...my standard tune mid 80`s + 8 has not ever overheated even in one of the hottest days that Italy had experienced while touring there a number of years past.
You may be interested to know that my tweaked 4.8 EFI nor my UK tweaked 4.6 EFI have never overheated in the says type of days. Of course, they were altered by myself not to, despite double the bhp.
The only occasion I boiled over when I was using an engine identical to yours (save EFI) rather aggressively
in the Dordogne on a day in 40C+. However, many EFI Plus 8s do overheat (along with Triumph Plus 4s).
The goal of the community should be to find out why many do and ours don't. That would be of great interest to the 3.7 Roadster crowd and so many other post-carb LR Plus 8s. I have given that a lot of thought.
BTW, our 3.5 engines (all of them until 1993ish) had a
design defect that encouraged blown head gaskets and were using tin rather than the later composite gaskets. That being said the 3.5s were more solid blocks than the later variants
(though Morgans did not have enough load to be effected by the later block variants or the cracked block slipped liner plague that ended the engine). Incidently, you are confirming the vital differences between carb'ed and EFI. In the case of your car, it is not simply lower bhp,
as Weber 500 fitted engines can achieve almost the bhp of a L-Jet 3.5 according to Hardcastle's dyno testing and higher than stock Hotwires and GEMS. People often forget that the less efficient burn of a carb'ed car is NOT wasted. The engine uses the unburned fuel as for unintended cooling factor. That is why your car has a thermostat opening at the lower 82C. If I used a 82C thermostat, it would NOT effect my running temperature..it would merely take longer to get where the EFI system wants to be. The key here is that the stock Plus 8 cooling system of the mid-1980s could cool YOUR car but not a concurrently made EFI Plus 8, for more than a decade afterward.
That is what should be pinned down. We two, for very different reasons, are not having any issues. But we should help others. As you state: "Yeah cooling Morgans of all types has ever been a hot topic...." (-: This recently come into focus again with the appearance of well-reviewed Morgan aluminum radiators from China, appearing everywhere at 25-35% of the prices well-known suppliers. Sadly, like Morgan aftermarket rads, they copy the traditional designs that don't work well.
Fortunately I am currently not in need of replacing either of the caps on my old +8 at this time,
If you are properly using an expansion system, new caps are merely a question of how safe you want your system to be for the extra few pounds it costs. Inevitably, an expiring cap (spring or flanges) expresses itself in failure. I carry spare caps in all my Morgans.
gmg
