Rb Engine Track Work Temp.

[abr33]

Im not sure blocking it is a great idea, though im not sure. I currently use a bypass hose

[kitto]

The water piping for an RB's oil heat exchanger enters the from the rear water exit for the block (also the feed for the heater) and exist the exchanger into the water pump inlet post thermostat.

Here's a question, what location should we be getting our oil temperature from?

Should we be getting it from the bottom of the sump or post oil cooler as it enters the engine's main gallery?

[GTR_JOEY]

Should we be getting it from the bottom of the sump or post oil cooler as it enters the engine's main gallery?

This is a good question, id like to know this and why..

[GTSBoy]

You need to know where it is hottest. It is not important that you are providing it to the engine at a good temperature (post cooler). What is important is that you know how hot it actually gets. As such, the sump (or post oil pump sandwich plate) is the best location.

Or both, if you want to know everything!

[DCIEVE]

Have to disagree, You want to know temp and hence viscosity at the bearings, the practical way to do this is measure the feed into the block.

Edited January 8, 2013 by DCIEVE

[GTSBoy]

Hah!

Question. When does oil break down?

Answer. When it is hot.

Second question. How do you know how hot it has gotten, if you haven't measured it when it was hot?

Second answer. You don't.

You shove "cool enough" oil into your engine and pat yourself on the back. But whilst hanging around in the main feed gallery, it gets hot. Maybe it gets hot enough that whilst it's actually in the journals it starts to crap itself. Oh well. So sad.

[GTR_JOEY]

so the answer is measure it at its hottest?

... still dont know where we are taking the reading from....The sump, the filter housing, before the cooler if your using one????

im not 100% clear on the flow of oil through an RB engine

[ARTZ]

well its going to be the same temp at the filter housing as it is before the cooler ya...

[GTR_JOEY]

well its going to be the same temp at the filter housing as it is before the cooler ya...

Yes of course

[DCIEVE]

Hah!

Question. When does oil break down?

Answer. When it is hot.

Second question. How do you know how hot it has gotten, if you haven't measured it when it was hot?

Second answer. You don't.

You shove "cool enough" oil into your engine and pat yourself on the back. But whilst hanging around in the main feed gallery, it gets hot. Maybe it gets hot enough that whilst it's actually in the journals it starts to crap itself. Oh well. So sad.

Given your bearing dimensions are fixed the variables affecting the bearing performance are speed, flow rate and viscosity. Viscosity can double in 10 deg increments depending where are you are in the temp/viscosity range (log scale). The industrial scale bearings I'm involved with trip on 'feed' lube temperature, given an increase in temp of 5 deg above the trip point can drop the viscosity to a point where bearings fail (lube film is dependant on viscosity, load and speed). Ideally you want to know the temp at the bearing but in reality you have to settle for going as close to the bearing as possible. Oil is tested regularly and replaced based on the rate of deterioration (in most cases contamination happens first).

Now I'll ask you, how do you measure the maximum temp the oil reaches? At best you can measure the temp in the reservoir/sump or after the pump/before the filter, so using your argument - you still have no idea what the max oil temp is nor if the oil has reached a temp where it will break down. Your best of getting the oil tested to figure that part out.

[ARTZ]

is there really going to be that much temp difference between the bearing and the filter though?

I mean the split second it gets hot at the bearing surely couldn't do damage that couldn't be read at the sensor/filter and knowing what temp you should ease up on it which seems to be around 120...

[gtr jet]

Where does the standard temp sensor read from?

[GTSBoy]

Now I'll ask you, how do you measure the maximum temp the oil reaches? At best you can measure the temp in the reservoir/sump or after the pump/before the filter, so using your argument - you still have no idea what the max oil temp is nor if the oil has reached a temp where it will break down. Your best of getting the oil tested to figure that part out.

It is FAR more conservative and safe to measure the higher temperature rather than the lower temperature. Your industrial bearings are often just that....a bearing. Sure, they may be massive with massive loads on them. Sure, they may be running very fast. But they are seldom embedded within a bloody hot cast iron heat source as well. The lube oil usually flows via a nice hose from the remote pump to the bearing and the performance of the bearing under load is sufficiently well known by the manufacturer and/or commissioning engineer that they can tell the operator to trip it off based on ain inlet temperature because they know how hot it will heat up to. In our engines the bearings' oil feed is in an uncontrolled heater so you don't know how hot it is going in. If you measure it in the sump at 120°C then you know damn well that it had to have been at least that hot in the bearing itself. If you measure it at 105°C after the cooler.......you have no idea what the bearing has been running at. Just a wild guess. Could have been 140°C and breaking down for all you know.

Engineering is about identifying what is important, not just working from other examples.

[bigmikespec]

Where does the standard temp sensor read from?

The heat exchanger where the oil filter mounts.... which is just before it goes into the engine. A couple of people here know what they are talking about.

Edited January 9, 2013 by bigmikespec

[gtr jet]

Thought so. Cheers mate.

[LANDSCRIBBLE]

I have the temp sensor on my oil filter relocator.. Didnt take much notice if it was the ingoing or outgoing side though : /

[DCIEVE]

Engineering is about identifying what is important, not just working from other examples.

In the interests of maintaining my sanity I concede, but thanks for the tip - I'll be sure to pass it on to my grads

[bigmikespec]

In the interests of maintaining my sanity I concede, but thanks for the tip - I'll be sure to pass it on to my grads

ZING!!!!!!!!!!

[GTSBoy]

I don't see the zing.

With respect to the location of the oem temp sensor.....that one doesn't really matter where it is. There is no oil cooler in the equation (oil-water HX notwithstanding) and so the oil temperature will be about the same whether measured in the sump, after the pump, after the HX or after the filter. That example in no way nullifies my position.

The people who I supervise are not engineering graduates. They have PhDs.

[bigmikespec]

The people who I supervise are not engineering graduates. They have PhDs.

Ooooh... now yours is bigger!