[Jeep Man]

Hello my learned and green-ish Brothers and Sisters.

My build:
1984 Jeep CJ-7 - Hyper9HV - IS

I've got everything but the adapter plate and coupler.

Todd at CAN EV is out and I'm not sure I want his standard one right now anyway.

At this point, I don't think it makes much sense to force the coupler to be the same crankshaft to flywheel bolt pattern as the original factory motor.

Given all the accepted knowledge that a lighter, aluminum flywheel is better, I'm going in that direction.

So, the question - I need a vendor / machinist / someone that can help in deciding if I should go with a keyed tapered shaft lock or an interference coupler.

The biggest downside to the interference coupler is, once you heat it up and put it on the shaft of your freshly bought $5k+++ motor, it's on forever. No changing it later.

The downside to the tapered coupler direction is the possibility of not being absolutely flat and fully 'down' on the new motor shaft.

But, if I'm reducing the flywheel to the lightest possible size (within safety and cost ~ 15 lbs or so), I've GREATLY reduced the compounding effect of the original design or the inertia stabilizing design of a flywheel.

So, maybe the combination of a light flywheel with a tapered shaft to a complete new flywheel bolt pattern might be better.

Thoughts? Anybody doing any work in this area?

Thanks,
Patrick

 

[remy_martian]

Meh....if you remove the constraint of getting the coupler off, intact, you can always get the coupler off with a grinding wheel and/or heat.

I would not run a flywheel at all - why have one?

 

[Jeep Man]

Meh....if you remove the constraint of getting the coupler off, intact, you can always get the coupler off with a grinding wheel and/or heat.

I would not run a flywheel at all - why have one?

No, that's stupid - grinding off an interference coupled connection is not a real thing. I'd have more luck with wishful thinking.

Why keep a flywheel - which is to say, you're asking me why keep a transmission?

MANY reasons but I'll narrow it down to 2 words - transfer case.

Get it?

Any other thoughts - anything?

 

[remy_martian]

Skilled hands and knowing that metals yield doesn't rely on wishful thinking

But I didn't ask you why keep a transmission - you kneejerked and asked yourself that question. You can couple the clutch hub to the motor shaft, and delete the flywheel, or have a coupler made that slides onto the tranny splines. Unlike an ICE, you can shut the torque (current) off to the motor when changing gears. If you put a shaved flywheel in there, all you're doing is creating a potential scatterbomb when it fails. Those usually take legs or feet off in the passenger compartment.

That's why.

Your project, you're The Decider...

 

[Jeep Man]

Skilled hands and knowing that metals yield doesn't rely on wishful thinking

But I didn't ask you why keep a transmission - you kneejerked and asked yourself that question. You can couple the clutch hub to the motor shaft, and delete the flywheel, or have a coupler made that slides onto the tranny splines. Unlike an ICE, you can shut the torque (current) off to the motor when changing gears. If you put a shaved flywheel in there, all you're doing is creating a potential scatterbomb when it fails. Those usually take legs or feet off in the passenger compartment.

That's why.

Your project, you're The Decider...

I'll give you kneejerk - fair enough.

So, in reverse order, bell housings + tub flooring have protected drivers and passengers for a years now from your bouncing betty metaphor so, whatever on that silliness.

As far as the other reasons, a pressure plate configuration is also a safety feature - if, for some insane reason, you don't have a kill switch and your motor runs away, the flywheel will burn up the pressure plate and force will cease to be transferred from motor shaft to transmission input shaft. Seems like there's a ton of safety features that will keep this from happening, loosing my right foot seems to be a stretch - don't you think.

Additionally, a transmission will serve, as it was intended, to reduce the RPM coming from the motor - all kinds of good reasons for that - right, you get that.

Also, in an off-road situation, casual, not hard core rock crawler, you need to be able to develop more torque at high reves - transmission.

Now, on to things tethered in reality - I need a transmission. so, any constructive ideas about the original question - help with a coupler / hub design - I'm looking for anyone that has done those from scratch, vendors, machinist, etc.

Every time I read anything on this site, I'm constantly reminded of that movie Mean Girls.

Real help, no derision please.

Thanks,
Patrick

 

[remy_martian]

You don't get it.

You're back to arguing for a transmission, which was never in question.

An electric motor revs normally at 6-10 grand to make its rated horsepower. An ICE, half that...if you build a race motor, sanctioning bodies require a blanket or scattershield around your magic bellhousing.

An electric motor can cut torque to zero with the flip of a switch. It has full torque from zero RPM. It does not produce power pulses that need filtering by a flywheel. "inertial stabilizing" on an electric motor sounds cerebral, but it's a joke.

