Gauges: oil temperature and pressure

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PanPal
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Gauges: oil temperature and pressure

#1

Post by PanPal »

I want to install an oil pressure and temperature gauge on a new project pan chop. What is the highest pressure a stock oil pump puts out? What is the high limit on the temperature for the oil? The accuracy is better if I don't get gauges with too much range.
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Re: Gauges

#2

Post by PanPal »

OK, no reply. I know oil pressure is low and flow is high. Is there any need to get a pressure gauge higher than 15 psi. I don't have a oil sensor light, I just want to be able to look down and make sure I have pressure and maybe see what changes occur as the engine heats up with different weight oils.
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Re: Gauges

#3

Post by Cotten »

I apologize that this comes across like a trite smart-ass'd comment,
but in all earnest sincerity,
you are better off watching the road.
PanPal
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Re: Gauges

#4

Post by PanPal »

I see people saying in prior post that they are running at 20 psi and 40 psi. They also have the aluminum pump installed though. I thought pressure was down around 3 psi?

Cotten, my attention span is not that long. I need other things to look at. :)
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Re: Gauges

#5

Post by caschnd1 »

My 2 cents: I'm running an S&S oil pump, so I'm not sure this applies to running a stock pump but...
I see 30psi at idle when cold 10psi at idle when warm. 50psi at cruising speed when cold (just leaving the house) and 25-30psi at cruising speed when warm. This is all using 50W motor oil. I haven't checked the pressure during summer months (didn't have a guage last summer) when I'm running 70W and it's 110+ degrees F outside. After sitting in a little traffic on a hot day, I could believe 3psi would be the result.
But I gotta agree with Cotton. Trying to look down at the gauge while cruisin' down the road and get an accurate reading is tedious to say the least. But then my gauge is mounted on the oil pump. I think the clatter from the top end will tell you pretty quick if you have an oil pressure problem (probably before you'd notice it on a gauge unless you watch it constantly).
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Re: Gauges

#6

Post by PanPal »

Thanks for the input caschnd1. Is your gauge liquid filled?

It's when I hear that top end chatter that I may take a glance at the gauge. At a stop light perhaps. I just think it may come in handy to have a gauge. I will install it on the pump also to replace that hex head bolt the prior owner installed in the NPT threaded hole.
drippy

Re: Gauges

#7

Post by drippy »

Just a general observation. The more info one has the better one is able to react. I agree that a pressure gauge and some idea of ranges would be helpful. I certainly don't advocate looking at my gauges constantly ( night flight....hmmmmm) but most of us are able to figure out when to watch the road and when to do an instrument check, otherwise with the attention level of MOST cagers we'd be dead. What is it with you and oil Cotten??
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Re: Gauges

#8

Post by Cotten »

Gauges can lie.
You can read very high pressure, but still have dangerously low flow. Or you can have great flow, but not even register on a gauge.
Without internal temperature sensors, and oil viscosity and RPM constants, and a calculator taped to your handlebars to punch them all into, your readings are only good enough to make you worry about naught.
Its a standard joke that a customer who buys a gauge will soon return to buy too-heavy oil.
Idiot lights save motors; gauges keep you guessing.
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Re: Gauges

#9

Post by Jack_Hester »

Cotton makes a very good point about the gauges. I run gauges on two machines, but the idiot light is the one instrument that will flag you as to a problem, first. A very good friend of mine has spent countless hours and dollars trying to get the oil pressure on his 57 Pan to match his Shovel. He finally went the route of an S&S high volume pump. First, he had an aftermarket pressure switch, that didn't even come close to the OEM, in pressure setting. Too high. So, his idiot light came on, even at a fast idle. Then, he shells out the bucks for the S&S pump. Got more pressure. Oil light still comes on at an idle. He doesn't ride it. I explained that his old pump was doing just fine, and that we needed to find him a good used, or NOS pressure switch, with the correct setting. It still sits, and he rides his TC model.

Flow is important. Low pressure warning of the idiot light is an indication of potential problems. High pressure is bad news for the bearing rollers, which has already been covered in an older post. In the hot Summer, light comes on almost every time, at an idle. Rev the engine slightly to compensate. You are increasing flow, which is what the engine needs.

Now, if you feel inclined to run the pressure gauge, get one with a 270 degree sweep (not referring to temperature, but angle or needle movement). The cheap ones that look like a miniature windshield wiper are so inaccurate, that you had better have an idiot light to back it up. It will not read anywhere close to correct. The 270 will have the zero point on the bottom left of the gauge, and the full sweep on the bottom right of the gauge. Get at least a 60 lbs. gauge, for the cold oil indication. The higher you go on the gauge, like a 100 lbs. gauge, the less accurate they are on the low pressure side of the scale. You can go with a 30 lbs., if you can find one, but you will eventually damage it. The single weight oils will almost always pump higher than this, in cold weather.

