Hot Rods Engine rev'd… generator did not.

I’ve been getting comfy with the coupe since the rebuild where I focused on the Late 50’s - early 60’s era. The goal was to stay true the more common speed parts of the era: 311 small block (first year 327, destroked and bored) the right heads and all the goods including a 4 speed Hydro, Hydro-Motive competition transmission. So like points, I choose to run a generator, not a look-a-like to be true. Friday I found the small block revs quick, somewhere around 7k my reman Delco generator went pop and flamed out… covering my vintage paint in a cloud of copper winding sparkle dust.


So... how or what would a guy have done generator wise back in the day? Is there a certain year shorty AC generator that is more robust or mix and match of desirable parts I should look for that spins better than others? I know the Jr Stock guys talk of pulley swap with deeper belt. Also see a difference in pulley fan set ups one piece vs the 2 piece alternator?
Looking for an education – thanks!

 

If you intend to use the upper rpm range, how about a bigger pulley on the generator (or smaller on the crank) to keep the generator rpm down even when the engine revs to the moon? Water pump also has a limit when it may cavitate rather than pump coolant well, so that's worth keeping in mind when raising the redline on the tacho far above what the parts were intended for.

 

I've wondered the same, but have not found the rev limit on mine yet. Probably won't with the '39 trans and banjo, but this 283 does rev pretty good.

 

Maybe you just need to try another generator. I had a similar failure on a Corvair several years ago. The engine spent a lot of time in the 3000-4000 rpm range on the freeway, and the commutator "exploded" while doing so. I think they just get old, and whatever is holding them together, fails. The replacement used generator is holding up fine.

 

You re-discovered why hot rodders ditched generators just as soon as possible. I wasn't there but I would bet with any serious high speed work the generator was removed or bypassed.

The heavy, spinning armature doesn't like 7,000 RPM remember the generator spins even faster: Also any surviving examples are likely very worn or at least out of tolerance by now. I think the runout spec is something like 0.0005"

 

Bitchen car Chris!!!!

 

X2 on changing the pulley to a bigger on the generator or smaller on crank.

 

Corvettes had a larger generator pulley. We used to put them on alternators to help keep belts in place. I think they are still available.

 

You want a pulley almost as big as the 'fan' behind it if going for high revs. The downside is low-RPM charging (not the generator's strong suit to begin with) will be even more sucky. Try McMaster-Carr for a pulley.

I used to explode generators on a regular basis 'back in the day', but replacements were only $10 at the wrecking yards. Not the case today....

The only real cure is an alternator. They can take it...

 

I think all of the High Performance/Solid Lifter engines had the large diameter deep groove pulleys. I could be wrong though.

 

Moriarity is right! I need to keep in perspective what the car is and driven. Doesn’t sound like there was any preferred generator that did better than another but the pulley trick seems most popular. Digging through my vintage magazines to see if there is was ever a write up - I’ll let you know.

 

https://www.ebay.com/itm/185428304923?

or something similar, might have the right look.

 

When I take mine up past 4500 it doesn't like it so much and doesn't charge for a little bit but then after a little while comes back to life for some reason. This usually only happens when I erase it at the strip but just the other day did some spirited driving in the same thing happened. But this was used when I put it on the car 15 years ago

 

That's one reason why the runout spec is important, the commuter needs to be almost perfectly concentric, good bearings &c, or the brushes can start to "bounce" at high RPM and lose contact, this will stop charging.

 

I was building a high reving 289 k-code hipo motor a few years back (for street use)...when explaining the purpose and rpm goals to various venders to get reliability at the upper rpm range I was seeking, a number of the vendors gave me the following pretty good advice..."just shift"...lol.

 

Mine was throwing spark the last time.....I think the rivets must be down on the armature.

 

Dump the generator and adapt a early 60's Mopar alternator. Mopar started using alternators in 1960 as a option on Chrysler models because of all the electrical stuff on them. By 61 they were standard on all Mopar cars. It will operate better than the generator and still be period correct. I have one i will be adapter to my 39 and for the 259 Stude motor slated for my 32 Tudor. I love the look of Generators, but hate how they work compared to a good alternator set up. Easy upgrade and they look pretty cool too.

 

Got a pic of one?

 

Same basic design from 60/61 all the way to 87. They still require a voltage regulator, which keeps the old vibe, and they span such a long period, parts a readily available. Honestly I'm surprised you don't see it more often on 60's period hot rods.


This is the early round back design used from 60/61 through 69.

 

I would imagine that it's because they look like the later alternators.

 

Just make sure to get an early one, from the 60s...they redesigned them for the 70s, to use an electronic voltage regulator, but they also made the diode area larger, and "square" looking. Most folks don't notice, but I sure do

and the early ones are getting harder to find, the chain parts stores sell you a later one in place of the early one.

 

As an example of one used back in the day, Here is a PIC i got from another thread here on the HAMB a while back showing it being used on the Sam Conrad Roadster. This would have been between around 64 65 most likely. Sam Conrad was a member of the LA Roadsters and his 371 Olds with a hydro powered 29 roadster on 32 frame has infected my brain for many many years.

 

Nice.

 

The early ones seem to be multiplying at a rapid rate on the shelf in my shop…maybe I should separate them.

 

Here's what you need. Frankly, I'd use an alternator with the separate voltage regulator.