Fan thru radiator questions (1 Viewer)

[rack201]

Put my fan through my radiator on the long weekend here in Australia. Managed to pull it out trackside and crimp off the broken bars and get me home.. but have a few queries..

Realise this is a known problem and I’m running the 80 series ‘yellow dot’ fan that is supposed to be less prone to flexing. The crossing wasn’t very deep and I was going very slow (maybe too slow?). I don’t even think the area where the fan contacted the rad would have been submerged but it’s hard to be sure.

I’d been idling for a while before the crossing and when at normal temp I can move the fan with some resistance so I’m surprised the viscous hub had enough lock up to force the blades through water hard enough to flex them into the rad. They are really stiff on this fan.

I’ve seen it suggested the cause is actually a vacuum created when water seals off the radiator surface cause the blades to flex fwd..

Just wondering what folks experience is. I probably need to check my engine mounts but can’t see that giving enough fwd movement for contact and I’ve never noticed any movement in my shifters.

Probably have to start tying off the fan for crossings going fwd.

2004 HDJ100 Auto

 

[hoser]

Some kind of cover will help. But even then, if you go too slow, the fan will get submerged and will act as a boat propeller, which it doesn’t do well.

 

[nissanh]

the blade can divert air very fast as it is less dense, but water is very dense, the blade cannot divert water back as air so water makes the blade to dance to their tune.. making the blade to flex forward.