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Post by redherring on Sept 2, 2015 18:29:16 GMT
Hi Guidedog, my answer is yes to all of the above! I am only 25 miles from Cromer cliffs if that was to form part of your solution!
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Post by guidedog on Sept 2, 2015 20:18:29 GMT
Hi Guidedog, my answer is yes to all of the above! I am only 25 miles from Cromer cliffs if that was to form part of your solution! I came to this conclusion because what happened to me. I recently had a new camshaft fitted by local garage. I had the same problem as you, Not trusting the garage I dived in to the block to find out why. The camshaft timing had been misaligned it was to far advanced. I reset the timing myself had no problems since. I looked at this way,as the revs increase so does your ignition timing so it starts to catch up with the camshaft so you a have better timing set up. Hence no over heating at higher revs. At tickover its to far out. The conclusion I came to maybe wrong I am not a mechanic. But worked it for me. I hope this works for you, reading the posts I come to the conclusion your problem has to be mechanical. You have done everything else. Good luck Bob
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Post by enigmas on Sept 2, 2015 22:13:29 GMT
Redherring if your car overheats whilst static in traffic then you can formulate remedies for the system in the driveway of your home. It doesn't' matter where it remains stationary, if the problem is as you say. A primary reason for running hot is usually too little advance at idle. (Running it a few degrees BTDC cause most of the energy from the fuel to heat the block) So what is the initial idle setting at 700 - 800 rpm? ( There should be no dynamic advance at idle speeds).
Try doing this as well. Start the engine, handbrake on, chock the wheels, put it into drive (only at idle speed) then raise the bonnet. See how long it idles like this before the temperature rises to an unacceptable level? Then wait till the engine cools again and do the same procedure with the bonnet closed. Compare the difference. This test provides a starting point.
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Post by guidedog on Sept 3, 2015 8:57:37 GMT
I agree with Enigmas's comments, indeed I went through all this myself, ranging from 6 degree's to 14 degree's BTDC. I am know settled at 10 degree's.
The advantage I had over you Redherring was that I only had one thing done. The temperature was OK before but not after. So I had reference point to start from.
Considering the amount of monies you must have so far a couple gaskets will be pennies in comparison what you have spent so far. Time spent 4 to 5 hours.
The only other thing I have sought out is top end noise. It would appear my camshaft & followers were not run in. That's another story.
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Post by gingerbeer62 on Sept 3, 2015 9:04:09 GMT
I have a Kenlowe fan on mine, fitted behind the radiator and very close to it. It does struggle a bit to bring the temperature down in traffic although it is quite old. When the car is moving it never needs the fan. The problem in the summer is that the fan is drawing in warm air to try to cool the radiator, so it will always be a problem and that is why modern cars have such powerful cooling fans. Do not have more than 40% antifreeze as it is thicker than water and so does not go around the system as quickly I fitted an electric fan to my Rover as well. 16" but put it on the front as a push. I think that fans work more efficiently pushing air anyway, but the room at the back was just too tight. After all, that is the way your radiator works with air pushing through it. Pulling air, I think is felt to be the norm only because traditionally the radiator fan is driven by the engine. Paranoia then set in and I was never sure what the temp was with the "highly accurate" Rover gauge. So I fitted a small digital gauge which reads very well. The probe is taped to the top hose with some black insulation foam over it and then bound with a nice thick black tape. You can hardly see it and the whole thing puts my mind at ease with regards to temp. Reading these posts with interest and I have to get back to my point - how does anyone know how hot the offending engine actually is ? I fitted a digital gauge, available very cheap on e-bay and double checked it's accuracy with a remote laser pointed type. Although the laser type can read inaccuracies depending on the surface reflectivity. All the checking can be done on the driveway. If the temp rises to normal, climbs above it then starts to cool down a bit, then you know that the thermostat is doing it's job. It is not a good idea to run an engine without a thermo as it may run far to cool in the winter time. After all, it is a heat engine !! Sat in traffic is not much different to sitting on the drive (depending on ambient temp) and will both prove if the heat exchange system is doing it's job. If you can sit on the drive idling for an hour with a reasonably steady temp in the 80s then the system stands a chance under load as it has added cooling (heat exchanging) with the air pressure increased on and through the radiator, hence more air flow and more