temp control again

[dazzer]

Previously had overcooling problems with the early 2000 mk1 lump on the early 2000 ventilation system. On this re-incarnation. with a complete body rebuild I've utilised the slightly later system. Massive improvement on air flow and distribution. Which when idling on the spot and the temp gauge reading just above normal (just over halfway with the electric fan cutting in and out 90 degree switch) the heating is lovely.

Unfortunately, once again, on the move the engine cools to just quarter on the gauge and the heating is just luke warm. This is once again the radiator and possibly the upgraded water pump being too efficient. its the same with an 82 or 88 thermostat. The manual fan is removed and I've now disconnected the auto fan switch and just use a manual switch which is only ever used stationary for extended periods.

Great for warm weather but pants in cold weather. My next thoughts is to fit an alloy radiator to save weight and maybe it will be less efficient. than the copper. The old upgraded square top is now approx 12 years old. Or fit one of the old fashioned manual shrouds.

Do the engines cool more on the standard set up when on the move?

Cheers
Dazzer

[glang]

Surely the first (cheapest) option is to put a standard pump back in and see how it behaves then....

[dazzer]

Like your thinking glang.

Standard pump on order.

Cheers
dazzer

[glang]

Let us know how you get on cos I might be interested in an uprated pump

[iggy]

mines a mk2 2500 temperature always stays around mid way on the gauge cant rememder what thermostat is fitted but its got the original viscous fan fitted

[thescrapman]

Did you put all new foamy seals in the heater box?

I had the cold outside air pushing past knackered seals cooling the air too much in the cabin.

[TedTaylor]

Is your thermostat opening correctly (at the correct temperature) ........ or even stuck open/part open!

If your thermostat does not open at the correct temperature (i.e. early) it can mean the engine can never (or with difficulty) achieve its correct operating temperature.

MUT

[dazzer]

Hi Guys
Thermostat is correct and checked and I've substituted it. There is no extra by pass the water system is standard apart from the updated pump and HD Rad. Yes did put the foam kit in and the heater is great when the engine up to temp stationary.

You've given me another idea though. I'll try restricting or blanking the by pass where it comes out of the thermostat housing. Used to do this on TR4s but that was to get all coolant running through the rad. It may make things worse. I'll give it an experiment.

Cheers
Darren

[glang]

Quoted from Spitfire6

Hi,
The thermostat controls the engine temperature.
The fastest water pump and largest radiator in the world should not cause your engine to run too cool.
Are you sure nothing is bypassing the thermostat apart from the heater return that should be going back to the suction side of the water pump anyhow?

When your gauge and heating in car is low; you are saying that the radiator is cold as well?

Cheers,
Iain.

I think an uprated pump could change the running temperature of the engine because for any given opening of the thermostat (as determined by the coolant temperature) youre now forcing more flow through. Then if the radiator is capable of cooling that flow down sufficiently to maintain the engine temperature theres no reason for the thermostat to close more so you have a stable system operating at a lower temperature.    

[RobPearce]

That logic assumes quite a shallow slope of response for the thermostat. I think the increase in pressure across the stat for a higher pump flow is small, too. I'm not saying the bigger pump will make no difference, I just don't think it's likely to be as noticeable as Darren reports.

[glang]

Yes the new pump would have to be quite an improvement over the original but then that wouldnt be too difficult looking at the 19th century item we have installed as standard in our engines. Some articles on line do actually comment on the risk of a less efficient cooling system at full load cos the coolant doesnt spend long enough in the rad - be interesting to hear when Darren installs the standard pump......

[glang]

Why do you say that Iain? And what was the problem with using an electric pump?

[Davemate]

Dazzer
I’ve had my heater bypassed due to a weeping heater matrix and my temp gauge has been sitting just over half or a tad higher way on my home from work if stuck in traffic . I’m running standard pump,rad and at the moment a 77 thermostat. On the odd occasion I’ve had to click on the electric fan just to lower the temp a tad.
Today I thought sod the leak I’m bloody cold so I reconnected the heater
On my home tonight I sat in loads of traffic and it took me an extra 40 mins to get home and that was all stop start traffic. I had full screen,full heat and the blower on (mk1 2000)
The temp gauge sat bang on normal so just having the heater blower kept the temperature down,as soon as I got moving after the road works the gauge dropped to under normal and the heater was definitely cooler within a few hundred yards
So :- as in the same situation during the summer I fitted a electric fan but only with an manual switch which I had to have on as well as the heater blower to keep the temp gauge at about 3/4 when sat in similar traffic, so my thinking is,it’s bloody freezing out at the moment so any air flowing through the engine bay will cool it rather quickly.

