Fan clutch options

[CaseyLegg]

Hi all, I need some advice: Does anyone know which fan clutch slips the most?
Its winter and I need el trucko to heat up faster. I am thinking the fan is cooling the block too much?
The truck was originally a diesel with AC but still has the stock (or stock style) fan clutch which is the most heavy duty fan they offer, or so I read. It spins pretty fast most of the time.
It now has a 350, no AC, a 180 degree thermostat, and a big ol' radiator. To make matters worse, half the morning commute is down hill until I hit the freeway. But on the upside it has a new heater core!
I need suggestions people!
Thanks much

 

[1987 GMC Jimmy]

I’d say just about any old thermal fan clutch is going to be the same song and dance. How about a 195* thermostat? That sucker will get toasty quick them.

 

[Matt69olds]

Cover part of the radiator with cardboard. That’s what I have to do in the winter with my diesel Ram. It takes FOREVER to warm up. I had to replace the evaporator core a couple years ago, installed a new thermostat, it took almost 6 gallons of coolant to fill it back up. Takes a while to warm that much coolant.

 

[CaseyLegg]

I’d say just about any old thermal fan clutch is going to be the same song and dance. How about a 195* thermostat? That sucker will get toasty quick them.

Do you suppose the 180stat is opening before 180?

 

[Matt69olds]

It should, I believe the 180 rating means it’s filly open by 180. Obviously, 195 would be warmer, and probably warm faster, but the cardboard is free, a easy experiment, and will probably work

 

[75gmck25]

I'm using a 195 degree thermostat, severe duty fan clutch, and a 3 row aluminum radiator, and I get heat quickly in my truck. Weather here is about 35 degrees now and it only takes a few minutes to get heat out of the heater.

I suggest switching to a 195 degree high flow thermostat as the first step, which will be cheaper than changing the fan clutch. The high flow thermostats open wider for better flow, and usually have at least one hole drilled in the perimeter to make it easy to get air out the system.

If you want to swap the fan clutch also, just get the standard duty Hayden thermal clutch, or equivalent. They come in versions for standard duty, heavy duty and severe duty. Rock auto is a good source to lookup and find parts numbers. The prices are also usually good, but it takes a few days for shipping.

Bruce

 

[CaseyLegg]

Thanks guys. Clutch and thermostat on order. Cardboard installation pending personal motivation!
The clutch is stuck on all the way according to the tests I did so that's a big contributor I'm sure.
I'll update this thread on my results.

 

[rpcraft]

Have you not ever seen big rigs with shrouds on the front of their grill for deep winter driving? You can do the same thing with cardboard fwiw if you really need things to heat up quickly.

 

[1987 GMC Jimmy]

Yeah, Roadkill did the cardboard on their Ford Ranchero on the drive to Alaska. Seemed to work well.

 

[Matt69olds]

If the fan clutch is locked, I would definitely replace it. When you first start the engine the fan will be engaged for a few seconds until the silicone inside is redistributed. After running a few minutes, but not hot, shut off the engine, the fan should spin a little on shutdown. If it reacts any other way replacing the clutch will probably help.

 

[rpcraft]

I used to have to do it on my 77 back in the day when I first got it but after replacing the radiator and water pump I discovered that the previous owner never installed a thermostat so when I put one back in it didn't need it so much but I live in a pretty temperate area.

 

[Rusty Nail]

Hayden
M-R-D gooduns

 

[CaseyLegg]

Clutch and thermostat seem to help.
I started daydreaming about those diesel heaters you see on ebay... Look nice but I don't think I would do it.