rubber has play , when the engine torques your losing energy when its solid mount the energy is transfered to the rear and that hopefully equals power to the tires
Update: Picture of Solid Motor Mount Ed ground off approximately 1" of rubber and that mysterious center plate to allow a cut piece of 1/8" plate (cut to the contour of the side plate) to fit flush. Welded the plates (one on each side) at top and bottom and volia'! Solid mounts. Not that the supports need it, but a byproduct of this type mod is that it doubles the wall thickness of the support plate where the bolt slot is - which looks better suited for the job it's designed to do IMHO. Pic 1 - grinding the sides down to allow the new plate to fit flush. Note the "mysterious" center plate. Pic 2 - After (picture note: the center hole was intended to allow a 1/2" bolt to tie the two plates together, however, the head of the bolt would've caused a stand-off of the support to the mount, thus the reason for either doing the weld I drew up, or what Ed did - weld a plate on each side)
I know, but there is a reason that the factory makes them flexible. If your tranny housing has to absorb all that sudden burst of "energy", things start breaking...
I used stock mounts on mine and put a chain and turn buckle from the sway bar mounting bolts to the water pump. Leave a bit of slack when driving around town, tighten at the drag strip. My car may not be the fire breather some on here have, but I bet if I hadn't done that I'd have replaced the drivers mount a bunch of times by now. My .02
The mounts are rubber to make for a smooth ride. Most people would not buy a car with solid engine mounts, too much vibration. The solid mounts use rotational force to transfer weight more effieciently to the rear of the car. Quicker response as well. The only time the tranny housing has to absorb any shock is if a solid tranny mount is used. Otherwise, the solid engine mounts play no part in tranny breakage because if a rubber tranny mount is left intact, there is no shock. Dave Edit: I run a bolt through my engine mounts. No issues with frame stand interference on mine. I must have slightly different mounts.
Actually, I think I got the idea of using the bolt from you in the beginning (which I thought was a great idea). I agree, there are obviously different type supports on the market. Do you have a link to a picture of yours?
I finally found the supports with "rivets" in them. ref: EBAY. I can't identify what the upper center area of the picture on the left is.
You could also use standard motor mounts to soak up most of the engine vibration and associated noise and then fab a cable safety that would keep from tearing the mount if your are launching hard and having trouble breaking mounts. Just remember with solid mounts every last bit of vibration from the engine is going to be transmitted thru the entire car. With the cable safety strap properly executed you will have the best of both worlds. Just my .02
