Ok, so I have the world's most drivable small block that ever hit 378 Ft*lbs on the scoreboard, now I'm thinking of ways to get more of that to the street. Now I have a 4 row radiator, but I'm still running my OEM flyswatter, and I removed my shroud, mostly because it was such a pain in the (your favorite body part here) to reinstall. IT sits in traffic in blistering heat, and only the most severe traffic jams make it sweat more than 160 degrees. Well, I want to do an electric fan, because I can hear my precious Torque drowning in that ineffiecient insect guillotine stapped to the front of my engine. My concern is the wiring, these things have to be triggered by some sort of thermostat, or manual switch, correct? well, instead of trying to deal with that, the only time I really even need a fan is when it is idling. So, my idea is to maybe get an MSD RPM activated switch to trigger the fan to shut off at 1200 RPM. Since the MSD unit will activate something at the desired RPM, I can just send the hot wire through the switch, and when activated, it sends the hot wire to ground, cutting the fan off. If there is a better way of doing this, please tell me, I'm brainstorming (watch out Steve, get your umbrella). I really think this will be adequate cooling, given that I use the Permacool pancake style unit, probably the 14" unit, which flows 2950 cfm, and only costs 9.5 amps, or .153 HP, not bad. How much airflow is required to cool a non air-conditioned motor with 330 HP/378 Ft#, that rarely, if ever, spins faster than 4500 RPM? I'm even seriously considering the serpentine belt conversion from March, it's less than $200, and underdrives everything. I have a stock alternator, but with the electric fans it might be worth the few extra bucks to get a later Mustang alternator, rated at 75 amps, it will fit, right? they look the same in the catalogue. I think that my factory alternator only puts out something pathetic, like 45 amps, definately not enough to trust electric fans, MSD ignition, and a Kenwood/Alpine stereo. If I'm being overprepared, and there's actualy no reason to need more alternator than what I have, then someone please give me a reality check. In fact, I'm interested in anyone's comments on these ideas, I'm trying to firgure out what's the best upgrade to do first, I can think of a million more. It seems the more I do to this truck, the more I want to do.

The TorqueKing

 

[updated:LAST EDITED ON 24-Apr-02 AT 06:54 AM (EST)]Careful if you use the MSD to trigger any fan switch, if the amp draw by the fans is too much you may blow out yer MSD. I would use the MSD to trigger a relay connected to the fan. But then again... every time your engine dropped below 1200 rpm the fan would kick on and off, on and off, on and, you get the idea? And since the greatest amount of current draw in an electric motor occurs at startup, this may not be the best way to go. Just my .02

 

Yeah I agree rpm activated sounds nice on paper, but I don't think it's very practical...I would use (in fact I have but did not install) a thermostat switch in the intake water jacket someplace, right near the engine thermostat is where the water is hottest...but I'm so used to reaching down and flipping my fan switch, I don't hardly think about it...I do strongly suggest running the fan through a relay and running a manual switch no matter what you do...that way you can override whatever configuration you have wired and turn it on if you start a long hard grade (like Baker grade in CA!!) in the middle of summer, etc.

I put on a 1-wire, 100 amp, GM altenator (Power Master) to handle everything...if I need to, I can go the their 140 with only an outlay of a few bucks!!

 

[updated:LAST EDITED ON 24-Apr-02 AT 01:10 PM (EST)]OK John, now you KNEW I would have to get in on this. I liked your fan to insect guillotine analogy by the way. The MSD switch is a cool idea (pun intended), but not as efficient as a temp controlled fan switch. I know you can see where I'm going with this. Even if your engine is cold, the fan would still switch on at low RPM's. With the temp controlled switch, the fan would only kick on when it'd actually needed. There isn't much of an effect on horsepower there, as proven in previous posts on how much H.P. is used by the alternator. I think it WOULD make a difference on the life of the electric fan (I.E. last longer if run less often). Something else I would like to say, is that I don't agree with the people who say an engine makes more power with a hotter thermostat. I have been around drag racing a lot. More power means higher miles per hour at the end of the run. Correct? You can have slower ET's due to tire spin, but if you have more horsepower, your speed will be higher. A cool engine that just barely has the oil warmed up will make higher MPH then the same engine that is running at say 200 degrees, therefore more H.P. every time. I know John knows this, but a cooler air/fuel intake charge has more stored energy due to the molecules being closer together. More can fit in the same spot then if they were warmer and further apart. That's one of the reasons nitrous oxide makes you go faster. It adds oxygen, but at the same time cools down the intake charge. Cooler is more efficient. At the same time though, a cooler engine also makes more pollutants. That is why the Ford engineers specify higher temperature thermostats. To help get past the emissions tests. NOT because the engine makes more power. I'll step off my soap box now, and get ready for the people who I'm sure will want to argue the point. By the way John, I checked out your pictures and your truck looks great with those rims. As far as you being the Torque King, just wait until I get my aluminum heads. I haven't decided on what brand yet. I'm running a heavily worked-on set of 69 351 Windsor heads right now with 1.9 and 1.6 Chevy valves. I'm cranking out 372 Lbs/ft at 4000, and 358 ponies at 6000. That isn't even PEAK horsepower. With better heads and a 2 1/2 inch exhaust instead of my 2 1/4 inch, I could run a less radical cam and still make more power then I am. And I've got a 94 Cobra 5 speed, so no converter robbing any of MY torque. Better hold on tight to that crown. Oh yeah, almost forgot. I suggest going to a later model alternator from a car/truck with A/C. Lots more amps. I use one from a late 80's Mustang. I swapped out the pulley from my old low amp unit. Eventually I'm going sepentine, and get a little MORE usable power. What size is that crown? (This competition is limited to 302's guys)

