Bob,
Yes, I've had electric fans for years, starting back with the OEM auxiliary
fan on a '84 Class A (brand forgotten) with a 454, which would overheat at
low speeds without the electric fan running. I used it occasionally back
in the 455 days with an OEM radiator. Since the Cad500 demanded an
aluminum radiator, regardless of electric fans, I don't recall having ever
turned them on (they're only manually controlled). You may have noticed
that they're low on the radiator, in front of the external oil cooler --
intentionally.
What probably can't be seen in any photo is the fact that I also have
complete ducting of air from the grille to the radiator -- far more
thorough than any GMC OEM setup. That may help more than the fans could.
It's worth noting that the Chevrolet P30 Chassis Owner's manual (available
at
bdub.net) specifically admonishes RV builders to be sure that engine
compartment air cannot recirculate to the front of the radiator -- EVERY
original GMC basically ignores that engineering guideline.
Ken H.
> Ken. I see a fan in front of the radiator in your photos. I've thought of
> doing something like that. So I could turn a fan on when having the engine
> off at gas/other stops. Even pulling the heavy loads that I do. I've never
> had cooling issues. But then again. The 403's have better air ducting for
> the engine. Bob Dunahugh 78 Royale
>