High Ambient Temperature

[cwchrisp]

Hello,
Would it be expected that an RM Saloon, without water pump, could operate in temperatures in excess of 35degrees C, without loss of significant amounts of coolant through the overflow vent?
Also, that the 22FZ carb. would not flood petrol through the top when normally it works well controlling the petrol level?
I am very interested to know if I have significant issues or I am expecting too much from an 89 year old car! (Its her birthday tomorrow! )

Chris

[Reckless Rat]

Well if its any use, I had a run out in my RP the other day. It was 35°c and there were no issues. Four blade fan mind you and SU pump fed carb.

[Barry Townsend]

I have no problems with the temperature on my RN and I've done the Renault thermostat mod to get it up to temp quickly. The gauge is pretty steady in all conditions now.
I did have some problems with setting the float height up on my Zenith but trial and error won in the end

[Mike Costigan]

I took my standard RM out on Friday when the Met Office claimed the temperature locally was 34°, and had no overheating issues. The run included several second-gear gradients, but no significant traffic, certainly no significant stationary moments. The story may have been different if I had encountered major hold-ups, but I do know that my car runs significantly cooler than a number of other local Sevens. 

But basically, no you are not expecting too much of your car! Your fuel problem sounds like evaporation probably caused by your engine overheating, rather than a weak mixture causing the overheating; I would suggest the first likely suspect is the radiator - has it been recently re-cored, or is it an elderly matrix that may be furred-up? Second area to investigate would be the waterways in the cylinder block and head, again prone to blockages.

[Steve kay]

Perhaps it is Welsh atmospheric pressure or a similar condition, but since totally cleaned head and block and with quite recent  radiator core, my Ruby never comes near boiling these days, no matter how slowly we ascend steep hills.

[Malcolm Parker]

My RL has never boiled since I had the radiator recored about 10 years ago and it has to cope with some ferocious hills in my neck of the woods.   The only time I have ever had a problem was on one of my runs on the climb from Dent to Dent Station, made worse by a following wind.   Actually the petrol in the float chamber was boiling, not the radiator coolant.   The reason was that where I had filled up with petrol only normal unleaded was available, whereas I always run on Super unleaded wherever possible.

[cwchrisp]

Thank you all for your experiences and I take heart that I was not expecting too much of my car.

@ Mike - The radiator hasn't been re-cored in the 13 years I have owned the car. It looks pretty original and I use distilled water to reduce block corrosion.
My problems occured on Friday too, with a short run and a lot of traffic.
I lost considerable coolant, though probably only to the bottom level of the upper tank, the carb was flooding near the exhaust pipe and a lot of fluffing and backfiring.

The combination of the short run, heavy traffic and hot weather probably caused the engine overheat.

I am using super unleaded petrol but was unaware that petrol can boil?

Chris

[Michael D]

  I've done the Renault thermostat mod to get it up to temp quickly.  

Barry: I've googled for that thermostat mod but cannot find a topic about it ..... could you provide one or - if not - a bit of elaboration on how to fabricate such a mod?    Work on my engine has commenced, I've acquired an external waterpump but indeed a thermostat. would help to get the  cooling system up to temperature a bit quicker (in the late eighties I ran my Triumph TR2 without thermostat for some time and it took ages to warm up)

[Mike Costigan]

It's buried in the What have you done today ... thread; look around page 147.

[Michael D]

@ Mike : thanks for pointing me in the right direction; that's a lot less sophisticated than expected....