The car is a 1949 triumph roadster ,i bought it on HJ,S website 3yrs ago.Lovely old car ,i,ve replaced a lot of bits,not the rad or pump. The car seems ok in winter and have bought an electric fan- a pusher-in front of the rad,have yet to fit it. Thanks for the advice
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Kevin,
Some good points there. I agree about checking the thermostat opening/closing. If it is the original, it will be the bellows type which usually failed in the open position but, whatever type it is, it could be getting slow to fully open. Also important to fit the right one -- in the absence of any data, and given the age of the design, I would fit one marked 82 degrees.
Replacing an engine-driven fan with an electric one is not always a good idea. I replaced the crank-driven fan with twin electric fans on my Triumph in about 1980 and the engine overheated in traffic. It took me a long while to discover that the original lowdown crank-driven fan helped to cool the oil by blowing air over the sump, whereas the two mid-mounted electric fans cooled the radiator only. At least, that's the conclusion I came to, and reverting to the crank-driven fan cured the problem.
As for the impeller, I don't think these had a tendency to corrosion. Remember, this engine was designed in the days when antifreeze was added only in the winter and did not contain anti-corrosives. The impeller is likely to be some form of bronze or gunmetal, i.e. non-ferrous. I could be wrong though!
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Chris, another quick comment!
When fitting the electric fan, remember that it will be blocking off part of the radiator so it will impede the flow of air through the radiator when it is not running. If for any reason it idoes not run when needed, it will actually worsen the overheating situation. It needs to be very reliable and set to come in quite early.
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And another one!
Chris, I just noticed your question about which way to turn the distributor. To advance the ignition you turn it opposite to the direction of rotation of the rotor. I've an idea you turn it anti-clockwise to advance on your engine, but best to check.
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Seem to remember in the old days my old man had a winter and summer strategy to keep the motly collection of old bangers running (well sometimes)
The summer strategy (carried out in spring) was
Drain all the coolant
Out with the radiator, reverse flush with a hosepipe.
Out with the thermostat, descale (soaked in lemon juice or vinegar over night)check it was working (pan of water and thermometer on the stove)
Back with the radiator, fill up the coolant (usually just tapwater), check the hoses and clips and the fan belt.
Seemed to work, never had overheating problems. (well we did once when he didnt do the winter strategy, the coolant froze, loostened a core plug, which then popped out under pressure when hot, pumped out the water, and siezed the engine on the A127 at the halfway house.)
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I,ve been running the car without a thermostat.When I recently added some bars leaks the temp gauge went up and she boiled over when i switched off.Usually it runs around75-80degrees,but always creeps up in heavy traffic.I plan to use the electric fan in conjunction with the old fan---extra help when stuck in jams.Thanks for the advice on the distributor.
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I would warn against using an electric fan in conjunction with the crank-driven one. They can often work against each other and impede the airflow (See Dizzy's post above.)
>When I recently added some bars leaks the temp gauge went up and she boiled over >when i switched off.
Why did you add BarsLeaks? Was the rad leaking?
It sound to me as if the cause of your problem is a bad radiator and a replacement or rebuild is needed.
Kevin...
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Kevin
I added bars leaks to try to cure a slight weep at the back of the head gasket when cold.Ihad the head off and hard seats put in for unleaded .,When I found the car it had been left untouched in a garage for30 yrs----seized!The head is already at 80lbs so no more torquing allowed. the weep seems to have stopped ,and pressure-oil- is 60.
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As a matter of interest how old are the hoses ie have they all been replaced or are they original.?
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Don't run without a thermostat. That could be your problem.
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If your cooling system was working correctly you would not need an electric fan.would suggest as has been said probably rad needs re`core.? as for running without thermostat it`s asking for trouble ie overcooling not overheating unless a blockage.
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When Aprilia says that running without a thermostat may be the cause of the problem, I think he is referring to the usual set-up where the open thermostat has a disc or sleeve which blanks off a radiator bypass port when it is open. This means that, without a thermostat fitted, some of the coolant will take the easy bypass route rather than going through the radiator.
However, I don't think the Triumph/Vanguard 2088cc engines had this bypass blanking feature. I think they simply had a small port which allowed a constant bleed to bypass the radiator, one reason why old engines took such a long time to reaching normal operating temperature. Still very adviseable to always have a thermostat in place though, to avoid overcooling (as mech1 said).
I also think mech1 is right in saying that an electric fan shouldn't be needed, though plenty of cars have them (eg Kenlowe).
I think Kevin slightly misunderstood me. I used electric fans IN PLACE OF the engine-driven fan and this is where I think I went wrong. They were home-made from heater motors fitted with Morris 1100 'pusher' fans. The idea was to give cooling when in slow-moving traffic in the days when I was one of those people who choke up summer holiday routes with a touring caravan.
Finally, I suggested a thermostat stamped '82 degrees' (start-to-open temp) but, thinking again, this might be a bit high for an engine of that vintage. Hopefully a handbook is available to specify the correct thermostat.
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'Finally, I suggested a thermostat stamped '82 degrees' (start-to-open temp) but, thinking again, this might be a bit high for an engine of that vintage.'
In the interests of education, please, Why? Because old rads won't stand the higher pressures that come with higher temperatures?
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Not so much the higher pressures but old cooling systems were designed round poor castings (leading to local hot spots), inefficient water pumps) and as a result the cooling is marginal at times.
