electric fans

[rsmlap]

John, thanks for the very good info on C3 cooling. My 80 runs around 200 at low speeds and idling, but creeps up around 220 or above on the freeway. Seems to me that it should be the reverse. This is with the AC off. Have only had the car a few months and have not used the AC enough to know what it will do. It does have a stock radiator so I think maybe that would be the first place to look. Also it has a 5 blade fan instead of a 7. The engine is from an 81.

 

[JohnZ]

Generally speaking, if the engine runs at normal temp around town but heats up on the highway, either the radiator has lost a lot of its efficiency (age, internal scale/corrosion, etc.), or there's a problem with airflow through it. Your '80 was designed as a "bottom-breather", with most of the highway cooling airflow deflected into the radiator from underneath the front fascia via the plastic air dam under the fascia. If that air dam is damaged or missing (they don't get along well with speed bumps or parking lot blocks), the radiator isn't getting the highway airflow it needs. If it's intact, and the A/C condenser and radiator are clean and free of debris (leaves, mud, bugs, etc.), chances are the radiator is the problem. Nobody ever expected the original radiator to last more than 10-15 years at the most.

 

[rsmlap]

Thanks John. the air dam is missing about 8 to 10" on both side of center. Looks like that would be a good place to start.

 

[Vette/Berlina-coupe]

-Dido on-- "so you're the one"...

-jus trashcan JohnZ's beloved albeit problematical galldang fanclutch-device and replace it with a quality non-slip stainless-steel bladed "FlexFan" as has been discussed here in the past (twice the airflow at idle), --and providing you're using a max. 180*-thermostat) and had the radiator-tubes rerodded (cleaned out) in the past 12-years as jz mentioned, -then you're going to be OK (especially if running a 4-row/radiator-core necessarily always with the full fan-shroud)... ~Bob vH
:dance

 

[rsmlap]

Could not say if anything has been done to the radiator. Just got the car last Nov. It is the product of a 1980 body and an engine from a wrecked 1981. So the 5 blade fan should be fine?