B Engine Tempetature / Electric Fan (1 Viewer)

[wmerlos]

Hey guys,

I have a 1975 bj40 w/ b engine and i want to know if it is working fine at 180- 215 degrees (farenheit)

I recently changed the mechanical fan for an electrical 16 inches fan activated by a thermoswitch at 93 degrees (celsius) cause i wanted to eliminate the fan shroud.

The thing is, with the old fan the temp gauge used to mark 180- 200 degrees (farenheit) but with the actual system the temperature goes from 180 to 215 degrees (farenheit).

I dont know the normal temperature ranges for the B engine, i mean im not sure when i have to stop the engine or if i have to do/ change something.

Does anyone know the b engine temperature limits?

When i have to stop the engine?

 

[lostmarbles]

Hi there Wmerlos.

Your photo shows an electric fan in use with nothing driving your water pump:

If you remove your fan blade from your water pump (because of swapping to electric-fan) you do realise that you still need the fan belt to drive the water pump?

Sorry - but the photo suggests you've not got an operational water pump there .... and that would inevitably lead to overheating..

 

[wmerlos]

Hi there Wmerlos.

Your photo shows an electric fan in use with nothing driving your water pump:
View attachment 934752

If you remove your fan blade from your water pump (because of swapping to electric-fan) you do realise that you still need the fan belt to drive the water pump?

Sorry - but the photo suggests you've not got an operational water pump there .... and that would inevitably lead to overheating..

Thanks lostmarbles,

My water pump works with the fan belt as you said ( i didnt have a better picture yesterday)

Im sending new photos to show you

 

[essar5]

Why eliminate the fan shroud? If it is in your way you can mod it to make it easy to remove, do a search to see. Without a shroud I would think your fan is going to have to work really hard to keep it at temp.

 

[lostmarbles]

Thanks lostmarbles,

My water pump works with the fan belt as you said ( i didnt have a better picture yesterday)

Im sending new photos to show you

Thanks.. I did find it hard to believe that you would have been silly enough to run your engine without any drive to your water pump LOL..

So back to your original question .....

If your coolant temperature is reaching 215 oF then I think that's too high...

Here's what the 1976 B-engine FSM (Publication 98082) says:

You can see that even the hotter thermostat should be fully open at 203 oF (which is 12 oF below 215 oF of course).

My experience is that our radiators are oversized when in stock configuration (with that huge shroud you removed and the water-pump-driven blade).

So your reduced performance could be from:

• the changes you've made in removing the shroud and converting to electric-fan (noting that your electric fan is only drawing air through maybe 50% of the your radiators surface area)
• clogged internal passageways in the radiator
• corroded or blocked fins on the radiator
• etc

So why were you so keen on getting rid of your original fan and shroud? Was it perhaps to do with your power-steering?

 

[gerg]

How many amps does your fan pull? 12? Don't quote cfm either as it's no reflection on how it will pull air through a rad. If it's a 20$ ebay special I doubt it's moving much air at all. Without a proper shroud it gets even worse. I'd put your stock stuff back on as your going to overheat it running like that... And you live like on the equator man! I actually like electric fans and have used them fairly successfully in the past, but i doubt I'd ever put one on a truck I owned again. You would need like a 50 amp well shrouded fan designed for rads to even come close to your stock one by the way.

 

[wmerlos]

Why eliminate the fan shroud? If it is in your way you can mod it to make it easy to remove, do a search to see. Without a shroud I would think your fan is going to have to work really hard to keep it at temp.

Well i did this because i wanted more space to install an A/ C system (in the future) and because the old fan shroud wasnt the original so i supposed an electric fan should keep colder the engine (because its closer to the radiator) ... anyway this problem happens too with the old system when i was driving uphill but i expected with this change to keep the engine between 170-190o f

 

[wmerlos]

How many amps does your fan pull? 12? Don't quote cfm either as it's no reflection on how it will pull air through a rad. If it's a 20$ ebay special I doubt it's moving much air at all. Without a proper shroud it gets even worse. I'd put your stock stuff back on as your going to overheat it running like that... And you live like on the equator man! I actually like electric fans and have used them fairly successfully in the past, but i doubt I'd ever put one on a truck I owned again. You would need like a 50 amp well shrouded fan designed for rads to even come close to your stock one by the way.

