Reverse-mount 12V alternator
Posted: Tue Jul 02, 2019 8:07 pm
After seeing the thread for the alternator solutions, I decided to start up something different.
I wanted to add a common, off-the-shelf 12V alternator to the Pinz, but currently the only solution is something over $1000. Rather than just try to do the same thing cheaper, I wanted to get the alternator up higher and away from the heat of the exhaust . Unfortunately, the only other place is blocked by the distributor.
Unless! You go with a reverse mount like so! I found an 80A 10SI alternator from Tuff Stuff that is fully rebuildable and has an awesome case size. Supports a 1-wire install, but I plan to do an OEM-style 3 wire.
Here's an image of what I want to do. After looking over the math for belt engagement, I plan to go higher than what's shown in the pic, but I have the exact number I need calculated.
In addition, I wanted to change the belt tensioning method to be a more tradition style versus the shims. This also makes the belt sizing easier.
So I designed this bracket that supports the reverse mount of a 10SI and uses 3 mounting locations on the motor. I made sure it could be made from a bent material, no machining. It gets waterjet cut, bent, and then I will weld up the mating faces to make it nice and rigid. I ran some analysis and with A516 (because I get it for the same price as A36) and my minimum factor of safety is >10 with the stress of alternator weight, belt tension, and torque transmitted through the V-belt. I have a prototype that I'm having printed to make sure measurements are okay.
I definitely didn't have to actually engineer the thing, but... it's what I do.
This is what it looks like all mounted up.
It obscures a corner of the fan, furthest from the cylinders, about a 5%-ish obfuscation, but clears the doghouse and lower shroud just fine.
Wanted to run this by the community and get some feedback and make sure there wasn't any issues I was overlooking. I appreciate the feedback in advance!
I wanted to add a common, off-the-shelf 12V alternator to the Pinz, but currently the only solution is something over $1000. Rather than just try to do the same thing cheaper, I wanted to get the alternator up higher and away from the heat of the exhaust . Unfortunately, the only other place is blocked by the distributor.
Unless! You go with a reverse mount like so! I found an 80A 10SI alternator from Tuff Stuff that is fully rebuildable and has an awesome case size. Supports a 1-wire install, but I plan to do an OEM-style 3 wire.
Here's an image of what I want to do. After looking over the math for belt engagement, I plan to go higher than what's shown in the pic, but I have the exact number I need calculated.
In addition, I wanted to change the belt tensioning method to be a more tradition style versus the shims. This also makes the belt sizing easier.
So I designed this bracket that supports the reverse mount of a 10SI and uses 3 mounting locations on the motor. I made sure it could be made from a bent material, no machining. It gets waterjet cut, bent, and then I will weld up the mating faces to make it nice and rigid. I ran some analysis and with A516 (because I get it for the same price as A36) and my minimum factor of safety is >10 with the stress of alternator weight, belt tension, and torque transmitted through the V-belt. I have a prototype that I'm having printed to make sure measurements are okay.
I definitely didn't have to actually engineer the thing, but... it's what I do.
This is what it looks like all mounted up.
It obscures a corner of the fan, furthest from the cylinders, about a 5%-ish obfuscation, but clears the doghouse and lower shroud just fine.
Wanted to run this by the community and get some feedback and make sure there wasn't any issues I was overlooking. I appreciate the feedback in advance!
