PLUS 8s: There is an immense amount of nonsense about cooling this lovely engine.
:( All engines and their fueling systems have a temperature
range they are meant to run at.
Plus 8s came in two basic versions, Carb'ed and EFI. The former runs lower temps becuase of the regulatory time they were installed and the fact that carbs are inefficient enough to that the uncombusted petrol cools the engine rather than powering it. EFIs are more efficent producing a more complete burn. So the Plus 8 thermostat is set to open at 82C for carb'ed cars, EFIs open at 88C. This is additionally confusing with Morgans and many have their rad fan switches at the bottom of the radiator, where the coolant is coldest and yet the dash temperature gauge is installed at the top of the engine, where the coolant will be its hottest. (I experimented and had rad fan switches put both at the bottom AND the top of the rad.) The temperature difference is 4 to 5C and can vary more (or less) depending on whether one is stationary of moving. Of course, the temperature reading is best taken from the top, but one gets used to a chosen placement.
I like my BIG fan (early Morgan fans were inadequate..even the early Spals) coming on when the gauge reads about 98C, if the rad fan switch is placed at the bottom of the rad and 96C if the rad fan switch is at the top. BTW, the temperature sender is just to the left of the thermostat housing if you are standing in front of the car. It should not be confused with the EFI temperature sender.
Please ignore the claims of massive horsepower increases. These are
largely "pipe"-dreaming fancies...though a cooler engine can produce
more power and leaves more room for "tweaking" than one which is
already running hot because of an inadequate cooling system.
|WATCHPOINT: Stainless steel is susceptible to embrittlement. When that happens, they lose their ability to flex and crack instead. As the ONLY advantage of stainless steel is that it does not rust, (after all it discolors very quickly..a sure sign of embrittlement). Embrittlement happens to stainless steel at constant temperatures of 350C+. Your Morgan will produce exhaust temperature highs that will be much more than that. The ideal exhaust pipes are ceramic coated mild steel.|
|WATCHPOINT national habits: Ceramic coating has become the goto exhaust treatment in most of the automobile affectionato world. Australia, Canada, the USA. Exhaust wrapping is very much the poor man's solution there. However, it has never caught on in the UK or Europe to the same degree. I feel that this is because the first purveyors of ceramic coating charged SO much that they killed that market for themselves. Prices overseas are MUCH cheaper. But in every country, you will find habit rules rather than common sense. The trick is to rely on your logic. There are DIY systems available in the UK at a much lower price.|
|WATCHPOINT Ceramic coating color: There is no contest on aesthetics. Exhaust wrapping quickly becomes filthy and thusly characterizes the engine bay. Stainless steel quickly turns brown/purple. Ceramic coating can be chosen in any color, though I would caution you against a "chrome" look in ceramic coating as it quickly goes opague, a dull bluish grey.|
Carb'ed engines often run at a lower range than their EFI counterparts.
This is why they are less fuel efficient. For example, the Plus 8 runs
a thermostats with an opening temperature of 82C with carbs but 88C
STANT (Thermostat Manufacturer)