Engine thermostat, with a difference...

[NB Esk]

Main difference being, not many others will cost £2776.82 + £35 delivery.  That's not for the complete valve, it's just for the replacement internal gubbins, I'll be having a rethink.

Anyway, engine concerned is Lister Blackstone EVM, and when I took the cover off, in order to clean and service the thermostatic valve, was a little dismayed to find there was nothing in there, it must have given trouble in the past and someone took the innards out and binned them.

I'll post pics of what things should be like but my question is:  Can anyone think of a very large vehicle style thermostat that I could adapt to fit.  The diameter is going to need to be approximately 80 mm.  For scale I've included a thermostat from a Merc truck (around 60mm) but as can be seen, it needs a much bigger one.

 

 

 

[John Hartley]

Is it possible to fabricate a thin steel plate to fit on the four bolt holes with the appropriate size hole for the stat. I have never seen one that big before.

Good luck.

[NB Esk]

3 minutes ago, John Hartley said:

Is it possible to fabricate a thin steel plate to fit on the four bolt holes with the appropriate size hole for the stat. I have never seen one that big before.

Good luck.

Probably wouldn't be safe to do it that way as it would lack the required flow through the open stat.  That's what I mean, needs to be a big 'un.  Hoping someone says a Cat D9 has one about right. ? or something like that....

 

 

 

[NB Esk]

Course the other way is, does anyone know where I might find the proper thing?  It's a Spirax Sarco type 58 with a C temp range.

 

Yes, have it on my eBay search list, 

 

 

[Boater Sam]

Well of course Spirax Sarco Engineering are still in business.........

[NB Esk]

Just now, Boater Sam said:

Well of course Spirax Sarco Engineering are still in business.........

Oh yes but that goes back to that price, that's from one of their agents.  Explained I was retired and trying to keep a historic vessel in good shape but that had no effect.  Received a nice email in return, basically saying "tough, that's the price "

 

 

[steamraiser2]

The core of your problem is the throughput. A vehicle stat, or even a Cat D9, will be too small. What you have is a Spirax version of a Mason valve, not common and very expensive. It may be worth contacting Woods of Crediton. They have a yard full of ex Royal Navy parts and may well have something to suit.

[BM 1051]

Is it possible to use a tube termostat from Volvo trucks or Penta, its a tube style one and big

I can measure one tomorrow.

 

 

https://www.ebay.com/itm/Volvo-Penta-Thermostat-82-C-D13C2-A-D13C4-D13C6-21613426-/123109657002

 

/Christian

[Boater Sam]

Is it just a thermostat though? It looks like a diverter valve or a mixing (blending) valve having 3 ports not 2

[NB Esk]

3 minutes ago, Boater Sam said:

Is it just a thermostat though? It looks like a diverter valve or a mixing (blending) valve having 3 ports not 2

I believe the data sheet describes it as thermostatic valve.  It's a fairly complex cooling system, with provisions for emergency cooling routines.  One tee runs coolant through a Serck type heat exchanger, while the other runs directly to the pump inlet.

 

 

49 minutes ago, steamraiser2 said:

The core of your problem is the throughput. A vehicle stat, or even a Cat D9, will be too small. What you have is a Spirax version of a Mason valve, not common and very expensive. It may be worth contacting Woods of Crediton. They have a yard full of ex Royal Navy parts and may well have something to suit.

Thanks, I'll check them out....

 

 

[NB Esk]

22 minutes ago, BM 1051 said:

Is it possible to use a tube termostat from Volvo trucks or Penta, its a tube style one and big

I can measure one tomorrow.

 

 

https://www.ebay.com/itm/Volvo-Penta-Thermostat-82-C-D13C2-A-D13C4-D13C6-21613426-/123109657002

 

/Christian

Appreciate it, a measurement would be good but I've a feeling it will likely still restrict the flow.

 

 

[crossley]

What you need is a 3 port amot valve. 

Try Amot controls. Come in all shapes and sizes, flanged, threaded bsp etc. We use them on main engines. That's a tiddly one. Some have 6or 8 elements in the casing. 

