where should the temperature gauge Read

Hello Chris,

Unfortunately, I don't have any specific links, but I will post a pic of one of my spare themostats that features a bleed notch. The advantages over a thermostat that features a jiggle pin are that there is less coolant passing the thermostat prior to opening, so warm up time is quicker. Jiggle pins do fail and end up floating around within the cooling system, which also extends warm up time as there is now an uninterrupted flow of coolant passing the closed stat thus extending the warm up time. I also feel that (and this is based on 26 years of driving my Rover) coolant temperature regulation is improved by this later design. From the manufacturing point of view, a cost saving no doubt as well.

Ron.

Update,..here are the pics as promised.

P6170187.jpg

The bleed notch is visible at 12 o'clock, and the thermostat is fitted this way.

P6170188.jpg

The bleed notch can just be seen at the top of the thermostat.

Ron.
 
Where do you get your thermostat from then Ron? Im guessing I should try an 88 degree as my cooling system has all been stripped and renewed but i also have not heard of this type, are they a standard thing, can I get one from halfords etc.
 
Halfords do a thermostat for a 3500. But it didn't have a jiggle pin so I didn't bother with it. Don't think it was like the one Ron has either, but I wasn't paying that much attention by then. I have ordered one from eBay. See links above. Cheers. Mick.
 
Hello Casper and Mick,

I have never been to Halfords, but I imagine it is like Repco, SuperCheapAutos or AutoOne... :?

The thermostat in the pics above came from a Land Rover Specialist. The part number is ETC4763, for Rover V8 engines, made in the U.K by QH.

Ron.
 
so what is the effective difference between running an 82, or an 88, assuming your cooling system can handle it. Is the later more economical or better heater or just more risky for over heating problems
 
Well, the Rover is designed to run an 88 stat. By this I mean the carbs are jetted (well, needled actually, but let's not split hairs) to suit an 88 or just over operating temperature; the piston to bore clearances will be designed for this temperature etc etc. If you put in an 82 stat, the carburation will be off, the clearances all over the engine wrong etc etc. Plus with an 82 stat the radiator and heater won't be able to shift as much heat - heat transfer is proportional to the temperature difference and we didn't change the ambient air temperature when we dropped the coolant temperature.....

The only advantage I can think of to fitting an 82 stat is if your cooling sytem is already knackered. In those circumstances you might win 5 minutes more running time before the temperature went out of control!

You may infer from the above that I don't approve of 82 degree stats! :wink:

Chris
 
Hello Chris,

I am going to take a different path entirely, but I can appreciate your argument as far as emissions and a warmer heater are concerned.

The official Rover workshop manual specifies a thermostat with opening temperature of 78 to 84 degrees C. It makes no mention of fitting an 88 degree thermostat. Further into the manual in the Cooling section, it states under the heading of Testing..."when immersed in hot water, the thermostat should commence expansion between 80 to 84 degrees C".

Running an 88 degree thermostat will see the needle well past the 5 before it opens, so nothing wrong with that in itself, but during hot weather the stat won't fully open until the coolant temperature reaches 98 degrees C or so, not a lot of room for error there when running with a fixed 5 bladed fan for cooling.

There is also the problem with block expansion and main bearing coming loose which would be exacerbated by running a higher temp thermostat. I have experienced such first hand, and at the most I have only run 82 degree stats.

Running carburettors will also see a drop off in engine power from using an 88 degree stat as compared to using an 82 degree model.

We are certainly on different paths this time Chris, but nothing like having a friendly debate... :D

Ron.
 
OOPS! I was thinking standard spec was 88! Teach me to reply without referring to the manual! The argument I put forward applies to stats under the standard spec and in reverse to stats over the standard spec. Interestingly, my manual specifies an 82 degree thermostat - item 26.45.01

P6 V8's are perfectly capable of shifting their main bearing caps without any encouragement from incorrect stats! It's a known weakness addressed by the later cross bolted block, with which your car is now resplendent! Just a pity they introduced a new weakness in the process that the P6 block doesn't suffer from - shifting liners! You're just going to have to go out and source a Coscast block, Ron :wink:

Chris
 
Hello Chris,

Well I have just had a look in one of my other Rover texts, this one being an Autobooks publication, and it states that for the 3500S with exhaust emission contol fitted (I assume this is the NADA model) the correct thermostat has an opening temperature in the range of 86 to 90 degrees C.

Yes the main bearing caps coming loose happened to my original 3.5 back in 1987/8 without referring to my log book. In the years that followed I ran with a 74 degree stat, but upon removal and inspection all the bolts that secure the main caps were below the minimum torque specification, so they were all on their way out again! My cross bolted 4.6 has top hat liners fitted, so no problems with shifting liners in that department... :wink:

Ron.
 
Put an 82 deg stat in, temp rises to the 8 fairly quickly, then normal driving sits between the 8 and the 5. But and why is their always a but, I am getting warm feet. Didn't notice this before. The vent for the heater does not feel like it's warm, the tunnel is quite warm up by your feet and I do have a stainless exhaust. Not sure if it warm before I put the stat in or I have only noticed it because I put the stat in. Could it be the stainless exhaust ?
 
happy days said:
Put an 82 deg stat in, temp rises to the 8 fairly quickly, then normal driving sits between the 8 and the 5. But and why is their always a but, I am getting warm feet. Didn't notice this before. The vent for the heater does not feel like it's warm, the tunnel is quite warm up by your feet and I do have a stainless exhaust. Not sure if it warm before I put the stat in or I have only noticed it because I put the stat in. Could it be the stainless exhaust ?
Click to expand...

I was always under the impression that the 82c stat was for summer use, and the 88c one was for winters. Not wanting to change my stat with the clocks, I opted for the 82 as I would be driving my car mainly in the summer.

The exhaust I had originally on Sparky had the stainless manifolds, a custom made y section and a standard middle and back end. The custom made section was very close to the sides of the tunnel and would keep your feet warm in the winter. Unfortunately it also kept them very warm in the summer :? . Have a look at the front section where it passes your feet and see how close it is to the tunnel. I had the front section remade in stainless, with instructions to keep it away from the sides of the tunnel, and then had it ceramic coated. I only did that as I was already coating the manifolds, you could always fit some heat shields.

Richard
 
You must log in or register to reply here.
Back
Top