Tempreture Confusion

[Sohail]

Hi folks, my 1976 Stag is fitted with a tempreture gauge which has degrees c and not a red area. What would be the equivilant tempreture on my gauge to the red area on the standard gauge ?

[marshman]

Any reading over 3/4 on the temp gauge is too high for normal running. Ideally - assuming the gauge and sender unit are OK - it should run somewhere between 1/3 and 1/2.

Roger

[Sohail]

Thanks Rodger for your reply. The gauge runs from 0-110c. Maybe I would be better having a normal gauge fitted with the red area. The car normally runs between 88-90 and on really hot days rises to about 93-95. This is so confusing.

[Ian Durrant]

93 to 95 is fine on hot days.

[Sohail]

Thankyou Ian that is reassuring. I get so worried and confused.

[Ian Durrant]

Glad its helped. I have driven several slightly more modern cars, where the electric fan doesn't even bother to cut in until 97 degrees C. I certainly wouldn't worry until you are getting close to 100 degrees on a hot day. With the stags 20psi pressurised cooling system and glycol based anti freeze the boiling point is way above 100 degrees anyway. A few degrees isn't going to cause head warpage, the problem starts when localised boiling causes hot spots in the engine. Hot spots create a massive temperature differential and that's what causes warpage.

[Dave M]

Thankyou Ian that is reassuring. I get so worried and confused.

It sounds like you may have a capillary type temp gauge fitted, is so these tend to be more accurate than the standard electrical type. The figures your quoting sound fine to me.
Dave

[wilf]

I have found that with most automotive gauges, some calibration is useful. For your temperature gauge, try to get the sender out and put it in a kettle of boiling water and see what gauge reading you get.

The last Smiths capillary temperqature gauges I fitted were both 10 degrees out (reading under). And so I used 90 degrees on the water temp guage as my "warning" point. (and of course, having done all of that, that particular car never, ever, overheated).

[V Mad]

My advice would be to err on the side of caution regarding the max safe temperature. Although it is true that coolant under 20lb pressure should not boil until well over 100 degC, dont forget that the gauge can only show the coolant temperature at one point in the system, ie at the back of the LH head. For example the temp at the mid point of the RH head where the two exhaust ports are next to each other is remote from the sender may be higher, and may be much higher for all we know.

My Sunbeam Tiger runs at 85 to 90 degC, and I would expect much the same from the stag, but I would not be happy with a stag showing over 95. Since Sohail's car has only reached that limit on a hot day it should be OK though.

[Sohail]

Thanks for all your comments and advice.

I have had a uprated rad fitted and electric fan and am in the process of buying a header tank. What other steps could i take to ensure that the tempreture stays at or below 90degC

[V Mad]

Check also that your engine fan works well enough. It has a viscous coupling, and these can go weak.

[Paul Goldsmith]

You could also consider fitting a cowl around the fan, which will improve it's efficiency at pulling air through the core.

Several on the forum have adapted a Mercedes cowl to good effect & cheaply from a breakers (on my own 'to do' list), I've found the following thread useful http://www.stag.org.uk/forum/showthr...=mercedes+cowl

[Sohail]

Thank you for your advise folks. The fan that was originally fitted was removed by the person who fitted the electric fan, should I refit this ?

[flying farmer]

I use only a Kenlowe 2 speed electric fan and no engine driven fan. I sometimes get the second speed cutting in when in traffic on hot days, but it never gets over 3/4 of the way up the gauge.
If you have a sufficiently powerful electric fan you should be ok. I made the mistake of fitting a large cheap ebay fan first time and it was a total waste of money
Some people prefer the belt and braces approach of both original and electric fan
Neil

[Sohail]

Thanks everyone for your very helpful advice and hope to see you around sometime, anyone own a Stag in the Bradford Area