What amp alternator?
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Racer
Joined: Jul 2013
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What amp alternator?
I want to replace the alternator on my 73. It will be a carb fed 383 stroker, with Vintage AC. The choices I see are 70-85-and 140 amp. Is there a risk going with the 140 amp? I am replacing the rear wire harness, and the engine harness. Thanks for your time and experience.
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
The problem with 140's is the shear size. If you have taller valve covers for RR's
I use the powermaster 105 amp single wire with the bigger pulley to not exceed 17,000 rpm.
I use the powermaster 105 amp single wire with the bigger pulley to not exceed 17,000 rpm.
Drifting
Joined: Apr 2008
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From: Lewisburg WV
thegazman
I didn't know that. Learn something new everyday. My CS144 is the same size as the original 60 amp.
Race Director
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I want to replace the alternator on my 73. It will be a carb fed 383 stroker, with Vintage AC. The choices I see are 70-85-and 140 amp. Is there a risk going with the 140 amp? I am replacing the rear wire harness, and the engine harness. Thanks for your time and experience.
Drifting
Joined: Apr 2008
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From: Lewisburg WV
Using Mike's rational: Your Vette came with a 190HP V8, why are you updating to a 383 stroker? The 190HP would surely get you to the grocery store.
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I just love how the word 'updating' gets thrown around as an excuse to make illogical decisions.
Le Mans Master
Joined: May 2002
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From: Lebanon Township New Jersey
That's what I was going to say. Larger alternator capacity, high flow water pump, high pressure oil pump - it all takes power to run. If you're concerned about the power getting to the rear wheels these aren't necessarily good choices.
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Drifting
Joined: Apr 2008
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From: Lewisburg WV
thegazman
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Le Mans Master
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From: Tennessee/Rhode Island
Wow as usual always fun!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
Wow as usual always fun!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
then we get into the problems of on my vette, electric fans, properly wired off the alt, and NOT the battery,.....IF anyone understand electricals, you know that a ~100 amp alternator is a help to the car electricals.....
Race Director
Joined: Jul 2001
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Wow as usual always fun!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
I'll give you a few reasons why an "updated" CS-144 alternator is a better choice than the 63 amp 12SI even if you do not have very high amp loads outside of the stock amperage draw overall :
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
4. The CS-144 will charge the battery MUCH quicker under higher loads.
5. If the car has any type of high amp draws beyond stock, the CS-144 will easily handle the load.
On my 78, I have Hella Euro Halogens (4)-55/60 watt low and 100 watt highs- and the stock 63 amp and 100 amp 12SI''s I had could not charge the battery with the lights on at idle.
Hope that helps!
He makes no mention of any non-stock accessories or add-ons. So again, what is a bigger alternator going to give him?
Team Owner
Joined: Jul 1999
Posts: 65,492
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From: Orange Park Florida
Racer
Joined: Feb 2012
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From: Charlotte NC
The OP mentioned he has Vintage AC in his car. I have the CS144 alternator in mine along with vintage AC and Dewitt SPAL fans. I like it and it was an easy installation.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 970
From: Tennessee/Rhode Island
Here is another reason: For the small difference to buy a new cs-144 with 2.5 more amp capacity, much more efficient etc versus the outdated 12SI, its a no brainer! There is a reason the 12si was discontinued and its not because the newer alternators were no better than the old.
Last edited by jb78L-82; Feb 11, 2014 at 07:39 PM.
Race Director
Joined: Apr 2007
Posts: 11,150
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From: South Western Ontario
Installing a higher current alternator means you need to upgrade the charging wiring. If you're not needing the higher current capability then why go to the effort? Changing the wiring will also mess-up the ammeter and it won't read correctly either.
Instead of a stupid pissing contest why not ask the OP if he's adding extra load?
Franks73 - are you upgrading or adding anything else electrical to the car and if so, what?
Instead of a stupid pissing contest why not ask the OP if he's adding extra load?
Franks73 - are you upgrading or adding anything else electrical to the car and if so, what?
Race Director
Joined: Jul 2001
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Not in the least:
Yes- the 10SI eventually reached it's output amperage capabilities at 63 amps. The 12Si reached it's limit at almost double that. The CS series doubles the output yet once again.
More reliable, no. More efficient, no.
1. The CS-144 will provide MUCH higher amps at low RPMS like at idle unlike a stock 12SI especially for later cars with A/C and rear electric defroster.
The OP has a '73. There is no rear window defroster like on later cars. The 61 amp alternator is sized to run A/C, even at idle, no flickering lights.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
'73 used a 10SI unit. They are renowned for outstanding reliability and durability. Cooling was not an issue on a 10SI. Mine went over 30 years before needing new brushes.
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
What higher amperage loads? See above comments about durability of the 10SI
4. The CS-144 will charge the battery MUCH quicker under higher loads.
Again, what high loads? The stock alternator recharges the battery just fine on mine.
The OP has a '73. There is no rear window defroster like on later cars. The 61 amp alternator is sized to run A/C, even at idle, no flickering lights.
2. The CS-144 will run much cooler than a stock 12 SI and will last longer as a result
'73 used a 10SI unit. They are renowned for outstanding reliability and durability. Cooling was not an issue on a 10SI. Mine went over 30 years before needing new brushes.
3. The CS-144 will be taxed MUCH less at higher amperage draws and will last longer as result.
What higher amperage loads? See above comments about durability of the 10SI
4. The CS-144 will charge the battery MUCH quicker under higher loads.
Again, what high loads? The stock alternator recharges the battery just fine on mine.
More reliable, no. More efficient, no.
Le Mans Master
Joined: Oct 2007
Posts: 7,445
Likes: 970
From: Tennessee/Rhode Island
i had a 10SI on a 73 Nova SS when i owned the car from 78-90. I went through at least 4 alternators in 12 years and 140,000 miles. Reliable No. it's foolish to state that the 10/12SI alternators are just as reliable as the later CS130/CS144 and plain misleading. Do some research on this issue and this fact will be evident. are the 10/12 SI alternators decent units? Yes. Are they just as good as later models? NO!
Last edited by jb78L-82; Feb 12, 2014 at 08:45 AM.