LOTSARED

'68 L36 427... bored/stroked 463ci, Edelbrock aluminum heads, street/strip cam, remainder stock, including clutch fan.

When my original clutch fan kicks in... man, that thing is loud. Sounds like a jumbo jet beginning to spool up under my hood. So, two questions... when should the thing kick in? It seems to kick in when temp guage is reading a low as around 150F. Is that normal/necessary?
And, are they normally very loud? I assume all that underhood drama means there's lots of air being moved. That's good, but I'd rather listen to the exhaust (or radio, or ...).
Oh, 3rd question... is it likely the mild engine mods would make the engine run hotter vs stock. Seems like the fan drama is more frequent than pre-mods.
Thanks all--

SIXFOOTER

If mods were making it run hotter than normal it would show up in the temp gauge, provided that it works. What kind of noise? Just fan/air noise, or mechanical noise?

Brown78

When I installed my first electric fan. It was so loud when it came on. It was a single fan. Now I have doul Flex-a-Lite fans I bought from Jegs. They are so quite. Funny how 2 can be quiter than 1...

markdtn

Some of the clutch fans are louder than others. Is it a GM fan clutch or aftermarket? I had a customer with a mid-90s Chevy pickup that the clutch was bad. Bought a Hayden replacement and he complained he could hear kick in and out. Replaced it with a genuine Delco unit and problem solved. Had a similar experience on a Grand Cherokee with a Hayden, OEM was much quieter.

There are instructions I have seen for changing the on temperature if it is a thermostatic clutch, not just a viscous clutch.