C2 66 big block electric fan

[joe gushen]

Although my 66 427/425 roadster is pretty stock, still looking nice after a fresh frame off, I drive it. In traffic or at a cruise it runs a little hotter than I like.Being numbers matching I need to protect that motor. I'm thinking of adding an electric fan. Keeping the stock fan on the motor. I'm 40 over and only running 10:1 compression for pump gas, correct timing.

I think I can mount one at the back of the radiator and the shroud shoud conceal it a great deal.

I know I'm not the only big block guy that has a hot running motor.

If anyone has any suggestions, I grately apprecitae it.

What kind of fan is recomended?

What size fan is reomended?

How and where to mount?

How do I control on/off for the fan?

Yes I tried the water wetter and all that stuff. This I believe is a good way to pull it off.

Thanks
Joe Gushen

[Jim T.]

Re: C2 66 big block electric fan

The following has been mentioned before on the discussion board about Corvettes heating up in traffic. Have you confirmed that you are running full time vacuum from your carb to the vacuum advance unit and also confirmed that your vacuum advance is working, and the correct one for your engine? If you have no vacuum at idle to the the vacuum advance unit, you do not have full time vacuum.

[Duke W.]

Re: C2 66 big block electric fan

Forget the electric fan or any kind of radiator snake oil. Convert the ported vacuum advance to full time. Do a little research in the archives. All who have so converted L-72/71s report much lower low speed driving temperatures.

Check Rick Snow's post about this after attending the National in Boston last summer.

The "normal" operating temperature with a 180 degree thermostast is 180-220. The thermostat just begins to open at 180 and is not full open until about 220. Engines operate best in this temperature range.

Duke

[Richard S.]

Re: C2 66 big block electric fan

Joe,

As Duke says, if you convert to full time manifold vaccum and install the correct vaccum can you will not believe how well....and how cool....your car will run....especially in traffic on a hot day.

Duke,

I cannot thank you enough for the advice and help you gave me regarding my overheating 67 427/435. I like to drive my cars and you made driving the 67 a fantastic experience....thanks again my friend.

Rick.

[Richard S.]

Re: C2 66 big block electric fan

Joe,

To be clear, by "correct vacuum can" I meant a can that will provide enough vacuum at idle....not an "NCRS correct vacuum can". Please refer to Duke's archived post of September 4, 2004..12:40 PM.

You should also know that aftermarket vacuum cans must be tested to ensure perform as they are supposed to. We tested four VC 1765 cans from NAPA before we found one close to the vacuum specs required.

[Duke W.]

Re: C2 66 big block electric fan

L-72s have a 12" VAC, which will work fine since the engine pulls about 14" at idle. L-71s have a 15.5" VAC, so it must be changed to the 12" NAPA VC 1765 or equivalent when converting to full time vacuum advance.

It's best to test the VAC to make sure it meets specs.

Duke