The Triumph Dolomite Club - Discussion Forum

Hi All, My 1850HL will be back up and running soon, but is in need of a new rad. I thought I'd use the oppurtunity to upgrade to an alloy sprint rad of the built in fan/switch design from Alicool. I'll likely be putting a TR7 lump in it in the coming years so thought I may as well upgrade the rad now rather than invest in refurbing the 1850 unit.

The rad comes supplied with fan and switch but I have the option of 72 - 82 or 82 - 92 degrees for the switch. Which one is more suited to the current standard 1850 engine and will this needed changing once i go down the TR7 route?

As this doesnt come with all the usual bits and pieces the electric fan kits come with (probe, adjustable termostat, relay etc) what else will be needed to fit it? Just a relay, wiring and some connectors?

I'll be sure to post some pictures and updates of the cars progress. It should drive like a different car when its finished

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1980 Russet 1850hl

Can't answer the question regarding the temp but having purchased one of these rads I can confirm you get a rad, fan and switch. If you want wires, relays, plugs or a variable pot then you need to buy all the gubbins yourself. It's not especially difficult to fit but you'll need to look at some instructions as the unit won't come with any.

I purchased my components from 12 volt planet online and spent a while planning my circuits and my routing to leave me with a nice job. There's some pics on my resto thread somewhere.

To be fair you probably don't need an aluminium rad for either engine. The standard 1850 one is quite poor, even a standard Sprint one is better as it has an extra row and is more tightly packed. But that said an ally rad of this design is inherently more efficient than either, though don't forget copper/brass is actually a better conductor of heat from the engine that aluminium. Where the aluminium wins is better transfer to the air through a different design of core, plus it weighs much less.

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Mark

1961 Chevrolet Corvair Greenbrier Sportswagon
1980 Dolomite Sprint project using brand new shell
2009 Mazda MX5 2.0 Sport
2018 Infiniti Q30

On the 1850 I had I used a 92 degree switch.
Mind you it did have an 88 degree thermostat whereas (for reasons unknown to me) later 1850HL models had an 82 degree thermostat .






Ian

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Cheers for the reply and info. I've already ordered the rad, but no yet received so at least I now know whats going to land on my doorstep. Did you use the standard switch or fit a a variable/adjustable switch? I've seen revotec do a variable one that threads in. So maybe I can match the threads and install one there rather than use a probe or hose link.

I'll try and locate your resto thread and take a look at the install.

I could still do with knowing what the ideal running temp is for both the 1850 and TR7 2L engines if anyone has the answers. From searching it sounds like the 1850 should be well in the 80's, so guessing I should go for the higher temp switch if I dont go variable. It would be the cheapest route.

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1980 Russet 1850hl

If it is a larger aluminium rad you want, you can just fit a much cheaper one from a Saab 900. It will just about fit without any body modifications.

Or Fiesta diesel

Tony

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Membership 2014047

Having done it, (indeed it was me who pioneered the Saab 93 radiator into a slant four Dolomite thing),
I am of the opinion that fitting a bigger radiator gives no improvement.


The weakest link in the cooling system is the so called expansion tank. Get rid of it and employ a proper header tank.
I have used Volvo 850 (but there are a multitude of others that will work).
The positioning of this is important, it needs to be on the nearside turret above the cylinder head. The reason being that you want
to have it located above the height of the engine's highest point, thereby if the low level warning is triggered the level won't have (yet) dropped in the engine.


Around 90 degrees is the best operating temperature for a slant four.




Ian.

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"Around 90 degrees is the best operating temperature for a slant four."

Thats good then, my modded cooling system is doing around 90 - 92 (at 3 points im measuring), a bit cooler once the cold air we are getting gets through the rad

Tony

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Membership 2014047

I was always told that thermal efficiency is about 88c and this website supports that.
http://www.davidboettcher.uk/thermostat.php

it also states:
Internal combustion engines operate most efficiently at relatively high temperatures, typically above 80°C - 85°C (176°F - 185°F). Wear on the moving parts is reduced and thermal efficiency is increased by operating at this temperature.

Lower engine temperatures result in inefficient combustion which causes increased fuel consumption, and increased wear with consequent reduced engine life.

However, if the engine temperature gets too high, boiling of the coolant leads to local steam pockets forming which severely reduce heat transfer in the affected area, usually the cylinder head, resulting in premature combustion of the fuel air mixture, also know as detonation or knocking, and ultimately damage to engine components (the cylinder head, valves and pistons).


