Alternator size help
08-28-2018, 11:46 PM
#1
Alternator size help I have a 2000 camaro ss with a cammed/bored .75 over 6.0. Last week I was doing a few pulls and noticed the car would stop pulling above 5000 rpms. I have had the stock 105 amp alt on. Well I wake up next morning to find out my voltage meter is in the red when I leave for work while driving and the car is spitting and sputtering. So I turn around and take off the alternator and check for any grounded out wires and checking the 1 wire that goes into the alt. Well all is good and connected. Even grounds are good. So I swap it out at AutoZone for another 105 amp and the first pull I do I look down and back into the red and spitting and sputtering. So at this point I take it off have it tested and they tell me its bad. At the time of that final pull my belt is sqweeking loudly. I get a refund and go to orileys and get a new belt along with a new TRUCK 145 amp alt. I get it all on and no more squeaking. If this one happens to blow tonight when I try it what could the issue be?? Was the 105 amp alt too small for a cammed 6.0 that's bored .75 over?? Please help. I havent had issues with this one but ive also been to nervous to get the rpms high as well.
08-29-2018, 12:56 PM
#3
Alternators don't know what they're bolted to.
Check your battery terminals and all ground straps and connections, especially the harness grounds to the heads and the ground down low behind the A/C compressor.
Have your battery tested as well.
Typically in an engine that has a cam and a higher idle RPM, the alternator will charge better. The 105 amp rating needs to be sufficient for all loads placed on the charging system, not what the engine revs to or anything else. If you're running the A/C, both fans, big stereo, etc. then the alternator amps may need to be increased. If the accessories on the vehicle are stock, then I wouldn't worry about the amps and keep the 105 on it. If the 145 fits, then you can use it also.
As far as peak RPM goes, I doubt you are anywhere near the critical limit for the Delco alternator. I've run stock GM alternators to 8600 RPM before without issue.
Check your battery terminals and all ground straps and connections, especially the harness grounds to the heads and the ground down low behind the A/C compressor.
Have your battery tested as well.
Typically in an engine that has a cam and a higher idle RPM, the alternator will charge better. The 105 amp rating needs to be sufficient for all loads placed on the charging system, not what the engine revs to or anything else. If you're running the A/C, both fans, big stereo, etc. then the alternator amps may need to be increased. If the accessories on the vehicle are stock, then I wouldn't worry about the amps and keep the 105 on it. If the 145 fits, then you can use it also.
As far as peak RPM goes, I doubt you are anywhere near the critical limit for the Delco alternator. I've run stock GM alternators to 8600 RPM before without issue.