Sprint running temperature.

[B8WLY]

Dear all.

What would you consider an acceptable running temperature for a Sprint.

I have just changed out an original radiator for a Roose Motorsport alloy rad with an electric fan that is plumbed in and working well.

I flushed the car and am now using Evans 180, and have no leaks on the system. I believe I have no air locks and the system is pressurized. The heater runs hot when engaged.

Changed over the voltage regulator from another Sprint I know was operating well.

The car sits at between half and three quarters on the temperature gauge however.

I tested the head and thermostat with a laser heat gun and it was around 84 degrees after a decent run.

Do the above readings sit within tolerance for a Sprint or is it still running on the hot side.

Cheers.

Richard.

[cliftyhanger]

84 sounds ideal. I assume this is the hottest part of the system (ie thermostat area) but you haven't said what thermostat you are using.
Waterless coolant runs a little hotter than water/antifreeze.

[B8WLY]

Thanks Clive.

I was also told Evans can run up to 20% hotter than conventional coolant.

The readings I have taken are from the thermostat housing and areas on the rocker cover.

I changed the actual thermostat and the temperature gauge sendor unit also, which made no real difference to the gauge reading.

Although it sits on the temperature gauge at just over half I am scared by to many head gasket change outs to want to have the car running hot.

I will keep taking the readings short term but at the present as soon as I stop between 82-84 degrees seems the average.

Cheers.

Richard.

[Carledo]

If it's around 84 degrees, that's fine. The stat of choice of most of us only opens fully at 82 degrees. I'd say the system is controlling the temperature just about perfectly.

An engine with an electric fan will always tend to run a little hotter, especially in traffic, but it's nothing to worry about, the leccy fan controls temperature much better than an engine driven fan and therefore allows a much narrower "margin of error" between "hot" and "too bl***y hot!"

I know it's difficult, Triumph drivers (not just Sprints) habitually drive with half an eye on the temp guage, preternaturally aware of every faint quiver of the needle and ready at a seconds notice to pull over and shut down the motor if the needle strays a few thou over the normal mark. It's a hard habit to break, but break it you should! With a cooling system as thoroughly re-engineered as yours to minimize the risk of catastrophic overheating, you have to learn to trust it and resist your natural, time honoured paranoia!

Although I personally have little time for waterless coolant, regarding it as an un-necessary expense (if the cooling system is operating properly, you don't need it!) it's one less thing to worry about. The low boiling point of water, even under pressure, is the main limiting factor of any water based cooling system. Remove the pressure and raise the boiling point and the engine will probably run happily at over 100 degrees without damage. It's excessive pressure on the "wrong" (ie coolant) side of a head gasket that blows it, remove the pressure, remove the risk!

What I suggest, is that you sit in the car, running stationary at about 2000rpm and wait for the fan to cut in. When it does, mark that point on the guage, either mentally or with tip-ex. Then stop worrying till the needle passes that point or the fan doesn't engage.

Steve

[cliftyhanger]

Or plan b. find a sender or gauge combo that gets the needle sitting in the middle.
(i did that for somebody when I had a lot of spare stuff. He thought, like you, heis car was overheating. A calibrated capillary gauge gave temp readings te same as yours, so it was perfect. After trying several gauges and senders, I got a pair that sat dead central, he was very pleased. Not sure he understood I hadn't done anything to the actual engine though)

[80Sprint]

Mine runs at 88 on a cool day and 90-92 on a warm day even driven hard on track.

[B8WLY]

Cheers gents for the replies.

34 years ago when younger and more foolish I used to go through head gaskets on Sprints monthly.

Being a lot older and I hope a little wiser I want to enjoy and get the most out of the car without overheating worries.

The car sounds like it’s within tolerance so that makes me a lot happier. The car in question is Tango which Will recently restored so well. I may change the gauge out just for a little more visual happiness at some point. Will sent me a “working” voltage regulator which also helped bring the needle on the gauge more central.

Few more little upgrades this summer to do then like most drive it in the sunshine.

[mahony]

Was out in my Sprint today , no temperatures taken but the needle on the move was dead half way and a tad over in traffic ( leccy fan fitted ).

[Carledo]

With such a wide range of fan senders available these days it should be easy to choose one that suits your paranoia levels.

On my Vauxhall powered cars, which run a 92 degree thermostat (!) I run a 98 cut in/93 cut out sender successfully, I'm sure a Sprint could handle the same thing but most Sprint owners are too paranoid for that, so I usually use a 90 degree cut in/85 cut out sender to ease their minds!

