New theory re overheating - poll needed?

[GrUmPyBoDgEr]

Going back even further; the car my Dad drove when I was a small lad, was an old 1932 Standard little nine.
That had niether pump nor thermostat, pure thermosyphon.
However the radiator was pretty big & I don't remember any cooling problems except for leaks in the old Rad'; often cured with "Coleman's mustard powder"
The big end bearings on the other hand were an annual job; often on the road, with a spare set of pistons complete with freshly leaded con-rods wrapped in newspaper in the rear seat footwell alongside a 5 gallon tin of oil & a tube of Bostik (Sp.?)
An easy job, just meant dropping the sump & threading the rods & pistons around the crankshaft.
Yes honest, I was the lad passing him the spanners
BMC, Leyland & finally Rover stuck to the system we know in our Elans practically until they were taken over by BMW
I can't remember filling problems on the Mk 1 Lotus Cortina that I owned for a couple of years. Admitedly I only had the head off once; due to a burnt out exhaust valve. Perhaps I was lucky in getting the coolant fill right.
As far as I can remember Ford introduced the modified thermostat housing for the "Escort" but I don't know why or if it was for the Mk1 or whatever.
Elanintheforest will know, won't you Mark
The suction trick you mention is in fact the production method used at BMW for all of its cars.
The system is subjected to a partial vacuum & the coolant is sucked up into the system. 100% every time & quick.
That's something that some dealers couldn't manage during servicing, the E39 5 Series was a real pain as I remember, but so was the coolant system Designer

Have a nice weekend
Cheers
John

[JJDraper]

You may be interested in the attached picture showing the rad fill point blocked up with a new cap at the thermostat, using one of Cliveyboy's units. Rad is also slightly modified to allow quick & easy removal (not me, some PO but works really well..).

Jeremy

PS taking next week off to really get stuck in to the rebuild.

[twincamman]

my car tossed the fan belt on the Q.E. a few years ago and I made it home 40 miles at 60 mph with the fan on [70 mph set the temp gauge rising too high] appears the cooling system set up a thermal inversion - my theory is the timing must be spot on and you will have no overheating grief -ed ORRRR your rad cap may be used up ---change it as the spring gets old and cant seal for the temp -- theres a pounds to temperature relationship ----ed

[65 Lotus]

I run a 180 ?F (82 ?C) thermostat in my S1 and have never had any issues with overheating. It has the original radiator with the filler on the top tank, and I run a 7 psi cap. Nothing installed on the front grill.

The only modification to the cooling system is a light-orange colored plastic fan installed on the water pump sheave rather than the standard 2-blade twisted metal component. I believe the installed fan is off a Europa or perhaps an Esprit (it was that way when I bought it). It does have a Lotus part number on it.

[Rob_LaMoreaux]

With the stromberg engine I used to run hot even with a three row radiator and the air blocks around the radiator.

After I tuned the strombergs to no run lean I didn't overheat.

With the weber engine I haven't oveheated and it runs a bit rich.

So one reason for overheating is running lean, but then everyone should know that running lean means the engine runs hotter.

Rob