heat exchanging and of course a greater coolant flow. I don't buy the perceived problem with the hot air somehow getting "trapped" under the bonnet, after all the underside of the car is all open and the air will flow down there to escape from the space. The space is after all slightly "pressurised" either from the engine fan or/and the air flow if car moving. Certainly don't worry about removing the under bonnet blanket. In summary, if anyone is having a problem it is far more likely that it can only be one or more of the following. Radiator - partially blocked internally, fins getting blocked impeding air flow, radiator losing coolant from faulty cap. A back flush may help. Pump - pump seems to be very robust. Engine - Engine channels could be partially dunged up if treatment has not been used in the past. A good backflush on a cold engine would help. Thermostat - faulty, either not opening early enough or not enough to obtain full flow. Do not worry about the perceived small space that the coolant appears to have to get through. It is basically a plate valve and a plate valve only requires to open 1/4 of the hole diameter in height to allow full flow. Coolant - Low ? The heater is above the level of the radiator and liquid from the heater will run back into the radiator when car is stopped say, overnight. I have found the best way to check the radiator level is when after the engine is cold (overnight?) and then if you have a look in the radiator the level will be up. Start the engine and the level will drop. Top up as required to the normal level and replace the cap. After the engine gets hot, check the cap is not leaking. I lived in West Australia for some years and between my dad and I we had 4 Rover P4s. Although a different engine to the one in question, I don't recall any overheating problems. Rovers were built to be exported abroad to Africa etc. I do recall problems with erosion of the head water space into the combustion space due to neither of us not knowing the value to water treatment in those days. "Why would I want to put put anti freeze in my engine in Australia?" View AttachmentView AttachmentView Attachment
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Post by enigmas on Sept 3, 2015 13:26:55 GMT
Some interesting points you've made there gingerbeer62. Hot air generally doesn't escape an engine compartment unless provision has been made for this! Early car designers were well aware of it and used louvres to extract heat both passively and dynamically (car moving forward through the air). Designers seemed to have lost sight of this from the 1950s onwards when the fashion was for lower more enclosed bodies and bonnet lines. The louvres incorporated in the bonnets of E Types were placed there for good reason. Unless moved by a dynamic force hot air tends to rise and fill a space and doesn't evacuate downwards (consider a hot air balloon). A moving car produces air pressure in front of it and if the design is adequate the air will be pushed through the radiator (not around or over it) as is the case with many cars of the 50s - 70s. If the under bonnet design is considered, hot/superheated air has a chance to exit somewhere...and that shouldn't be down and through the transmission tunnel. Most modern cars evacuate hot air from the engine compartment through an open area at the rear of the bonnet just in front of the windscreen. This is not an accident of design! The Rover P5 bonnet is well sealed at the rear. So a P5B sitting in traffic for an extended period of time tends to pool heat under the bonnet. This heat soak causes issues with the carburettors, fuel lines and bowls, until eventually there's a fuel vaporisation problem. Not forgetting that the air filter snorkel is also drawing in this super heated air affecting the mixture! Add to this, that the P5B runs the transmission cooling line through the bottom of the radiator adding extra heat to the coolant. As for the thermostat, coolant has to dwell in the radiator for a specific time or a 'heat exchange' can't occur! If the thermostat is removed, there is not a sufficient period of time for the hot coolant to be reduced in temperature. The thermostat also fulfills another function in that it provides resistance for the water pump to work against. This increases the pressure within the block and also raises the boiling point of the coolant.
Another issue (generally in modified cars) is if the block has been fitted level in the engine bay. If so, steam pockets can form at the rear of the heads causing the radiator cap to constantly blow out and relieve the 'steam' pressure within the system. If the block is raised at the front air pockets will naturally migrate forward to the radiator, typically self bleeding.
As for mechanical fans (efficient ones) these produce a continuous stream of air over the engine and keep vital components free of heat soak. Ever notice how brittle many of the engine compartment components in some moderns become.
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Post by Deleted on Sept 3, 2015 13:41:20 GMT
Crikey, something else to worry about!
It's ideal Rover weather at the moment in SW England. About 15c. I was Rovering out and about in heavy traffic yesterday and the ambient was about 18c. No problems.
