Pressure Gauge Adapted

[polebridge]

The OPRV is rated 55-60 psi. John mentioned 80 psi but I think that was for a much shorter time. What weight oil are you using?

 

 

Right now I am using 15w/50 full syn. Pardon my ignorance but what is OPRV?

[Guest ratchethack]

Oil pressure relief valve.

[polebridge]

Oil pressure relief valve.

 

Thanks Ratchethack. Any idea of what oil pressure is normal at idle with a warm engine? Does 40psi sound about right?

 

Thanks

[raz]

Thanks Ratchethack. Any idea of what oil pressure is normal at idle with a warm engine? Does 40psi sound about right?

Did you read John's report earlier in this thread? I think he had 60 psi at idle. I'm not qualified to answer if 40 psi is OK, but my guess is it is, as long as you've got the 60 on higher rpm.

[Guest ratchethack]

Thanks Ratchethack. Any idea of what oil pressure is normal at idle with a warm engine? Does 40psi sound about right?

 

Thanks

Depends slightly on wot wt. oil you're using and ambient temp., but unless you're running something goofy and/or at extreme ambient temps, I'd be as happy as a clam with 40 lbs. pressure fully warm at idle. Now there are those who are evidently inclined to slice 'n dice this to distraction. But lacking any symptoms to be concerned about under any and all conditions since I installed my "Pete Plate", I haven't given normal idle pressure or running pressure a thought ever since -- exactly as planned. Given real-world probabilities, lacking any symptoms going forward (such as evidence of a stuck PRV or loose filter, neither of which I'm the slightest bit concerned about), I don't expect to give it much thought ever again. But o' course, that's just me.

[Paul Minnaert]

what is the max reading you get on a v11? I ask because thinking of mounting such a vdo thing, and they have them to 5 or 10 bar. Would 5 be enough?

[dlaing]

what is the max reading you get on a v11? I ask because thinking of mounting such a vdo thing, and they have them to 5 or 10 bar. Would 5 be enough?

Ryland3210 got a maximum reading of 80PSI which is 5.52 bar, so it probably is not enough. Too bad, because it would be nice to have the accuracy of the 5 bar meter.

[raz]

what is the max reading you get on a v11? I ask because thinking of mounting such a vdo thing, and they have them to 5 or 10 bar. Would 5 be enough?

Those 80 psi John and Polebridge witnesses would be 5.5 bar, but that is just for a short time when stone cold. I was thinking of buying a Vega kit from Stein-Dinse, ranging 10 bar but I think I would rather have one ranging 5 bar as the OPRV is 4.2 bar and a 52 mm unit is pretty low resolution.

On the other hand, a 10 bar gauge would show needle almost in the middle for normal operation, which is pretty sane.

[dlaing]

Thanks Ratchethack. Any idea of what oil pressure is normal at idle with a warm engine? Does 40psi sound about right?

 

Thanks

I ain't qualified either, but my guess is that as long as you are getting more than a few psi, oil will get delivered.

A few things might be effecting your 40psi compared to Ryland's 60psi.

Actual oil viscosity at time of test.

Filter bypass valve relief pressure setting. (different brands and models have different spring ratings.)

Condition of filter.(but there is a school of thought that Guzzi filters never bypass, so if you follow it, you can ignore filter's effects on pressure)

Idle speed.

[dlaing]

Those 80 psi John and Polebridge witnesses would be 5.5 bar, but that is just for a short time when stone cold. I was thinking of buying a Vega kit from Stein-Dinse, ranging 10 bar but I think I would rather have one ranging 5 bar as the OPRV is 4.2 bar and a 52 mm unit is pretty low resolution.

On the other hand, a 10 bar gauge would show needle almost in the middle for normal operation, which is pretty sane.

One thing to keep in mind is that Ryland got a reading of 80PSI at about 0C using 15W-40.

In Scandinavia you may ride in much cooler temperatures. Hopefully you will be using a 5W synthetic in those conditions, but the point is you may experience more than 80PSI.

Maybe there is a maximum pressure rating for that 5bar gauge???

Or you can buy Ryland's 100PSI gauge kit

[raz]

One thing to keep in mind is that Ryland got a reading of 80PSI at about 0C using 15W-40.

In Scandinavia you may ride in much cooler temperatures. Hopefully you will be using a 5W synthetic in those conditions, but the point is you may experience more than 80PSI.

