The “after” photo is what I had on my 2002 Plus 8. The black expansion tank where shown. 15psi cap on it and blank cap on the rad. The term “expansion tank” is very apt!
Correct. Well spotted. It is merely that this placement is no longer ideal as the earlier one, another concession to modernization forced upon the MMC. That is a very hot place to put a expansion/recovery tank. It is a manufacturer/ government cultivated illusion that internal combustion engines have changed significantly over the last 120 years. Still a varying number of pistons driven by air/petroleum/sparks producing heat et al.. (shrug) Far more driver aids now tho, along with regulation-driven weight.
By keeping this tank filled to the correct level it prevents air getting back into the system. That air is either trapped airlock expelled into the tank or fresh atmospheric air.
Yes..as it is not only the reservoir filled but the filled hose length between tank and radiator, which was muchly shortened by 2002. Air had to go a much longer way before they abandoned the Hotwire (3.9s) configuration. The less coolant in a system, the harder it is to cool or be effective. (duh). Same with motor oil.
I find all this stuff intellectually intriguing!! One can trace the route of all technological history, good and bad, by merely understanding its effect on trad Morgans.
I have no wish to soapbox an universal preference for expansion versus recovery systems. However, there are some cars/engines that are better suited to one than the other.
gmg