Well yes, because of the relay i used it is working at 12V but i dont think this is the problem because it activates at 200f and turns off at 180f keeping the engine in those ranges. The problem comes when i drive uphill , then the temperature goes to 210-215 f so a long hill could damage the engine

I saw in the forum many suggestions/ recomendations of this upgrade so i decided to do it cause i supposed a closer fan to the radiator should keep it cooler than the old and rusted fan shroud , and thats why i wish to know your experience about this

 

[gerg]

Yes your fan is 12volt. My question was how many amps does it draw... As in how powerful is it?

My ford Taurus fan had it's own built in shroud that covered the entire radiator. You can get them new if you do a goggle search for about 100$. I would say it would be sufficient for medium duty use. If you want AC you will want to put it in front of the rad anyhow. In that case why don't you trim the shroud back as the fan sits so far back off the rad it will give you plenty of room. If your overheating with the stock fan then it's not working properly. you could do a search on here for refilling the fan fluid clutch with silicone and seal up all the leaks between the rad and the shroud. The stock system honestly is the most simple and most powerful set up.

 

[essar5]

Well i did this because i wanted more space to install an A/ C system (in the future) and because the old fan shroud wasnt the original so i supposed an electric fan should keep colder the engine (because its closer to the radiator) ... anyway this problem happens too with the old system when i was driving uphill but i expected with this change to keep the engine between 170-190o f

So you were having the same results with the stock setup as compared to your new electric fan install. Do you know what condition the radiator is in? Clogged fins, full of gunk, old and needing to be re-cored or replaced? Coolant looks good and is topped off? Thermostat and radiator cap are both in good working condition? Basic stuff I know but it sounds like the problem is a combination of things having an effect on the system.

 

[wmerlos]

Yes your fan is 12volt. My question was how many amps does it draw... As in how powerful is it?

This is the fan that im using.

 

[gerg]

Most warm climate countries don't use anything other than water so it's a good guess there is just a bit of rust floating around in there. The old brass rads are pretty tuff. I've cleaned many with rad flush chemicals which usually are acidic. There isn't any aluminum in these systems so there pretty safe with those cleaners.

 

[wmerlos]

So you were having the same results with the stock setup as compared to your new electric fan install. Do you know what condition the radiator is in? Clogged fins, full of gunk, old and needing to be re-cored or replaced? Coolant looks good and is topped off? Thermostat and radiator cap are both in good working condition? Basic stuff I know but it sounds like the problem is a combination of things having an effect on the system.

1. I will check te radiator. This could be the problem because i dont know if previous owner used water to fill it and how long.
2. Coolant is ok, was changed a few months ago
3. I dont have thermostat ( not necesary in my country because we have tropical weather all the time)
4. Radiator cap is new

Probably i will need to work / change the radiator...

 

[gerg]

So it's a 14-16 amp fan which puts it in the little sister helper fan category. It isn't to replace the main unit. I've used a fan just like yours for my intercooler and it actually couldn't move any air at all through it (4 inch thick core) so I seriously doubt it's doing much for your rad. I'm not trying to rain on your parade, but ive been down this road before and it's an uphill battle all the way and in the end, when you've got it all sorted out, your relay will go, or your sender, or your controller. I've been there which is why I say put your efforts into getting your stock system up to snuff.

 

[gerg]

Any electric fan worth it's salt will give a chart of its performance in cfm vs static pressure (resistance) which let's you know if it's suitable for the application. Usually rads have .5- .8 inches of static pressure for most fans as a ballpark. Your fan was most likely measured with nothing in front of it to provide any resistance at all and thus it's cfm rating is very misleading. I've seen charts with fans like your that will flow as little as 150 cfm at .4 inches static pressure. Which is what I'd expect an AC rad thickness would be like. We have really thick brass rads that need steep paddle fan blades with high amp motors.

 

[gerg]

If you really have to use one, buy one of these. They fit your rad with almost no trimming and will cut your finger off if your not careful.... Don't say I didn't warn you.....and yes I have used this fan myself.
http://www.ebay.com/itm/LINCOLN-MAR...Parts_Accessories&hash=item5b04a2d497&vxp=mtr
g

 

[watrob]

From the photo's your electric fan looks like it covers just over half the radiator only, does not have any shroud what so ever, and would need to have twice the thickness in blade pitch to move the air for the diameter its covering the radiator at the moment. You only have to compare your original static fan to your electric fan and see its smaller and you have lost about 25% of cooling also with no shroud.

The one Gerg has in his post on eBay shows a properly made fan with shroud.