Question about Poly Mounts
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Joined: Apr 2002
Posts: 531
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From: Northern New Jersey
Car: 91 Firebird Formula
Engine: For me to know.....
Transmission: and you to find out....
Question about Poly Mounts
I remember reading a while back that someone on here replaced their motor mounts with poly ones and the strut tower brace didnt fit anymore. Later on they went a different company that sold poly mounts and THEN their strut tower brace fit. In short can anyone tell me which mount keeps the motor at the same height and which one raises the motor??
Later..
Later..
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From: Fort Mill, SC, USA
Car: '88 Iroc, '91 RS, and a '70 RS
Engine: 5.7 TPI; 5.0 TBI; ZZ4/T56 on the ag
Transmission: A4, A4, slated to be a T56
I installed the ES mounts and could not tell a difference. I'm not accusing anyone, but they HAVE to go in only one way.
Ed
Ed
I had Prothane mounts and they raised my engine considerably. I had to get rid of them to get my RPM intake to fit. I do not understand why everyone wants urethane mounts. The camaro mounts are captured in a metal shell, they are next to impossible to break. I bought into the urethane is better but went back to stock rubber, i prefer the stock rubber ones. My mounts were original ( 18 years old ) and were not broken or badly worn. The rubber are also quieter and cheaper.
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Joined: May 2002
Posts: 1,218
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From: Chicago, Il
Car: 1987 Trans Am
Engine: Lt1
Transmission: T56
I just redid mine but I'm not even close to putting in the engine yet. I used Prothane mounts and I measured the bolt hole to the top of the mount prior to and after the change. The difference came out to be approximately 1/8" The car is an '87 Trans Am and the old mounts didn't exactly look all that great. They had cracks and looked stressed. I am not sure but 1/8" doesn't sound like much but couldn't some washers help along the brace mounting holes?
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Joined: Mar 2000
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From: Land O Lakes, FL
Engine: 5.7
Transmission: 700R4
Axle/Gears: 3.27
Yes the big problem is the 1/8 inch difference plus the difference of the poly ones not giving as much with the engine weight added. So with the engine in, it will be more than just the 1/8 difference.
I'd say it raised mine a good 1/4 inch. The only thing that I liked about it is that my exhaust fits tighter to the car now.
Later
I'd say it raised mine a good 1/4 inch. The only thing that I liked about it is that my exhaust fits tighter to the car now.
Later
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Senior Member

Joined: Apr 2002
Posts: 531
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From: Northern New Jersey
Car: 91 Firebird Formula
Engine: For me to know.....
Transmission: and you to find out....
would a strut tower brace fit if you raised the motor 1/4 inch?? I guess it just depends on mount/strut tower brace setup huh?? Im trying to visualize this setup before I go and do it on my car. I really dont want any surprises..ya know what I mean?
laiky~ I have seen motor mounts break on F-body's...granted I havent seen a ton of broken mounts but here and there I find mounts broken on them. I guess the reason why I want poly mounts on my firebird is because its "just the thing to do."
Bare with me..If you ever go to classic car shows you see a lot of cars from the 50's with a ton of hp in them. I think its pretty safe to say that all those cars at these shows have a ton of hp but are probably "babied" by their owners. Yes its kinda stupid to build a car like that but people do it..Next month (depending now what I learn from this thread) I might be one of these stupid people. Just my $.02. Later..
laiky~ I have seen motor mounts break on F-body's...granted I havent seen a ton of broken mounts but here and there I find mounts broken on them. I guess the reason why I want poly mounts on my firebird is because its "just the thing to do."
Bare with me..If you ever go to classic car shows you see a lot of cars from the 50's with a ton of hp in them. I think its pretty safe to say that all those cars at these shows have a ton of hp but are probably "babied" by their owners. Yes its kinda stupid to build a car like that but people do it..Next month (depending now what I learn from this thread) I might be one of these stupid people. Just my $.02. Later.. I didn't mean to say they CAN'T break, just that even if the bushing lets go the clamshell will keep the motor down. Thst is unless you have seen the shell brake? MY brothers 84 still has its originals and mine did too. I also bought the urethane because it seemed like the thing to do. I would have left them but i needed the room. Luckily i welded the nuts to the frame when i had the control arms off!!
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Joined: Apr 2002
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From: Northern New Jersey
Car: 91 Firebird Formula
Engine: For me to know.....
Transmission: and you to find out....
Laiky~ No..I havent seen the shells brake. That's a good idea welding the nuts to the frame though. I dont think anyone ever mentioned doing that before. Later..
Dan
Dan
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Joined: Mar 2001
Posts: 146
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From: Fort Wayne,In
Car: 1989 Formula 350
Engine: 355 HSR
Transmission: Rossler 700R4
Axle/Gears: 9 bolt/3.27
i put in ES then i lighten the engine by about 60-75 lbs. Now i have a vibration about 2200-3000 RPM(while driving) I was wondering if that height difference could cause that. PS also have the poly tranny mount(with the little plate installed)
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