Thread: clearance of electric fan on SBC

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I moved my SBC back 4" so I can install a mechanical fan instead of having a push electric fan mounted on the front as I do now. Then I got to wondering if the electric fan should be mounted as a pull fan instead of using a mechanical fan. Unfortunetly if I did mount the mechanical fan it would only cover the bottom 1/3 of my radiator as I have my engine low because of intake and carb clearance. I don't know if the fan would cool the engine enough with the fan sitting that low even if I manufactured a shroud for it. Your thoughts?

Hey 37, I've talked to several guys about this and it seems your going to have cooling problems with your current setup. You would be better off with the shroud but with the fan at 30% of the radiator, that's what you'll get 30%. It makes it worse if you are running an automagic and A/c.

Wit a push fan on the front of the radiator, you're effectively blocking off most of the airflow. An electric fan needs to be mounted behind the radiator pulling air through.

With a proper shroud, you'd probably get enough airflow with the mechanical fan. However, you DO need a shroud. Otherwise, the fan does no good. Another thing to consider . . . most new cars have electric fans.

Absolutely run the biggest electric fan you can behind the radiator. Electric fans are much more efficient than mechanical fans, because at idle, where you need the fan the most (traffic lights, etc.) the mechanical fan is only spinning at maybe 1000 rpms. WIth a really good (SPAL) electric fan, it will feel like a hurricane comparatively.

If you want, build an aluminum shroud around the electric fan, but I don't run one on my truck, and I live in Florida.

Don

There is a water pump riser that is especially made for the SBC. It raises the water pump and fan up 5 inches, to center the mechanical fan in the radiator. The pump riser is all aluminum. I have one on my SBC in my '32 Ford. The price is kind of steep, around $200, but it works great. You still need to run a fan shroud for the best cooling performance. The pump riser also uses a GM six cylinder water pump instead of the V8 pump. I use the Hi-performance six cylinder pump with no problems.

While the price sounds high, the pump riser also comes with additional brackets to mount the alternator on the drivers side and an AC compressor on the passengers side.

You want the fan at the top of the radiator if possible. That's where the hottest coolant enters the radiator and you get the maximum delta-T.

Kitz

Kitz, what are you running on yours??? Do you have any pics?? You might have told us allready, but I have a terminal case of CRS anyway !!!!!

AFCO radiator with Spal 16" puller fan. Notice how high up the fan is? First time I ever practiced what I preach.

Notice the coat hanger needed to hold the BBC together ..........

Regards, Kitz

Dang good thing you mentioned the coat hanger Kitz!!!!!! Great looking setup even if it is a chebbie....

Originally posted by Dave Severson
Dang good thing you mentioned the coat hanger Kitz!!!!!! Great looking setup even if it is a chebbie....

It's not a coat hanger, it's a block girdle. Keeps the casting at 90 degrees at high RPM

Denny I've got about 5" for clearence now which is going to leave me about 1" of free space.

Looks like it will work for me then.