Last January I ordered two thermostats, the Motorad 439 180 and the Britpart black PEL 500110 180. Got an Ultrgauge a few months back to monitor the temp and other BS. The temps haven't fluctuated all that much, mid 190's while cruising and up to 208 at idle ( which I think is high, nothing to base that on). It's 21 degrees tonight and drove the truck to dinner just to see how low it would run with below freezing ambient air ( I am aware that intake temp will be higher). Anyway with the intake temp at 53 I would hit 201 engine temp when cruising around 37-40mph. 201?!

I want to swap the Britpart in but wanted to see if anyone had any Ultragauge readings that would show that it runs cooler than the Motorad. I am aware on the inline mod but I really just want input on the Britpart 180.

Thanks

 

Is that Britpart T-stat the black one that says 78*c on actual T-stat when you look inside from top opening? If so then it should run cooler than your numbers, when I had it on mine like couple of years ago it went up to max 197-198*f, that was on 90*f ambiant with AC on ideling for 20 min in a parking lot, at slow cruising wouldn't go over 186-188*f, (I know it would run a little hotter if it was sub freezing temp when cruising but not 201,! Something must be wrong)
As for motorad I have never had one to if better or worse.
(I have switched to inline for couple of years now)

 

I just went and checked and yes, it does say 78* inside. I will swap it I when I get a chance.

Thanks.

 

Those are high numbers for a 180 stat, but not horrible.

Remember these things were designed to run at 212+ for emissions reasons and many still run that hot with the original stat.

With the OEM 180 grey one I get 188.6 cruising and up to 199.5 at hot idle.

Just had the chance to change out the TBH gasket and had to rebleed the system... I decided to use the top off through the bleed hole (while engine is cold) method to get the last bits of air out just to keep from making a mess with coolant.

I also have a convenient up hill facing parking spot so first thing in the morning I open the bleeder and top off. Took about 4 days of doing that to get all the air out. The interesting part was that I had temps like you when there was still a small amount of air in the system. Not even enough air to make waterfall sounds so I might never had noticed without the Ultragauge. But none the less I was quite surprised how long it took but I only knew because I know what temps I had before the repair and thus kept going until I got back to those numbers.

So you might make sure you have ALL of the air out of your system before deciding the results of your current and your new stat.

 

You are a wise D2 maintainer and an excellent suggestion to get a real world comparison.
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I can vouch for Dave03S on the OEM 180 stat. I'm getting the exact same temps that he is running after installing new hoses, radiator & stat about a week ago. Took 3 days of bleeding the system to get all of the air out. Now when I idle it might get up into the 190's with the highest reading so far at 201. Cruising on the interstate or around town and it clocks 188.6 fairly consistently.

Before going with the OEM 180 I was running the grey 180 sourced from Atlantic British and was running temps in line with Frank4.

 

I'll bleed and see what that does. That OEM 180 stat is high isn't it?

 

With these 180 degree thermostats, has anyone tried a different mixture of coolant? Instead of 50/50, anyone try 60 water/40 coolant or 70/30 mixture?

 

Frank, Lucky 8 has it for around $80 so yeah. Worth it though if you ask me.

 

The coolest mixture I found was 100% H2O which is inline with most other observations. Obviously that's not practical for long term use or in many climates. My understanding is temps will rise a bit with as the % of coolant increases.
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