Jack
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Re: Gauges

#10

Post by Arthur »

PanPal: I have a stock oil pump with a gauge and a warning light. My engine and oil pump are in good shape, so I think this information should be typical for stock setups: The oil pressure varies a lot with the temperature and speed of the engine, which I have been told is normal. At cold start, it runs 40 pounds or more. After warming up, it runs about 20 pounds at cruising speed, but drops to less than 10 pounds at idle.
My gauge goes to 60 pounds, and is not liquid-filled. It's old, and came with the bike, so I don't know where to get one like it.
Of course, different oil pump bypass springs are/were available, so the pressure range I have described would presumably move up or down with a different spring tension.
I know nothing at all about engine temperature gauges. Sorry.
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Re: Gauges

#11

Post by PanPal »

I understand there are variables with a gauge and feel I can figure out a few things without adding a calculator. This is a recently purchased bike with no indicating sensors of any kind. Hell, there's only 6 or so wires on the whole bike. I want to stay away from a lot of wires until I start playing with LED's. I figured a chrome oil pressure gauge and a oil temperature gauge would not clutter up things and allow me to monitor things a little. The previous owner has 70W racing oil in it. He said he did it because he was having heat problems, Prior posts suggest thicker oil causes heat problems. With these two gauges installed, I could compare differences with different weight oils, no real need to rely on the readings as factual readings. And without an oil pressure sensor when in doubt, a quick snap on the throttle at a stop light along with some movement of the oil gauge needle may be of some use when in question. A little information is better than no information when everything about this bike is new territory.

Jack and Aurthur much appreciate the input and detail on the gauge. The only stock part on the engine is the pump. The motor is pretty hopped up. There is much to learn and observe in my attempt to avoid tears and $$$$$

Cotten, I always get something good out of your input after pondering it a bit, but who's been pissing in your Corn Flakes ???
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Re: Gauges

#12

Post by Cotten »

It is sad watching generation after generation chase the same wild goose.

'53 and later hydraulic units are probably the best indicator of how an engine is oiling, as they change note when underfed, and hammer violently in the event a flow/pressure problem.. And listening to them doesn't take your eyes off the road.
You'll be cranky too, when you reach my mileage.
I'm so jaded, I have to be paid to ride.
(I'd enter a scowling smiley, but I hate smileys too.)
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Re: Gauges

#13

Post by 108 »

Panpal, I have SW oil and amp gauges and both warning lights on the reworked dash of my '48 FLH .It has the original pump (rotor valve removed) and a finned tube cooler with synthetic 50W . All my pressures run the same as Caschnd 1's and they seam accurate but thats not the whole picture. After a while you learn what the normal pressure changes and needle movements are and then later, if something changes inside your engine you may see a difference on the gauge. It's comforting being able to see its OK! I've never checked oil temp. I guess I wasn't concerned with the cooler and synthetic can take alot more heat.
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Re: Gauges: oil temperature and pressure

#14

Post by 58flh »

I know this post is old!--But I still see Questions about -(my guage reads 0 :shock: )---Its like this--Use the Idiot light!--If it goes out when you light-up the mill--YOUR GOOD!--I use it for -(IF the oil-light DONT go out!)--NOW you have a SERIOUS PROBLEM like the Pinion bushing spun & NO OIL is Flowing thru the motor!--If I get to a RED-LIGHT & its Idleing --MY LIGHT SHINING RED!--Brapp the wick a little & the light is off!--(THIS IS NORMAL OPERATING PAN MOTOR!.)--If your doing 50MPH & the LIGHT comes on--Then its a problem & usually 1 Of 2 things Pinion bushing , or Oil-pump Key broke!).Todays Guages are set for HI-Pressures More then a pan can do!--SAVE YOUR $$$$ & use the light at fireing-up when cold!--If it goes out & it may go out just with 2-priming kicks!--GO & ENJOY your BIKE!/Looking down for a number on a alcohol filled gage is pretty dangerous as your peepers are off the road for a second!//Kind of like todays kids & texting while driving!------RESPECFILLY---RICHIE! 8)
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Re: Gauges: oil temperature and pressure

#15

Post by PanPal »

Wow, this was an old post! The motor on this bike has been rebuilt and brought back to stock 74 specs. I took out the high compression pistons, high lift cam, and heavy valve springs. Had Headhog repair my original case and match it to the gear side case that was on it. I went with the pressure switch but havent wired in a light to it yet. I agree with all the advice I was given back when this post was written. I listen to what the motor sounds like and if I question oil flow I check in the oil tank and see if oil is returning. No gauges on any of my rides! Hydraulics will tell me if oil flow isnt right. I would think the light would be more helpful if running solids.
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