Solid Steel Motor/Trans Mounts

SCrazy

SCCoA Member
My current solid rubber motor mounts are blown and I'm considering switching to solid steel mounts.

This car is almost exclusively a drag car so I'm not hugely worried about vibrations etc.

I will probably also lower the motor a little bit in the process to pick up a little hood clearance.

In addition I would redo the tranny cross member and tranny mount. Currently my long tube header collector flanges fall right on top of my tranny cross member and that is a big P!TA so I'll fix that up as well.

I want to do all this before I do any final adjustment on my rear end pinion angle.

Has anybody done solid steel mounts, observations on vibrations etc?
 
I've never done solid steel mounts, but I would imagine the vibration would be pretty bad! My reccomendation would be to replace the motor mounts with 2 hockey pucks on each side and a grade 8 bolt going through them. That's what we did on the lemons racer, and it works great. The hockey pucks absorb some vibration, but when you get on the gas, all the torque is pulling on the bolt, so it won't rip like the solid rubber mounts. Also doing this will lower the motor about 1/2-3/4". And the best part of it all, your motor mounts will only cost about $5 each!
 
I have done solid steel mounts.

Basically welded a thick piece of pipe inbetween the two stock motor mount brackets, that simply replaced the rubber section. I set up a block on a k-member with one stock mount and tacked the new on in place, then repeat.

I ran them on my car for a little while and ended up not liking them. They worked fine and caused no problem with the motor. However, they completely eliminated lope of the cam at idle. The whole car would vibrate slightly instead of rock back and forth. The vibration wasn't bad. After you got above about 1500 rpm, it was pretty much unnoticeable over the exhaust and whatnot.

For a race car, I'd just go for it.

I can't comment on longevity and if they might crack or anything, because I only had them on my car for about a month.

My car used a stock tranny mount.

Phil
 
On my car, i got new solid rubber mounts. I took a piece of plate and welded it to the tab to make it strong. Then i welded plate on both ends to fill the window it. I did this on both sides. I have pretty much zero movement. Cheap easy fix.
 
From my build thread
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My current solid rubber motor mounts are blown and I'm considering switching to solid steel mounts.

This car is almost exclusively a drag car so I'm not hugely worried about vibrations etc.

I will probably also lower the motor a little bit in the process to pick up a little hood clearance.

In addition I would redo the tranny cross member and tranny mount. Currently my long tube header collector flanges fall right on top of my tranny cross member and that is a big P!TA so I'll fix that up as well.

I want to do all this before I do any final adjustment on my rear end pinion angle.

Has anybody done solid steel mounts, observations on vibrations etc?

Brian,

I put steel mounts in my 93 SC many years ago. The mount on the right shows the bottom, which was welded to the lower mount after initial fitting and securing with a nut. No noticeable vibrations, but that car has a 5.0 based v8 so it might have less vibration that the SC v6 motor.

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David
 
Phil/David...what you've done is pretty much what I was thinking about doing.

When you did this did you also switch to a solid transmission mount? Does the transmission mount do anything other than locate the back end of the tranny? I doesn't seem like it would see a ton of forces.
 
Phil/David...what you've done is pretty much what I was thinking about doing.

When you did this did you also switch to a solid transmission mount? Does the transmission mount do anything other than locate the back end of the tranny? I doesn't seem like it would see a ton of forces.

Brian,

If going with solid motor mounts, you must use a rubber or other flexible transmission mount. BTW, an easy way to gain additional clearance from your headers on the transmission mount is to shim the transmission mount with some washers..to maintain proper angle, shim both sides of transmission cross member where it bolts to the body of the car an equal amount. There is plenty of room to stack flat washers for shimming.

David
 
Really?? I would have thought once you go solid then everything should be solid...what is the thinking behind this?

I think it was to allow for chassis flex...if you go solid on all mounts, trans mount or tail of transmission tends to break. Researched it pretty extensively when doing the solid motor mounts on my car. If using a solid transmission mount you need to use flexible motor mounts and vise-a-verse.


David
 
After some research I guess that makes sense. You don't want to be bracing the chassis with the drivetrain!!
 
You REALLY don't want to use a solid trans mount with rubber motor mounts. The motor mounts allow the motor to twist the trans at the front, while the trans mount does not, somethings gotta give. Buddy of mine split the cases of two powerglides b4 he figured it out, the second one was a borrowed unit:eek:

Adam
 
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