Engine thermostat types?

[JD955SC]

So I have to make a presentation on engine thermostats. Besides troubleshooting, how they work, what their purposes are, etc I have to have info on different types of them according to the person who is evaluating my presentation. This slide very much initially confused me. I have only ever encountered the traditional wax pellet type that we are all familiar with. What I have found in researching is the following types:

Electrically heated wax thermostat- the thermostat itself largely functions the same as a normal wax type with the additional function of a heater circuit controlled by the ECM that can fool the thermostat into opening before the coolant itself reaches the opening temperature

Electrically actuated thermostat- its a valve controlled electrically by the ECM, opening and closing as commanded

Bellows Thermostat- bellows filled with alchohol that expands/contracts with coolant temperature thus opening or restricting the passage. I don’t think this one is used and i doubt I will ever encounter it but I plan on including it just to cover my bases.

Any other types that I need to know about?

 

[Truck Shop]

https://www.hemmings.com/stories/article/some-like-it-hot

 

[Coaldust]

I should dig up my presentation and save you the work. I listed the three major designs as;

Blocking
Partial blocking
Choke

 

[OzDozer]

There's also the early bi-metallic thermostat.

However, probably a good way to do your presentation is to outline the history and development of thermostats as we know them today, so your audience can see how the ideas behind thermostats developed.

Chrysler engineers were at the forefront of a lot of automotive engineering development and pioneered the introduction of the bypass-style bellows thermostat.

However, it was Cadillac, in 1914, that actually pioneered the idea of the bypass-style thermostat, but with a far more crude version, compared to Chryslers 1934 refinement.

The guy below has a good webpage on early automotive thermostat development, with references.

Thermostats

 

[JD955SC]

I should dig up my presentation and save you the work. I listed the three major designs as;

Blocking
Partial blocking
Choke

Is this referring to type of thermostat itself or the method which it bypasses? If you can find that presentation I wouldn’t mind taking a look at it for ideas and information I am unaware of if you don’t mind.

There's also the early bi-metallic thermostat.

However, probably a good way to do your presentation is to outline the history and development of thermostats as we know them today, so your audience can see how the ideas behind thermostats developed.

Chrysler engineers were at the forefront of a lot of automotive engineering development and pioneered the introduction of the bypass-style bellows thermostat.

However, it was Cadillac, in 1914, that actually pioneered the idea of the bypass-style thermostat, but with a far more crude version, compared to Chryslers 1934 refinement.

The guy below has a good webpage on early automotive thermostat development, with references.

Thermostats

This presentation is aimed more at teaching service personnel the types and troubleshooting thereof. It is part of the interview process for an instructor position. I may include a very brief slide but as history is not as necessary for relating the function and troubleshooting plus coupled with time limitations I may not have the time for it.

 

[Coaldust]

Yeah. The function of the bypass. For sure. When I’m back in the office, I’ll dig up my engine curriculum. I spent extra time covering cooling systems when I was teaching. That was at a state college, then a Caterpillar dealer, then at a University.

Because cooling systems are not understood. It’s obvious, reading the threads on HEF.

When I was on Caterpillar DSTAB ( dealer service training advisory board ) and the Northwest ThinkBig dealer committee, it was emphasized that 60% of Cat engine failures were cooling system related. That’s looking at Service report data. I don’t recall the acronym for that. I’m sure the other OEM’s are similar.

 

[Truck Shop]

it was emphasized that 60% of Cat engine failures were cooling system related.

That's totally believable-spend thousands on a rebuild and never consider rebuild/re-core
radiator, much less install a new pump or rebuild the fan clutch.

 

[Nige]

That's totally believable-spend thousands on a rebuild and never consider rebuild/re-core
radiator, much less install a new pump or rebuild the fan clutch.

And proof, if any were needed, why a certain D5H owner can't see any need whatsoever to properly clean the radiator both internally/externally plus drop the belly guards & clean the mud out from round the engine oil pan. You can lead a horse to water..........

 

[ahart]

If I could like this post twice I would ^^^^^^^^^^

 

[Welder Dave]

I feel better now after spending $1100 to have my rad re-cored when the engine was rebuilt. I don't remember exactly why I did the rad. It might have been the shop that did the engine suggested getting my rad checked. The rebuild wasn't related to over heating.

 

[JD955SC]

Got it finished tonight. Did a rough rehearsal yesterday and added a slide and did some editing for it.

I think it’s going to be good.

 

[JD955SC]

I feel better now after spending $1100 to have my rad re-cored when the engine was rebuilt. I don't remember exactly why I did the rad. It might have been the shop that did the engine suggested getting my rad checked. The rebuild wasn't related to over heating.

It is definitely not wasted money to have the radiator replaced or reworked with each rebuild.

Even if it’s not a problem that prevents it from becoming a problem in the near future.

That's totally believable-spend thousands on a rebuild and never consider rebuild/re-core
radiator, much less install a new pump or rebuild the fan clutch.

Way back when I first started I put a long block in an old track loader.

My mentor and I suggested replacing the water pump while we were moving all the stuff over. Shot down of course.

Well the water pump started leaking immediately. It would have been easier to change it while the engine was sitting on blocks out of chassis but that would have been too easy.

 

[Nige]

Got it finished tonight. Did a rough rehearsal yesterday and added a slide and did some editing for it.

I think it’s going to be good.

I'm sure we'd all like to see it when you get it done.

 

[Acoals]

I'm sure we'd all like to see it when you get it done.

^^^^

 

[barrelroll]

I ran into one a while back that was an ass kicker. Using a temp gun it appeared the thermostat was working, you could see temps change with it open and close though it was overheating. The problem was 1 of the 2 ears holding it together broke and it was opening sideways not allowing full flow. If you want a picture I can try and dig up a picture if you want it.

 

[Welder Dave]

Pics. are always good.