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Discussion Starter · #1 ·
We have an advanced 9" dc electric motor in a 92 mustang coupe. Right now we are designing the motor mounts and we don’t know if it will be ok to face mount this motor "in essence, have the motor hanging off the transmission". The transmission will be solidly mounted.
 

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Hi. I don't know that specific motor/transmission setup but I would say the DC motor will rip your trans mounts off fairly quickly. In fact, I would put quite a bit of emphasis on strapping that DC motor down with a solid steel base to heavy duty motor mounts.

JR
 

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We have an advanced 9" dc electric motor in a 92 mustang coupe. Right now we are designing the motor mounts and we don’t know if it will be ok to face mount this motor "in essence, have the motor hanging off the transmission". The transmission will be solidly mounted.
Think of it this way..... have you ever seen an ICE mounted on the trans only? lol I know the ICE is heavier... but that 9" could generate as much or more torque depending on controller and what was originally in the vehicle. Make a centre ring mount and/or front mount.
I made a ring mount for mine + I uses a miniature shock absorber to absorb torque twist. ( it was there on the ICE... so I just adapted it). There are lots of examples out there.
 

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Discussion Starter · #4 · (Edited)
What I'm thinking about doing is make a plate between the bellhousing and electric motor that would be tied into the right and left subframes of the unibody. The rear trans mount will be factory then the front trans mount will be as I said tied into both sides. The 9" DC will be face mounted to the plate then the rest of it will just hang out into the engine compartment.


I've been looking at a lot of pics and vids. I've see mounts welded directly to the motor case on some motors.... is this an OK practice? Also can the larger bolts on the cast iron motor housing be removed and mounts be bolted on in those location?
 

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Discussion Starter · #6 ·
The weight will be supported by a face plate between the motor and the transmission. The cast alum. bellhousing will not be holding the load of the motor.
 

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The motor will be fine, I've seen the 9 inch used in old VW Beetles (no motor mount.) The plate mount idea is used in some race cars so it is a valid plan too, if you mount that plate to something substantial. Here is my Prestolite MTC-4001 mounted that way.
 

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In drag racing that's called a mid plate (the plate that will actually mount your motor and the front of the transmission). The biggest issues with your plan are the bolts. You will have 150-ish pounds of motor secured to the vehicle only by the bolts. I'm not saying that's necessarily a problem, but some thought should go into it. The bolts will be subjected to additional shear and tension loading, so I would recommend the highest quality/strength available. Ditto for the bolts securing the drive end head to the motor frame, and the bolts mounting the plate to the car. Following these suggestions may be overkill, but that's the standard for custom work and racing - over-engineer, because you don't have access to extensive materials engineering data and testing to support just using "enough".
 

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Discussion Starter · #10 ·
I've been looking at midplates throughout the day on the net. I didn't use the term because I figured most EV guys probably would not know what I was talking about. Pretty much I'm making a midplate that is commonly used on a small block ford (302/351 bellhousing). Grade 8 should be good to go?

Also can the bolts in the side of the cast iron motor be used to make mounts on? I've already built one electric stang, I call the prototype, but this one hopefully will be even better.
 

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...Grade 8 should be good to go?...
Yeah Grade 8. The size depends on what the motor is drilled and tapped for, how many there are, and what you can fit.


...Also can the bolts in the side of the cast iron motor be used to make mounts on?...
The bolts on the side of the motor frame are holding the field coils in place. I'm not sure about exactly what they're screwed into, how much pressure it can stand, and if there would be any ill effects. You need Major to chime in on that one. Personally, I would use the field coil bolts for this. I would drill and tap new holes just for the mounts.
 

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Discussion Starter · #12 ·
Are you saying that I could drill/tap into the cast iron motor case and bolt on from there?

I've see several pics w/ hooks protruding from motors that people are using to chain their engine hoists too... I just haven't figured out how they are mounting the hook. I assume if they are lowering the motor in w/ a single hook on the housing then it must be able to be drilled/tapped.
 

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Are you saying that I could drill/tap into the cast iron motor case and bolt on from there?

I've see several pics w/ hooks protruding from motors that people are using to chain their engine hoists too... I just haven't figured out how they are mounting the hook. I assume if they are lowering the motor in w/ a single hook on the housing then it must be able to be drilled/tapped.
Those hooks are big magnets - just kidding! :D Pretty certain they are drilled and tapped. A bottom-tapped, blind hole might be nice, depending on the thickness of your frame.
 

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Discussion Starter · #14 ·
seems that 1 piece of angle iron under the motor bolted directly upwards w/ a gusset on each side would hold the weight .... the torque... not so sure.

I know its not a mid plate design but i've got a lot of ideas in my head right now. Check out this MSPAINT pic and see what you think.

 

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Looks good for supporting the weight. Go with something like 3/16th wall angle iron for the crossmember. If you're combining this with the midplate, you'll have a very strong setup. I'm all about racing-oriented stuff so that looks normal to me. I've noticed that some of the conversions here use rubber in the motor mounts to isolate the chassis from vibrations and noise. Also, if you use solid front and mid mounts, use a solid trans mount, or vice versa. Allow them them to move, or not move, as a cohesive assembly.
 

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Discussion Starter · #16 ·
i'm still scared of drilling/tapping the case. Seems like the material is pretty thin... IE not enough threads. Also the drill bit might come in contact w/ the field coils.
 

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i'm still scared of drilling/tapping the case. Seems like the material is pretty thin... IE not enough threads. Also the drill bit might come in contact w/ the field coils.
Just weld or bolt a round band clamp style electric motor mount to the angle iron. Same end result, but no drilling and tapping. It supports the weight, while the midplate controls the torque.
 
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