Topic: digital oil temp readings

[azuredesign]

Hi, I am using a sensor in the drain plug, and wonder if having it located there gives an accurate reading for the actual temp of the oil itself, and whether my oil cooler is doing too efficient a job.

I note that when  cold, at 70f or so I read 65 psi oil pressure with a mechanical gauge in the main journal at idle.. At 170f- about 30 lbs, and  at 190f about 20lbs. 195f is about the max I can get while stationary.
All done on a 55f day 10-40 mineral oil
836cc with oil cooler as shown.

If anyone else is using a Daytona (Shindy) gauge, could you let me know what you see for higher readings?
Thanks!

[01Thomas]

Hi
You obviously want to measure oil temperature, but what oil temperature? The oil in the cyl head will be somewhat hotter than the oil in the little sump and that again will be hotter than the oil in the oil tank.

So the question becomes:
what do you want to know the oil temp for? Just because it looks cool having a guage up there? Or because you want to warm the engine up slowly so that you can tell when the oil is up to operating temp and only then will you gas it?
In my opinion your most valuable oil temp is the oil in the oil tank. There you will be measuring 'bulk' oil temperature; it will be stable and not given to transient excursions. The oil drain plugs in the sump and in the oil tank are identical so swapping them around is not a problem either.

regards
Thomas

[azuredesign]

Thomas, thanks for thinking about what I wrote and replying.

I am concerned that oil may be restricted from lubricating the cam and valve gear because it is not hot enough.
Perhaps the thing that is bugging me the most is how can I tell if I am getting sufficient oiling before I eff up another cam and followers. I guess one answer is to remove the valve cover at certain intervals and look at the cam lobes. I was hoping that someone using a similar setup could tell me what kinds of temps they were seeing. A friend told me that optimum operating temp for mineral oil is 215f.

I talked to Mike Rieck and he suggested making a cover for the cooler for the cooler seasons here in MA, which I am doing. My concern is should I be seeing higher temps when the bike is not moving? Do I need this oil cooler and the extra quart or so of oil I am using? Hell, I just found out that the common thinking among physicians concerning taking statins and niacin for regulating cholesterol may very well be hogwash, maybe coolers are not helpful in controlling friction?




FWIW, I do not like the way the digital gauge looks, but dont really give a rats ass about it.

[azuredesign]

OK, Anyone have a link for a manual cut-off valve for an oil cooler?

[azuredesign]

Found them from Earls.
Thanks for all the help!

[nokrome]

    I run a digi oil temp gauge on my 850 kit with power arc ignition, heavy porting and an Earls 2x12 oil cooler but I have my sensor installed in the 1/8" NPT port that that comes off the main oil galley  in the center of the engine right behind the cylinders.
    Your oil temp vs pressure numbers are pretty much identical to mine but I am running 20-50 and 100LL avgas. My engine tends to run hot if I am running 92 pump gas and when my gauge hits around 215-220f I will start to get early signs of pre-detination, this doesn't happen with the avgas, the temp usually doesn't get above 210.
    I don't know what the temps are like without the cooler because I have never run this engine without it.

[azuredesign]

Nokrome,

Thank you for your info! Sounds like you have plenty of compression, and really need the extra cooling.
Interesting to know that 215-220 is about max temp! I have been using 93 pump gas with a Dyna 2000, and 10-40 oil. Any idea how much oil you have in the system. I am running a long oil filter and finding that somewhere around 4.5- 5 qts is midway on the dip stick.

Once again thanks for the help!

[nokrome]

I have a custom oil tank that tops out at a little less than 4qts.
  I dont know that 215 to 220 is the max oil temp, from what I understand oil temps can get a good deal higher and still be ok. I think my pre-detonation is a symptom of a high cylinder head temp that happens to reach the pre-det point at the same time that my oil is reaching 215 to 220.

[rklystron]

I have a video using an infra-red camera showing the heat signature of many engine components. The oil Temp in the oil res when it came up to temp is around 250F.
The oil filter is about 210-220F. This is a high end IR camera. If you wish you can see the video here. https://www.youtube.com/watch?v=EqURz5nPG68. I was surprised the temps got that high, but have verified this is indeed the case. Interesting I must say.

[azuredesign]

Thank you for posting this! It looks like measuring oil temp in the sump gives a significantly cooler temp than measuring in the main galley. My max readings of ~200f sump temp do not come close to top end temps. It would be really cool to use some sort of fan system to approximate the effect of air velocity at different road speeds, the see how the temps differ. I bet fairing design for cooling could be optimized in this fashion.