Maloclm

Cheers all. The Alicool rad is already on order and I'll give it a shot with the higher temp switch.

It'll look nice and get rid of the mechanical fan, even if the increase in size isnt needed!

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1980 Russet 1850hl

Is he painting it for you? Or you leaving bare?

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Mark

1961 Chevrolet Corvair Greenbrier Sportswagon
1980 Dolomite Sprint project using brand new shell
2009 Mazda MX5 2.0 Sport
2018 Infiniti Q30

In the "good old days" of engine driven fans and huge rads, it was customary to provide a bit of wriggle room in engine running temps, hence the use of different thermostats for summer and winter at 82 and 88 degrees respectively. A modern cooling system with a proper expansion tank and electronically controlled electric fan keeps the engine temp controlled MUCH more precisely, so the wriggle room is no longer needed and you can afford to run at a higher average temp. most modern stuff runs between 88 and 92 degrees as a normal range, with the fan deploying at 95 degrees and disengaging at 90. The Carledo's Vauxhall engine has a 92 degree thermostat as standard and the stock fan sender that accompanies it deploys at 97 degrees and cuts out at 93.

But it can take slant owners, who customarily drive with one eye on the temp guage, quite a while to overcome their paranoia and adjust to the reality of a guage that seems to be ALWAYS over the half way mark once the update has been made and as a result tend to set their fan deployment too low for fear of overheating that, in reality, will not be happening.

Steve

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'73 2 door Toledo with Vauxhall Carlton 2.0 8v engine (The Carledo)
'78 Sprint Auto with Vauxhall Omega 2.2 16v engine (The Dolomega)
'72 Triumph 1500FWD in Slate Grey, Now with RWD and Carledo powertrain!

Maverick Triumph, Servicing, Repairs, Electrical, Recomissioning, MOT prep, Trackerjack brake fitting service.
Apprentice served Triumph Specialist for 50 years. PM for more info or quotes.

My zetec van runs about 98 and fan is in at 103!

Tony

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Membership 2014047

I've had to experiment at lot with radiator / thermostat and fan switch settings in the race Sprint in the past and have used that knowledge in both my road Sprints. All of that is also relevant to the 1850.

I've ended up with the factory standard 82C thermostat and, in the car with a standard radiator, a Revotec unit in the top hose set to start the fan at about 95C and go off around 85C. Incidentally I've replaced the standard temperature gauge in all three of my Sprints with one where the actual temperature is displayed, making life so much simpler.

In the auto car I've fitted a Porsche 944 radiator (alloy and bigger) that has a standard type screw in switch to control the fan that has a similar on/off range. However they seem to be a standard screw fitting and are available in a number of ranges. I believe it is sensible to have the fan being switched on at a temperature of at least 10-15C higher than the thermostat opening and also switched off above that of the thermostat too.

The ultimate test of whether the setup is correct can only be done when driving. Under normal driving the fan should NOT come on, but it should when stationary or running in slow traffic on a hot day.

You do need to run the fan using a relay setup as they all use high amps. Remembering that engine coolant temperature always rises when you turn the engine off, you might want to consider using an 'always live' power source rather than a source that is only on with the ignition. That way if you stop with a hot engine, the fan will continue to run until the radiator switch turns it off. I live at the top of a long hill so engine temp is always high when I get home!

Geoff

The popularity of these aluminium radiators puzzles me.

Whilst they have now been tested in various cars and can be seen to ‘work’ there seem to be several variables over the standard:

* They are made from a less efficient material in terms of SHC
* We don’t actually know how their capacity compares to standard (though this could easily be tested)
* We don’t know how the fin and tube areas compare
* The colour is less efficient for purposes of radiation (though the term ‘radiator’ is actually misleading)
* My experience of aluminium radiators in ‘modern’ cars is they have a far shorter life than copper/brass before oxidation takes its toll on the fins.

Having been to where they are made, and now knowing how they are made and from what components, and having held discussions with them about how they might make fuel tanks for ‘us’, I’m fairly certain there has been no ‘engineering’ involved.

I can get a standard Sprint radiator recored with the correct matrix for about £100, yet the alicool version is £250.

Can someone explain their appeal to me please, and why they are considered to be an ‘upgrade’?