Electric fan opinions
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
First off, a 12SI is not brushless, never has been brushless, never will be brushless. It was a 1980 design weak *** attempt by Delco to upgrade the 10si. I serious doubt it makes a true 50 amps HOT at 1000 rpms, but even if it does, so what? You don’t idle at 1000 rpms. The difference in 700 idle speed and 1000 idle speed is huge. That alternator will do NOTHING at 700 rpms...
One key fact you are forgetting which is huge is that HOT temp voltage is what you need to be concerned about. Alternator output drops big time when they get hot, along with increased resistance on the rest of the system. A 10-12si is not vented well, has a cheesy fan and will certainly drop voltage when it gets hot.
Where as a CS144 is vented well, has a huge fan, large bearings and designed to carry heavy loads and high temps. It was used on 90’s caddies, corvettes and Impala SS. As for eating belts and high rpms, your comments are asinine. I have been on the same belts for 8 years, my car goes 6300+ rpms every time I drive it and I have never ate or thrown a belt. Your comments are just dumb.
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Is 71Vettelover really TooBroketoRetire?
If so, that explains a lot.....and I’ve wasted a lot of time typing.
Race Director
Joined: Apr 2007
Posts: 11,152
Likes: 890
From: South Western Ontario
Powermaster give an idle output at 2400 alternator rpm. They assume 800 engine rpm idling and a 3:1 pulley ratio. You have to look for that data because they only list the current at "idle" in their catalog with no qualifiers on what idle means.
So, the output number claimed for their alternators will drop a lot at 700 engine rpm and a 2.5:1 pulley ratio. A stock design 140A, CS144 alternator will outperform a 150A Powermaster 12SI at idle using the same pulley ratios. The Powermaster lists 100A where the CS144 would produce 110A under those same conditions.
Last edited by lionelhutz; Oct 30, 2017 at 02:10 PM.
Le Mans Master
Joined: Jan 2001
Posts: 6,746
Likes: 1,387
I've had a 63 amp 10si,
a 94 amp 12si,
and now a 140 amp CS-144.
I replaced the 63 amp 10si because it could not support anything beyond the basic electrical system that my 1968 came with (and I had refurbished it and it was working well).
The 94 amp 12si was ok and could support my EFI and Electric Fuel Pump, but cannot support, at idle, the Mark VIII fan that I installed later.
The 140a CS-144 can support every load I put on the vehicle and maintain ~13.5 VDC, at idle, with every load energized.
Within the last year I swapped out the CS-144 for the 94 amp 12si (I was testing and I have a 12si to CS-144 adapter plug so it's easy), and the 94 amp 12 si works ok as long as I do NOT energize every load (A/C, EFI, Elec Fuel Pump, and Mark VIII fan, +lights and whatnot). It really does not support the Mark VIII fan coming on at idle--- voltage drops below the standby secured battery value and ammeter goes negative. Pretty dang obvious.
I'm still glad I have my 12 si in case I need to swap it in, but NO, I would not recommend it for long term use.
***ALSO- those folks that think these alternators are brushless really need to open one up just for educational purposes.***
a 94 amp 12si,
and now a 140 amp CS-144.
I replaced the 63 amp 10si because it could not support anything beyond the basic electrical system that my 1968 came with (and I had refurbished it and it was working well).
The 94 amp 12si was ok and could support my EFI and Electric Fuel Pump, but cannot support, at idle, the Mark VIII fan that I installed later.
The 140a CS-144 can support every load I put on the vehicle and maintain ~13.5 VDC, at idle, with every load energized.
Within the last year I swapped out the CS-144 for the 94 amp 12si (I was testing and I have a 12si to CS-144 adapter plug so it's easy), and the 94 amp 12 si works ok as long as I do NOT energize every load (A/C, EFI, Elec Fuel Pump, and Mark VIII fan, +lights and whatnot). It really does not support the Mark VIII fan coming on at idle--- voltage drops below the standby secured battery value and ammeter goes negative. Pretty dang obvious.
I'm still glad I have my 12 si in case I need to swap it in, but NO, I would not recommend it for long term use.
***ALSO- those folks that think these alternators are brushless really need to open one up just for educational purposes.***
Last edited by carriljc; Oct 30, 2017 at 01:28 PM.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Is 71Vettelover really TooBroketoRetire?
Reason I ask is I have been using a 110 amp 10si with two cooling fans totaling 30 amps worth of draw for the the last 7 years with no issues.
The 10si I use produces 65 amps at 600 Idle rpm's. I Idle at 650 in gear.
I can run everything the car has including A/C and lights without the voltage dropping below 13+ volts. So why do I need a bigger alternator for my purposes?
I've put 16,000 miles on the car since this mod with no adverse effects. Given the kind of driving I do it doesn't make sense to go through the additional time and expense of up upgrading if what I have works and works well.
Battery is 5 1/2 years old now and not showing any signs of slowing down. So I would say the 10si I have is sufficient.
Haven't had any electrical failures or problems to speak of either.
So before condemning the 10si to the junk heap, it may be be worth looking at an upgraded one if you don't have a need for the the max output of the alternator and only the need for the additional amperage at idle.
Last edited by REELAV8R; Oct 30, 2017 at 03:29 PM.
Race Director
Joined: Dec 2004
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From: PARADISE
St. Jude Donor '09-'11-'12-'13-'14
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
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Burning Brakes
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Thread Starter
Advanced
Joined: May 2016
Posts: 61
Likes: 1
Truthfully? I plan on using the chineseium champion radiator. It appears to be the "cookie cutter" option for the champion radiator. I'm all about trying new things, but if others are successful, I see no reason to reinvent the wheel. I'll post back with solid part numbers and installation pictures. It will be controlled by the Holley sniper unit. Wish me luck.
Burning Brakes
Joined: Jan 2012
Posts: 943
Likes: 73
Truthfully? I plan on using the chineseium champion radiator. It appears to be the "cookie cutter" option for the champion radiator. I'm all about trying new things, but if others are successful, I see no reason to reinvent the wheel. I'll post back with solid part numbers and installation pictures. It will be controlled by the Holley sniper unit. Wish me luck.
But I was wondering about the two speeds, the web site says 2900 cfm and 2500 cfm, just wanted to make sure about that. Pics would be great! And yes, good luck.
Race Director
Joined: Apr 2007
Posts: 11,152
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From: South Western Ontario
That should be a really good combination.
Make sure you use a heavy duty relay. If you use any kind of spade or other quick connect make sure they are high quality parts too.
I would not use a Bosch style relay. It won't stand up in the long run. You could parallel 2 Bosch style relays but that would still be questionable. I would recommend finding a relay rated for around 75A.
Make sure you use a heavy duty relay. If you use any kind of spade or other quick connect make sure they are high quality parts too.
I would not use a Bosch style relay. It won't stand up in the long run. You could parallel 2 Bosch style relays but that would still be questionable. I would recommend finding a relay rated for around 75A.
Race Director
Joined: May 2003
Posts: 10,956
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From: California
go Brushless... brushed fans are a thing of the past like flat tappet cams and the 8-track
http://www.deltapag.com
http://www.deltapag.com
Thread Starter
Advanced
Joined: May 2016
Posts: 61
Likes: 1
go Brushless... brushed fans are a thing of the past like flat tappet cams and the 8-track
http://www.deltapag.com
http://www.deltapag.com
Call me me old fashioned, but brushes rubbing a commutatator makes me happy. Really it's the price, efficiency be damned lol