My general opinion on guages is that they sit where they sit, so long as that's not off the red end, i'm not that bothered. "Normal" is a polite fiction! Both the Carledo and the Dolomega run a sort of mix-n-match temp guage with a Triumph dial and a Vauxhall sender running through the Lucas voltage stabiliser. Haven't driven the Dolomega long enough to find a stable reading yet but the fan comes in just over the 3/4 mark. On the Carledo the fan comes in just under 3/4 but the "normal" running temperature is only just above the 1/4 mark. Even on the hottest summer day and at somewhat illegal speeds, if air is passing through the rad, it won't get up to 1/2 way. That ONLY happens when sat idling in traffic and boy does it climb fast! On the upside, the fan brings the temperature back down equally rapidly, as does getting moving again.

On the subject of paranoia, I had my own moment a couple of years ago when the fan sender failed on the Carledo, in heavy, Friday afternoon, Birmingham city traffic. All the more embarassing, I had our own Alun (xvivalve) aboard at the time. I now have a manual override switch for the fan! Once bitten........

Steve

[B8WLY]

One thing I did forget to mention that may be relevant is after starting the car the temperature is at half on the gauge within three minutes of leaving the house.

It climbs rapidly and then levels out.

Do most Sprints do this or is this particular gauge just a bit lively ??

Any thoughts ??

[Carledo]

One thing I did forget to mention that may be relevant is after starting the car the temperature is at half on the gauge within three minutes of leaving the house.

It climbs rapidly and then levels out.

Do most Sprints do this or is this particular gauge just a bit lively ??

Any thoughts ??

This is really what you WANT to happen, but most 70s cars rarely achieve. An engine works best at the highest temp it can sustain, the quicker the warmup the better. This is WHY cars have thermostats, to speed up the warmup phase! Having a leccy fan helps as it's not being cooled unnecessarily by the engine driven fan during warmup as the standard car is. Even a viscous fan still runs on idle when not locked in by rising temp. With the Evans coolant too, which heats up faster and sheds heat slower, your situation is unsurprisng. Almost predictable.

I have a Sprint auto about me that has a Davis Craig programmed electric water pump fitted. This works without a thermostat but when cold the pump doesn't run at all, then runs in pulses of maybe 10 secs in every 30 till running temp is acheived, for a quicker warmup. This car also gets to halfway (170 degrees F on the capillary guage) really quickly, then levels off, usually within 2 miles driving. This seems part of the design criteria, even at "normal" temperatures on a cold day, the pump doesn't run continuously. On hot days, if the temp rises above a programmed point with the pump in continuous operation, the fan is deployed. It took a considerable time for me to trust it! But it seems to work well and the running temp is ALWAYS within a handful of degrees of 170F no matter what the ambient is or how fast you go!

Steve

[B8WLY]

Cheers Steve.

All the responses have helped put my mind at rest that the cooling system is working correctly.

Thanks to all who made comment.

Cheers.

Richard.

[sprint95m]

84 sounds ideal. I assume this is the hottest part of the system (ie thermostat area) but you haven't said what thermostat you are using.
Waterless coolant runs a little hotter than water/antifreeze.

On a slant four the hottest part of the engine is usually the back of the cylinder head.
The front of the thermostat housing is not a good place for the temperature gauge sender unit, in the BL workshop
manuals there is a warning and explanation about this.

There are different versions of Evans Coolant.
Powercool 180 is the version suitable for Dolomites. When I used it I noticed no rise in operating temperature.



Ian

[James R]

Sorry daft question......

There are various options with the Evans Coolant Powercool 180.

There seems to be an "Evans Power Cool 180 Waterless Coolant" and also a classic variant "Evans Classic 180 Waterless Coolant".

I assume that we should be using the classic variant. or does it actually not make any difference which you use??

[sprint95m]

Sorry daft question......

There are various options with the Evans Coolant Powercool 180.

There seems to be an "Evans Power Cool 180 Waterless Coolant" and also a classic variant "Evans Classic 180 Waterless Coolant".

I assume that we should be using the classic variant. or does it actually not make any difference which you use??

Your question is not daft at all James.

Dolomites should use the Powercool version rather than the classic version.


(I determined this from their US website and, after I had pointed this out on the forum,
Tony MacKillop contacted Evans Europe who confirmed what I had found.)



Ian