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Post by gingerbeer62 on Sept 3, 2015 14:32:07 GMT
Some interesting points you've made there gingerbeer62. Hot air generally doesn't escape an engine compartment unless provision has been made for this! Early car designers were well aware of it and used louvres to extract heat both passively and dynamically (car moving forward through the air). Designers seemed to have lost sight of this from the 1950s onwards when the fashion was for lower more enclosed bodies and bonnet lines. The louvres incorporated in the bonnets of E Types were placed there for good reason. Unless moved by a dynamic force hot air tends to rise and fill a space and doesn't evacuate downwards (consider a hot air balloon). A moving car produces air pressure in front of it and if the design is adequate the air will be pushed through the radiator (not around or over it) as is the case with many cars of the 50s - 70s. If the under bonnet design is considered, hot/superheated air has a chance to exit somewhere...and that shouldn't be down and through the transmission tunnel. Most modern cars evacuate hot air from the engine compartment through an open area at the rear of the bonnet just in front of the windscreen. This is not an accident of design! The Rover P5 bonnet is well sealed at the rear. So a P5B sitting in traffic for an extended period of time tends to pool heat under the bonnet. This heat soak causes issues with the carburettors, fuel lines and bowls, until eventually there's a fuel vaporisation problem. Not forgetting that the air filter snorkel is also drawing in this super heated air affecting the mixture! Add to this, that the P5B runs the transmission cooling line through the bottom of the radiator adding extra heat to the coolant. As for the thermostat, coolant has to dwell in the radiator for a specific time or a 'heat exchange' can't occur! If the thermostat is removed, there is not a sufficient period of time for the hot coolant to be reduced in temperature. The thermostat also fulfills another function in that it provides resistance for the water pump to work against. This increases the pressure within the block and also raises the boiling point of the coolant. Another issue (generally in modified cars) is if the block has been fitted level in the engine bay. If so, steam pockets can form at the rear of the heads causing the radiator cap to constantly blow out and relieve the 'steam' pressure within the system. If the block is raised at the front air pockets will naturally migrate forward to the radiator, typically self bleeding. As for mechanical fans (efficient ones) these produce a continuous stream of air over the engine and keep vital components free of heat soak. Ever notice how brittle many of the engine compartment components in some moderns become. I have had thoughts about the engine air intake as well and have been considering an option of re-routing the intake to below the engine (as in a lot of modern cars) or at least lower down where it is a bit cooler. Some nice looking pipe should do it. As we all know, cooler air coming in is denser and more efficient as far as the engine is concerned. Against that, have you considered the vast amount of air that is being consumed/removed from the hot area above the engine by the engine intake. That surely is an advantage for having the intake over the engine. Seems like it could be a trade off. I may try the repositioned intake late on and see how it goes. Cheers Colin
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Post by redherring on Sept 3, 2015 15:17:35 GMT
Sorry, can't always reply quickly as I'm at work! Firstly, the 4.6 is mated to the original BW box, dare say it wouldn't like it if I used the engine to it's full potential, but I have no intention of doing anything other than classy cruising! Had the box completely overhauled anyway, so can't foresee a problem. The cam timing issue is interesting, presume it's mounted on woodruff key so yours must have been at least one tooth out on sprocket? Did this affect the smooth running also? Tend to agree with you though,might try messing with the ignition timing before I pull front cover off. Thankyou very much for that suggestion, food for thought especially with modern fuels burning so hot. Just to make clear once more for all contributors,not only is the engine brand new but also pump,hoses,radiator. In fact, it's all new!!
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Post by guidedog on Sept 3, 2015 16:18:16 GMT
Hi Redherring, I'm afraid I confused my garage I got an uprated timing chain kit which was adjustable, typical me I went OTT. So the timing was less than one tooth out.
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Post by redherring on Sept 4, 2015 11:13:46 GMT
Adjustable timing chain eh? Sounds interesting, does it involve cable ties being tightened or slackened?
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Post by guidedog on Sept 4, 2015 12:16:55 GMT
No don't be silly, do you remember the little clips on bicycle chains. Well there you go.
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Post by Warwick on Sept 5, 2015 4:58:49 GMT
... "Why would I want to put put anti freeze in my engine in Australia?" It snowed in the Stirling Ranges in WA a few weeks ago!
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