Info needed: Morris C8 radiator

[pauldavies]

Guys there lies the conundrum "no thermostat", don't use them here in QLD but maybe I will need to find one! I purchased some bronze today and will make a new filler tube and castelation ring on Wednesday, I am borrowing a friends lathe to do the job. The spring I am sending to a company in Brisbane to make a stainless replacement as no-one does bronze springs anymore, I haven't overfilled with coolant as from your early advise Richard I just touched the core and at least 4 litres of coolant blows out so it is excessive and that is with stopping straight away. It is interesting that it blows as the temp gets to running temperature so the thermo theory could be correct. Any idea on spring tension?
Regards
Paul

[Mike K]

Originally Posted by pauldavies

I purchased some bronze today and will make a new filler tube and castelation ring on Wednesday,
Paul

OK sounds good . Bronze isn't cheap . You could try making a new filler tube from aluminium as a 'test run', doing this will also check your set up in the lathe. Then if the alu one fits OK , go for it with the bronze . I'm always nervous when machining a piece of expensive metal , one slip up and its junk

[Richard Farrant]

Originally Posted by pauldavies

Guys there lies the conundrum "no thermostat", don't use them here in QLD but maybe I will need to find one! I purchased some bronze today and will make a new filler tube and castelation ring on Wednesday, I am borrowing a friends lathe to do the job. The spring I am sending to a company in Brisbane to make a stainless replacement as no-one does bronze springs anymore, I haven't overfilled with coolant as from your early advise Richard I just touched the core and at least 4 litres of coolant blows out so it is excessive and that is with stopping straight away. It is interesting that it blows as the temp gets to running temperature so the thermo theory could be correct. Any idea on spring tension?
Regards
Paul

Hi Paul,
The brass ring should have a rubber sealing ring bonded to the lower side, is this missing on yours? Remember this does not seal the radiator cap, it only seals off the air gap above coolant in the header tank when you remove the cap to check the level, so you do not overfill.
Another thing that gets overlooked is the fan belt, is it gripping and adjusted correctly. Some British vehicles used belts of a different V angle to the standard A, B and C varieties. You may have to compromise, but worth checking as belt may be slipping at times.

[guy labbe]

I am a bit puzzled by this discussion. I have two Morris C4 for the moment and didn't find a thermostat in any of these two engines and even don't can find a notification about a thermostat in the workshop manual.

On my C4 the airlock valve was missing but luckily I did found a complete set up in Norway.

[guy labbe]

on the left side of the picture you can see the air lock set up.

[Mike K]

Originally Posted by guy labbe

I am a bit puzzled by this discussion. I have two Morris C4 for the moment and didn't find a thermostat in any of these two engines and even don't can find a notification about a thermostat in the workshop manual.

On my C4 the airlock valve was missing but luckily I did found a complete set up in Norway.

Even If a thermostat is not an original item in the 4 cyl. engines , it is worth Paul trying a thermostat as an experiment because it might be the answer to his issue. Are there any more of those NOS parts from Norway available ? It has been ages since I last heard from Rolf.

Without a thermostat in the C4 , there must have been some kind of restriction in the coolant outlet from the engine, limiting the coolant flow to the header tank . The thermo syphon system requires that there is a significant temperature difference between the engine and the radiator , this difference aids the coolant flow . If the engine and the radiator are at the same temperature ie no thermostat fitted , then that is not ideal and can lead to problems

[guy labbe]

That's a fine answer but what about the non existed thermostat in the workshop manual ? for sure i think a thermostat is the best way to go but on these engines I have I don't can really find the provision to fit a thermostat ??

[pauldavies]

Hi gentlemen and where do I start, machining isn't a problem as it's been my trade since I was 15 so no issues there it was just getting use of a lathe, the current castelatated ring has a rubber seal although the reason I am making a new ring is the one I have is distorted due to hammering the thing to remove it over time also I will make the funnel with a thicker flange to stop warpage. I have lapped the ring but where the rubber seal sits it has high spots under the castelation points and these high spots can prevent a good seal. I also have new rubber to make a new seal when all is done, in regards to the thermostat it does mention one in the manual but for only "quick warm up reasons" and not for any pressure holding in fact the engine has a bi-pass pipe that goes around the thermostat. I will send my spring to a company in Brisbane on Monday as they reckon they can make a stainless replacement, not sure the new pressure of this spring will have any adverse effect but my reasoning would be it will greatly improve the seal at this point. Fan belt is working and no slippage noted. The manual doesn't show the thermostat but does mention it so I for no other reason than elimination of a problem would like one if anybody knows where?
Thank you all and I am open to all advise, thanks for the photo Guy and my assembly is the same as yours.
Paul

[Richard Farrant]

Originally Posted by pauldavies

I will send my spring to a company in Brisbane on Monday as they reckon they can make a stainless replacement, not sure the new pressure of this spring will have any adverse effect but my reasoning would be it will greatly improve the seal at this point.

Hi Paul,
The only thing that lifts the sleeve off its seat against the spring is the screwing down of the radiator cap, to allow steam to escape, so spring rate would not appear to be too critical.

regards, Richard