JCK,
Since you are U.S. based I will offer some suggestions. Temperatures in the U.S. in the summer are generally much higher than those in the U.K. or Europe aside from the odd day or so.
I have a 58 +4 which I bought in Hong Kong in 1972 so have quite a lot of experience running in very hot climates---I now live in Arizona where a 115 F day is not abnormal. This car is road registered, but has been a vintage racer for over 40 years. It is slightly overbored and runs a higher compression head, both contributing to higher operating temps.
Some suggestions, moving from the cheap and easy on up:
- Flush cooling system, opening all the taps on engine block and bottom of rad.
Check condition of hoses. Run engine while flushing radiator.
Check condition of radiator cap. Add a full bottle of water wetter after refilling.
- Old Morgans did not come with closed system overflow. Consider putting in a
simple overflow tank. One with a drain at the bottom, over time you will get a lot
of sediment to drain out.
- Cut a piece of heavy rubber sheet width of radiator and about 10-12" wide and
affix this to the bottom crossover bar and back under the radiator using an
alloy bar and bolt to the bottom of the two radiator mounts. This creates a
block and forces air up thru the radiator.
- Call up the guys at Morgan Spares and order part # 500-838 cowl box scoop.
This replaces the existing box and directs air up into the radiator. Powder coat
it first if not already coated.
This ends the simple/cheap approach.
- Install an alloy radiator. Readily available from Morgan Spares as well.
- Take off the old belt driven fan and install an electric fan, puller if you have
space or pusher if you do not. I have a Kenlowe pusher on the 58 and a
puller on the 86 +4. Installed in 1976 and still going.
From 1972 to date I have never had overheating issue. I ran 5,000 + miles from Boston to Sacramento on the Great American Race--no issues.
Do one thing at a time so you can measure results.
Lots of other things you can do, such as a finned alloy sump but get progressively more expensive.
One thing I have found. My engine runs cooler and better with NGK BP7HS spark plugs. Runs much better than with Champions or even the NGK BP6HS plugs.
No explanation for this---just trial and error.
Good luck.
TS
