Oil Pressue Gauge Damping

[renobruce]

The liquid filled gauges quit working once the oil is hot.

[salty_monk]

Interesting thought on this today, browsing the manual for the 83750ES 16v TSCC engine. It gives figures for an oil pressure test.

It quotes:

Above 36PSI but below 78PSI at 3000RPM.

This is with the engine hot (warmed up for 10min at 2k rpm or 20 min if it's winter).

If this is the case wouldn't that be way off the gauge if Jim is using the same pump / gear?

Dan

[renobruce]

Interesting thought on this today, browsing the manual for the 83750ES 16v TSCC engine. It gives figures for an oil pressure test.

It quotes:

Above 36PSI but below 78PSI at 3000RPM.

This is with the engine hot (warmed up for 10min at 2k rpm or 20 min if it's winter).

If this is the case wouldn't that be way off the gauge if Jim is using the same pump / gear?

Dan

The 16 valve 750 uses a plain crank high pressure motor. It has the same oil pump gears, but they run much higher pressure. The same gears in an 8 valve motor will increase the pressure by a few psi.

[Tom MLC]

I'll be able to test this on my red hotrod, if I ever get her running! I just put 750 oil pump gears in.

[posplayr]

I have an update on the pressure guage. I posted here a description of the problem the Bourdon gauge suffers from vibration. It needs to be mechanically damped or teh internal mechanisim will be beat to death.

http://www.thegsresources.com/_forum/showpost.php?p=1144976&postcount=9

The technique described in this tread does work,(to stop needle bounce due to engine pressure pulsation) but once your guage gets hammered enough the hydraulic damping will do nothing about needle bounce once those pivots on item #4 get worn.

On mine you could see little flecks of brass dust on the face. That is from the wear at the pivots. Relocating to the handlebar is a must for longevity.

I should mention, I think RenoBruce does provide an oversized rubber O ring that is a must if you do an engine direct install. Figuring out a way to do even more rubber for shock isolation would help even more. I took the o-ring off before I realized all this and the damage accelerated.

[Kris V]

I use liquid filled (glycerin)15psi gauge`s on all of my bikes. I get the gauges from Northern Hydraulic catalog and they last a long time (years) and the more you buy the cheaper they are. They have all kinds of pressure sizes for about 18-20$ a piece. All I do is drill the plug and tap it and install it and ride it. Never had a problem with them .

[Kris V]

The liquid filled gauges quit working once the oil is hot.

They start working at 8-9000 rpm

[renobruce]

They start working at 8-9000 rpm

Exactly. Once the oil is hot, you need to redline your engine to get them to move.

[renobruce]

Jim, I think you were definitely on to something when you stated earlier in this thread that the opening feeding the gauge should be smaller. VDO has recently re-designed their gauge, and I noticed that the opening on the bottom is about 50% smaller than before.