Help cooling 427 SO

[priobe]

Hello all,

I would like to get some already working advice on a cooling system for a 427 SO.

I will have a 15 inch Black Magic fan with twin fans in the front for extra cooling.

Question :
I would like to have the main 15inch fan to monitor the temperature between 200 and 190. If the temperature rises above this I would also like to have the twin fans to help bring down the temp.

If this is not recommended I and open to any suggestions that will work in keeping the motor at a good temp.

Thank you in advance

[SCOBRAC]

I use a single black magic 150 with great success. The 150 is exactly the size of the Contemporary's fan support and drops in in front of the rack in pinion tube. The fit is awesome and it draws far more air than the AC Delco unit that came on the car. I used a March tensioning rod in stainless for support. It is a great fan. I found the support brackets fexilite included a little cumbersome. If you haven't seen them they would be more at homein a full size pickup... As long as you don't mind the cheepo hot dipped gazvanized look. That's fine. I'm sure it keeps costs down. The all thread supplied is similarly more at home on a Home Depot shelf than a Cobra.

My local sheet metal shop knocked a pair out of .125" 308 stainless on their hydocutter. They look great and are right at home with 12 pt ARP stainless fasteners holding it all in place.

The Black Magic comes stock with a 180-220 degree range of adjustment. I actually prefer it to come on at about 170 so I recalibrated the rheostat, it generally come on at 170-175 Once it kicks on it seems to work flawlessly I made the change in fall but so far it works well without a problem. I had a 180 thermostat in the car before I went to the Black Magic fan. With the original AC Delco fan this meant I was at 195-200 most warm days. Hot days it could see 210 in traffic. That's too hot for my taste on a 40 year old engine running 12:1.

I put a 195 Napa Auto Parts Superstat in this fall when I changed fans. It seems to be opening early. I cant seem to keep the car at 160 on these cool spring mornings (spring has sprung here in California).

I'll let you know what happens as temps increase. I may replace the new thermostat before that. I seems unlikely I'm getting enough conductive cooling (off the block /heads) to keep the temps as low as they have been after an hour on the open road.

[priobe]

My Fan came with the kit from EM and I haven`t pulled out of the box yet. I was going to purchase the thermostatic switch from Painless.

The Thermostat that comes with the fan is it the type that goes under the radiator hose?

Are you using the twin Fans?

priobe

[SCOBRAC]

Yea it is a metal tube type. It will mount to the radiator tank or wrapped to to a hose. My 150 had it built in. If I had it to do over I might have gone with an aftermarket external unit with a little more control this one comes with a fixed length of metal tubing the sender uses to transmit to the switch, it actually is a hollow tube that uses pressure to activate the the controller. It's pretty rugged but you need to be careful not to kink it or it will not work properly. You can't shorten it either.

The recalibration of the controller was pretty straight forward but it requires a bit of electrical knowlwdge and I'm sure I voided the warranty doing it. I called Flexalite tech and the guy had never heard of anyone doing it. I explained thew nature of the application and he seemed to understand why I wanted to keep the nearly 40 year old side oiler cooler than the 180 degrees the unit can be adjusted down to. But he wasn't sure how to do it, but promised to get back to me. Well after 2 hours of waiting I got tired of waiting and just did it.

The controller doesn't need to be out of the fan assembly but it is far easier to do this if it is. I took my controller out and did this in the kitchen. I heated water in the microwave. Using an IR thermometer I got the temp to 170-172. Looking at the back of the rheostat there is a hole covered with a sticker, remove the sticker and insert a small phillips screwdriver. Turn the screw slowly counter clockwise to lower the operation temp. The unit will click as it turns on. I used an ohm meter to verify continuity. But as it clicks when the switch is on it isn't really critical. recheck the water for desired temperature a few times to make sure it is where you need it to be. Use a bit of electrical tape to weather proof the hole and reassemble.

I never did hear back from Flexalite tech. I called him a few days later and told him what I did, how it was done. He didn't seem amused.

[priobe]

You said you wanted to keep the temperature lower than 180?

I have heard people debating about keeping the temperature around 190 and people seem to agree that this was a good temp for air/fuel mixture.

Are you running standard carbs or are you running webers?

[SCOBRAC]

Engine temp. is a double edge sword. On one hand an engine operating at 140-160 wears out twice as fast as one operating at 190. The other side is detonation occurs faster as cylinder head temps increase. Almost 50% faster at 200 than at 180 degrees. This is only important as compression reaches 11:1 or more. At 12:1 a 190 degree engine will detonate at 38 degrees btc. This applies to cast iron heads, aluminum heads take more heat and resist detonation far better.

Many engines need 190 degrees to run well, my 428 needed 185 to run well. This 427 seems happy at 180-185. I shot for 180 because it is the safest as far as detonation, but still allows for a pretty clean running engine. As mentioned with the new fan I installed a 195 thermostat. I don't want it to run cooler than 180, I just want the fan on before it hits 180. But I live in a climate that will get 105+ in the summer and easily range from 80-95 degrees 6 months out of the year.

All cars run more efficiently and cleaner the warmer they run to a point. Clean Air standards adopted in the late 60's were the reason most manufacturers went to a 195 degree thermostat in the late 60's before that it was 160-180.

I run dual Holley 660's.

[M & M]

priobe

I believe the most import aspect to keeping the engine cool is the radiator...... not he fans. You can have all the fans and air you want but if your radiator does not have capacity then you are done. Obvisouly the more fans will help once you have a great radiator, depending on the driving conditions.

I am running a nascar type radiator with only a single fan in the rear. I do not like the looks of the fan(s) in the front but that is just my personal opinion. I do not have cooling problems. In fact most of the time until air temp get above 75-80 degress I never have to turn the fan on. I am running lower compression which helps too, under 10 to 1.

Put your money in a great radiator, not all the fans!

2 Cents!

Mike

[SCOBRAC]

Indeed the radiator is key. no matter how many fans you have an undersized radiator will never keep up.

[priobe]

M&M

Thanks for the input.

The EM kit came with a Griffen radiator 3 row which I think is pretty good.

What I wanted to do is have the temp maintain around 185-200 but still have the fan cycle on and off. I did not want to have a constant fan running. I like the dual fan in the front (sorry) but I also want to have these fans cycle as well

Thanks why I was aking how everyone else wired the fans with what thermostatic switch

Are you running a thermo- switch?

[M & M]

Actually I am not that high tech! LOL

I just turn mine on by hand. Not the best way to do it I admit.

One of these days I will wire in a thermostate to be safe. BTW I usually try to keep it around 185 give or take.

Mike