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Hot And Bothered


Guest jamesandrew

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Guest jamesandrew

hi have an S7 2.0 pinto on standard carb,runs fine but temp is about130 to 140.viscous fan turns although not very fast,not sure if gauge is faulty, afew drops of water from rad expansion pipe when stopped after a run,but does not blow off at rad cap,thinking of taking thermostat out and trying it to see if it is sticking

prievous owner said always ran hot but never overheated. any idears many thanks

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How do you know that it's running hot? Just because the gauge says so is nothing to go on with a Ford, especially when it's in a kitcar.

 

There are a number of things to check first.

 

Is the temp sender the correct one for the guages (NOT the engine) ford use about 8 - 10 different senders, and they all *move* differently depending on the temp. So you need to find out what gauges you have fitted, then get the correct sender for them. Robin Hood used to supply Escort guages of various models.

 

Next you need to check that the thermostat is fitted the correct way round see here

(note: also from this link, you'll notice a thermostat that opens earlier, whilst this is good, it will not cure an overheating problem)

 

Don't forget to check your ignition timing, an engine with not enough advance will run hot.

 

Last but not least, if you have the viscous fan still fitted, it could be knackered, but it also needs cowling in, you have to drag the air through the radiator, not from around the sides. Check this page

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Top up the radiator and then start the engine with the rad cap still removed. When the thermost opens the pump will blow any air to the radiator, so keep squeezing all the hoses and topping up the rad as it warms up. When no more bubbles put the rad cap back on. Make sure the rad cap blow off is connected to an overflow bottle with the tube end in coolant, then as the engine cools it will draw coolant from the overflow bottle back into the radiator. I run a Millets alloy drink bottle sat in a bicycle bottle cage as an overflow tank (Drill bottle cap for pipe to radiator and second pipe vent to air). Just shake bottle to check coolant level till system bled and levels settled. PS: Make sure your rad cap has two rubber seals and a little spring loaded return valve in the centre.

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Guest jamesandrew
Just read Big Jim's reply about gauges. I run a mark 5 escort clock (supplied with 3a), when running at 70mph the temp points to the M of the NORMAL text. Hope this helps.

Gauges are smiths and would think temp sender is standard sierra not sure how to check.No cowling round viscous fan not enough room previous owner fitted

this,thinking of trying an electric fan in nose cone or behind radiator if enough room if so how do i remove viscous fan.

thanks for your replys

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Guest Nigel Novice

There was an issue with the rubber seal/washer going all squidgy and restricting flow, and there's always the old favourite trick of drilling a small hole in the stat in the 12 o'clock position to allow air to pass

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to check the gauge disconnect the wire going to the sender unit and put the wire to earth it should go to hot on the gauge then remove from earth and it should drop to the bottom if it does the gauge is ok

Im sure the viscos is left hand thread

 

jon HTH

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Gauges are smiths and would think temp sender is standard sierra not sure how to check.No cowling round viscous fan not enough room previous owner fitted

this,thinking of trying an electric fan in nose cone or behind radiator if enough room if so how do i remove viscous fan.

thanks for your replys

There is no such thing as "Standard sierra guages" there were various gauges fitted to the sierra, depending on which model, and what date etc.

As I've already said, there are at lease 8 different senders (I actually think it's 10, but won't argue over 1 or 2) The difference is noted by the plastic insert that you can see on the connection end of the sender, they are different colours, black, white, green, brown, orange etc.

 

I also have Smiths 100mm clocks fitted, I made sure that I had the correct sender, by buying one to suite at the time I bought the clocks.

I've just been to check it, and it has a black insert, so try one of these.

 

Also ref the cowling, there has to be room to cowl in around the fan, or at lease block the spaces around the top & sides of the radiator so the air has to go through the rad instead of round it.

 

Earthing the wire only shows that the clock is working, and the wire isn't broken, nothing else, it certainly doesn't show if you have the correct sender or not.

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Guest jamesandrew

Have taken rad out to get to 4 bolts holding fan on (not left hand thread),how do i get the viscous centre unit of water pump pully,4 nuts around pully+one big slim nut behind viscous unit,need this out of way to fit slimeline electric fan as only 60 mm to70mm clearance

regards andrew

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Guest pwlcarz

Andrew

 

S7's have a tendency to run hot especially with the standard single core radiator as half the rad is blocked by the metalwork of the monocoque tub (assuming you've check for all the obvious problems described above). Certainly mine did and was in the habit of boiling up in warm weather in traffic or after a run.

 

I cured mine by going for a Coolman twin core rad and slightly higher pressure rad cap. This, plus silicone hoses all round and so far (2 years) has never boiled up since.

 

I still us the Viscose Fan as I couldn't figure out how to get enough clearance to fit an electric one as a "sucker" but did fit a manually switched fan in the nose as a supplement if I ever get stuck in prolonged traffic Q's. If you get one fitted let me know as I would be interested.

 

The other thing that helps is to provide a good exit route for hot air out of the engine bay - I fitted a vent in the bonnet as well which made a difference.

 

Good luck.

 

Peter

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It's very easy to become fixated on the figures on the gauges and ignore the physical symptoms and signs of a fault. If you are overheating and don't stop the engine boils and you can't miss that. You don't describe it.

 

Improving cooling system efficiency is a good thing. Maximum air in the nose, duct it so it all goes through the rad and give it a good escape route out from under the bonnet. Fans are useful if stationary and up to about 30mph. After that the air is moved through the rad by the cars speed not the fan. So a fan doesn't help if the engine is close to boiling at 80 mph. A more efficient rad like a modern ally rad of the same size or a copper rad with a bigger heat exchange area such as twin or triple core does increase cooling. Finally things that make the engine make more heat like weak mixture, retarded ignition and driving furiously need to be looked at!

 

Water boils at 100C at atmospheric pressure. A 15lb rad cap takes that to (15 + 14.7 = 29.7psi) 122.5C. A 25lb cap would take that to 130C before the water physically boiled. If you haven't got a 25lb cap or stronger and the water does not physically boil then it does not reach 130C regardless of what the gauge tells you. I think you run hot like most sevens but your gauge is telling porkies as it has the wrong sender.

 

It's all in the above responses to your first post. An electric fan is unlikely to make much difference to engine temperature above 30mph even though it's a 'good' thing to do.

 

Nigel

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Guest jamesandrew

Thanks for help some very useful advice

 

Have not checked ignition timing as dont know how to do this,think i will need strobe gun? am running on unleaded+additive as 83 engine i think.

 

Removed fan and hub (left hand thread) not enough room for electric fan, max space 50 mm with fan and hub removed so put back on,thinking of dual core

coolman rad from gbs but dont think it will fit as 25 mm gap between blades and single core rad, coolman rad is 2 inch depth mine 1 inch so blades will possibly scrape rad

 

Could i fit a rad approx 40cm high x 50cm long in nose cone on home made brackets +electric fan in front of shocks (s7 car), only problem i can think of is top hose will be lower than engine and hoses will be longer

 

many thanks

andrew

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You can move the rad into the nose cone and set at an angle. There was some discussion that it may be more efficient at an angle to the airflow. A longer bottom hose doesn't matter. The top of the rad being below the engine does. You need to fill and allow to self-bleed from the high point of the system so putting a header tank/swirl pot in the top hose would sort that. Do check with Smiths and get the right sender for your gauge.

 

Nigel

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