3B/13B-T Fan Clutch and Fan Upgrade

[hotgemini]

Are the Blue/Red 1HZ/1HD fan hubs to suit the larger stud pattern? The dummy engine on a stand I'm using for mock-up purposes is from a Daihatsu Delta and has the solid fan drive, but all the bits will eventually go into my BJ74 w/ H55f which has a viscous hub, which I assume from your other thread will have the smaller bolt pattern, but I haven't measured.

I don't actually have any cooling issues at the moment, 12 months ago it got a new water pump, new (potentially dubious quality) stock replacement aftermarket fan hub, new taller 1HD style copper brass radiator.

However I'm about to start towing around a 1500kg (that'd be 29.5 hundredweight if you're in liberia, burma or other backwards countries that don't use SI) offroad camper trailer and I'm hopefully about to have the front of my motor apart anyway for a rotary injector pump, gear driven vac pump and gear driven PS pump swap, so it would make sense to do any cooling upgrade while I'm there.

 

[Greg_B]

I'm wondering if the lip is a BJ73 vs BJ74 thing? I've never seen one on a BJ74 but I don't know anyone with a BJ73 (at least not one with an original 3b and matching radiator).

my 1989 (blue block) JDM BJ74 has the lip on the fan shroud.

gb

 

[hotgemini]

Okay, strike that theory. Might have to look at build codes and I don't think I care that much

 

[FJBen]

One thing I've learned ESPECIALLY in the 70 series, is that Land Cruisers follow the "Toyota Code"

 

[jblueridge]

Lip is cut off.

 

[jblueridge]

I ended up drilling out the spot welds holding the remains of that lip in place. The 2 layers of steel were a breeding ground for rust.

I always tell my students that without Math and numbers, it isn't Science.
Here are the numbers comparing my old fan to the new one. The measurements are after I trimmed the new blades. The new trimmed fan is still 1/2" wider or 1/2" closer to the fan shroud. Hoping it won't hit.
I don't know very much about fluid dynamics so I can't say if this overall increase of about 40% is how much more air will be moved.

Fan​	blade length​	blade width​	area of 1 blade​	number of blades​	area of all blades​	increase of area​
8 bladed	4.125​	3.125​	12.891​	8​	103.125​	1.2987​	= 30%
7 bladed	4.125​	2.750​	11.344​	7​	79.406​
Fan​	center/ mounting ring radius​	distance to blade center​	effective radius for center of blade​	increase of rotation speed​
8 bladed	4​	2.06​	6.06​	1.0899​	= 9%
7 bladed	3.5​	2.06​	5.56​

 

[OGBeno]

I ended up drilling out the spot welds holding the remains of that lip in place. The 2 layers of steel were a breeding ground for rust.

I always tell my students that without Math and numbers, it isn't Science.
Here are the numbers comparing my old fan to the new one. The measurements are after I trimmed the new blades. The new trimmed fan is still 1/2" wider or 1/2" closer to the fan shroud. Hoping it won't hit.
I don't know very much about fluid dynamics so I can't say if this overall increase of about 40% is how much more air will be moved.

Fan​	blade length​	blade width​	area of 1 blade​	number of blades​	area of all blades​	increase of area​
8 bladed	4.125​	3.125​	12.891​	8​	103.125​	1.2987​	= 30%
7 bladed	4.125​	2.750​	11.344​	7​	79.406​
Fan​	center/ mounting ring radius​	distance to blade center​	effective radius for center of blade​	increase of rotation speed​
8 bladed	4​	2.06​	6.06​	1.0899​	= 9%
7 bladed	3.5​	2.06​	5.56​

Standard or metric? I am assuming standard?

 

[jblueridge]

Sorry. yes standard inches with much estimating.

 

[Indestructible 47]

Might be worth noting, or not but the hdj79 has by far the best cooling system that Toyota installed in the 70 series untill the v8s came along. The hdj79 radiator is a good deal bigger but I will need to verify the fan and shroud.

 

[jblueridge]

Yes, there are certainly numbers related to radiator dimensions. Harder to pull air through a thicker core maybe.
I've got my a/c condensor too.

My BJ74 shroud has a great fore-aft gap between the fan blades and the radiator. Seems like the radiator and condensor could be moved aft allowing for an intercooler in the front position behind the grille.

 

[jblueridge]

Here's the SI or "Metric" version

Fan	blade length (cm)	blade width (cm)	area of 1 blade (cm2)	number of blades	area of all blades (cm2)	increase of area
8 bladed	10.478	7.938	83.165	8	665.321​	1.2987​	= 30%
7 bladed	10.478	6.985	73.185	7	512.297​
Fan	center/ mounting ring radius (cm)	distance to blade center (cm)	effective radius for center of blade (cm)	increase of rotation speed
8 bladed	10.16	5.2324	15.3924	1.0899​	= 9%
7 bladed	8.89	5.2324	14.1224

 

[OGBeno]

^^ Moar better.

 

[littleafrica]

I assume this is not possible on a 3B in a BJ42? Asking for a freind haha.

 

[cuteo100]

From an HDJ79 I assume?

The fan clutch (16210-17070) and the fan (16361-17040) are both available in the US market for whatever reason. Makes me think they were applicable to the HZJ79 mine trucks we received in North America.

Might give those two a try. Thanks @Hulsty

@cruiseroutfit might have these in Aisin form and would probably be the better/most cost-effective way to go.

@OGBeno Did you ever try using this combo and how did they fit?

 

[OGBeno]

@OGBeno Did you ever try using this combo and how did they fit?

I did not. I decided it was easier to blow up the engine instead.