Whether a clutch and flywheel is there is relevant to your question. Whether a coupler is removable is also relevant.

As I said, your project. You already know the answers, so why ask?

 

[electro wrks]

An electric motor can cut torque to zero with the flip of a switch.

Without some sophisticated electronic controls, there still would be the rotational inertia of the motor's rotor to deal with. This would be at least several times more than the rotational inertia of a clutch disk in a typical flywheel/ clutch disk/ pressure plate set-up. This extra inertia generates more force for the transmission gear synchronizes(syncros) to overcome to shift gears. This is why it can be difficult to shift gears with an electric motor drive that doesn't have the disengaging clutch set-up. This may be unacceptable in J-man's application where he want's to quickly grab a different ratio in the transmission and possibly a high/ low ratio in the transfer case. Or, possibly two wheel to four wheel drive.

An electric motor revs normally at 6-10 grand to make its rated horsepower. An ICE, half that...if you build a race motor, sanctioning bodies require a blanket or scattershield around your magic bellhousing.

I believe the Hyper9 motor has a relatively low operational RPM and as a permanent magnet motor, very unlikely to over-speed. https://evwest.com/support/HyPer_9HV_144V_Performance.pdf
A user of any motor would need to confirm the safety of a given motor/flywheel combination.

Getting back to your original questions, J man. canEv seems to be one of the few good producers of these critical parts. You might check with the canEV parts retailers to see if they have any back stock, or leads on used parts. The critical areas of concern with the design of the coupling are keeping it attached to the motor shaft. And, if you use a flywheel/ clutch set-up, good axial and radial run-out( as you pointed out), and some provision for a pilot bearing(bushing). The adapter plate must have accurately located and close fitting alignment dowels, just like the OEM bellhousings and canEV plates.

 

[Jeep Man]

Without some sophisticated electronic controls, there still would be the rotational inertia of the motor's rotor to deal with. This would be at least several times more than the rotational inertia of a clutch disk in a typical flywheel/ clutch disk/ pressure plate set-up. This extra inertia generates more force for the transmission gear synchronizes(syncros) to overcome to shift gears. This is why it can be difficult to shift gears with an electric motor drive that doesn't have the disengaging clutch set-up. This may be unacceptable in J-man's application where he want's to quickly grab a different ratio in the transmission and possibly a high/ low ratio in the transfer case. Or, possibly two wheel to four wheel drive.



I believe the Hyper9 motor has a relatively low operational RPM and as a permanent magnet motor, very unlikely to over-speed. https://evwest.com/support/HyPer_9HV_144V_Performance.pdf
A user of any motor would need to confirm the safety of a given motor/flywheel combination.

Getting back to your original questions, J man. canEv seems to be one of the few good producers of these critical parts. You might check with the canEV parts retailers to see if they have any back stock, or leads on used parts. The critical areas of concern with the design of the coupling are keeping it attached to the motor shaft. And, if you use a flywheel/ clutch set-up, good axial and radial run-out( as you pointed out), and some provision for a pilot bearing(bushing). The adapter plate must have accurately located and close fitting alignment dowels, just like the OEM bellhousings and canEV plates.

Exactly and, again, it's needs a transfer case thus, I would have to build a complicated adapter from motor to blah, blah - THANK YOU Electro - I'm giving up on whatever bug is up Remmy's bum, back to the ONLY question I needed an answer to.

So, CAN EV is out of stock till next year, 'first quarter' according to Todd one of the owners. They were my first choice and would have been happy to get that done but, he decided not to sell me his last one or something not worth going into now. Doesn't matter, he doesn't have them and now I'm more interested in making my own.

Does anyone have any other ideas on a shop that has any experience making one?

Thanks,
Patrick

 

[brian_]

An electric motor revs normally at 6-10 grand to make its rated horsepower. An ICE, half that...

Not quite, automotive gasoline engines typically make peak power at something in the range of 4500 to 8000 RPM; a peak under 5,000 RPM is rare, and none produce peak power as low as 3,000 RPM. Yes, slower than typical EV-sized electric motors, but not half the speed.

 

[brian_]

An electric motor can cut torque to zero with the flip of a switch. It has full torque from zero RPM. It does not produce power pulses that need filtering by a flywheel. "inertial stabilizing" on an electric motor sounds cerebral, but it's a joke.

It's true that the torque fluctuations of an electric motor are minimal compared to a typical engine and so there is no need for a flywheel, but it doesn't appear from the original post that the intent of the "inertial stabilizing" comment had anything to do with filtering power pulses.

