Electric Cooling Fan, Where does the Thermostat

[Industrial Toys]

I dismantled a small Onan Generator I received. Nice little Isuzu 3 Cylinder Diesel. But Onan had a blower on the front whee a fan would normally be and the rad in some space saving place. I ordered a rad and electric fan off E-Bay. It came off some Yanmar 3 cyl Diesel, brand new.

It doesn't come with a stat. I have no experience with electric fans. I would have preferred a conventional fan, but that was just too much bother.

So where does the stat go? On the motor, or on the Rad. To me, it would make more sense on the rad, but I have seen stats for electric fans that look like they thread someplace into the motor.

And what temperature should one go for? Any benefit to an adjustable one?

Thanks

 

[dickfoster]

I dismantled a small Onan Generator I received. Nice little Isuzu 3 Cylinder Diesel. But Onan had a blower on the front whee a fan would normally be and the rad in some space saving place. I ordered a rad and electric fan off E-Bay. It came off some Yanmar 3 cyl Diesel, brand new.

It doesn't come with a stat. I have no experience with electric fans. I would have preferred a conventional fan, but that was just too much bother.

So where does the stat go? On the motor, or on the Rad. To me, it would make more sense on the rad, but I have seen stats for electric fans that look like they thread someplace into the motor.

And what temperature should one go for? Any benefit to an adjustable one?

Thanks

I put an electric fan in an off road vehicle once. I put the temp sensor right through the radiator core. It slipped right in so mount it in or to the radiator core in some way. The temperature would depend on the vehicle and what kind of engine maintenance is used. EFI engines tend to want to run somewhere around 200F for gas. Typically just below the temp of the thermostat.

 

[franklin2]

I have used one of these you can buy at the local parts stores. It controls the fan directly, no relays. Some mount in the radiator fins, some mount in the upper radiator hose.

 

[Industrial Toys]

In the hose?

 

[SimS]

Check out your FLAPS for a electric fan tsat kit or browse ebay or Amazon. There should be quite a few options. I prefer a sender screwed into the engine's cooling system with a relay driving the fan itself.

SimS

 

[franklin2]

In the hose?

Yes. The one I bought says to drain the coolant a little bit, take the clamp loose on the upper radiator hose, slide the hose off, insert the probe fully into the hose and then slide the hose and clamp back up on the radiator. Then tighten it over the small part of the capillary.

I didn't like this at first, it gave me a small leak at that spot. But after I tightened it a couple of times it quit leaking and it works ok. I believe some of them clip onto the radiator fins, but you have to be careful, it can be affected by the airflow through the radiator.

 

[George2615]

Many classic car guys use a fan control like Franklin posted. Usually the probe is attached to the back of the radiator and picks up ambient heat. Other types use a sensor that screws into the water jacket but those operate at a fixed temp usually 160 or 180 deg. The variable control style can make the fan come on at a given temp. Plus, a lot of guys add an additional toggle switch to override the stat to run the fan manually.
I don't like sticking the sensor bulb in the hose due to potential leaks or over tightening can crush the capillary tube making it non functional.

 

[Industrial Toys]

A pic of my latest project:



And after a bath:




I also realize, that I know nothing about the water jacket of an engine. I ran the engine, connected to the water faucet, and now worry about freezing. I poured in a little anti freeze, but didn't have much.

 

[dickfoster]

Yes. The one I bought says to drain the coolant a little bit, take the clamp loose on the upper radiator hose, slide the hose off, insert the probe fully into the hose and then slide the hose and clamp back up on the radiator. Then tighten it over the small part of the capillary.

I didn't like this at first, it gave me a small leak at that spot. But after I tightened it a couple of times it quit leaking and it works ok. I believe some of them clip onto the radiator fins, but you have to be careful, it can be affected by the airflow through the radiator.

Get serious, they slip through one hole through the fins in the core. About equal to one bugs worth of blockage. I would rather do that than introduce a coolant leak. I probably would have gooped it with some RTV if I had done it that way.
BTW I was born right down the road in Waynesboro, a long long time ago.

 

[Industrial Toys]

In my way of thinking, monitoring rad temperature would make more sense. When shut off, that fan would continue to run as long as that engine is hot, long after the fan has cooled the rad down.




A slightly better view of the blower. I have never seen this before.