OK thanks. So you took the ends off with a hand grinder, bench grinder, dremel, snips, etc?

 

Angle grinder.
I'm going to be doing another one soon and was thinking of trying a jigsaw.

 

jigsaw sounds nuts. i'm concerned with bending the metal over or uneven cuts with an angle grinder. on the bench maybe...which I don't have. ill drop by the local machine shop and see if they can do it for a few bucks.

the fan is an 18" to start. So I guess we're talking around 17 3/4 to 17 7/8. I'll measure it so we can let others know.

I'm psyched for the HD hum. Not so much for any decrease in mpg. maybe i'll change the fuel filter to help pick it up.

 

also, I'm doing an Advance Auto pulley and or tensioner replace to quell the "belt screetch" it will be sounding pretty when I get that done.

i'm going with the:

Dayco No Slack Idler/Tensioner Pulley, Light Duty
Part No: 89006
Tensioner Pulley

That's a pretty easy swap out for a mechanic right? Bearings are inside so you don't need any special tool I imagine.

 

I kept seeing that the HD clutches fit a lot of Chevys. So I went to the boneyard and found a 98 GMC Sierra V-8 4WD pickup, with this fan on it. $10 for fan and clutch. Too big for Disco, so removed 100% of fan shroud for testing. Mounts great, clears everything, had to zip tie the cable to tranny line temp sensor out of the way. Blows a lot more air. But on a test run at dusk for 10 miles it did not drop my temps that much. I put this off to the lack of fan shroud.

However, it does point out that in a pinch you can pull something off a Chevy and it will work. The Chevy fan is plastic, deeper pitch, and I may play with cutting it down with shear or tin snips.

Put Chevy boneyard clutch on Rover fan, perfect fit. With shroud installed went for 5 mile drive and temps dropped to 176 - 180 with AC on. Seems like about 6 degrees better. Also at extended idle I was getting up to 207, this got to 201.

Checked with photo tach on pulley vs fan tips, clutch is staying 90 % engaged, feels like more air. Now keep in mind that I have a 180 stat, and everyone's well aged cooling system will be slightly different.

I like cheap experiments.

 

Wow, you're dedicated Savannah. I went for the fan parts yesterday and overheated. I think my fan went from appearing to work fine to not working at all. It's parked until I get my set up this weekend.

I noticed that when the gauge got to almost 3/4 (as I was pulling over) the oil light would gently flicker as in loose connection, not flashing. If I gave it a little gas, it would immediately go away. After she cooled down and I added some distilled water no light, all fine. We just did all the oil bits so I'm hoping that doesn't signify anything.

**There seemed to be a lot of wetness around the expansion tank with that center hole pretty filled with coolant. Not strong smelling btw. I replaced that once. I can't see any leakages yet. I might need another replacement as well.

Since it appears that I am going to need new AF, maybe I should flush it and go green. Where are we on that argument again?

 

OK, I'll bite. So you work cheap under a big tree?

 

No, I work on my things under a 200 year old live oak, my house was built in 1842. Back then no garages. No paved driveway. Just on old farm house, built out of heart pine (Boy Scouts call that "fat lighter"), if it ever catches on fire the volunteer FD will bring the wieners. At the office I have a 75 foot long shop with 5 ton overhead crane, 14 foot door, air conditioned, etc. I tossed in the shade tree because some other members disparged the humble village idiots, who made America great. At least I don't have any concrete for the oil to stain and the home owners association to whine about.

Now to your points.

A. Oil light coming on briefly means that you have overheated to the point that the oil has thinned out, and pressure has dropped below 7 PSI. You are in the "Kill Disco" region. I would work very hard to resolve overheating, stop driving until it is taken care of. Oil change would be a good idea. This time of year you can run 20W50. You would think that Rover, too cheap to put in a gauge, becasue they spent all the design money on the alarm system, would have used a higher value low oil warning switch. It basically will let you drive around with 9 pounds of oil pressure....

B. When engine is warmed up, and stopped, fan should not spin a whole revolution by touch. The reason I tell people to also spin it when cold is that if it spins when cold, it is no good (also helpful in prowling the junk yard). It may warm up and start spinning, and that is also bad clutch. The visocus fluid (some kind of silicone oil) is forced out through the front seal of the unit, making it look dirty. In some areas of the world guys can't afford a new clutch, they just drill two holes in it and bolt the halves together.

C. At 207 F, my guage is still down at 8:00. At 3/4 your are in the shake and bake area - U bake da engine and you shake out da piggy bank.

D. Severe overheat (perhaps just once), and certainly chronic overheat can lead to warped heads and bad head gasket, or a bad gasket can cause over heat. Then you can have the cylinder liner that drops loose from the severe overheat, and it costs several times a head gasket fix. Of course, with thin oil and high heat, engine wear increases exponetially.

E. If you can borrow a scanner that reads live data you can more quickly see that you are making progress, or not. So instead of thinking it is fixed, you can see that you are getting up above the normal temp way before the guage startes to wander.

F. My experiments with the Chevy clutch are to show that you can use something else if nothing is available (and that could be available parts, available cash, available credit credit card balance). Lots of guys that buy an older Disco enjoy the off roading, but may not have the disposable income to maintain it by a dealership. This weekend I am going the see if I can modify the Chevy oversize fan to work inside the DISCO shroud.

G. Your expansion tank is wet perhaps from the cap venting under increased pressure above the cap relief valve's 15 psi. This should go away when the fan / overheat is fixed. With just water in there, you won't be able to take much heat, as the coolant helps raise the boiling point of water. Since you are on a first name basis with the parts house, you may want to borrow (rent) a coolant system pressure tester, Disco Mike says 18 PSI and it needs to hold it for 15 minutes.

H. Convince your significant other that you are secretly testing the marketting claims of the laundry products industry as part of a class action lawsuit...

 

Just a thought regarding Chevy fans... if you're poking around in the boneyard for fans, take a peak under the hood of some Cadillacs to see if you can find one with the correct rotation for our rigs. There's a good chance that the bolt pattern will be the same for the Chevy clutches, and that the diameter will be smaller than the Chevy truck fans. Also, the Cadillac fan blades have a higher/steeper pitch than the truck fans so it'll move more air.

Used to do this with SBC v-belt motors in Jeep CJs, but haven't considered it for our LRs.

 

A good tip, will see what I can find. For the three day weekend, all parts at one yard near me (LKQ) are 50% off. A u-pull-da-partz is a great education, the tuition is low, and you get to practice on somebody else's chassis.