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Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 11:01 am
by simmit
MB50 engine cooling seems no better than adequate in UK conditions but I'm unsure how it would cope on a fast road in Europe with hot summertime conditions so would appreciate comments.

MB50 rad was removed and thoroughly back-flushed, a new thermostat fitted (genuine Ford which was tested and opens at 88C) yet the typical engine running temperature on a fast run is 95C (and slightly higher on a hot day), the temp gauge has been tested not faulty. Perhaps 95C thereabouts is not critical but my view is that if the cooling system cannot contain temperature at 90C (stat. fully open) then it must be suspect and likely at some time to give grief.

Having experimented with airflow to the rad. and concluded that without major alterations little can be done to establish a more laminar efficient flow (for better effect) I'm coming to the conclusion the rad itself must be improved.

Rad frontal area cannot easily be increased unless it is laid close to horizontal (which, provided reasonable airflow through, ought not be a problem). Has anyone tried that?

Alternatively, I'm told modern design aluminium radiators can now be made more efficient than older design copper/brass rads. Has anyone tried replacing the original rad with same/similar size ally one?

Any other views on the subject?

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 11:08 am
by scimjim
Simply back-flushing a rad gives no real indication of the internal condition. I suspect you simply need a new rad/core?

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 11:20 am
by ScimmyMike
Presumably the fan cuts in then out when stationary, my 6b ran hot and occasionally did a kettle impression, re-cored radiator and since then it was fine no matter what the weather sat there at an indicated 90 all day with fan cutting in and out as it should do, as Jim said it's probably silted up by which I mean the silt is bonded to the core tubes and flushing won't remove it, it's down to lack of use compared to a modern car combined with cross flow radiator, this I was told by me rad re-core chap and it does make sense, if the cars constantly in use as a daily driver then the silt etc doesn't get chance to settle out.
Had a 2nd re-core after a leaking rad and despite annual flushes the bottom 1/3rd or the rad was already 25% silted up and that's after 5 years.

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 11:34 am
by simmit
scimjim wrote:
Wed May 16, 2018 11:08 am
Simply back-flushing a rad gives no real indication of the internal condition. I suspect you simply need a new rad/core?
Fully accept your point. Though the rad was done by rad specialist who said it was fine.

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 11:53 am
by peter freeman
The temp on our MB9 rarely gets to 90deg. Have you still got the two speed fan fitted - according to the first owner of MB9 a bigger / better fan was fitted before he sold it on

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 12:10 pm
by simmit
ScimmyMike wrote:
Wed May 16, 2018 11:20 am
Presumably the fan cuts in then out when stationary, my 6b ran hot and occasionally did a kettle impression, re-cored radiator and since then it was fine no matter what the weather sat there at an indicated 90 all day with fan cutting in and out as it should do, as Jim said it's probably silted up by which I mean the silt is bonded to the core tubes and flushing won't remove it, it's down to lack of use compared to a modern car combined with cross flow radiator, this I was told by me rad re-core chap and it does make sense, if the cars constantly in use as a daily driver then the silt etc doesn't get chance to settle out.
Had a 2nd re-core after a leaking rad and despite annual flushes the bottom 1/3rd or the rad was already 25% silted up and that's after 5 years.
Interesting, the 6b rad is actually thinner then the MB so what do we conclude from that?
That aside, for the extra cost would a modern design ally rad be better bet than re-core existing?
And, if new rad is contemplated then would vertical flow be better than cross-flow?

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 12:29 pm
by gtcse8
Gonna be expensive with a new Rad.
Don't forget it incorporates the Oil cooler too.

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 12:40 pm
by simmit
peter freeman wrote:
Wed May 16, 2018 11:53 am
The temp on our MB9 rarely gets to 90deg. Have you still got the two speed fan fitted - according to the first owner of MB9 a bigger / better fan was fitted before he sold it on
If everything working OK the fan ought not be operational over say 30-40 mph, I believe, and I have problem(?) at speed.
As MB9 works fine then unlikely much wrong with basic design so I'll not waste time trying to improve it. From discussion so far, most probable MB50 rad core is in need of attention. Other possibilities I suppose are (1) engine waterways blocked or (2) water pump dodgy but lets hope not!

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 12:42 pm
by simmit
gtcse8 wrote:
Wed May 16, 2018 12:29 pm
Gonna be expensive with a new Rad.
Don't forget it incorporates the Oil cooler too.
No oil cooler on MB50.

Engine cooling (rad. etc.)

Posted: Wed May 16, 2018 12:47 pm
by simmit
ScimmyMike wrote:
Wed May 16, 2018 11:20 am
Had a 2nd re-core after a leaking rad and despite annual flushes the bottom 1/3rd or the rad was already 25% silted up and that's after 5 years.
Makes me wonder what the coolant passages in the engine itself are like if the rad silts up that quickly.

Engine cooling (rad. etc.)

Posted: Thu May 17, 2018 6:39 am
by DARK STAR
It helps if the hot air can get out of the engine compartment ...

Engine cooling (rad. etc.)

Posted: Thu May 17, 2018 11:04 am
by simmit
DARK STAR wrote:
Thu May 17, 2018 6:39 am
It helps if the hot air can get out of the engine compartment ...
That's cool!