Help with unusual motor mounting

[Tremelune]

I'm converting a classic Mini to electric and I'm at the point where I need to get the Leaf motor mounted up to the Mini front subframe. My plan is to get everything aligned, cut, and tacked up with an emphasis on good fitment, after which I'll have a professional welder come by for the real deal. I have manilla folders for mockups, and time to kill...

My first question is this: Should I build everything from steel or try and modify the OEM mounts for the motor side? One of the mount points on the motor has a 1" protrusion in the center of the bolt holes.

The subframe is 12AWG 1.25" OD chromoloy 4140, and the OEM motor mounts are...some flavor of aluminum. I was planning on using 0.25" thick steel plates for the mounts if I didn't use the OEM stuff.

If anyone has a favorite source for existing mounts and styles that might work for this weird motor/subframe combo, any advice is appreciated!

Left:

Right:

Rear:

OEM mounts:

 

[matt_i]

Do the OEM mounts fit? You know those work for that engine. So no guesswork there, just fabricate the adapter bracketry and structure.

I don't know your HP but probably any rubber element chassis bushing would work within reason and could simplify the design somewhat. Protection could be needed if near heat sources.

 

[joe_padavano]

You should make maximum use of the OEM Nissan motor mounts, especially the rubber isolators. These are tuned not only for NVH but also to prevent fatigue loading from starting and propagating cracks in the aluminum housing. By far the best plan is to bolt the original mounts to the motor and build adapters or brackets from there to the subframe. Make any custom brackets OUTBOARD from the rubber mounts.

 

[Tremelune]

Unfortunately, the unmodified mounts are way too large for the Mini—they'll contact the body outside the subframe, and I'd rather not cut that up. I was thinking I'd cut off the the arms, and weld the plates to a smaller rubber/poly mount.

Torque will be a maximum of 210ftlb.

Edit: Although maybe not all of them...I'll measure better...

Edit 2: Nah, they're too big. It's tight in that Mini engine bay!

 

[Jagmandave]

Hey Tremelune,

Glad to see you're still going on with your Mini/Leaf conversion, I agree with others that if at all possible you should try to use the OEM Nissan rubbers, but I would simply cut and weld up some steel brackets to attach them to the subframe.

Good luck!

MiniDave from Restoration Mini, TMF etc

 

[Tremelune]

Thanks Dave! It's looking like no matter what, I'm gonna have to do some modifying, cobbling, trial and error...but that's the "fun", right?? At least I can't leave the house for a while...