Rubber versus polyurethane engine mounts
Rubber versus polyurethane engine mounts Hear me out. I've got a 63 Chevy II wagon ls2/t56 swap with just at 2k miles post swap. I put Energy One polyurethane mounts both engine and transmission. The car pre LS swap with a small block and 4 speed was smooth as could be, everything mounted in rubber. I like many others unknowing though tougher stiff = better. I had a insane vibration anything above 70mph and worse on deceleration. A couple of days ago after reading some old threads here on ls1tech I bought and put in a OEM rubber trans mount and to my delight it made a big difference in felt vibrations. I still like the idea of poly engine mounts but what about putting a rubber mount on the passenger side only to soak up more vibrations and leave the Energy One poly on the driver's side. Anyone try such?
Hear me out. I've got a 63 Chevy II wagon ls2/t56 swap with just at 2k miles post swap. I put Energy One polyurethane mounts both engine and transmission. The car pre LS swap with a small block and 4 speed was smooth as could be, everything mounted in rubber. I like many others unknowing though tougher stiff = better. I had a insane vibration anything above 70mph and worse on deceleration. A couple of days ago after reading some old threads here on ls1tech I bought and put in a OEM rubber trans mount and to my delight it made a big difference in felt vibrations. I still like the idea of poly engine mounts but what about putting a rubber mount on the passenger side only to soak up more vibrations and leave the Energy One poly on the driver's side. Anyone try such?
TECH Resident
Joined: Jun 2011
Posts: 936
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People have reported using poly on both engine and trans like you originally had, makes everything so stiff that it cracks the transmission case.
Similar to your idea, I've also heard of people using solid mounts on only the driver side and rubber on the passenger and transmission. The driver's will be under tension when the engine torques at WOT, which puts a lot of stress on that engine mount.basically trying to pull it apart. Then the rubber is used on the passenger side and transmission to soak up the engine vibration without making the whole combination over-constrained.
Similar to your idea, I've also heard of people using solid mounts on only the driver side and rubber on the passenger and transmission. The driver's will be under tension when the engine torques at WOT, which puts a lot of stress on that engine mount.basically trying to pull it apart. Then the rubber is used on the passenger side and transmission to soak up the engine vibration without making the whole combination over-constrained.
