Oil temperature off a t bar?

[Helga]

If you attatch a tbar adpter with a 50mm spur off the original sender in an Aircooled t25, would a sender in that 'dead' end of pipeline give any sort of decent temperature reading? I know it would give a fine pressure reading, but temperature?

I'm arguing about this with friend - I say it wont!

[toomanytoys]

No, pointless as the oil needs to pass over the temp sender to give any kind of reading... all you would get is inducted heat which would tell you nowt..
If the oil system is in good nick and the cooler clean.. A head temp gauge is far more usefull as it tells you whats actually going on when the engine is under load..

But any gauge is usesless if there are missing tins and seals (I cant believe how many aircooleds are trunning around with missing engine bay seals... VERY VERY bad..) or the engine is badly set/serviced up etc etc.......

[Helga]

Thanks toomanytoys, but, and this is a question I have asked but not had an answer to before: what IS the engine bay seal on an Aircooled? Which of that many seals are we talking about? Is it the big one that goes all the way round the tinware in the engine bay... almost like a rubber skirt? Mine is there but not 'stuck' to the van, it is stuck to the engine though...

[Helga]

As for the head temp gauge, the problem is where to put it on an Aircooled, the ones I have seen - for the third cylinder, under the spark plug apparently have mixed results...

[toomanytoys]

Yes its the seal around the tinware and should be clipped on to the engine tin and be a snug/touching fit to the bodywork... to prevent hot air from underneath coming back int to the "cold" engine bay to "cool" the engine... (which obviously hot air doesnt do so well...)

Under the spark plug is better than the EGR port... as it directly above the combustion..

[Helga]

Thanks, yes it is a reasonably snug fit. I'll take alook at spark plug sender now. Thanks!

[toomanytoys]

Oh and I am 99.9% sure the type 4 doesnt have the no3 timing retard either, thats a type 1 based engie thing... so it doesnt matter which plug it goes under.. although you could fit a sender under each and have a switch to go between each one to be sure.....

[Helga]

Ha ha - the list of things and expense grow lol... four senders and one gauge and a switch... as a matter of interest will those ring type sparky senders work with any sort of gauge, or does it have to be one designed for that kind of sender?

[toomanytoys]

You could try it in each position for a while to see which one runs hotter..
Well.. the correct gauge is going to work better, but you could "calibrate" a gauge to work.. but thats a lot of hassle unless you happen to be an instrument tech...

Funnily, I have a data logger, 12 channels and it will read a wide range of temps... I will be setting it up on a couple of experiments over winter.. monitoring engine and gearbox trends... I have some improvements in the pipeline and want to cover all bases... but thats a different kettle of fish...

[Helga]

Good lord...

I'll leave that complex job for a while lol

12!!

Makes me nervous just thinking about it!