Stovebolt.com Forums The Shop Area The HiPo Shop Someone talk me out of a crazy idea...

A bunch of places these days (such as my work) have special parking reserved for hybrids. I have been toying with the idea of putting together some kind of hybrid drive for the 58 just to troll security.

I also just sorted out that I have a 265 rather than the 283 I thought I had.

What weird problems would I create by using the PTO port on the SM420 for an electric assist? I am envisioning something similar to the GMT800 system that used a 48V motor in the bellhousing to provide a torque boost.

I am not worried about the controls side of it, more the mechnical problems I could run into from backfeeding the PTO.

YESSSSS!!!!! Go for it! Anything to tweak the tree huggers' noses is OK in my book! You could even use a small 3 or 4 speed transmission between the drive unit and the PTO to give some extra torque for getting the vehicle moving from a stop- - - - -maybe a passenger car 3 speed from a torque tube driveline from the early 1950's. Those transmissions are tiny, but they had enough torque capacity to move a full size car down the road.

Since the PTO drives through a set of straight cut gears on the cluster gear assembly, there would be some noise involved. At one time, the big 28 volt DC starting motors for radial aircraft engines were dirt cheap from military surplus outlets, but those things were WW II surplus. It took a lot of torque to crank up a 9 cylinder, 1200 HP Wright Cyclone engine on Dad's B-17. The truck pullers used to adapt them to run a hydraulic pump for power steering on their pulling rigs.
Jerry

If this guy [thefoat.com] can do over 100 mph in the 1/4 mile on two forklift motors, you could hook one up thru a PTO on your truck. You'd have plenty of room for batteries in the bed. BTW, that video was taken at the drag strip I used to run on just north of Anchorage. That pass wasn't quite 100 MPH, but I've seen him do over 100.

I was thinking something like this: https://www.evwest.com/catalog/prod...;osCsid=2966c1ba58f8827f28b96223aa30f1f9

48VDC could come from 4x batteries mounted along the frame rail under the bed. It has 70ft-lbs of torque up to about 2000RPM, which is about where the 265 gets its wind.

It would take some creativity to couple the potentiometer throttle with the engine throttle, but nothing some time with the mill couldn't solve. The regenerative braking system comes with a mode for operation inline with the brale lifht switch.

If the PTO would not get mad being backdriven at those speeds, I think it would be fairly easy to do.

Now I just need to find a PTO and a few thousand dollars to build it...

As far as the noise, I suspect it would be similar to the electric humvee I built in grad school. It had a straight cut planetary for the "transmission" as well. It was a lot of fun to bang around in and mess with people.

How do you intend to get 48 volt Alternating Current from DC batteries?
Jerry

I have an extra 420 PTO if necessary!

Ed

The controller takes 30-60 VDC and converts it to AC to run the motor.

Honestly I am just toying with the idea. I was half hoping the design of the PTO would prevent it so I could put the idea to rest.

My top priorities are getting my brakes and rear diff in order so I can safely get on the road. Once it is safe to stop and go, then I can start considering other upgrades.

The current sticking point that I need to think more about is shifting gears. Since the PTO is on the transmission side of the clutch, the electric motor would stay engaged even when the clutch was pressed in. As long as the driver did not try to rev match using the throttle, it should work if the regenerative braking was turned down. Most EVs and controllers* start regenerating when the throttle is below a programmed threshold. That would wreak havok on shifts, but it looks like it can be turned off in this particular controller.

The ROI on this idea would be purely entertainment to screw with the treehuggers and show off at car shows. There is certainly some value to that, but maybe not enough to be worth the cost. The upside is that I could be driving it while working on it by just disengaging the PTO.

The GMT800 version of this picked up 2-3mpg city and lost about 1/2mpg highway, so the operating cost benefits are pretty minimal.

I sat down for a while after my transmission thread and spent a while re-evaluating my short term and long term goals and have backed off a lot of the things I was going to do right away. I originally planned to get it on the road quickly so I could start enjoying it, but I fell into "while I am here" scope creep and it ballooned into a much larger project.

My long term plan is to do a high tech tech upgrade to GMT800 technology across the board (LS, AWD, ABS, etc), but that is a 10k+ project and I just don't currently have the resources for it. Once I get it driving (hopefully this summer) I can decide if a mild hybrid conversion would entertain me enough to push out the big upgrades.

*all that I have worked with, but I am not willing to commit to it being a universal truth

Use an intermediate roller clutch from a Turbo 350 transmission to let the drive free wheel while you're shifting. Just machine an aluminum housing to adapt the roller clutch between the drive motor and the transmission. The vehicle will freewheel as you let off the loud pedal and allow up and down shifts with no load on the driveline.
Jerry

Jerry, I will have to look at how that would work. I am not intimately familiar with the inner workings of the TH350. Is it a one way clutch like a ratchet or something? Or would it need an additional linkage to engage/disengage?