Anyone have a modification that will keep the Discovery V8 running cooler? I'm not talking about just a thermostat, but something that will bring temps down 10 or 20 degrees on the high-end.

My Discovery 1 4.0 V8 runs in the 180's cruising on the highway, but at lower speeds, slowed down by obstacles offroad, on climbs, and in low-range, I'm often running over 200 with excursions over 220. I try to keep an eye on the Ultraguage, blast the heater core when I need to, and give it a break before it goes to 230. I want to drop temps in those conditions down by 10 or 20 degrees and not have to keep burning up the cabin with the heater core.

An aftermarket radiator is tricky to fit, and going to be costly, because they are and then I'd need a oil cooler as well and if I could fit all that and still the AC core and all the stock fans, I don't know. Anyone worked this out before?

What about fans? I run the stock mechanical clutch fan and the twin electrics for the AC. I wonder how they compare to other options like a Taurus fan or an aftermarket electric fan. If I convert to electric for the main fan, should I ditch the stock twin fans to improve flow since they obstruct quite a bit?

Are there any alternative mechanical fans I can fit to get more flow?

I wonder if I could put another heat exchanger somewhere and plumb it off the heater hoses with T's or something. I can't think of a good place.

What about water pump mods? Are there any better pumps for the rover v8? Are electric pumps any better?

 

I've been reading more about this, and I think the first thing I'm going to try is to remove the twin AC pusher fans which almost certainly "blow" (can't say they "suck"), ditch the mechanical fan, and try an aftermarket electric puller fan that can provide maximum flow even at low engine rpm.

I'm skeptical I'll find a high performance water pump for this engine, but I might look out for an overdrive pulley.

 

1. Consider that rad may need attention. Eval by infrared thermometer, warmed up, top to bottom on fins. More than 10F spread indicates lower rows cooler from internal clog. Rod out by indy rad shop is $70 in my area.

2. I replaced fan and clutch for $19 from boneyard, 2000 Blazer. Fan much deeper pitch, moves more air. Clutch fits our water pump.

3. Be sure all fans suck a paper towel toward grille. My PO reversed polarity to the condenser fans and I would overheat slow and idle.

4. With 180F stat, I ran 178 last weekend on road with AC on, and when parked with AC on it would go up to 189. Low 80s outside. In the 97 degree days in summer I would go above 212 at idle. My radiator is now compromised, it reads 25F difference top to bottom, after rod out I then had HG problems, did HG work, let rad dry out, and what ever was in there coated the insides. I'm not sure a 188K rad can take rod out again, I may just buy a $240 aluminum replacement.

5. There is a plug on the intake, below the coolant sensors. On older trucks it was part of the heater circuit, would be a place to plumb on extra cooling, if you can find a place to mount it and electric fan.

6. BP Utah and others sell a WP with larger bronze impeller.

 

This keeps coming up, I was driving dads avalanche today and noticed the temp gauge says normal is 210*F all aluminum v8

So what is normal on rover? I am starting to think it is around the same and we are all just fighting an up hill battle for no reason, when mine was running hot it would not get hotter then 210/212

Thoughts? Figure OEM stat is what 195*?

 

Dad's Avalanche is not sporting the Buick design from the early 60's. If you look back at older v-8 manuals, Rover said to test the thermostat to be sure it was fully open at 82C (180F). Now the Rover engines are pretty close, but the pollution laws changed, and now they run them much hotter. So if you have a stat that opens at 195, it will be about 15 degrees hotter when fully open. A little above that and Rover turns on the electric fans to cool it back down to the operating range of the thermostat.

With all the head gasket probems, and cylinder sleeve problems from over heating, many take that extra 10 degrees as a little insurance policy.

IMHO the temp range of any engine should be close to the opening point of the thermostat, which is the minimum temp that will be maintained. If load and ambient temps increase, the system regulates by opening the stat more and more, until it reachs wide open temp. At that point the thermostat is no longer controlling the system, you are at the mercy of airflow and coolant volume and radiator transfer characteristics.

The curse of the Rover is the poor heat gauges, especially the ones driven by the ECU, which tell you everything is 50% middle of the gauge OK from about 130-240F. Sorry, but 235-240F a'int normal. But your truck could have been running around on "slow roast over hickory coals" foir a long time, but thinking everything is "cool" and normal. In an old Ford pick up the temp would be noted moving from "E" to past "M" on the gauge, so you could worry about it.

Of course I'm an old school guy stuck in the swampy humid land where it gets below freezing 3 days a year. And 98+ many days a year. I like my 178-183F D1 at 60 mph. My Kia van has 270K at 180F. My 93 Mercedes has an 82C thermostat I put in when I got it.

 

I do agree with your thinking since it is an old school type engine design, just never seen so much coolng probs on a single type engine used for so many years

I thought the old ford temp gauges were just for looks ESP the trucks 70/80's

 

I think the problems are more instruments not letting you know things are edging up, and with the engine design, you don't have much margin for error. Up north guys can enjoy the warmer 192-195 stat, but you want to have something like a Ultra Gauge so you can keep an eye on things.

 

That state may be OK for cold climate but not the summer where I live with a/c on, maybe they are trying to tell us something with the side vents on newer rovers, need to let the heat out

 

Not so much. Spike tested his underhood with a remote thermometer, about 150 all over, regardless of conditions. The main things you can easily change are base temperature (thermostat selection); how fast the air moves past the radiator (fan selection, good clutch); and healthy radiator (rodded out). If you are driving at 60 mph you have 5280 feet per minute of forced air flow. At idle you don't, more like 800-1100. There will be a change in temp. I can drive freeway speeds with AC on in hot weather and be in the 178-183 range. Guys that are always running 210 - 217 or 221-227 have to wonder what is going on under the hood. Slow roasting over hickory coals if you ask me.

Gramps used to change from winter to summer thermostat....

 

on topic= i'd think, the only realistic option besides keeping existing components to best condition and the 180, could only be the, mentioned, addition of an extra exchange from heater hoses. makes since, more volume in system, more time to cool before returning through system. but what a pita, to find room to add more components, to an already cramped compartment. (run it up the A pillar and strap it to the roof rack? )

off topic= not trying to thread jack, but you overheating doomsayers, make me constantly question my system. So at idle with ac on i am at 188. cruising the highway i am at 193. would you think that point to slow flow radiator? or something else? either way i will not be touching anything. just curious