Will this effect performance much?

[Car #4]

I swapped in a new rad into my 68 Charger and now the fan is pretty much fully immersed in the shroud. I know it should only be 1/3 to 1/2 way in but how much will this effect the amount of air it will pull?

 

[steve340]

How far from the actual radiator is the fan???

 

[R413]

A more urgent problem is that belt so close to the heater hose. There is a factory bracket to shield that hose.

 

[Rusty knuckles]

A lot more than you'd realize I think. Believe engine masters did a show comparing horsepower losses with various accessories.

 

[Car #4]

A more urgent problem is that belt so close to the heater hose. There is a factory bracket to shield that hose.

It’s been that way as long as I’ve owned the car. Hasn’t been a problem.

 

[Car #4]

How far from the actual radiator is the fan???

1.75”

 

[Car #4]

A lot more than you'd realize I think. Believe engine masters did a show comparing horsepower losses with various accessories.

Various accessories? I don’t consider a fan shroud an accessory so I’m not following your drift.

 

[steve340]

OK 1.750 inches is plenty.
The theory as I understand it the fan is supposed to be out of the shroud a bit to allow the air drawn through to "spill" off the fan blade tips.
In practice I am not so sure it will have a big affect.
Have you run it and experienced a problem?
Looking at your second pic I think you may be OK. I would be OK to run/test the fan where it is now.

 

[Car #4]

OK 1.750 inches is plenty.
The theory as I understand it the fan is supposed to be out of the shroud a bit to allow the air drawn through to "spill" off the fan blade tips.
In practice I am not so sure it will have a big affect.
Have you run it and experienced a problem?
Looking at your second pic I think you may be OK. I would be OK to run/test the fan where it is now.

I have not run it, I just put it in on Friday and the car won’t come for another six weeks or so.
I’m annoyed by where the new rad places the shroud. The design could have been better here. Not sure how I could retro fit the shroud to make things better. Things are never as simple as you think they’ll be.

 

[Cranky]

Was thinking about a shorter fan spacer but looks like there isn't one.....but I'm also thinking it's going to be ok like it is.

 

[Car #4]

I was wondering about a shorter spacer but the one now is only an inch and I could barely get the bolts in. A shorter one would leave no room for fingers. I also wondered about skipping the clutch and putting the fan right on the water pump but that might leave it out too far and I’d have to get a different fan with a smaller bolt pattern. I don’t even know if that’s available.

 

[Fran Blacker]

Isn't there a shorter clutch fan? If you look carefully the fan blades are a 1/2" oros ahead of water pump pulley.

 

[steve340]

Don't fix what isn't broken.
Try it and see what happens first.

 

[Rusty knuckles]

Various accessories? I don’t consider a fan shroud an accessory so I’m not following your drift.

What I was getting at is they normally dyno engines with electric water pumps, no fans, etc. On one episode they ran the engine like that. Then they added a mechanical waterpump, various different fans and if memory serves a fan shroud. If I remember right the difference between a shroud and no shroud was 10hp. I don't know about the offset but I think having your fan in the shroud will certainly suck more hp than one spaced off a bit.

That said unless you're competitively racing is probably way more important to keep your engine cool and I don't think you'll ever notice 10hp on the street.

 

[ruffcut]

Yes, if it's not broke, don't fix it! ruffcut

 

[snakeoil24]

I was wondering about a shorter spacer but the one now is only an inch and I could barely get the bolts in. A shorter one would leave no room for fingers. I also wondered about skipping the clutch and putting the fan right on the water pump but that might leave it out too far and I’d have to get a different fan with a smaller bolt pattern. I don’t even know if that’s available.

Just use studs with nuts and then no worries