stating minmum oil perssure for this motor. So, if some of you have some values, T would really appreciate to get some feed back on that.

tudawgs · Posted: February 16, 2006, 9:44 pm Post subject: Re: High Volume Oil Pump?

The theory behind the high volume oil pump is a simle one. As we all know the oil in the Xs never leaves the engine which causes the oil temperature to rise significantly and subsequently lowering the viscosity. Under these circumstances the stock oil pump has a more difficult time maintaining adequate flow. The higher volume pump enshures consistent flow at these higher temperatures while when the oil is cooler the pressure relief valve compensates . In a racing enviroment the high volume pump would be of the most benefitbut, under normal circumstances a simple external oil cooler and filter would be of greater benefit. I added the above items when I had oil heat problems after built th 750 rephase and all has been well 6000 miles later.

kitw1977xs650 · New Member Joined: Feb 16, 2006 Posts: 3 Location: Norway

Thank you for a good answer. As mentioned, I bought mine just a monthe ago. Already while driving it home, winter time in Norway, I potential saw a need for improved cooling as the cooling fins does not seem that well sized, and that I saw the oil warning light flasing at low rpm. Of cause the combination of increased flow, and external oil cooler is a very good idea, to avoid overtemperature, as cooler effeciency increase with flow.

I read some postings yesterday on another XS650 forum, were one of the members connected a gauge to the oil pipe (up to cyl head) and measured oil pressure to 3psi at idle and 20psi at 7000rpm. So these motor really run with low pressure. I think this is valuable information for all XS owners as these values are not well documented in the books. This also gave answer to my questions, as my switch need about 5 psi. I plan to install both oil temperature- and pressure- gauges, as sufficent oil flow and with right temperature is important for all motors.

Jusupov · Posted: March 4, 2006, 9:28 am Post subject: Re: High Volume Oil Pump?

kitw1977xs650 wrote:

Already while driving it home, winter time in Norway, I potential saw a need for improved cooling as the cooling fins does not seem that well sized, and that I saw the oil warning light flasing at low rpm. ..
This also gave answer to my questions, as my switch need about 5 psi.

I disagree a bit about the cooling fins design Smile

First, as you've noticed the oil pressure in XS650 is too low for the most of the oil pressure switches and meters. And for the XS650 (containing only roller bearings) oil pressure is no issue. The flow of oil is. Oil flow meter would be nice but a bit difficult to implement (if you do not want to lessen the reliability).

I did ride the last season with oil temperature measurement. Even in the hottest days here in "neighbouring" southern Finland (temps about 30 C) the oil temp never went above 90C in the road. The cooling fins below the motor are quite cleverly designed. But ofcourse in those days riding in a city is a problem - but more to the rider than to the motor Very Happy

kitw1977xs650 · New Member Joined: Feb 16, 2006 Posts: 3 Location: Norway

Thank you for your information, Jusupov. I felt it was running warm, due to the oil lamp flashing, the smell of hot oil etc., plus my visual evaluations of cooling fins, but it is all just impression as I had no temperature measurement. If it is running with a oil temperature of 90degC, it is not bad. Thank you for sharing this information. Rgds Kjell Inge

650tango · New Member Joined: Jun 10, 2008 Posts: 3

I installed Mike's high volume oil pump on my 80 xs650 and am not sure how much oil to add when doing regular oil changes. It could be my imagination but it seems if I add the stock amount ~2.5 quarts, the engine is over-pressurized and gets real hot.

So, I've been adding less. Am I good as long as whenever I check it, hot or cold, the oil level on the dipstick is between the two marks?

Is it better to have it on the low end? How low is too low?

Bike info in case it's pertinent:
Stock engine, no tach, k&n air pods, reed breather valve; just replaced idle mixture screws and set at 2 turns out. Runs and idles great.

Thx -Sam

xsjohn · Posted: June 21, 2008, 2:44 pm Post subject: Re: High Volume Oil Pump?

From my limited research ball bearings can be damaged by too much oil......they can slide in the races if over oiled causing them to be damaged............80's were the first year of epa regs and were extremely lean and will get very hot above 80 degrees if they are put to work.....

xsjohn

drifter · Posted: June 21, 2008, 4:14 pm Post subject: Re: High Volume Oil Pump?

>>The theory behind the high volume oil pump is a simle one. As we all know the oil in the Xs never leaves the engine which causes the oil temperature to rise significantly and subsequently lowering the viscosity. Under these circumstances the stock oil pump has a more difficult time maintaining adequate flow<<

Japanese bikes have been (and still are) running wet sumps with no problems for many many years. I doubt that the XS has any more heat problems than any other Asian air-cooled bike. The amount of oil is about the same as other bikes and a vertical twin, or 4 all generate about the same amount of heat. This being so, why do you think the XS has such overheated oil problems?

Dave

drifter · Posted: June 21, 2008, 4:20 pm Post subject: Re: High Volume Oil Pump?

>>and that I saw the oil warning light flasing at low rpm<<

On many bikes (Yamaha, Harley, Honda, Kawasaki that I know of) the owner's manual states that this flickering of the oil light at idle is completely normal and not to worry. I have never had a problem with a bike because of the flashing at idle oil light. Never a heat related problem. The thing is with older bikes, one oftern doeasn't get the manual to remind them that such things are normal and not to be alarmed.
However....owners should do what they will, but I trust the manufacturers who spend many thousands of hours in R&D. They probably know more than I do.

Dave

jimmythetrucker · Full Member Joined: Mar 12, 2008 Posts: 1283

Jusupov is right -- with roller bearings, a constant flow of clean oil is what's most important. With roller bearings, "high" oil pressure (40-50 psi) is impossible to achieve without installing some sort of irrigation pump and a fire-hose nozzle.

Nobody who lives in a temperate zone needs to worry about oil temperature anyway. In a place like Yuma, AZ, where ambient temps in summer average 110 degrees F or more, an oil cooler is arguably a good idea. In a place like Iowa, where ambient temps in summer average 85 degrees F or so, an oil cooler is a waste of money. I run 20-50 GTX all year round, all of my life, and never had any problem. The one bike I had that flashed an oil light at idle was a brand new Honda CB750 Custom. It came from the factory loaded with 10-40 oil. I switched to 20-50 GTX at the first change and the problem (if it was a problem) went away.

So that's my advice to guys who get a low-pressure light at idle. Switch to heavier oil. Buy beer & wine with the money you save on aftermarket parts.

xs1961 · Posted: June 21, 2008, 6:54 pm Post subject: Re: High Volume Oil Pump?

...Ive stuffed 20/50 into every bike Ive owned in the last 40 years,(cheap & good when hot) from Triumph's & Beeezas ,Yam 650's right through to Guzzis & GSXR1100's & they all thrived on it... Clean oil is all that counts..Dont thrash from cold & Change every 1000 miles..
The XS motor is built like a tractor,over-engineered, a few times over the years Ive drained the oil one night & forgotten in the morning(beer) & ridden a few miles before remembering without any damage to the motor apart from a few scuffs in the bore!
The only bikes from experience that benefitted from high-volume pumps were my old Bonnevilles, the Morgo pumps could squeeze oil through a gungy cranks sludge-trap.. Wink

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