Motor mounting, solid vs transplate vs poly etc

[Slick]

I was planning on some "rubber" motor mounts (poly, rubber, call it what you will) but some local friends tell me I'm nutz for not just solid mounting it...then a local hot rod shop owner tells me I'm nutz for not using rubber. What is everyone using? How about a midplate/transplate? Can I use JUST that and forget the front mounts all together? Engine is a TT 302 if it matters.

My friend who wants it solid says being TT I want it as solid as possible. He's also pushing for the midplate mounting which I like but can't seem to find to many options for other than making my own (why not, everything else is front scratch I guess...)

Opinions? Also any options for places to get midplates would also be appreciated.

Thanks!!

[rocketman]

I you solid mount the motor the tranny has to be done to,if not it will break the tailshaft housing off the tranny.Don't ask how I know.

solid mounted motor is going to viberate like hell and be a pain to drive.

A midplate can't be done without solid mounting everything,If it's not a race car I would worry about and just get some good urthane mounts.

To fit a midplate will require alot of firewall,chassis,header problems.

[Slick]

Thanks for replying.

Like I said I figured on urathane also, but a friend local with a 68 camaro has had many engine configurations in it and always solid mount, it doesn't vibrate, he listed off a million cars today that run solid mount. I found an older post on here today while searching that a few people said they ran solid also with no problems, one said his has less vibration than his friend with urathane...hell now I don't know :willy:

It's all custom on this thing including the firewall which is being cut out this weekend most likely so whatever is involved with a midplate shouldn't be an issue, just seems like it would have to be crazy strong to hold the engine and tranny from the middle, I've found a few midplane installs that seem to all use a front engine plate also, so maybe you can't just use the midplate?

Thanks,

[Bad Bowtie]

Jason,
What I'm considering is using a solid on the torque side (drivers side) with the pass. side being rubber and the trans mount being rubber. It will be awhile before I get to test it though just mocking up motor and tranny now. Just food for thought :thumbsup:
Jack

[Scotch]

Jason,
What I'm considering is using a solid on the torque side (drivers side) with the pass. side being rubber and the trans mount being rubber. It will be awhile before I get to test it though just mocking up motor and tranny now. Just food for thought :thumbsup:
Jack


Bad Bowtie is right on. I have consistently solid-mounted the driver's side and rubber mounted the pass. side. It's a little more vibration than all-rubber mounts, but you don't have to worry about busting a mount either.

With the TT deal, you want it stable - that plumbing doesn't like to move around. But, if you plan to street drive it for any honest length of time, the solid/plate mounts will be loud and transmit tons of vibration through the chassis. If it's just a track-only car, this is fine.

Everything is a compromise. Be honest with yourself about where the car will be used the most, and the answer will be clear.

~SP~

[nitrorocket]

How much power will you have? I run poly with no issues, you WILL NOT break a poly mount! :D

I did not really notice a difference between motor plate, poly and rubber as far as vibration in my car if that helps any. :cool:

[rocketman]

I don't know how you guys get away with mixing motor mounts like that,I have seen alot of broken blocks because of mixing mount motors.

[fatlife]

Thanks for replying.

Like I said I figured on urathane also, but a friend local with a 68 camaro has had many engine configurations in it and always solid mount, it doesn't vibrate, he listed off a million cars today that run solid mount. I found an older post on here today while searching that a few people said they ran solid also with no problems, one said his has less vibration than his friend with urathane...hell now I don't know :willy:

It's all custom on this thing including the firewall which is being cut out this weekend most likely so whatever is involved with a midplate shouldn't be an issue, just seems like it would have to be crazy strong to hold the engine and tranny from the middle, I've found a few midplane installs that seem to all use a front engine plate also, so maybe you can't just use the midplate?

Thanks,


actually you should never run a solid tranny mount, always use a rubber tranny mount, even with solids up front

[Slick]

Thanks for the input guys. How about some reasoning though? Why does a tranny need a rubber/poly mount? etc. I just got a ride in my friends TT camaro with solid everything and the only vibration was my head bouncing off the back of the seat when the boost kicked in ( god damn), and that thing is not tuned at all, he's never messed with an accell gen7 and it's ROUGH right now and that's the only vibration I was feeling, when it spit and sputtered. Is it just in how the engine is built?

[JUSTANOVA]

actually you should never run a solid tranny mount, always use a rubber tranny mount, even with solids up front

I know on dirt track stock cars they use solid front mounts and a poly/rubber rear mount so they don't break the trans case due to chassis flex,

the way our dirt modified is set up is with a midplate and solid front mounts, and we are always tightening the motor mount bolts and midplate bolts. The whole car shakes at an idle but that could be something to do with the camshaft that doesn't level out till about 4k rpms.

[Scotch]

I don't know how you guys get away with mixing motor mounts like that,I have seen alot of broken blocks because of mixing mount motors.


Really? I've never seen a single one. By having at least one rubber mount on the passenger side, all the vibrations have a place to go. The solid on the driver's side doesn't move at all, and it can't break.

I've never seen a block break because of this. With all solid mounts, I've seen the stock block bosses break in extreme applications, but not with a mix.

Interesting...

~SP~

[TravisB]

We mount most of ours solid.......Motor and trans!

[tyoneal]

Mount it with good poly or rubber mounts, then chain the drivers side. Driving around all is smooth and it won't vibrate you to death.

When you decide to get down on it, the chain will do it's job and you won't have to worry about breaking a mount.

I ran a BBC with 650 hp. It worked like a champ and it is an easy AND inexpensive way to solve your problem.

tyoneal

[nitrorocket]

Chaining is a horrible idea, that would snap a block instantly off the trans brake for sure! If it ever gets a hard shock it could break the block, for sure if it is an aluminum block.