Frame mounted alternator..

[RoadRacer]

Hey all,

I'm looking into mounting my alternator to the frame, not the motor (SBC btw). The frame is in the way for mid or low mounts, so I'm stuck with the alternator waving high in the air or WAY off to the side (and still high).

Given we have a solid mounted motor, I'm thinking it'll work.. and as far as I know, alternators can spin either way. (The fan is directional, sure, but mine is open to the elements, I'm not worried about cooling)

Anyone done this?

Lower is better for roll center too, these things aren't light :)

This is my planned location.

191882

Thoughts?

[Ford & Jeep Fan]

If you really want a clean look under the hood You might think about a alt mounted (runs off the driveshaft) on the rear axle. be warned if you spend a lot of time stopped in traffic idling this might not be the best option.

[RoadRacer]

If you really want a clean look under the hood You might think about a alt mounted (runs off the driveshaft) on the rear axle. be warned if you spend a lot of time stopped in traffic idling this might not be the best option.

It’s not for a clean look per se, my car isn’t even painted ;)

It’s for function.. the bracket I have today has a lot of flex in it and it’s hard to even keep the pulleys lined up at different rpm’s.

[Mastertech5]

Hey, the coyote is mounted backwards, although it is on the engine. Go for it. You might have problems keeping the belt on it it flexes too much when you torque the engine unless there is a spring loaded tensioner.

[GoDadGo]

Are you running a short or long water pump?
> I'm running the long water pump on my SBC powered MK-4 and have a simple setup from March.
> The alternator is on the passenger side of the car mounted in a pretty high position.
> I'm only running an alternator and have no power steering or AC.
Could this work for you or do you have the short water pump?

https://marchperformance.com/chevy/chevy-small-block/pulley-and-bracket-kits/long-water-pump.html/chevy-small-block-long-water-pump-deluxe-22011-c.html

[RoadRacer]

I’m short water pump. No ps or AC either but I can’t find anything else that’s as low (or as tidy) as what I’m doing with the frame mount. The 33 frame literally wraps the engine it’s so tight.

[GoDadGo]

I’m short water pump. No ps or AC either but I can’t find anything else that’s as low (or as tidy) as what I’m doing with the frame mount. The 33 frame literally wraps the engine it’s so tight.

Ugh!...I've got nothing for suggestions....Darn!

[Dgc333]

Take a look at the ultra mini alternators from East Coast Auto Electric. I have one on the Hemi in my Speedstar. You may find you can mount it down low like mine.

191890

[RoadRacer]

It worked out well. I used an old generic sbc mount, and bolted to chassis, then tested it out - worked perfectly through the rev range. I need to find a ~42" belt now, and weld a tab to the chassis for the adjuster.

but the theory worked out well, and was very easy.

191891 191892

[Mastertech5]

Nice job. I tried to like your post but when I click it the thanks and like links disappear and it says 2 likes and won't add mine. Wierd.

[GoDadGo]

Steve's Stupid Question:

Is it spinning the alternator the correct direction?

[RoadRacer]

Steve's Stupid Question:

Is it spinning the alternator the correct direction?

No, but alternators work either way. It doesn’t reverse polarity like you’d think. Something about actually AC internally and diode(s) convert to DC and spin direction isn’t relevant.

[GoDadGo]

No, but alternators work either way. It doesn’t reverse polarity like you’d think. Something about actually AC internally and diode(s) convert to DC and spin direction isn’t relevant.

Something I Did Not Know!
Thanks & Good Luck!

[Mastertech5]

It's because the alternator produces a sine wave which is produced by the spin in either direction and then the diodes convert it to DC. That's why it's called an alternator for alternating current. The old generators did produce DC.

[progmgr1]

While the above discussion about electricity being created independent of spin direction is correct, the fan inside the alternator is highly directional - to the point that you get very little air flow when you spin the fan backwards. The problem is that heat is released any time you push electrical current through a coil of wire. The alternator could cook itself under high load conditions. For that reason, the FFR Coyote Installation Instructions recommended using a specific Honda alternator that was designed to spin clockwise - the correct direction for our inverted alternator installation. IIRC, I bought mine from Rock Auto, and their website included the spin direction in the alternator specs. I suggest you keep a close eye on the alternator temperature during your shakedown drives.

Keith HR #894

[RoadRacer]

While the above discussion about electricity being created independent of spin direction is correct, the fan inside the alternator is highly directional - to the point that you get very little air flow when you spin the fan backwards. The problem is that heat is released any time you push electrical current through a coil of wire. The alternator could cook itself under high load conditions. For that reason, the FFR Coyote Installation Instructions recommended using a specific Honda alternator that was designed to spin clockwise - the correct direction for our inverted alternator installation. IIRC, I bought mine from Rock Auto, and their website included the spin direction in the alternator specs. I suggest you keep a close eye on the alternator temperature during your shakedown drives.

Keith HR #894

Totally get that Keith. Remember that my alternator is still fully exposed to the wind - no hood or sides - it'll have plenty of airflow. That fan might be important under a normal engine bay but I'd be amazed if I have a problem. But yes, I will be watching!!!

[cob427sc]

A segmented V belt? Haven't seen one of those on a loooong time.

[Ford & Jeep Fan]

Totally get that Keith. Remember that my alternator is still fully exposed to the wind - no hood or sides - it'll have plenty of airflow. That fan might be important under a normal engine bay but I'd be amazed if I have a problem. But yes, I will be watching!!!

If I remember correctly most alt fans suck the air in from the back and the air exits the front of the case.

[RoadRacer]

A segmented V belt? Haven't seen one of those on a loooong time.

The green one? Yes, I keep that around for measuring exactly how long a belt I need. Obviously I don't use it on the street. :)