QUestion about ALternator pulley size and belt size

[-=Jeff=-]

the LT1s at some point when to the later style CS-144, it is a larger case ans will not fit in the LT5. I have tried a couple times.

Basically you need the Early style CS-144 not the late style

[-=Jeff=-]

Billet Alt on CF

http://www.corvetteforum.com/forums/...lternator.html

[5ABI VT]

found it easy search http://www.corvetteforum.com/forums/...lternator.html

[5ABI VT]

Originally Posted by -=Jeff=-

Billet Alt on CF

http://www.corvetteforum.com/forums/...lternator.html

lol beat me to it

[5ABI VT]

Originally Posted by -=Jeff=-

the LT1s at some point when to the later style CS-144, it is a larger case ans will not fit in the LT5. I have tried a couple times.

Basically you need the Early style CS-144 not the late style

Interesting info there. Ill relay that to mechman. I sent an email and will call the above guys as well. I was in touch with them quite a bit last year and funny only a few months later I ended up with a zr-1 It sounds like the same alt at mechman to me, same internal description etc.

[WVZR-1]

That billet unit looks like it's based on a CS130-D with an "internal fan". There would need to be lots of documentation I'd think done and also with the CS130-D you would need to maybe fabricate a rear brace mount. Here's the LT5 mounting that I believe is consistent for all.

LT5 Generator mount.png


Once the mounting was confirmed a CS130-D would be probably a very good service replacement. They're known for very high and consistent output at lower RPMs for newer electronics where the older CS144 often wasn't sufficient or effective.

Did Craig or no one else ever attempt the one from the CF thread? Seems like maybe a good bit of effort to accomplish what?

[5ABI VT]

Good question but Im guessing that he didn't have many people lined up for it for a group buy. my motor got delayed.. and now delayed again thanks to my z last year .. but I'll be buying one for that car as well. I contacted quality power and have been trading emails with them the last few hours. They have one that is a direct fit for the z they say. My last question was about alternator pulley size options or if I could use my oem pulley. I will measure my pulley tonight. The quality power is a nipponDenso unit with the hairpin wire technology which I believe is the same as the mechman units. It has a dual rectifier and twice the diodes for durability and their amperage claims are in line with mechmans. The outer design however does differ as the quality power unit looks to have a traditional casing with the stator sandwiched in between while the mechman has a solid housing out of billet. There isn't too much of a price difference I think. ($500 vs 580)

btw anyone know how to measure a pulley correctly? ie. measure outer diameter.. use a wire around the top of the ribs? bottom of the grooves etc? the difference may be minuscule but Id sure like to know

Its funny though that digging into alternators.. I cant help but feel the same way about engine parts. Im actually excited for my stereo system, and exlectronics in the car. now the grounds are beefed up and with this alt anything that needs power should be happy. I will however fire up my current alternator to ensure it works and make some videos of it being tested etc while running. I may just sell it cheap or keep it as a spare not sure just yet.

[WVZR-1]

The links I posted explain the "how to measure" and the pitch dimension is critical for belt alignment BUT changing the manufacturer is going to change the style of pulley available. Everything other than the diameter and the width is worthless, you'll need to use mounting points to bracket(s) to calculate what's required OR send your alternator to the source for them to determine what's actually needed for pulley alignment.

[Dynomite]

Tech Info - Calculating Alternator Pulley Diameter

[WVZR-1]

I believe that GM always tried to maintain a ratio of something near 2.8:1 for the CS144 alternators and that would result in an alternator RPM of 2240@ 800 crankshaft RPM.

Using Cliff's 6.875 (crankshaft pulley diameter) and the 2.44 (62mm often mentioned stock alternator pulley diameter) the ratio would be 2.818(6.875/2.44) so that seems to be in the vicinity. I believe I've seen that the later CS144's will do 75AMP/14V at that alternator RPM. You could of course check the output of the alternator on the car at various engine RPMs to evaluate or confirm.

If you decided that you're using another alternator of some sort because of "electronics" you need to evaluate the equipment's needs and then ask the vendor of the alternator what ratio is going to be required to supply the required power at what ever RPMs that you choose. Vendors I believe often stretch the performance quotations of their product so you might want to be cautious. Now you just need to hope that there's a pulley diameter available with the correct belt routing to accomplish your needs.

Are there any specs from either of your vendors that mention the AMP/RPM outputs of these alternators. Alternators get pretty testy, we did some fleets and emergency equipment that had rather outrageous requirements and in many cases a single alternator wouldn't accomplish it or they were some very unusual configurations.

Your situation is that it also needs to FIT a rather restricted install space. I believe if I were you I'd just consider a build of yours to a MAX AMP from off the shelf parts, pretty it up by "blasting" the case halves as "JEFFZ51" mentioned someplace in your discussions.