 

[brian_]

I believe the Hyper9 motor has a relatively low operational RPM and as a permanent magnet motor, very unlikely to over-speed.

Due to the controller (rather than the PM motor design), an AC motor will not overspeed under its own power - the controller simply won't drive it faster than it is configured to run, even with zero load.

 

[brian_]

At this point, I don't think it makes much sense to force the coupler to be the same crankshaft to flywheel bolt pattern as the original factory motor.

I agree. Even the couplers provided by CanEV are related to the original engine's crankshaft flange only by the desire to use the same flywheel that the engine used, so that the same clutch can be used, so that the transmission works with it. You can certainly use a different flywheel and/or clutch (or no flywheel or clutch at all), and select a coupler to suit the combination of components that you are using rather than what the vehicle originally used with an engine.

 

[brian_]

If you put a shaved flywheel in there, all you're doing is creating a potential scatterbomb when it fails.

Only if the flywheel is cut down by someone who is massively incompetent. Most the material in a flywheel is there for rotational inertia, not to transmit torque or to support the clutch. An EV conversion doesn't even use the starter ring gear, which (with the material supporting it) accounts for a substantial part of a stock flywheel.

For an example of how minimal a plate to transmit engine torque can be, look at the flex plate from an automatic transmission installation... and keep in mind that it is still larger and stronger than required because it carries the starter ring gear. Of course a plate (whether a modified flywheel or a custom part) used with a clutch needs to be more substantial, because it is one face of the clutch system and it reacts to the clutch clamping force.

The flywheel of our race-prepared Honda was roughly cut in half by a local machinist using a lathe, still retaining the ring gear and using the stock clutch, and it had no problems. A flywheel for an EV could be considerably lighter, without the ring gear, while still using a clutch.

The clutch for an EV - assuming that one retains the clutch for shifting purposes - can be much smaller than it would be for the same vehicle with an engine, because it doesn't need to handle slipping to get the vehicle moving. If using optimal parts the "flywheel" and clutch assembly can be very light, but there's no need to go crazy... it's a Jeep, not a race car.

 

[remy_martian]

Didn't know that VW diesels, diesel Toyota minitrucks, and Ford F250 Powerstrokes, all ICE, made peak HP above 4500 RPM

 

[brian_]

Didn't know that VW diesels, diesel Toyota minitrucks, and Ford F250 Powerstrokes, all ICE, made peak HP above 4500 RPM

I specifically excluded diesels (that's both the VWs and the PowerStrokes), and current Tacoma engines peak at 5500 RPM (4 cylinder) and 6000 RPM (6 cylinder). Yes, diesels are ICE, but the argument that an electric motor produces peak power at twice the speed of a typical ICE based on the slowest-turning ICE - the diesels - is just not sensible. The transmissions, clutches, and flywheels of even those diesels are not in trouble at the speed of motor typically used in a conversion, and the proposed HyPer 9 doesn't run any faster than a common car engine.

By the way, typical EV motors make their full rated power over a speed range starting from about 3,000 RPM to close to their maximum operating speed. The HyPer 9 IS system is not limited in power to protect the battery (because it isn't configured for a specific battery), so it is allowed to produce as much power as the available voltage allows... and the peak power is still reached by 4,000 RPM @ 144 V. If using a transmission, there is no need to run most of these motors any faster than the engine which they replace.

 

[electro wrks]

The clutch for an EV - assuming that one retains the clutch for shifting purposes - can be much smaller than it would be for the same vehicle with an engine, because it doesn't need to handle slipping to get the vehicle moving.

From a torque multiplication POV, it's true less slipping is needed. However, most ICE clutch set-ups are designed to produce a higher grip on the clutch disk as RPM increases. This keeps the pedal pressure low at start-up and accommodate the increasing torque produced by the engine as the RPM increases.

Most electric motors can produce their max torque at start-up when the clutch torque capacity is low. This can produce clutch slippage and damage and why some EV converters use high grip racing clutches to try to prevent this.

So, you might want to go bigger, rather than smaller, clutchwise

 

[Jeep Man]

Meh....if you remove the constraint of getting the coupler off, intact, you can always get the coupler off with a grinding wheel and/or heat.

I would not run a flywheel at all - why have one?

- No one cares Remy, go build your own and stop hijacking threads.

Not quite, automotive gasoline engines typically make peak power at something in the range of 4500 to 8000 RPM; a peak under 5,000 RPM is rare, and none produce peak power as low as 3,000 RPM. Yes, slower than typical EV-sized electric motors, but not half the speed.

