Fan clearance too tight?

[HT413]

Just installed the flex-a-lite flex fan and have some damn tight clearances. It's a standard 2 1/4 inch deep fan. The motor leans a bit back on its mounts, so the fan has only 3/8" clearance between fan and core at the bottom and about 1 1/2 inches at the top. In fact, its a 17" diameter fan because an 18 inch fan would've contacted the bottom radiator tank. Clearance between between fan and crank pulley is about 3/8". Is this a problem?

The motors a 413 out of a 1972 RV which are known for clearance problems due to a spacer attached to the factory harmonic balancer for the forged crank.

Fyi, the car came sans fan, as the car wasn't quite complete when i bought it. Now i know why there was no fan installed lol.

 

[HT413]

Come on, i cant be the only one here with radiator clearance problems.

 

[RustyRatRod]

Interesting choice of belt drives.

 

[67 coronet]

shouldnt be a problem unless you hit something.i bumped a freinds car at about 5mph in a charger with that same fan and it stabed a hole in my radiator.never had a problem before that.you will prob get better cooling with it that close anyhow.

 

[HT413]

Thanks 67. I'm just happy it fit at all. After endless combinations of spacers i thought i'd have to resort to a low clearance flex fan and an electric pusher fan to help.

Yeah rust, pulleys came w the car, I'm not a big fan of it - ugh, sorry for the pun. I think he resorted to it because i understand these truck motors are a bitch to align the pulleys. Thought about swapping to original and still might but it'll do for now.

 

[69Bee]

You should have a fan shroud, and try to find a shorty fan spacer instead of the longer one. If you can't find one, get a machine shop to turn/mill it down for you.

 

[sublimegtx]

Interesting choice of belt drives.

You ain't gonna break that belt!:no:

 

[62MAX]

If you're smart you will ditch the flex fan and use a mopar fixed 7 blade fan.The flex is OK for racing but flattens out at speed and will not move the amount of air that a fixed blade fan will.

 

[HT413]

Thanks, 69, i plan on getting a shroud for sure... I ordered one only to realize i dont have the stock 29" radiator for 1969. Its 29" wide but has no id numbers anywhere so i just need to go to a show i guess to find one like mine and talk to the owner. Wish i realized this before Carlisle. The mounting bracket is totally different tirns out.

I started w an assortment of shorter spacers. Prob i found is the crank pulley sticks out just as far as the water pump pulley, so i need to space the fan way out to get clearance.

62max - i agree - stock is the only way to go... i just wish one would fit. I think the blade itself is too deep but also an 18 1/4 inch blade would contact the bottom radiator tank. I was forced to go w a 17 inch diameter fan which gives me 1/2 inch clearance from that bottom tank. Once i sort out the cooling, get a shroud, etc i may revisit this.

My biggest fear was / is under heavy acceleration, could the chassis flex possibly cause me to lose clearance. Only one way to find out!

 

[RustyRatRod]

If you're smart you will ditch the flex fan and use a mopar fixed 7 blade fan.The flex is OK for racing but flattens out at speed and will not move the amount of air that a fixed blade fan will.

That's the whole purpose of a flex fan. You can throw the fan in the ditch after 40 MPH anyway. The blades are degigned to straighten out at high RPM and reduce drag on the engine and add a little HP. Now, compared to the Mopar Viscous fan package, that flex fan ain't quite as good. But I am not sure he has enough room for that.