 

I know, right. we don't need to have guys with 400 cube Winsors in on this. Yeah, I guess I could get used to the fan, but can I run the thermostat off my factory unit in the intake, and if so, can I get a themostat to come on at 160 degrees? I'm probably going to stick with my factory alternator, it makes 61 amps, and the electric permacool that I'm looking at only draws 9.5 amps, and it pushes 2950 cfm, then I'll have all the accessories underdriven with the March serpentine conversion kit, then this beast will revv-free like it was a 300 degree duration cammer in a 2800 lb. Mustang. I'm going to go wash it, it deserves a bath for the first time in over a month. Finally, it can run as good as it looks.
The TorqueKing

 

oh, by the way, I appreciate the advice on the RPM switch, it does seem a little too unneccesarily complicated- the epitome of why I'm studying engineering. I hate complexity in all forms, that's I have an old truck. That stupid fan would come on and of like a yoyo in traffic, and I'm sure that the excessive starting/stopping isn't good on the motor. Thanks for the reality check.

John F. Daly III
The TorqueKing

 

[updated:LAST EDITED ON 24-Apr-02 AT 04:49 PM (EST)]Why not buy a Temp Switch for a later model car with an electric fan. As I was reading both yours and Sauersf100's life story when it dawned on me. Lets take GM (I know I know), the 84 Century I had used a temp switch to activate the fan. Kicked in at 160 degrees I think. All you would need to do it wire it in with a relay and Presto! You have a temp activiated fan switch. If memory serve me right, it is a 3/4" pipe thread 2 prong switch. Looks just like the temp sending unit but has a much better snap on connector. Which is carried by all most every parts store on the face of the planet. Also if you compare the Ford to GM you'll find they are alomst identical. So no one will know you are cross breeding your masterpeice. Oh yeah cost, $12.00 for teh temp switch and $7.00 for the pigtail(connector), relay is your choice.

 

Hey Mark, will I have to have a seperate sensor, or can I splice it into my water temp gague? It would be a really slik setup if I could use just one gague, I'm shooting for simplicity here.

The TorqueKing

 

A guage works on an entirely different principle than a switch so you need two sensors. Also you could wire the temperature sensor in series with the RPM switch so it only operates when the engine is warm AND idling. Try a lower RPM setting nearer your actual idle speed so it does not operate in traffic. Use the signal to operate a good 30A relay with a fuse. If you are willing to put up with a little more complication a time delay can be added to the circuit so the engine has to be warm and idling for say 10 seconds to operate the fan. This is why the auto makers went to computer controls. The computer already knows the engine temperature, and RPM's etc. so they can operate the fan under any condition with only one wire to a relay.

I operate a 400 so I can't run in your competition. The 400 was built for brute low end torque. You can tell where my heart is by my "name".


over!

 

 

Yeah, Torque Rocks, I built mine for torque, and love it everyday! There's an ancient Chinese proverb: You buy horsepower, but you drive Torque! ok, it might not be Chinese, but it is true.

The TorqueKing

 

[updated:LAST EDITED ON 29-Apr-02 AT 10:00 AM (EST)]One thing to remember guys, the fan is not engaged 100% of the time. It is engaged only when the air in front of the clutch gets hot enough to engage the bimetal spring. Going down the road, or idling without the AC on keeps the fan disengaged. Power draw is less than 0.5 HP on a disengaged fan.
I like your electric fan only cooling idea. It is good for the low load condition, as well as AC performance at idle.
My entry for torque/HP
1990 302 - modified dyno'd at 390 ft-lbs 4250 RPM, 410 HP 5650 RPM.
I'll be happy to fill anyone in on the specs if they want.
BTW - The electric fan should get its signal from a thermocouple in the coolant. It will give you a better hysteresis for the on/off cycle. You will run a lesser duty cycle. Your alternator and your fan will thank you for it.

 

RonBo, I know this is off from the topic, but I would very much like to check out your specs for your engine. Those are very impressive numbers from a 302, especially at those RPM's. Could there be a stroker kit involved? If you would care to share your secrets, my e-mail is sauerf100s(No Email Addresses In Posts!) Thanks

 

TQKing sorry for the delayed response. Been fixing a bent jeep body and radiator for a friend. The fan temp swith can be mounted in the thermostat housing. Yes, I am refering to the old ugly thing with the thermo-vac switch. Which no one wants to keep on their engine. But it would work in this instance. It would only come on after the engine warmed up and the thermostat opened. A plus for you HP scavangers. Plus you can hide the wires on the underside of the upper radiator hose to boot.

 

Thanks Mark, I appreciate the advice. I'll probably just do the manual switch in the cockpit, it'll be even better than switching on or off automatically. I can definately appreciate your story about the speed shop idiots, I've people just like them. I guess it's up to us to show them justice on the strip, and more importantly, on the street.

John F. Daly III
The TorqueKing