LM Hybrid? Crazy idea?

[Toyguru]

Ok, so I've been trying to think of a way to add a mild hybrid system to my LM, and today I had a thought, so wanted to bounce it off some more experienced Corvair owners to see what the general consensus would be.
I'm an auto tech, not an engineer, but I have a fair bit of experience with EV stuff and very familiar with that end of things, but my budget is very limited.
I have most of the parts I think I'll need from previous small EV conversions, except batteries, which I can source later if the concept works.
I'm not interested in doing this for outstanding mileage gains, but more as way to add some bottom end grunt when wanted, and it could function as a stop/start system to prevent idling a lot in traffic.
Here's the basic concept:
I would replace the alternator with a Briggs Etek motor which can produce about 18hp and 40 ft lbs for short periods of time. The motor would also act as a generator to charge the 12v battery and charge the small 48v battery pack through a suitable charge controller(s) like those used in a wind generation system. The Etek is a "pancake" permanent magnet dc motor that is very efficient and fairly light and compact for the power output (and I already have 2 of them)
The belt would be replaced with a hexagonal drive belt that would work well with the direction change and transfers torque better than a traditional v belt.
The motor would have a pulley about the same diameter as the crank pulley, maybe a bit smaller, and could potentially crank or assist the engine up to 3000rpm. It wouldn't involve a huge amount of fabrication, and hopefully completely reversible if I ever wanted to go back to stock.

That's the basic idea, thanks for reading through it, any thoughts?

[Nickshu]

Going to start stop on demand like modern hybrids might require some serious fuel injection and ignition technology.

Sounds like a fun way to waste a lot of time and ALOT of money. Go for it!!!

[Toyguru]

Not that ambitious, wouldn't have the same kind of start/stop as modern cars, but could shut off engine during long stops and just use the electric motor to crawl along in heavy traffic, that kind of thing.

[azdave]

Fun stuff to think about and you're likely to learn a bunch along the way even if it doesn't seem like a good idea to others. I say go ahead if you want and concentrate on the concept of using the alternator location to provide both a charge for the batteries and an e-assist on demand for the engine.

First configure the e-boost motor in place of the alternator and only worry about it assisiting the engine for your early proof of concept. Forget about making it charge either set of batteries or how the throtle would be managed. The car can run a long time with no alternator in use. Just get to the point that you can prove your e-assist idea is viable by making a simple speed control (or on/off switch) that you can enable as you do some acceleration comparisons.

I would advise to approach it in small, managable steps so first get the e-assist working using the standard pulleys and belts if possible. After you have that figured out then work on how you will wire it for charge/discharge and how the throttle will be managed. Up to this point it would probably be easy to reverse the mods with only a few hours of work if you lose interest or it's not worth the effort for the extra HP.

Only after all of that is fully successful would I ever consider going further with ideas of start/stop.

[SteveH]

This is a cool direction! When I read the title I thought someone was going to do what I had been thinking about. That is to replace the front with an electric drive. Would make it "sorta" AWD, and could be interesting way to "hybridize"

This sound like a MUCH simpler way to apply the tech in a useful way.

Will be following this.

[Hank_jackson]

good afternoon all



I believe there is a flaw in your idea, using the pulley system you would actually be turning the main engine all the time
shutting it off would do little I believe, the losses incurred would negate any benifit and possibly destroy the main engine
a better way would be to find a way to drive one or both front wheels with the electric morors.
and then your Idea just might be doable.

Hank

[Toyguru]

Thanks for all the input!
The hub motor idea would be a great way to go if I had a larger budget for this, but I wanted to try something simple with parts I have on hand, as azdave suggested, small steps to try proof of concept to see if the pulley system will work and go from there.

Hank, I don't see it as a flaw, I see it as a more efficient way to assist the engine and start it up. I wouldn't want to shut down the engine and use the electric motor stand alone, except maybe at very low speed for very short distances. Even if the motor can make up for the cooling fan drag on accel, it would be an improvement, and just fun to try out.

Keep the comments coming, it's great feedback!

[miniman82]

Seems like it would be a lot easier to drive the front of the trans with an electric motor with the clutch locked in, disconnecting the engine from the drivetrain. You'd have to do a portion of the Crown V8 conversion to the trans and probably a fair amount of body cutting to make it fit, but it would be a lot easier than trying to replace the alternator with a motor.


Like replacing the V8 in this pic with an electric motor?

[azdave]

Seems like it would be a lot easier to drive the front of the trans with an electric motor with the clutch locked in, disconnecting the engine from the drivetrain. You'd have to do a portion of the Crown V8 conversion to the trans and probably a fair amount of body cutting to make it fit, but it would be a lot easier than trying to replace the alternator with a motor.


Like replacing the V8 in this pic with an electric motor?

Easier?

He's curious to see if an electric motor in place of the alternator would be beneficial. Anything past that is a major undertaking.

I do agree that a start/stop system is out of the question with such an arrangement.

[Hank_jackson]

good afternoon all

Ok with that said I would probably use an A/C style bracket to mount the motor and use an A/C or air pump pulley to modify

I think it would be less modification to the existing systems, no need to remove the alternator or modify the mount for it

I could take some pics of the way an after market compressor mounts if you like.

keep us informed I am real curious how it works out

Hank

[Toyguru]

Hank,
That would very helpful, thanks!

[turnert7696]

Here's a thought, how about mount the motor in the location of the starter? If I'm not mistaken, that's how some of the new hybrid hypercars work. That way, you don't have to worry about transferring power through the belt.

[Toyguru]

I don't think there's enough room to fit the Etek motor there, and the gear ratio would be too high and over rev the motor.
I have a different motor that is smaller in diameter, and higher rpm, but is quite long, and lower power (4 hp cont)
Anybody know how many teeth on a PG ring gear?

[turnert7696]

I didn't think of that... You'd need a small gearbox to change the ratio to one that would better suit it.

[PressurizedPancake]

I think your concept is very interesting. Would this be similar in concept to how the 5.3L hybrid Tahoe operates? After driving a relative's hybrid Tahoe, and seeing her get 20+ MPG regularly, I've always wondered if this could be adapted to existing technology.

The two things I can think of that come to mind not knowing exactly what your pancake motor/generator looks like, I'd keep in mind that the Corvair accessory drive rotates opposite of "conventional" engines, and also I'd probably have a pulley or adapter to use an existing serpentine pulley machined to bolt onto the Corvair pulley/damper to keep the load off the already fragile stock V-belt system on the Corvair. This also gives you more options on mounting locations for the pancake unit.

Good luck and keep us posted!

[Hank_jackson]

Toyguru

could you post a pic or two of the motor you are talking about.

will try to post a couple of pics of the compressor from my other computer, probably tomorrow

Hank