pros and cons to poly motor mounts?
#1
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I have a poly trans mount and am planning on doing a head/cam swap soon and was thinking to change the motor mounts while the car is in parade rest! What is the benefit to having poly mounts over the stockers? I have read that they are very much worth doing, but why? what kind of differences did you notice with them in?
Just kind of a newbie with too many questions on my mind.
Curtis
Just kind of a newbie with too many questions on my mind.
Curtis
#3
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I guess some of the energy that would have been absorbed by the softer motor mount will be transfered directly to the drive train and chasis.
I suppose it will put more stress on parts like the u-joints, the differential, etc. And like gearhead said, you will likely feel more vibes throughout the car.
On the positive side, I imagine you'd get a slightly more responsive reaction when you step on it. Also, as you are probably aware, since the motor will not twist as much, it will help prevent having your exhaust bang on the floor.
I suppose it will put more stress on parts like the u-joints, the differential, etc. And like gearhead said, you will likely feel more vibes throughout the car.
On the positive side, I imagine you'd get a slightly more responsive reaction when you step on it. Also, as you are probably aware, since the motor will not twist as much, it will help prevent having your exhaust bang on the floor.
#4
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You'll wish you'd done poly motor mounts sooner once you get them in, I only did the driver's side and it made a huge difference. It really tightens the car up. You really should have poly motor mounts anyway since you already have a poly tranny mount. I've heard it's bad to have rubber motor mounts with a poly tranny mount. The motor is wanting to rock from the weak rubber mounts but the tranny stays put with the more solid poly, and some say it could crack the tailhousing on the tranny. I know I've read something like that on here before.
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Absolutely do at least the driver side mount. If you're dealing with a poly trans mount already then I'd be surprised if you even notice a difference in NVH with the poly motor mount(s). What you WILL notice, however, is much less engine vibration at idle, which is a good thing if you're going to go with a lumpy cam. Also, this is a great mod if you have any exhaust-banging-the-floorpan problems since it will really reduce the movement of the drivetrain during hard accel or shifting.