- Zackly

It's true that the torque fluctuations of an electric motor are minimal compared to a typical engine and so there is no need for a flywheel, but it doesn't appear from the original post that the intent of the "inertial stabilizing" comment had anything to do with filtering power pulses.

- Zackly

Due to the controller (rather than the PM motor design), an AC motor will not overspeed under its own power - the controller simply won't drive it faster than it is configured to run, even with zero load.

- Zackly

I agree. Even the couplers provided by CanEV are related to the original engine's crankshaft flange only by the desire to use the same flywheel that the engine used, so that the same clutch can be used, so that the transmission works with it. You can certainly use a different flywheel and/or clutch (or no flywheel or clutch at all), and select a coupler to suit the combination of components that you are using rather than what the vehicle originally used with an engine.

- Zackly
I bought an entire set this morning - the guys over at jeepforum - who are NOT EV experts, helped me figure it out - I'll post what I got in a separate post.

Todd did a great job filling a crazy complicated problem but you're right Brian - it's not ideal at other then in the category of Plug & Play

Only if the flywheel is cut down by someone who is massively incompetent. Most the material in a flywheel is there for rotational inertia, not to transmit torque or to support the clutch. An EV conversion doesn't even use the starter ring gear, which (with the material supporting it) accounts for a substantial part of a stock flywheel.

For an example of how minimal a plate to transmit engine torque can be, look at the flex plate from an automatic transmission installation... and keep in mind that it is still larger and stronger than required because it carries the starter ring gear. Of course a plate (whether a modified flywheel or a custom part) used with a clutch needs to be more substantial, because it is one face of the clutch system and it reacts to the clutch clamping force.

The flywheel of our race-prepared Honda was roughly cut in half by a local machinist using a lathe, still retaining the ring gear and using the stock clutch, and it had no problems. A flywheel for an EV could be considerably lighter, without the ring gear, while still using a clutch.

The clutch for an EV - assuming that one retains the clutch for shifting purposes - can be much smaller than it would be for the same vehicle with an engine, because it doesn't need to handle slipping to get the vehicle moving. If using optimal parts the "flywheel" and clutch assembly can be very light, but there's no need to go crazy... it's a Jeep, not a race car.

- Again, Zackly

Thanks Brian - I'll post what I ordered this morning next.
Patrick

 

[Jeep Man]

Based on the jeepforum guys suggestion and talking to the folks at RAM Clutch, I've ordered this package.

Flywheel: 2511 – ALUMINUM FLYWHEEL CHEVY 153 TOOTH - $379
Clutch package: 88760HDX – HDX CLUTCH SET GM DIAPHRAGM - $299
Website: https://ramclutches.com/

Ordered!

 

[brian_]

From a torque multiplication POV, it's true less slipping is needed. However, most ICE clutch set-ups are designed to produce a higher grip on the clutch disk as RPM increases. This keeps the pedal pressure low at start-up and accommodate the increasing torque produced by the engine as the RPM increases.

This makes sense, except that normal clutches are not centrifugal, so grip doesn't change with speed. Yes, some drag racing clutches have a centrifugal component, but that has about the same relevance to a Jeep CJ with a HyPer 9 as Formula One aerodynamics and suspension tuning.

Does your clutch have levers as shown in this example, preferably including places to put weight on the levers to change the effect?
How to Make Key Adjustments to a Drag Racing Clutch
If not, you don't have a clutch which uses a centrifugal system to engage with more grip at higher speed.

Most electric motors can produce their max torque at start-up when the clutch torque capacity is low. This can produce clutch slippage and damage and why some EV converters use high grip racing clutches to try to prevent this.

So, you might want to go bigger, rather than smaller, clutchwise

You might want to go more aggressive (in the same sizze), since smooth slipping is not required. On/off behaviour is fine.

For this particular project, given the motor plan, any random clutch used with the Jeep's original transmission should be more than adequate.

 

[brian_]

Based on the jeepforum guys suggestion and talking to the folks at RAM Clutch, I've ordered this package.

Flywheel: 2511 – ALUMINUM FLYWHEEL CHEVY 153 TOOTH - $379
Clutch package: 88760HDX – HDX CLUTCH SET GM DIAPHRAGM - $299
Website: https://ramclutches.com/

Ordered!

Did you ask if you could get that flywheel without the ring gear, since you have no starter to use it? It looks like the ring gear may be held on by bolts, so you might be able to easily remove it. You can just leave it, since the flywheel inertia is not critical.