Classic cars forum & vehicle restoration.

[Kleftiwallah]

I'm restoring a BSAFWD TW31, now to the (seemingly) silly question. To protect the engine I'm installing an oil temp sensor and gauge. Could someone knowledgeable confirm that the sensor should be immersed in oil at normal working level?

Cheers, Tony.

[Minxy]

Depends what you mean by ' working level'?

When the engine is running the galleries and respective feeds are under pressure and contain oil with little or no air. When it gets to the top end it drips down into the sump to be picked up and pumped around again. You could put a sensor in the sump so it is in contact with the oil there but the temperature there is likely to be less than in the main engine.

The simplest way is to remove the oil pressure switch, fit a 'Y' piece and put the pressure switch in one and temp sender in the other.
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Hillman minx convertible. Lanchester LD 10

[alanb]

Please excuse my ignorance but why do you need to know the temperature of your oil? Surely a water temperature gauge is of more value as the boiling point of oil is approximately 3 x that of water.
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old tourer


Morris 8 two seater

[Kleftiwallah]

I feel more info is needed. The engine is an air-cooled 1012cc V twin Hotchkiss. Alanb - no liquid coolant.

Thanks for all those informative replies. I'll use a hole drilled in the engine casting by a previous owner to fit an external oil pump to install the oil temp sensor. I've re-installed the original oil pump.
Cheers, Tony.

[alanb]

Sorry for my ignorance I've only seen 4 cyl water cooled BSA's
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old tourer


Morris 8 two seater

[ka]

Quite intrigued with this thread.
Should you go ahead and fit an oil temperature gauge, at what temperature is the oil too hot, and what can you do about it? the logical conclusion is to fit an oil cooler, but the original question is still paramount.
At what temperature would you expect oil to operate in a water cooled engine, no matter an air cooled. Does the age of the oil have an effect on optimum temperature?
I am all for having gauges to get some indication what is happening under the bonnet, water temperature can be addressed by stopping, topping up etc, oil pressure gives a warning of an early mechanical failure, oil temperature???
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KA

Better three than four.

[colwyn500]

[ka]

I have a modern BMW bike, with oil engine cooling, using a separate pump and oil cooler, known as the 'oil head'. It has the bar graduated temperature gauge, but to bring it back to the link, it has an oil thermostat that works as a water one does.
Some years ago we went to the Morgan Lakedistrict camping weekend, towing a small trailer with the gear in it. Returning down the M6/M1 (time constraints) I adjusted the cruising speed by watching the water temp gauge and the oil pressure gauge, when the pressure dropped I slowed down to allow the water temp to fall, therefore the oil pressure to climb.
I am not a huge fan of synthetics in classic vehicles, but that being said, BMW recommend everything from Mineral to Full synthetic in the beemer, and accepting that engineering tolerances and running temperatures are far wider in an air cooled engine, starting with oil the consistency of water will give the advantage of protection from start-up.
When starting the engine in the Mog, I always spin it over until I have oil pressure, before turning on the ignition.
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KA

Better three than four.