crashandburn
1/2 ton status
Does the 6.2 take pretty much the same alternator as any other Chevy V-8? I am looking at higher output, maybe one wire alternators, and just want to know that it will fit before I buy one.
CK5
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6.2 alternator
- Thread starter crashandburn
- Start date
bailey9r
1/2 ton status
I don't know why but I bought 4 alts for my 6.2 (86) and none worked even though they were for the 6.2 discount auto (ok I do know why those two didn't work 
) and two from other suppliers. I took my original to a rebuilder and he wound it to put out like 30 more amps and it has worked flawlessly for a year now. 
) and two from other suppliers. I took my original to a rebuilder and he wound it to put out like 30 more amps and it has worked flawlessly for a year now. v30mongo
Registered Member
Most 6.2 diesels in C/K andR/V were fitted with the Delco 10-SI altenator, usually of about 60 AMP capacity. An option on the P series truck was the Delco 27-SI altenator of about 100 AMP capacity. It took diffrent mountings on the engine. If you can find a P series truck in the junk yard with the 27-SI option, you are in luck. Or mabe companies like Leice-Neville can provide a larger altenator and the required mounting brackets. A nother option is the altenator from the CUCV military truck series. They have two altenators, one 24V and the other 12V. With this you will need to have the altenator, mounting brackets, and the voltage regulator with the wireing harness.
thedrip
1/2 ton status
Thats not quite true about the CUCV's. They have two 12v alternators, with floating grounds. One has the ground hooked to the block (chassis ground) and goes to battery 'A'. The 2nd has the ground hooked to battery A's positive terminal (12v above ground), and the positive hooked to battery B's positive, which provides 12v to battery B as well. The end result is that A and B in series make 24v, but each alt is only making 12v. All of this isn't true of the ambulances, which have an alternator that produces 12 and 24v.
crashandburn
1/2 ton status
Let me word this differently, as I didn't really state my intentions that clearly. If I bought a 100 or 140 amp alternator out of Jeg's or Summit, universal for a GM, would it bolt up?
v30mongo
Registered Member
Remember, the word "universal" can mean anything. If the replacement altenator is made from a Delco 10-SI or is a 10-SI clone it will bolt up. The only thing is that has the correct belt pulley set for a V belt or serptine belt.
ANy 10SI or 12SI will bolt up.
Just make sure you get the right pulley for it, I had one from a Cadillac and it had serpentine pulley on it and I made them change it to V belt.
I installed a 140 amp CS144 "large case" on my 6.2 powered K5. It's not exactly a direct bolt-on, but fairly easy:
- you need to modify the existing harness or buy a cheap adaptor harness to go between the new alternator and existing wiring
- shimmed the upper bracket up
- replaced the coolant fitting that comes out t-stat housing from a straight piece to a 45 degree
- still required notching the upper bracke to clearn the above
Obviously had to use a v-belt pulley. It works okay but the power required to turn the alternator is on the verge of what a single v-belt can handle.
- you need to modify the existing harness or buy a cheap adaptor harness to go between the new alternator and existing wiring
- shimmed the upper bracket up
- replaced the coolant fitting that comes out t-stat housing from a straight piece to a 45 degree
- still required notching the upper bracke to clearn the above
Obviously had to use a v-belt pulley. It works okay but the power required to turn the alternator is on the verge of what a single v-belt can handle.
crashandburn
1/2 ton status
Got it, thanks. I will make sure it is a 10si or 12si, and try to stick with the small case.
