Adding 3 gauge sets

[rScotty]

I've still got a question arising from having put one of those 3 gauge mini sets on our YM165d maybe 25 years back....This is the analog kind of gauges with little 1" clockface dials. Mounts under the dash. Total cost back then was definitely under $50. Luckily for me the gauge and mount came with a bag of pipe threaded adapters. I say "luckily" because the stock threads that Yanmar taps into the engine block for fluid connections are not at all what I expected.... even if they are darn near to being NPT. Anyway, Yanmar's block threads do turn out to be the same as most Japanese cars/tractor/motors use. Guess that's why they were in the bag.

After unscrewing the stock oil pressure sender from the motor, one of the adapters provided was used to mount a plumber's brass "T" into the hole where the oil pressure sender used to live. With this "T" in place, one side of the "T" could mount the sender for the idiot light and the other side sent pressure to the new gauge. It makes sense to have an idiot light for the oil pressure and it's simple. No reason not to do so.
I forget just how, but something similar must have been done to the charging gauge because the lights and gauge both work on that system too.

BUT...and here comes the question....eventually........... I didn't do the temperature idiot light in the same way because because it seemed better to insert the new temperature sender deep into the block just like the original temperature sender had been.
And I already knew that an overheating idiot light was redundant because having overheated it once my hair still stands up remembering the sound the blow-off valve made. An instant reminder that I was sitting three feet from a 16 hp steam whistle......Railroads and bull elephants probably still pause on that date in simple admiration of the sound. I thought the world had ended.
No idiot light could compete with that. An overflow bottle would muffle the sound, but those early thermosiphon systems didn't come with such niceties as an overflow bottle. Just a hose to spray overheated fluid onto the ground and away from the driver.

All of which is just the long way to say that I don't know if there is an alternate water jacket access for the temperature idiot light.
So that's my question: Is anyone who has accessory gauges also running the stock temperature sender/idiot light as well as a sender for a temperature gauge?? If so, how so?
thanks, rScotty
..............

 

[winston1]

You can go to post #46 in this thread and see how another Scotty did it. http://www.tractorbynet.com/forums/yanmar/12770-adding-guages-your-yanmar-5.html

 

[Scotty Dive]

Rscotty - I have two extra of those upper radiator hose adaptors still. 30 mm and 32mm Let me know if you are interested and I will send them along to you gratis just pay shipping

 

[Smoody]

Funny you bring this up..I just got a ym1700 and on the left side of block where lower rad hose connects there is a plug that is exact same size as the plug that the temp sender on the top is screwed in. I assume is an extra location to add a gauge. I have owned many models and this is the first I have seen it..

If you all need a pic let me know.

 

[California]

Smoody I think that plug is the coolant block drain. My YM240 (similar) and YM186D have a small hose from a fitting there to the radiator lower tank. The YM186D has a drain at the midpoint of the hose. I think this configuration is common on Yanmars. If you are talking about something different, excuse me.

I'm not convinced measuring temperature at the bottom of the block is meaningful. As I noted in another thread I observed near 100 degree lower temperature at the bottom radiator tank compared to the top tank.

 

[Smoody]

What I am reffering is on the engine block and has a bolt in it...the coolant drain you refer on some models is bolted to the frame beside oil filter, and yes I have seen the small hose connected to it..I see your point about the reading that low not being accurate... I dunno for sure either and it may be a drain...never seen it on my others..I'll get a pic

 

[Smoody]

First pic is the coolant drain California mentioned..second is the plug on left side of block.

 

[rScotty]

I'm not convinced measuring temperature at the bottom of the block is meaningful. As I noted in another thread I observed near 100 degree lower temperature at the bottom radiator tank compared to the top tank.

Darn! Now you've given me reason to add yet another temperature gauge! The temperature differential in a thermosiphon cooling system is good to know.
Thanks....I think....
rScotty

 

[California]

First pic is the coolant drain California mentioned..second is the plug on left side of block.

Ok I'm home in town and can't see my gear at the moment. But I thought on mine that drain device in the left picture was midway in a small hose between the block and the lower radiator tank. Maybe I'm imagining things. The copper washer under the plug might suggest an oil passage??? Is it in line with the oil pressure sensor?

Scotty I didn't mean to lead you astray. If whatever you are doing worked for 30 years, why change now.

Seems to me the upper tank temperature is the only one relevant unless you are going deep scientist and trying to improve the default design. Me, I just admire what Yanmar designed and try to keep it maintained. I have a brand new temperature gauge that I never installed after I figured out that mowing chaff is the only thing that can cause overheating here. Flushing the fins instead of installing the gauge turned out to be the right course to take and I've never seen overheating since. Anybody want a nice street-racer pro temp gauge for well below cost?

I posted the following yesterday for Smoody:

Here's temp observations I posted long ago for my YM240 (YM2000). Readings were made with a HF infrared thermometer just after the engine had been working hard, right after mowing:

140 degrees on the bottom of the oil pan, 165 at the lower block, and 195 near the injectors, at the upper radiator hose fitting, and at the radiator upper tank. The radiator lower tank was below 100.

 

[rScotty]

Scotty I didn't mean to lead you astray. If whatever you are doing worked for 30 years, why change now.

Seems to me the upper tank temperature is the only one relevant unless you are going deep scientist and trying to improve the default design. Me, I just admire what Yanmar designed and try to keep it maintained. I have a brand new temperature gauge that I never installed after I figured out that mowing chaff is the only thing that can cause overheating here. Flushing the fins instead of installing the gauge turned out to be the right course to take and I've never seen overheating since. Anybody want a nice street-racer pro temp gauge for well below cost?

Not astray, just off to the side. Your tractors are both water pump cooling systems with thermostats and it's hard to go wrong with that. They are probably going to cool pretty well no matter what. Frankly I wish mine had a water pump and thermostat too.

But with a thermosiphon cooling system like on the YM135, 155, 165 and some older greys, cooling circulation is by density gradient and in the summer they are sensitive to the proportion of antifreeze in the cooling water to keep it cool. The slight differences in heat transfer between different water/glycol proportions are easy to see on the gauge. And then there's winter temperatures with the opposite problem.....
It wasn't too hard a few decades back when antifreeze was Prestone or competitors and all had the same basic concentration. Now there is a ton of modern anti freezes, coolants, and pre-mixes. It takes a chemistry book and some research to properly change the radiator fluid on a thermosiphon type. I've got some samples in the deep freeze right now trying to get a baseline.
You're right. What I had in there had worked for 30 years...I should have just left it. But I got to thinking that maybe some fresh fluid would be good...don't know why. Anti-corrosion was my excuse.
For the guy with a thermosiphon cooling system living in a very cold winter climate - who doesn't want to drain and fill the radiator differently for summer and winter, knowing the differential through the radiator might just be worthwhile. It lets you know how the heat transfer is doing and at what point you can add a bit more glycol.
rScotty