 |
PM |  | |
Quote | | |
Reply | | |
Full Topic | |
| Joined: | 03-12-2005 |
| Location: | Kingman, Arizona USA |
| Posts: | 532 |
| Status: |
Offline
|
[...]At idle it will stay about half way, but driving and especially on the interstate it will climb to about 3/4 or a little more.[...]
Depending on the exact temperatures involved, that sounds to me like normal behavior for a JH engine in warm weather. Under normal street driving conditions, coolant temperature will be about 100°F above the surrounding air temperature.
Engine operating temperature is also sensitive to ignition timing. If you set the timing at idle to somewhere between 8° BTDC and 12° BTDC, and plug the hose to the vacuum retard capsule, your baseline coolant temperature may decrease by as much as 20°F.
Some of the post-JH water pumps used in Lotus cars have improved impellers that offer much greater coolant flow. One of these, and a bit of smoothing to the rectangular coolant opening in the engine block, should eliminate virtually any cooling problem not caused by a mechanical fault or gross mis-tuning of the engine.