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There are a lot of factors here but the pro/con list is pretty straightforward. I think a little more info would help here.
To begin, if you are going to move to electric I believe you will need a better than stock alternator. If you have not already done this then it would seem to make sense to stick with a clutch fan.
There are a lot of factors here but the pro/con list is pretty straightforward. I think a little more info would help here.
To begin, if you are going to move to electric I believe you will need a better than stock alternator. If you have not already done this then it would seem to make sense to stick with a clutch fan.
Doing a 454 conversion from my 350ci in a 1972 4-speed with new rad and rad support. Fun cruising car - not a strip demon. Alternator is updated from stock and should be just fine.
Definately Pros and Cons.....I am on the fence here myself with it.......my 72' has a powdercoated 7 blade and mint clutch that works awesome.....but it weighs like 12 pounds!
This weight is at the snout of the pump and is rotating..... I love the original look and performance but an electric fan setup would open up the area and let the accessory drive spin free......BUT......electric fans require some power and they are at the mercy of being electrical, which means they can fail......where as the mechanical just keeps on spinning.
I have a pretty hot 406 that spins up fast and the weight is a concern to me......
Their dual fan setup is pretty decent.
-not crazy about a single electric, if it goes youre stuck. (Single spal 26" in vid, make some noise some dont like it)The 2200 cfm single seems ok but have afeeling once summer hits an upgrade will be needed.
-Electrical upgrade covered already
-Extra space is a plus..everyones different. To do it over Id go back to a nylon mech fan and this as a secondary so Im not gauge watching. OEM fans are pretty reliable too.
Do not like temp fluctutations esp with lash...oh well.
-Like the idea of wiring in an indicator light.
Theres no right or wrong answer, like oil everyone has their preferences.
I put a dual fan with shroud set up from a c5 ( can't recall the exact year right now) into my 78 restomod with an L98 tpi set up. As much as a drop in as you could hope for. Had to trim a small part of the shroud where it hit an upper a arm. One fan controlled by the ecu the other has a switch in a cylinder head. The beauty (IMHO) is that the fans are stock GM so if there is a breakdown most supply houses either have a replacement or can get one quickly. However, wiring and alternator upgrades must be done.
I put a Dewitts dual fan & aluminum radiator on my 72 454 last year and it was well worth the money. I went with the black version so it looks more OEM.
Pros: car doesn't even come close to getting overheated, more engine bay room, mechanical fan horsepower loss eliminated.
Cons: noise of electric fans running.
I've been using an electric fan for years. (10+). No failures. Best cooling solution and no mechanical horsepower loss. Reliability not a concern, since both my other newer vehicles (and all new cars these days) are factory equipped with electric fans. Never had a failure in hundreds of thousands of driving miles.
Their dual fan setup is pretty decent.
-not crazy about a single electric, if it goes youre stuck. (Single spal 26" in vid, make some noise some dont like it)The 2200 cfm single seems ok but have afeeling once summer hits an upgrade will be needed.
-Electrical upgrade covered already
-Extra space is a plus..everyones different. To do it over Id go back to a nylon mech fan and this as a secondary so Im not gauge watching. OEM fans are pretty reliable too.
Do not like temp fluctutations esp with lash...oh well.
-Like the idea of wiring in an indicator light.
Theres no right or wrong answer, like oil everyone has their preferences.
You'll need a big alternator if you go to an adequate electric only setup, I would recommend an OEM conversion, very reliable, cheap, easy to replace.
If you're adding AC and don't have overheating problems now, consider an aftermarket fan, keep your mechanical, run the electric off a trinary switch and temp sensor. I did this on my 69 LS conversion.
Actual flow of aftermarkets looks to be best gauged by their amp draw.
my vote is for C5 setup too. shroud is same size-shape as C3 radiator. GM never liked to pay warranty claims so they build their stuff pretty durable. plus a buncha engineers designed the fans-shroud to cool that amount of power in a car that size. as opposed to teenagers tie-wrapping fans thru the rad fins. i needed a shroud for my 75. whole C5 setup cheaper than a beat orig shroud. actually Cuisinart had a good idea. idiot lights for temp and oil pressure.
Last edited by derekderek; 04-22-2019 at 07:05 AM.
Given that you already have an alternator that will handle the load, my opinion would be electric as well. The pro's far outweigh the cons here.
I am going with a dual 11" setup for mine. It is a proven method and easy to fab up brackets to make it work with our radiators. Having a second fan also provides some peace of mind against motor failure.
Not sure of the spal amperage draw, but I used some oem dual fans that could pull 40 amps. I think my 68 alternator put out about 60. Get over 100 amps, newer cars are over 200. And don't try to run them off the existing fuse block, use a separate harness.
Originally Posted by Lord Melbury
I´m will use the dual Spal kit on my 355 L46 -69, no AC. Too what alternator shall I upgrade, any suggestions?
Mine are out of a newer Chevy Malibu. there isn't much space for me at the top so they fit great. They are wired independently with relays to separate water ports. one in the head and one in the intake. This means they reach temp at different times. this is important in managing the power spike involved with the starting of the fans. It also provides redundancy. As an additional safety measure, I have lights on the dash that come on when they come on and an override switch. My big *** motor runs right around 190. The 2 small fans on the front are trans coolers with their own fans.
Don't forget the airflow. the nose needs to be sealed off from the engine bay to force air through the radiator or it will run hot at speed.
BTW, I fabricated my core support because mine was rusty and not what I wanted. It interferes the hood hinges so now I have a lift off hood with Dzus fasteners.
04-20-2019, 09:27 AM
Elec Rad fan vs clutch fan
I love the original look and performance but an electric fan setup would open up the area and let the accessory drive spin free......BUT......electric fans require some power and they are at the mercy of being electrical, which means they can fail......where as the mechanical just keeps on spinning.