Maybe there is a maximum pressure rating for that 5bar gauge???

Most of us never ride in sub freezing-point temperatures. Anyway I don't expect pressure to go much higher. The acceptable OPRV range according to the WHB is 55-60 psi or you should otherwise fix it. But I'm guessing the initial higher value is not caused by a bad OPRV, but the OPRV like everything else will not do exactly what you might expect with cold and thick oil. Hopefully we can now analyze this issue in 12 pages without really having a clue

 

FWIW, as a comparison the oil lamp should go away somewhere between 2 and 5 psi! Just so you get the picture. Me thinks that is very low...

 

Or you can buy Ryland's 100PSI gauge kit

Pound is a currency. Inch is an ancient unit based on the width of a carpenter's thumb. Wake up

[dlaing]

Pound is a currency. Inch is an ancient unit based on the width of a carpenter's thumb. Wake up

And a bar is get drunk(if you can afford the alcohol)

It would be nice to get good resolution at that first PSI.

Ryland, do you have any other gauge options other than PSI.

The 0 -100 PSI range is perfect, but these Europeans need bars like mars needs women!

[Ryland3210]

I've been away all week, so I'd like to catch up on a couple of things. Sorry for taking so long.

 

First, the 80 plus psi readings I mentioned only occurred on startup, cold engine. In the test I did at 0 C, it looked like it would have kept climbing past 80 psi at higher RPM.

 

Once my bike warms up, idle pressure can go as low as 25 psi at 1100 RPM on 90 degree days after a long ride. It is very sensitive to RPM, and went below 15 psi at the original 600 RPM idle it ran at when delivered. That made me a real believer in the importance of at keeping idle at 1150-1200 (my personal target). On hot days, cruising at 3,500 RPM, it can go as low as 55 psi. On average days, say 80 F, it runs 60-62.

 

Based on my measurements, the gauge needs to be rated at 100 psi (7 bar) or more. I prefer the 270 degree dial with a gauge rated well above the expected pressure for long term life and accuracy. A 270 degree dial's needle moves more with pressure changes and catch the eye more readily. It's also easier to read with accuracy.

 

My cold temperature test showed that higher viscosity oils build pressure faster than lower, eliminating the concern that it might take longer than lower viscosity. This, together with pressure readings under various conditions motivated me to use 20W50 oil instead of lower viscosity.

[pete roper]

I've been away all week, so I'd like to catch up on a couple of things. Sorry for taking so long.

 

First, the 80 plus psi readings I mentioned only occurred on startup, cold engine. In the test I did at 0 C, it looked like it would have kept climbing past 80 psi at higher RPM.

 

Once my bike warms up, idle pressure can go as low as 25 psi at 1100 RPM on 90 degree days after a long ride. It is very sensitive to RPM, and went below 15 psi at the original 600 RPM idle it ran at when delivered. That made me a real believer in the importance of at keeping idle at 1150-1200 (my personal target). On hot days, cruising at 3,500 RPM, it can go as low as 55 psi. On average days, say 80 F, it runs 60-62.

 

Based on my measurements, the gauge needs to be rated at 100 psi (7 bar) or more. I prefer the 270 degree dial with a gauge rated well above the expected pressure for long term life and accuracy. A 270 degree dial's needle moves more with pressure changes and catch the eye more readily. It's also easier to read with accuracy.

 

My cold temperature test showed that higher viscosity oils build pressure faster than lower, eliminating the concern that it might take longer than lower viscosity. This, together with pressure readings under various conditions motivated me to use 20W50 oil instead of lower viscosity.

 

 

All of this looks perfectly normal and right on the money to me.

 

Pete

[Skeeve]

My cold temperature test showed that higher viscosity oils build pressure faster than lower, eliminating the concern that it might take longer than lower viscosity. This, together with pressure readings under various conditions motivated me to use 20W50 oil instead of lower viscosity.

 

In this application, pressure & flow are not equivalent. The reason the higher viscosity fluid builds pressure faster is because less of it is going where its needed. Guzzis have never needed the heavyweight oils that the old Harleys did; in fact, there's a wonderful story about the correct oil from back in the days when Berliner was importing them. Of course, that was back in the days of straight wt. oils, which are getting hard to find these days. Yay for multi-viz!