I going to change over to an electric fan. I would like to hear what has worked for you. Is there an advantage to a single or dual fan setup? I have a 69 350 with the plastic shroud. Also I am going to install air in the future.

 

Dewitts dual Spal fan setup. Not cheap but pretty much bullit proof.

 

 

Changed my 1979 over to Dewitts radiator with dule Spal fan. Had a problem with light weight 30 amp spaid fuze holders. Changed to heavy duty problem solved. Took fan schroud off, not needed, more room to work and added Spreader Bar. Car Has A/C the Spal fan you will need to add a 3 rd., relay for the A/C, so when the A/C kicks on the fans also go on.

 

search for taurus or mk4 fan

 

Save yourself about $800 and go junkyard diving for a good taurus or mk4 fan. You'll be just as cool.

 

I'm not sure what prices you are looking at? When you buy a MK4 you buy FANS ONLY and you need to get wiring/relays/switches, and create mounting brackets. Our dual fan kit for $425 has all that.
If you want to compare apples to apples, we sell the dual fan alone for $298, and we are offering a 10% CF on all fans and Direct Fit radiators.
http://www.dewitts.com/pages/product...asp?ProdID=211

 

That's a pretty good deal, of course, i could easily make my own harness, and get a switch for 20 bucks. But for the novice electrical guy, it might make sense. How does the air flow of the above unit compare with the MK4 unit?

 

I can't specifically say, but apparently there are no standards for testing airflow on fans.....obviously it will vary a LOT with the 'load' or obstruction to airflow, on the backside as well as the frontside....
a/c or ATF coolers etc obviously obstruct airflow through the rad....

I can say this, the Spals really SUCK, pull that engine down to temp very quickly even in 130f+ FLORIDA traffic...and I have just a single row stock F body radiator, nothing fancy....

 

Here is a link to DeWitts fan testing.
http://forums.corvetteforum.com/c3-t...pal-duals.html

And the graph:


I will tell you that I have the dual Spals on a BeCool radiator (done before DeWitts was really selling the stuff) and I love the setup.

 

I have dual C4 fans. Very similar to Spals I believe. Do a google search for "big block from hell" and you will find the article I used.

 

I have DeWitts dual fan set up and radiator on my 68' 427 and am VERY happy with the entire set up.

 

I tried first, using a single 16" fan. Got too hot. I custom built a shroud for that fan next. Better, but no cigar. Then I got the dual spals. NEVER A PROBLEM SINCE!

I'm using a factory type copper/brass radiator, since I couldn't afford aluminum one when I built the motor.

 

I'm in Texas, and the summers are hot... not uncommon to have high 90's and 100's degree weather for months on end. Heck the lows are 85 for months on end. Typically June thru part of September. Will these dual spals keep me cool?, better so than the mechanical fan set up?
Also
1. Do these fans run all the time or are they regulated with a temp sensor/thermostat of some kind?
2. Do they spin at different speeds or is it just off and on, 1 speed?
3. Is a third fan on the, pushing add any more cooling?
Thanks,

 

i run a 16 spal. no shroud needed. temp is roughly around whatever the thermostat im running at the time is and stays there. i generally put in a 185 in winter and a 160 in summmer. i hate automatic switches- they all stuff up or leave you stranded at some time so i just have a manual switch on my dash . if my temp ever gets hi i just flick the switch .

 

fan 100 bucks new from ebay
relays and switches maybe 40 total
mounting bracket. 1.00 from home depot
on/off temp probe 20 from summit

satisifaction of building something and putting it all together myself AND have it work wonderfully.-dare i say it? priceless

 

Do you happen to have a write-up on what you did & parts you used?
sounds like a great solution for the Vette Hobbiest on a budget.

 

The ONLY fans I have seen with the little rubber flappers in them, to aid the airflow through the shroud when at speed, is the Spals....all the rest of the shrouds are solid, and so impede more airflow....

IMO fans should have their own mounts, independent of the radiator, and the shrouds should be almost air tight to the back of the radiator, making max suck on the airflow, in traffic the little flappers close on the Spals, so best of both worlds....

My car is FI, so the computer controls the fans....any temp sender can be made to work, just what position it needs be in, and of course the temp range set correctly...

 

I also have a 69 350(now a 383 425HP). How many times have you taken the shroud out?
I went with the DeWitt's set-up. The install was a bit tricky, but my car hasn't been over 195 since! Even in July when it was 100 degree's out. If my radiator hadn't been new, I'd have gotten the aluminum set-up with it.
The only problem OI had was the switch failed and the fans ran constantly. DeWitt's replaced it at no charge.
The look?: well let me tell you, dumping that cracked old shroud(obviously had been taken in and out more than the 3 or 4 times I've done it), and the clutch fan...much cleaner look.
I also have A/C, and with the 383, I was worried if it would cool it, no effing problem! I did have to upgrade to a 105 amp alternator, that was a little more than $100.
1st class set-up from a 1st class operation, case closed. Now your question is answered.

 

I went the cheap route and it has worked nicely so far. I used Ford Focus fans and built a shroud form aluminum stock.