IIRC my 1953 Rover 75 ran with a 75C thermostat : when I tried a winter one at 82C it boiled 'cos, by the time the thermostat had opened, a localised hot spot lead to steam forming in the head.
When you did the head did you clear out the block waterways? After standing 30 years sludge would have hardened and narrowed some internal waterways. If you add Barr's leaks any loose sludge would maybe have condensed somewhere.
FWIW my advice would be: Drain and reverse flush engine. Refill system with plain water and a flushing agent . Rubn for 45 minutes. Reverse flush again.
If you have a head leak you may then have to add more Barr's Leaks.
madf
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small extract taken from the readers digest/AA book of the car 1974.........to clear a blocked radiator, drain and remove the radiator, replace cap and block off overflow pipe. turn the radiator upside down and pour about a cup full of household ammonia in through the bottom hose opening, fill with water until full, allow to stand for several hours, then drain carefully, turn radiator right way up and thouroughly flush through with clean water until it runs clear.
alternatively, soda crystals may be mixed with cold water in a non-mettalic container and used instead of ammonia, caution, the radiator will become hot to the touch.
maybe a bit draconian by todays standards, but it may save buying a new radiator.
billy.
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Dizzy,
didn't misunderstand you, just didn't express myself clearly enough.
What I was trying to get across was that changing/disturbing the airflow can have detrimental results. I've been told, but haven't checked, that the ECU in my Chevy switches the electric fans off above a certain speed because they actually restrict the airflow and it's better to let them 'freewheel'.
Similarly, a 'relatively' low efficiency crank-driven fan sitting close behind an electric unit may cripple both of them. (Is there a Fluid Dynamicist in the house?)
A really silly question for Chris now, but one that hasn't been asked.
Are the hoses OK? You don't have one that could be causing an airlock?
Kevin...
PS. Dizzy, you're right. The impellor is probably bronze.
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This evening I drained the system,part filled with water,added holts flush,topped up and ran the car for a few miles.When I opened the drain taps abit oflimescale and sludge came out.Irefilled with just water and ran the car,the temp went up to 90 but didn,t over heat.I have replaced the thermostat. MY problem is when i sit in traffic the temp rises,yesterday in my modern car I sat for 30mins without moving!.Any way I thank you all for your time and am heading towards giving the rad an overdue birthday present,it seems the system is partially blocked
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Kevin - thanks for the explanation. I now understand and agree. I didn't explain things clearly myself either. First I ran the electric fans without the crank fan but this didn't work so I refitted it. That wasn't much better so I reverted to the crank fan on its own.
In my case, the crank-mounted fan was low down and the twin electric fans were high up. I think you are right, they impeded each other -- stirred the air up rather than drawing it cleanly through the radiator.
Mapmaker - the point I was trying to make about lower temp thermostats in older cars is that an 82 degree start-to-open thermostat will need getting on for 100 degrees to fully open and this could lead to localised or general boiling in a low pressure system such as exists in older cars. As I'm sure you know, raising the pressure raises the boiling point.
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Couple of points here, if I remember correctly the fan set up on this is the same as a TR2-4a and is part of the balance/torsional damping of the crank. We have had a few (TR Register members) have cranks break on these after fitting electric fans AND removing the old ones. The jury is still out as to why but be warned it does happen. Also as someone has pointed out its not a conventional as in modern type of thermostat. It has a plate that once open blanks a port in the head and the engine SHOULD NOT be run with out a stat or with the wrong one. Most engines rely on the stat for correct water flow and can locally overheat if run without. Note that this engine is prone to cracking heads so even more important to run the stat and sort out any overheating. AFAIK the stats for these are A. B Expensive for the right one and B. only available in one temp.
Anti freeze is not a good conductor of heat it is their for anti corrosion & frost protection only. Max I'd run would be 25% no more. I suspect that the rad is partially blocked which running on modern fuel which increases engine temps or that the block is silted up. I'd run a tin of rad flush in it for a week then pull a hose off to dump the lot in one go. It may need a professional rad overhaul, which would mean it wuld be a modern uprated core. Finally when you did the head did you let the liners move? If it has that will cause overheating as well. As someone said most of this period of cars were marginal on cooling when new, now given modern fuels, faster running and xxx years of clag in the cooling system, no surprise that people have problems.
Finally post a question on the TR Register (www.tr-register.co.uk) forum as huge knowledge their on these ex-tractor engines....
Jim
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Have just been sorting similar problems on my 1942 car. Drained coolant, removed thermostat and reverse flushed, added cleaner (cant remember which make), ran engine for about 30 minutes, drained and flushed again and then filled 50/50 water/antifreeze. Also used a hose to clear all the flies and debris out of the radiator core.
Apart from all the good comments above about checking timing etc its always worth putting a compression gauge onto each cylinder. Low pressure can indicate a blown gasket which, if blown between the cylinder and the water jacket, can lead to overheating and coolant loss. Low compression can also point to a valve problem. These older side valve engines can be a bit prone to overheating if the exhaust valves dont seat properly. I would at least check the valve gaps but, depending on when the valves were last ground or lapped and also, depending on what fuel and mileage you have done since the days of leaded petrol, I would think about removing the head and checking the valves. My exhaust valves were not in very good condition in spite of having done only 6000 miles since a full rebuild.
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