changfa 1115 and oil pressure sending unit

[dmarkh]

I've ordered the banjo adapter from Utterpower and found a matching water temp and oil pressure gauge set I like. I understand at start time these engines can put out as much as 300 psi but have also read (somewhere) that a sending unit that can handle 125 psi would be OK. The gauge I'm looking at, the MFGR says that they use the same sending unit on another type gauge rated for 150 PSI. So he assures me that it can handle continuous pressures of 150 PSI and thinks even that short bursts of over 150 PSI would be OK.

I live in central FL and don't plan to move north. Would anyone recommend or NOT recommend trying this gauge/sending unit on the 1115.

The gauge I'm looking at is here: http://www.glowshiftdirect.com/MaxTow-Oil-Pressure-Gauge.aspx

Thanks for any recommendations.
Mark

[dmarkh]

Well, talking to myself, I'm gonna try this with a stubber valve inline.

[vdubnut62]

Sorry Mark! I'm not aware of anyone here but maybe MobilBob trying one of George's banjo adapters , and I'm not sure of that. I certainly haven't tried one.
You weren't ignored, I am  just ignorant!
Ron.

[mobile_bob]

me? i would never attach an oil pressure sender or gauge to a changfa, save for the rarity
that has the oil pressure regulator mounted on the rear crankcase cover.

the problem is cold starts, oil pressure can spike very high, some reports of over 300psi
which will like blow up most sensors and gauges.

now if you use the banjo fitting and take oil pressure off there, feed  it to a small external regulator
(hydraulic regulator with 1/4inch fittings?) and put the sensor or gauge line on the regulated oil pressure, then i am ok with that.

in my opinion, the oil pressure ought to be regulated to around 60psi cold (maybe 30psi hot) in the first place, there is really no need for insanely high oil pressure, and

it takes power to drive an oil pump at 200-300psi, far less at 30-60psi, and the stress on the pump drive out to be much lower too?

fwiw

i think most folks shy away from making recommendations for fear that something goes "pop" while the engine is running unattended, and then what?  you got oil all over the place at a minimum, a lost engine at medium, and a potential fire which in most cases would be the maximum risk.

if a sender/sensor or gauge is rated at 150psi, i would never exceed that even for a second, actually if it were rated at 150 i would target for no more than 100psi continuous and no more than maybe 125 intermittent. 

bob g

[dmarkh]

me? i would never attach an oil pressure sender or gauge to a changfa, save for the rarity
that has the oil pressure regulator mounted on the rear crankcase cover.

the problem is cold starts, oil pressure can spike very high, some reports of over 300psi
which will like blow up most sensors and gauges.

now if you use the banjo fitting and take oil pressure off there, feed  it to a small external regulator
(hydraulic regulator with 1/4inch fittings?) and put the sensor or gauge line on the regulated oil pressure, then i am ok with that.

in my opinion, the oil pressure ought to be regulated to around 60psi cold (maybe 30psi hot) in the first place, there is really no need for insanely high oil pressure, and

it takes power to drive an oil pump at 200-300psi, far less at 30-60psi, and the stress on the pump drive out to be much lower too?

fwiw

i think most folks shy away from making recommendations for fear that something goes "pop" while the engine is running unattended, and then what?  you got oil all over the place at a minimum, a lost engine at medium, and a potential fire which in most cases would be the maximum risk.

if a sender/sensor or gauge is rated at 150psi, i would never exceed that even for a second, actually if it were rated at 150 i would target for no more than 100psi continuous and no more than maybe 125 intermittent. 

bob g

Thanks mobile_bob. I have a stubber valve that is supposed to deflect spikes of over 80 PSI. I thought it might take care of this issue. It would go between the banjo bolt and sending unit. It was designed for fuel pressures but might this work?

Thanks
Mark

[mike90045]

It was designed for fuel pressures but might this work?

ONLY if the oil is as thin as fuel - that would be really hot!  Thick oil may be to viscus and inhibit the valve action.

[dmarkh]

It was designed for fuel pressures but might this work?

ONLY if the oil is as thin as fuel - that would be really hot!  Thick oil may be to viscus and inhibit the valve action.

Thanks for that. I was wondering about that but assumed if the oil was too think I just wouldn't get any pressure at all.

I'm looking into this one then.

http://www.dieselmanor.com/isspro/R7798.asp

I'm stubborn.

Mark

[Ronmar]

Or you put a valve on the line and only open it when you are interested in looking at the warm running oil pressure:). The popup  will tell you there is OP at startup, then if it is vital to know what the actual number is, you can crack the valve and take a peek.  Open the valve after shutdown to bleed back the running pressure stored between valve and gauge...

[dmarkh]

Or you put a valve on the line and only open it when you are interested in looking at the warm running oil pressure:). The popup  will tell you there is OP at startup, then if it is vital to know what the actual number is, you can crack the valve and take a peek.  Open the valve after shutdown to bleed back the running pressure stored between valve and gauge...

I like that idea. Seems like a good compromise. I should probably not use the port behind the fly wheel though huh? Ouch!!

Thanks
Mark

[Derb]

Is it feasible to run a by-pass valve and return line from the oil gallery back to the sump regulated to by-pass at a predetermined pressure (40 PSI ?)  at which point a 0 to 100 PSI guage would give you an accurate reading but not self destruct on cold start. This would also unload the pump and associated drive gear to a degree. Cheers.

[dmarkh]

Or you put a valve on the line and only open it when you are interested in looking at the warm running oil pressure:). The popup  will tell you there is OP at startup, then if it is vital to know what the actual number is, you can crack the valve and take a peek.  Open the valve after shutdown to bleed back the running pressure stored between valve and gauge...

I like that idea. Seems like a good compromise. I should probably not use the port behind the fly wheel though huh? Ouch!!

Thanks
Mark

This is what I ended up doing. It works. After we are running at normal temps my pressure is around 60 lbs?

Mark