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Jeff Shackell
United Kingdom
42 Posts |
 Posted - 02/12/2011 : 21:43:22
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Hello all
In this cold (er) weather I am finding that the PB water temperature does not get very high, it made it to about 50 today. The oil temperature remains barely off the peg. Is this normal at this time of the year or should I be seeing higher temps? I do have a muffler for the radiator on the PB but have not worked out how to put in into place yet.
The J2 on the other hand runs very warm, when its running, which it is not again at present.
Is there something very different with the J2 and PB engines that would determine that the J2 runs hotter?
Sorry, basic questions, still finding feet!
Many thanks
Jeff
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David Allison
United Kingdom
665 Posts |
Posted - 03/12/2011 : 07:16:19
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Jeff
You may find the radiator on the J2 is blocked - however the standard J engine doesnt have a water pump and the rad is smaller so that may account for some of it.
I always blank off at least 1/2 the bottom of a MMM rad if the ambient temp is below about 10 degrees C.
I use strips of tank tape - simply removing strips as the engine gets hotter.
The oil temp will come up eventually as the engine warms up but the sump is a very effective oil cooler and with a low rad temp there is nothing to keep the oil warm.
Regards David |
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JMH
United Kingdom
911 Posts |
Posted - 03/12/2011 : 08:36:31
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Jeff,
Your J2 temp guage lies to you! Without a water pump, the engine works on a thermosyphon principle, so the outlet at the head will always be much hotter than the base of radiator. If you warm up a J Type at fast idle, you can get 70deg on the guage with the bottom of the rad only just getting warm. The down side of this is that your block will still be cold! I had it drummed into me at an early age NEVER rev a J until it's properly warm through. You should always see well over 80 deg, if not investigate & consider a muff if necessary, we use one in Winter for "normal" running, but you don't need one "round town" as it gets hot enough.
On the flip-side, if it's clogged in any way, you can boil a J when the engine temp is still low, as all you are doing is boiling water off the head.
JH |
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George Eagle
United Kingdom
3240 Posts |
Posted - 03/12/2011 : 17:45:36
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Hi Jeff
This subject was well covered in the past - including the fitting of a modern thermostat.
You should be able to use the search facility to access the discussion.
George
NA0960 fitted with a thermostat! |
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Jeff Shackell
United Kingdom
42 Posts |
Posted - 03/12/2011 : 19:09:52
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Thank you very much for your replies. I have now had a look again on the topic in past posts.
On testing the J2 today and with no misfire problems after going round and round the town, I could feel that the radiator was slightly hotter at the top than the bottom, but it was hot at the base. Should I consider then that the radiator is not blocked and doing its best? Running temperature was up to 85 and sometimes 90, even today. The misfire issue continues to baffle me, it has consistently played up, even when I thought I had cracked it. But today no misfire. It has been suggested to me that this is because it is colder and the distributor and the like have not really warmed up, so the potential for condensation in the distributor is not there. It all seemed warm enough to me in the engine bay.
So with the PB that runs very cool in the winter I have it would seem an MG for winter and another for summer. I knew I needed two cars!
Regards
Jeff |
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bahnisch
Australia
674 Posts |
Posted - 04/12/2011 : 10:01:27
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| Jeff, I have resisted joining in on this topic but coolant temperatures have long intrigued me. All of my cars have fairly new radiator cores but seem to run at vastly different temperatures. All are thermo-syphon. My F-type Magna (with new, modern core) seldom goes above 80C whereas my 1912 Rover (also with a new, modern core behind the honeycomb) runs at about 90C and boils on long hills even on a cool day! It holds buckets of water so topping-up is not necessary. My PA (with original honeycomb core) used to run at 90-odd C but never boiled as I recall. All seem to have suitably-sized radiators, it must be something to do with flow? Thermo-syphon was quite a good idea, I believe that Ford Tens used it well after the war! |
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