either cavitations in the water pump, running lean,
or static air flow as the air passing under the car
limits air through the radiator.
fixes.... larger water pump pulley, richer needles
in the carbs, lower the nose and raise the rear end
a bit to minimize the air under the car pressurizing the
compartment which can limit the air 'through' the
rad. from doing it's job.
----- Original Message -----
From: "James Schulte" <email@example.com>
Sent: Tuesday, May 10, 2005 7:07 PM
> Friend has a 69 MGC and his temp gauge is moving from N to 3/4 H when he
> doing 70 on the highway. It lowers to N when driving more civilized. Has
> rad that was checked out OK and a new 13 row oil cooler. Thermostat is a
> and new. Any thoughts?