11-02-2021, 10:07 PM
I've been doing a light re-commissioning of an Austin Seven (I've known the owner for a while, but I've recently taken it over) and got to the point this week of driving it round the block.
It cut out the first time round, but after I put some more petrol in it went round twice nicely, before starting to steam... (it was -3 deg C ambient).
The radiator isn't the best, and the fan is spaced a little far away possibly.
Also, there's a little oil in the water (though no water in the oil) so I suspect I'll need to take the head off and look at that (one of the head studs sheared off years ago).
I ran it up again stationary at a lively tickover, and it took 6 minutes for the rad water to go from 5 deg C to 80 deg C in the rad header tank.
the bottom of the rad was pretty much cold.
I've taken the hoses off and back flushed the rad and the engine expecting to get a tonne of crud out, but got nothing (Indeed the coolant in there was really very clean).
I happen to have a thermal camera that connects to my phone - using that the engine seems to be warming fairly evenly (I was expecting no. 4 to heat up quicker/get hotter):
The rad seems is stripy and WAY hotter in the header tank than anywhere else. Can it be blocked such that water won't circulate through it by thermo-syphon, yet flows freely when a hose is attached?
I realise that the thermosyphon will be creating a very low pressure difference...
Does anyone have any good diagnosis tests? Or do I have enough evidence already?
Thanks,
James
It cut out the first time round, but after I put some more petrol in it went round twice nicely, before starting to steam... (it was -3 deg C ambient).
The radiator isn't the best, and the fan is spaced a little far away possibly.
Also, there's a little oil in the water (though no water in the oil) so I suspect I'll need to take the head off and look at that (one of the head studs sheared off years ago).
I ran it up again stationary at a lively tickover, and it took 6 minutes for the rad water to go from 5 deg C to 80 deg C in the rad header tank.
the bottom of the rad was pretty much cold.
I've taken the hoses off and back flushed the rad and the engine expecting to get a tonne of crud out, but got nothing (Indeed the coolant in there was really very clean).
I happen to have a thermal camera that connects to my phone - using that the engine seems to be warming fairly evenly (I was expecting no. 4 to heat up quicker/get hotter):
The rad seems is stripy and WAY hotter in the header tank than anywhere else. Can it be blocked such that water won't circulate through it by thermo-syphon, yet flows freely when a hose is attached?
I realise that the thermosyphon will be creating a very low pressure difference...
Does anyone have any good diagnosis tests? Or do I have enough evidence already?
Thanks,
James