V12 Thermostats
 

Following on Grant's recommendation of the Dayco thermostat, it appears that is only available in Australia, and I wasn't able to find a source that ships to Canada.

I was looking at a Gates 33188. Has anyone tested one for the proper amount of movement of the bypass blocking foot? I didn't want to be buying a pile of useless thermostats if someone here has tested other brands. I have some Waxstat thermostats in both 82 and 88, and sure enough they don't move quite far enough. The 88's moved to 39mm, and the 82 moved to ~40-41mm. Thanks for any help!

Damn, their website kind of sucks as specs go.

Best I can work out, is 35mm closed, and I will assume an 8mm travel of the bulb wax, giving 43mm wide open.

The picture is generic, so blind flying really.

Can we pay someone in Aus to ship a bulk order up here?

These are the other type Grant suggested I use and they have been fantastically reliable. My temp sits under the "N" or on the "N" all the time, irrelevant of ambient.

https://www.supercheapauto.co.nz/p/t...80/329350.html

I would be happy to send some up your way if you were struggling.

I could get a freight quote first and you could pay via PayPal.

I would be guessing freight cost of around USD$50.00 for a box that would hold about 20 or 30 units I would imagine.


Craig

Thinking outside teh square.

That stat I use fits MANY cars, and not all are Aussie only applications.

This is a link to the Dayco Aust application page for that thermostat, and I feel sure that looking at other brands for some of these Mitsubiushi, Hyundai, Kia, Mazda, will be fruitful in the brands you are stuck with.

Hope it works, beer #4 just went down, HA.

https://dayco.com.au/buyersguide.aspx?P=DT18A

I agree with Grant, there will definitely be a brand over there that matches the Dayco and the TT228.

If you get stuck let me know.

Craig

Isn't 41mm the magic number? When I last bought thermos the Jaguar-boxed items from SNG (or similar) were correct. Part number EBCxxxx (I'm on two sips into my first cuppa coffee so I'm a bit weak on details at the moment)

Anyhow.....

Could a couple millimeters one way or the other come down to manufacturing variance? I mean, these are inexpensive mass-produced things. My gut tells me that you could buy fifty of the little devils...several of each of the common brands.... and, on testing, find this amount of variance. Brand-against-brand and within the same brand as well.

Cheers
DD

i ordered some of the Dayco DT18A stats several years ago from an Australia supplier and shipping to the US wasn't bad at the time. I was looking to buy some replacements recently and the shipping costs for the Daycos or the Tridons is prohibitive.

Based on recommendations in another recent thread on V12 thermostats with proper measurements, I ordered some Stant 45398 superstats from Amazon. The price is good. I'll have to drill bleed holes as there is no jiggle pin. I plan to test them out this weekend and check the opening measurements. I agree with Doug that I'm sure there are variations even within each brand.

I spent some time looking at Rockauto's listing today and a few trends seem to emerge in the listings for the V12. There are thermostats with a jiggle pin, and those seem to have a shorter cold length than those without a jiggle pin. I looked at Stant, Motorad and Gates brands. The jiggle pin thermostats are listed as having a cold length of 31mm. The without jiggle pin ones have a cold length of 35mm. If I take an assumption of 8mm movement ( which seems about right in my tests) then the without jiggle pins come to 43mm, which is the magic number.

Like Doug, I have bought thermostats from Jaguar and while I didn't measure them going in, the used ones I kept on the shelf are all 32mm cold. My car seems to sit with the gauge on the right side of the N mark, and it didn't before this last batch of thermostats. When I stove tested my old 82 thermostats they extended to just over 40mm, so seem to have more movement than 8mm. The 88's I tested didn't have as much movement.

I can get the Gates for under $5, so I'll order a pair and see what happens. The joys of Rockauto, $4.21 vs the local parts store is $41.99.

Speaking of thermostats, i used a laser thermometer to measure the temp of the thermo housings while idling and at the centre of the ‘N’

i had 85 celsius on the LH and up to 90 on the RH

Does that sound ok?

Never measured it.

Read pages and pages about this and basically put it out of my work plan.

The distance from the mounting flange TO the by-pass port hole is 41mm, and that needs to shut BEFORE the stat gets to "fully open", Once the stat gets to full open its lost control of the cooling system, and havoc is coming up fast.

Remember a stat does NOT simply open slowly and stay there, NO WAY, they are constantly "opening and closing", ever so slightly, as needed to regulate the actual engine temperature. They work HARD, and that's why they wear out. I have always replaced them at around the 5 year mark, which is the usual radiator out and clean time.

Once that port gets closed, 100% of the coolant is FORCED through the radiator, and that's where the integrity of that sucker kicks in, or out.

The double pass radiator is "expected" to lower the temp of the coolant by a VERY approx 15c. Hence the "overheat fan" switch being an 85c setting.

Both mine have Efans, and the RH is thermo switched by that OE switch, and when that fan kicks in, the needles on both temp gauges are just "kissing" to top edge on the "N". and quickly lower to just under the "N" whyen they switch off.

The LH fan is A/C only, and if that sucker is on, the temp gauges sit just shy of the bottom of the "N", even in summers 47c, sooooo, the RHthermo fan never kicks in with the A/C on.

I spent many days, and even more beers, waaaaaay back (1992ish), working out "floating temp gauge" issues with these V12 cars. and that stat length was what eventually smacked me into submission, and it really was that simple. Whether Jag have got it right now, I dont know, never used their stats since then.

IMO, yes. I'd be happy with that

Cheers
DD

Th thermostats I ordered arrived, and I just tested them in a pan of water. They are 34mm closed, and 43mm open, so plenty of movement for what we need. This is a Gates 33188S. I have not put them in the car yet to test operation, that's later this week.

I pulled out the old Waxstat brand thermostat, rated at 88. I boiled it quite vigorously and it begrudgingly moved to 38mm. Until the pan of water was at a roiling boil it was only moving to 36-37mm.

As best I could measure, it appears the bypass port is 42mm from the front face to bypass machining on my 6.0. The old thermostats easily left a 5mm flow path, which is about what the thermostat itself opens, so no impediment to recirculation at all.

For reference, in this thread https://www.jaguarforums.com/forum/x...pgrade-248467/ we discussed thermostats too. I eventually tested this thermostat for a 1992 V12 engine:
https://jagspares.co.uk/thermostat-82c-v12-engine-ebc3576-3.html

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Opens: 82°C
Full travel/stroke: 8mm
Total height cold: 36mm
Total height hot: 44mm
It has a jiggle pin

Tommaso

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