07-25-2020, 12:57 PM | #1 |
Registered User
Join Date: Sep 2011
Location: N.C.
Posts: 133
|
Alternator question
Hi all,
I guess my question is similar to cwcarpenter98 My question is, I have an 8103-7 alternator which is rated at 105 amps. When my truck is in drive my engine rpm drops to about 550. At this rpm (when my Taurus fan kicks on) my amp needle is jumping like crazy and truck runs poorly unless I give it a little throttle. If I increase my engine idle RPM then my truck wants to lurch into gear. Probably need to change my torque converter again but it seems to drive great the way it is. Back to what I really hope someone can answer is, what alternator can I use at this rpm. I am running the stock crank pulley which I am not sure of the size? Is there an alternator out there that I can swap with or a pulley that will speed up the alternator I am currently running. I will also be adding a vintage air unit this fall. Thanks in advance. |
07-26-2020, 12:01 AM | #2 |
Registered User
Join Date: Jul 2012
Location: Whitehorse yukon
Posts: 1,218
|
Re: Alternator question
I am not familiar with that alt number
What is your truck and engine combo? I got rid of the external regulator on my 68 in 1990 for si style 105 smp alt I still noticed my light dim at idle Putting pops 72 on the road going with a cs130 altenator with serpentine belt setup The cs 130 cs144 have a better output at idle |
07-26-2020, 09:38 AM | #3 |
Registered User
Join Date: Sep 2011
Location: N.C.
Posts: 133
|
Re: Alternator question
Thanks for the reply. I think my current alternator is a cs130 type. The 8103 is the part number. It would have run on mid 90's cars with serpentine like a 94 Buick. I don't have serpentine I have a v belt. My truck is a 66' 283 with vortec heads that was built by a speed shop in Raleigh. Has a little bit of a cam so the idle is lower when in gear, about 550.. Would a cs144 bolt up to the stock brackets? I'm trying to determine which alternator would be the most effective at idle and not affect the output curve on the alternator at higher rpms?
Thanks |
07-26-2020, 11:31 AM | #4 |
Registered User
Join Date: Jul 2012
Location: Whitehorse yukon
Posts: 1,218
|
Re: Alternator question
I know cs144 is larger in size
I would think it has same output at idle as its little brother cs130 My understanding is the cs style has 80 % output at idle compared to a much lower si output Si altenator is the previous version of altenator starting on 73 up c10 trucks You can try a smaller pully on your alt to drive it bit faster |
07-27-2020, 08:43 AM | #5 |
Registered User
Join Date: Jan 2016
Location: Washoe Valley, NV
Posts: 110
|
Re: Alternator question
I have a similar alternator on my 1971 K20. It has a TPI motor out of 1986 Corvette, but the alternator is off of a 1990s Chevy Pickup. Running a serpentine belt. I have a 16 inch SPAL electric fan. My idle is computer controlled right at 750 RPM and I don't see any issues when the fan kicks on other than sometimes the AMP gauge needle dips on fan startup. 550 RPM is a really slow idle speed.
Have you tried just bumping the idle up? |
08-21-2020, 07:25 PM | #6 |
Registered User
Join Date: Oct 2015
Location: Ottawa, Ontario, Canada
Posts: 750
|
Re: Alternator question
The cs130 alt are smaller and they do not get rid of as much heat as the CS144. The cs130 much hard to repairs( take longer to repairs on a cs130, then a the CS144)
and the cs130's are know for bears going bad on the rear. The CS144 have much better cooling more AMP selection can be taken apart easier then cs130. The two draw backs are the CS144 Alt is bigger then the big SI 70-80 Caddy Alt. And the CS144 weight is heavy of all SI-CS Alt. CS144 is made more like the SI style for the most part witch makes it except for the in proved cooling better charging at low idle. And can be easy to add to most trucks set ups. This link may help you. https://bowtieguy.proboards.com/thre...t-grade-cs144d
__________________
1977 REG cab Long Bed with a 1984 Front Clip, 82 305 .60 over 9.0.1 flat top pistons, 4bbl, TH350, w/84 SS-intake & cam , w/ 1977 big block rad, 1975 gear box, 1984 master w/ metric fittings top & SAE fitting @ portion block, 1975 3.42 gear open diff. Duel 77-87 Factory air cleaner, duel inlet from rad support . Down sized 9' to new 8' Steel flat bed Was a 77 454 w/308 gear. Taken out 550 lbs. up front with motor clip change. |
08-21-2020, 08:56 PM | #7 | |
Who Changed This?
Join Date: Jan 2013
Location: Simi Valley, CA
Posts: 10,081
|
Re: Alternator question
Quote:
__________________
~Steven '70 Chevy 3/4T Longhorn CST 402/400/3.56 Custom Camper Simi Valley, CA |
|
Bookmarks |
Thread Tools | |
Display Modes | |
|
|