I'm replacing my LG4 with a fairly hot 350 soon. I figured I should replace the stock fan, as I've heard they are prone to flying apart at high RPMS....
It also seems to roar at over 4000rpm, I thought i'd get a quieter style one as well...



Just wondering if I have a clutch style one, and if I should get the same type as a replacement?

Do I want a flex style fan???

at summit, part # FLX-1017 , would this work?

I'm pretty green when it comes to this, any help would be appreciated. Thanks

 

Out of curiosity, have you considered an electric fan?

Yes, that is a clutch.

As for either a flex or a clutch, that would depend on what kind of RPM's and the desired use of the engine would be as they both have their pros and cons.

 

That looks similar to the clutch fan setup on my '83 LU5.As far as I've read the 7 blade units(again from what I've read so far standard was 5 blade)came with HD cooling w/thermal clutch.When the clutch engages the fans are noisy.Like Stekman said you have to weigh your options.Best to read through the cooling posts should give you some direction.An electric fan setup will be quieter,only running when needed.Look through the stickys posted on wiring setup for either a single or dual fan electric setups.

 

Well I could do an electric one, but I think with the added cost of the unit, and annoyance of wiring, it wouldn't be worth it to me.

Pure street car, 6000RPM red line.
A flex style fan replacement ? same size? (17" or whatever it may be...?)

 

May not be your cup of tea, but here's an option at least:

https://www.thirdgen.org/techbb2/sho...hreadid=317211

JamesC

 

hmm, interesting...
fans could have been taking from what vehicle in the JY? motors seperate?


I'll think about that, i'm pretty good with wiring, but I wanted the easy way out, as I'm pretty occupied with other aspects of the vehicle....

I guess i'll need a spacer, and a flex fan? same diameter?

 

ok, my stock fan is 17".
so say I get a
summit 17" fan:
sum-g4940
and a summit 2" spacer to replace the clutch:
sum-g4955

Would I be ok with this? None of these fans say "not for use over 269HP" or something like that, yet I've heard that cooling needs are linked to HP, and running RPM....? Is this what I want for a hot street 350?

 

I have heard stories of flex fans grenading when the rivets let loose. But that's more or less with the higher RPM race engines as far as I've heard.

On a street engine, you should be ok. I ran one for a few years on my Caprice's LG4 with no real issues - but that stayed below 5000 rpm as well.

As for the fan itself, yes 17 should be fine - try to find a cfm number, though.

 

ok, i'll check on that, any CFM # that i'd be looking for? something that's "good enough" for 400HP? (that's unrealistically high, but i'd rather be safe than sorry...)

 

Sonix:

I've got the single electric fan (87 LG4) hooked up to my 350 and have never had a hint of trouble overheating here in SC where we run the AC 9 months out of the year. Once you've got hedders, no smog and good tune it'll run cooler than you think, until you get on it.

The LG4 electric fan is a much less expensive alternative to the dual electric fan setup. Really cleans things up in front of the engine too. Of course you know you'll be good with the summit fan at less than $30 US and no hassle, but you may want to put the electric fan on your list of things to do later.

 

hmm, ok, fair enough. thanks