[NB Esk]

1 hour ago, crossley said:

What you need is a 3 port amot valve. 

Try Amot controls. Come in all shapes and sizes, flanged, threaded bsp etc. We use them on main engines. That's a tiddly one. Some have 6or 8 elements in the casing. 

Okay, ta.  Will check them out...

 

 

[john.k]

I would modify the setup to use a original style piston valve to fit operated by a gate valve type spindle with a handwheel.........the engine has been running happily without anything there for 50/60/70 years.......why tempt fate by mucking around with thermostats,where the original doesnt seem to have been satisfactory..........the nearest cheap thermostat I could suggest is from a 71 series inline GM..........they have a modicum of cast bronze in the design to please the purist,and are quite large.........most big engine thermoststs work like that by modulating flow between cooler and bypass back  to engine.

[NB Esk]

4 hours ago, john.k said:

I would modify the setup to use a original style piston valve to fit operated by a gate valve type spindle with a handwheel.........the engine has been running happily without anything there for 50/60/70 years.......why tempt fate by mucking around with thermostats,where the original doesnt seem to have been satisfactory..........the nearest cheap thermostat I could suggest is from a 71 series inline GM..........they have a modicum of cast bronze in the design to please the purist,and are quite large.........most big engine thermoststs work like that by modulating flow between cooler and bypass back  to engine.

I wouldn't want to have any visible modifications as things have been like this since the 1950s.  I will check out that thermostat though.  A possible reason for this valve failing is that it wasn't installed correctly in the first place.  The makers data sheet clearly states it should be installed vertically.  I'm sure it would still have operated okay, the problem would possibly arise when the system was allowed to freeze.  Mounted horizontally the valve would still have water in it (even if the system was drained) or behind it, engine side, if it's sealing was good.  It ought to have had a drain on its inlet side.  There was plenty of evidence of freezing over the years, as I know to my cost, having recently replaced a Serck heat exchanger that had frozen and burst a previous metal stitched repair. ☹️ Thanks for the input.....

 

 

[john.k]

if you cant change the outside appearance ,I doubt anything will fit in the available space ,and work...............the only other alternative is a blanking plate with a metering hole to stop the mass recirculation of coolant direct back to the motor................running without a thermostat in a bypass system often causes localized overheating,without raising the coolant temperature overall.

[Eeyore]

Any replacement thermostat needs to sit in the centre of the casting with the sensing element facing the flow from the engine; probably from the base of the “T” , where the sensing element appears to be in the first image. Draw a line between “x” and “z” in your first image to give an indication of its position. In this configuration port “x” would be the bypass, and port “z” would be the flow to the cooler; the body may need rotating 180 deg should the flow differ from the original internal setup. A restrictor will be needed in the bypass to ensure the flow to the cooler (when the stat is open) is the flow of least resistance. So a little machining to provide a seat for the stat, and modification to the cover to hold the stat in place; possibly a perforated tube under the cover to hold the stat?

[TheBiscuits]

It/she has run for years without the innards.  If you are not intending to tow a fully laden train of puddings uphill, don't bother!

 

You are quite unlikely to be working the engine to anything like it's capacity, so don't worry about it - certainly not at three grand a go! 

 

(I don't believe I have to explain this to a Yorkshireman!)

 

You are more likely to be running cool than hot without the thermostatic valve, so open the throttle more in the deeper channel and run it for longer for the sake of your engine.

 

 

[Tony Brooks]

On 29/04/2019 at 19:04, Boater Sam said:

Is it just a thermostat though? It looks like a diverter valve or a mixing (blending) valve having 3 ports not 2

Agreed. It is most like the early vehicle bypass thermostats and those fitted as after fitments to some vintage engines where the cylindrical part around the outside moves up and down. Personally I can't see any automotive part doing the job.

[john.k]

The water pump seal for a 6YEN Ruston engine was $450 from GEC Diesels ,ex UK............the exact same seal from Perkins was $6,over the counter..........