Drilled thermostat

[Charless]

Is anyone knowingly running a drilled thermostat and remembers what it was like undrilled? Or the other way around!
I recently fitted a new one and thinking it couldn't do any harm, drilled a 2 mm hole fitted at the 12 o'clock position.
Some of the symptoms I now experience don't appeal and I wonder if it is the drilling or something else.
e.g. it takes 15 minutes to warm up enough for the engine to tick over at 850rpm and for the heater to be delivering the usual blast. If I didn't find it such an awful job I would put another undrilled one in and compare.
Has anyone else similar experience?

[Rob Bell]

Wow - the drilled thermostat mod - now's that is a blast from the past Charles

Yes, the problems you've encountered (namely pronounced increase in warm up time) is exactly what the modification does. In fact, some racers drilled as many as four holes (I don't remember how large, but it'll be on the net somewhere) - and it certainly helped with the prevalence of HGF on race engines where the boy racers would give their engines death from the get-go without warming the engine up properly first

In fact, if you make too much of a bypass flow, the engine may never fully warm up at all...

[mgtfnut]

I thought about it at the time, 2005/6, but went the other route of thermostat under the washer bottle.

What happened to all that data Rob that some guy tracked that was so useful at that time?

[Charless]

The hole is 2mm, which is what was discussed around then. I think at least one of the race fraternity tried no thermostat at all - but he probably had a roof on, hard hat and racing overalls! I do 40 miles to work more modestly, with a polo shirt, fleece and hatless but with the top down so early warming is desirable, but perhaps less important as summer approaches.

Jerry, was it Dave Monks you were thinking of?http://mgf.ultimatemg.com/group2/common ... ailure.htm

[Rob Bell]

You beat me to it Charles - I think it was Dave's data you were thinking of?

Charles, it would be interesting to log your engine coolant temperature, inlet temperature and rpm from cold on the way to or home from work one day using the pscan.

I can do the same with mine - we can then compare the data!

[mgtfnut]

Jerry, was it Dave Monks you were thinking of?http://mgf.ultimatemg.com/group2/common ... ailure.htm

Aha, that's where it is - thanks. This convinced me to go this route in 2006, touch wood all has been fine ever since

[Charless]

Rob,
I should be happy to try but when you say log, do you have a program in mind which can log pscan data against time as I won't be able to keep stopping to safely record it. Sadly it would be impossible to log against distance as well, I happen to have a second F with the same engine type and original thermostat(but s/n 120 units = one week) later, so I could do a comparison for the identical route myself.
This might be almost as impressive as Dave's original work except that he monitored various thermocouples; and I wonder if pscan times out on live data? Interesting project even for a lazy git....

[Mykel]

Charles, I have never understood why people are afraid of using the standard ’stats anyway. The cooling system is way oversized for our cars, basically in outside temperatures of below 15 degrees (British summer, haha!) even the heater matrix gives sufficient cooling with a stuck closed thermostat (been there, done that!).

If you’re actually trying to prevent the “thermal shock” thingy about the ’stat opening close to the cylinder head and allowing cold water from the rad into the head, you might want to swap the setup for a PRT one from the TF. Sounds an easy fit – which it isn’t, mainly due to the heater hoses not being the same diameter. Apart from that it’s a straightforward swap.

On my TF I use a Land Rover PRT, rated at 88°C, whilst many people suggest to use an 82°C one. Never had any problems with this, car warms up quickly and engine temp up to standard within 2 miles.

To be honest, I would rather be concerned about a massive difference between oil temp and coolant temp when I think of head issues …

[Charless]

Hi Michael,
I absolutely agree with you - we are way overcooled and 225k miles suggests my recent drilling was not out of need -just idle interest. I used to put tinfoil over the bottom of my rad in winter to get it up to full heater more quickly!
Ho hum, silly me, I should have left well alone when fitting the new stat - but I was curious.
If Tony gets his two post lift back in commission I may go to all the faff of replacing the drilled one! Meantime I have noisy alternator bearings and a blowing flexipipe to fret about.
Happy Fing,
Charles

[Rob Bell]

Hi Charles,

The latest release of pscan have the logging function built in

I’ll find the instruction link for you

[Rob Bell]

If I were to go down the PRRT route, I’d fit it in the same place as Jerry and Dave - much easier to do