10si alternator or 12si....
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
12 si is obviously bigger.
Are you wanting a stock case 100 amp or a new smaller style 100 amp?
Most of us running electric fans ended up converting to a CS144 alternator from an early 90s caddy/impala etc.. If you are using factory big block alternator brackets, the lower bracket will need to be cut/rewelded to accomodate the 144. This is truly the best up grade if you have a lot of electric draw.
I have pics if you need em.
Are you wanting a stock case 100 amp or a new smaller style 100 amp?
Most of us running electric fans ended up converting to a CS144 alternator from an early 90s caddy/impala etc.. If you are using factory big block alternator brackets, the lower bracket will need to be cut/rewelded to accomodate the 144. This is truly the best up grade if you have a lot of electric draw.
I have pics if you need em.
Thread Starter
Race Director
Joined: Jan 2002
Posts: 11,616
Likes: 350
From: No Where USA
12 si is obviously bigger.
Are you wanting a stock case 100 amp or a new smaller style 100 amp?
Most of us running electric fans ended up converting to a CS144 alternator from an early 90s caddy/impala etc.. If you are using factory big block alternator brackets, the lower bracket will need to be cut/rewelded to accomodate the 144. This is truly the best up grade if you have a lot of electric draw.
I have pics if you need em.
Are you wanting a stock case 100 amp or a new smaller style 100 amp?
Most of us running electric fans ended up converting to a CS144 alternator from an early 90s caddy/impala etc.. If you are using factory big block alternator brackets, the lower bracket will need to be cut/rewelded to accomodate the 144. This is truly the best up grade if you have a lot of electric draw.
I have pics if you need em.
Stock case.
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
http://store.alternatorparts.com/727...lternator.aspx
Here is a 12SI, 140 amp high output alternator that is 3 wire like the factory alternator. It is the same size case as a 10SI and should fit your stock brackets without modding. If you are wanting a 10/12SI case, this is the guy to go through.
I got my CS144 from him back 7 years ago/19k miles and its still working strong. It charges great at 800 rpms and I have a LOT of electric load... Hell my fan alone is 35 amps continuous.
I still think a CS144 would be more reliable for a 140 amp as it cools better, bigger case, bearings etc but.... I'd bet the 12SI will be fine .
Here is a 12SI, 140 amp high output alternator that is 3 wire like the factory alternator. It is the same size case as a 10SI and should fit your stock brackets without modding. If you are wanting a 10/12SI case, this is the guy to go through.
I got my CS144 from him back 7 years ago/19k miles and its still working strong. It charges great at 800 rpms and I have a LOT of electric load... Hell my fan alone is 35 amps continuous.
I still think a CS144 would be more reliable for a 140 amp as it cools better, bigger case, bearings etc but.... I'd bet the 12SI will be fine .
Last edited by ajrothm; Jan 29, 2017 at 05:47 PM.
Thread Starter
Race Director
Joined: Jan 2002
Posts: 11,616
Likes: 350
From: No Where USA
Thanks for the suggestions guys. I bought one from Summit today. I had the same one in my 80 and it worked fine. So I thought it would work good in this car. I just have the electric fans.
