Motor plate: Attach or not?

[RockinRobin]

I've had problems with my GenIII hemi throwing serpentine belts. It is only used to run the water pump, no alternator, etc. I bought a motor plate just to use as a backing plate for a Big Block Chevy electric water pump, many choices and much lower prices. The motor sits nice and still on solid steel motor mounts. So the question is should I put in some angle irons on the frame rails and bolt the motor plate in or just let it ride on the frame rails? 750 Flywheel HP

 

[ScampMike]

won't it vibrate like the dickens against the frame if you don't?

 

[bOb shingler]

bolt it in.

 

[A body]

I actually put threaded inserts into my frame and use an "L" to bolt it into place. Allows for easy access to bolts and allows the engine to come straight forward for r/r ease. My plates on my engines rest on the frame.

 

[RPMagoo]

I welded tabs onto the sub frame, and bolted the motor plate to the tabs. -- I'd say bolt it in for sure. -- My 2 cents.

 

[brian6pac]

1st, if it's throwing belts check pulley alignment.
2nd, if you are using all 3 original style rubber mounts don't you think if you bolt the plate solid it will cause a binding problem? I do.
Bolt the plate solid and remove the front rubber mounts, you also need to make a mount to keep all the weight off the trans mount when the car launches.
Use all the rubber mounts and leave the plate loose to move.
My 2 cents.

 

[RockinRobin]

1st, if it's throwing belts check pulley alignment.

Yep, it's pulley alignment, pulley side play (Schumacher unit), and failing belt tensioners.

2nd, if you are using all 3 original style rubber mounts don't you think if you bolt the plate solid it will cause a binding problem? I do.

Yes, I agree if I was using rubber motor mounts it would cause a binding problem. I have solid steel mounts.

Bolt the plate solid and remove the front rubber mounts

I don't have rubber mounts, what I'm considering is bolting the plate to the frame rails AND keeping the solid mounts in place.

 

[brian6pac]

I would go ahead and bolt it down, it will stop it from vibrating.

 

[RustyRatRod]

Is this a trick question?

 

[RockinRobin]

Is this a trick question?

Sort of, because I bought a motor plate, but really not to function as a motor plate. In my application it is there merely to serve as a backing plate for the electric water pump.
For those of you who haven't priced an electric water pump and backing plate for a gen III hemi, the choices are limited (there is only 1 that I am aware of) and expensive.
This custom milled motor plate was actually cheaper than the one backing plate on the market!
I could just cut the wings off the motor plate, but what if I want to use it's full potential sometime down the road? I guess I'm trying to have my cake and eat it too.
The next question is possible vibration, and maybe it will, but motors strapped down tight with solid motor mounts don't vibrate, they shake. The shake has never been annoying since it is a track only car and if it did cause noise you would never hear it when the motor is running with open headers right under your seat.
It looks like I need to just go ahead and bolt them down, I just wanted you to understand the logic behind considering not to.
Also my approach is purely from a racing point of view, I don't care what it would sound like on the street with mufflers and rubber motor mounts because that's never going to happen.
I thank you all for your input!

 

[ScampMike]

I'm thinking by bolting it in you're tying one more thing in tight.. and it being a race car, anything the stiffens the frame is a good thing...

 

[RustyRatRod]

Well, you chose that combination. I am not sure the motor plate will pass tech without being bolted down. Plus, imagine the devastation if you were involved in a serious accident your engine WILL become a projectile. By not bolting it in, you are risking the safety of not only yourself, bot others as well.

Do the smart thing. Bolt it in.

 

[RockinRobin]

I am not sure the motor plate will pass tech without being bolted down.

Best reason yet!

 

[LeftyJD]

My vote would be bolt it down and lose (cut out) all the sock mounts/hardware. You'll come out about even on weight and have a stiffer, safer car. Other option would be cut the ears off so only the section that is actively being used as a spacer is left. But that seems like a step backwards to me.

 

[MMissile]

If for no other reason...to me, an un-attached motor-plate looks dumb.