Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Thermostat - which to buy

The thermostat on my Morgan has decided to remain closed No wonder it was running hot!
I have found a replacement on Rimmers site but I have a choice of 3.
One is identified as Aftermarket for £3.78, another is OEM at £18 and a third Genuine Landrover at £22.34
Rutters have one for £16.44
Needless to say they all look the same although I am reluctant to get the cheap aftermarket one.
Any thoughts?

From the perspective of operation, a wax type thermostat when it fails normally fails closed, an alcohol type thermostat usually fails open ( so they were considered the better option ). Alcohol types used to be slightly more expensive than the wax type, but wax types are more common.. That might explain cost, but it just might be a retailer milking the cost.

I used to drill 3 small holes in the 'stat flange to allow some 'bleed' if it failed shut, ok the engine takes a little longer to warm up but used to be a bit of a hot summer / racing failsafe

The one in my Plus8 had these holes in it. I took it out to flush the system when replacing the coolant. Put it back in. It is a good idea as it allows a small flow through under closed conditions.

A single 2mm hole in the thermostat rim positioned at the top also aids bleeding coolant after refill when thermostat otherwise closed. Some thermostats are supplied with hole in rim already and tiny split (jiggling) pin in same which aids the bleeding I'm told.

Make sure when you fit the thermostat you put the hole at 12 o'clock.

Not heard that before, please explain.

Or perhaps more important ensure the drilled hole is oriented on supporting flange to be at highest point to aid self bleeding. If the thermostat flange lies in the horizontal plane it makes no difference of course.

12 o'clock standing where?🤔