I’m thinking about restricting the air flow through the front grill with some sort of screen,probably cardboard to see if it works and then something better if it works

Ps
In the mornings on my way to work at 05:30 during my non stop run of 3.5 miles my temp gauge just about gets to 1/4 or just under and the heater blows cold or luke warm if I’m lucky or unlucky as it just fogs the screen up

[glang]

Corse the heater output temperature not only depends on the coolant but also the outside air temperature - colder air in colder out. However once your engine is warmed up the thermostat should control the coolant temperature regardless of air temp but as they are pretty crude the range can be quite wide and then because the car temperature gauge is calibrated to a narrow range any slight change can look worse than it really is....

[Davemate]

In very hot weather
Hot air not only flows through the rad but also flows over the engine
In very cold weather
Cold air flows through rad and over the engine
so in theory in very cold weather the engine could never get “up to temp”
And in very hot weather it could be “ up at running temp” before your even start the engine
And yes I’m mean in “ over extreme temps” at both ends of the scale

So to answer Dazzer original question

It all depends on the weather,and if your moving  

[ferny]

Blank some of the radiator.

When I had an MX5 radiator with a 1300 engine I had the same issue. I had to blank over half of it in winter to get warm air.

[RobPearce]

Blanking part of the radiator in cold weather was common practice back when our cars were built.

[poppyman]

There are quite a selection on ebay at the moment

Cheers, tony.

[Davemate]

Quoted from poppyman

There are quite a selection on ebay at the moment

Cheers, tony.

What are they listed under, having trouble finding them  

[poppyman]

Quoted from Davemate

What are they listed under, having trouble finding them  

Under " car radiator muff" Non for the triumph range but item 302543952961 looks like it would adapt
Cheers, Tony.

[thescrapman]

I am struggling to believe that air flow past the engine is enough to  drop the temperature of the coolant in the block. You would struggle to get the car to run cleanly. The radiator should be stone cold as the thermostat should be closed.

[Dogsbody47uk]

What temperature thermostat are you using? I run my 13/60 on an 82 Degree, but Triumph also recommend an 88 degree one for cold conditions. Cheers, Dave.

[Nick Jones]

I have this issue with my A6 TDI.

It always takes a long time to warm up, even in summer - it's a direct injection diesel - they don't waste much heat.  However, if the thermostat isn't spot-on' it'll never warm up unless you're caning it and even then will take 15 miles.

The correct OE thermostats made by Wahler have a rubber seal to give tight shut-off.  They cost £40 + in UK.  You can buy will-fit alternatives from reputable manufacturers but they don't have the rubber seal and it would seem that they don't seal well enough as I've tried two now and they are worse than the slightly shagged proper one.  They work as expected in a saucepan and seem to shut fully but don't have the desired effect.  I've just bought the real deal (from Germany at half the cost of the cheapest I could find here) so we'll see.

Guess the moral of the story is even a little flow will go along way if there's not much waste heat.  Moderately surprised this is an issue with a Triumph 6 though - the Vitesse gets up to working temperature in about a mile - quickest one in our fleet.  Heater still rubbish though somewhat improved now the crappy Smiths valve has gone to live in the bin.....

Nick

[nang]

You've got to ask yourself, why did our cars work well 40 years ago and give trouble today ? Rubbish replacement parts ?
Tony.

[dazzer]

OK no results as yet from the water pump changeover as only just doing it! but a few pics of the difference in design and a new Rad fan configuration/weights etc. As a recap I'm trying to reduce overcooling on the move (fans not engaged)

Old pump originally from racestorations: Expensive but completely reliable and definitely keeps everyting cool approx 7 years old. Alloy machined rotor and body. weight 1kg

New standard pump: all steel/cast. cheap as chips, weight 2kg.

New square top alloy Radiator: fitted with 2 x 10" slimline Comex. just fits with oil cooler in front. Weight 4.6kg

Old square top Rad with 4 x 52 row upgrade . Weight 10.1KG! Bur definitely keeps things cool.

So All back together this week for the test.

Cheers

Darren