Motor / trans mounts - rubber or poly?

Discussion in 'Camaro Questions' started by Skaal-tel 79, Mar 15, 2007.

  1. Skaal-tel 79

    Skaal-tel 79 Veteran Member Gold Member

    Jun 20, 2004
    CFB Petawawa, Ontario
    Just like the topic says - which is better? What's really the difference?
  2. m pozzi

    m pozzi Moderator Staff Member

    Definitely rubber. The drivetrain has to be able to move. Solid mounts (like polyurethane, etc.) will quickly fail and I've even seen the bolts break when serious HP and torque were applied. In one case, the block actually cracked during a heavy launch. The stock OEM mounts should be more than adequate for your needs.

    If you're putting out some monster RWHP, there might be a high-performance mount available and you might want to post this question in the Competition section of the Forum.

    Mary Pozzi
  3. GetMore

    GetMore Veteran Member Lifetime Gold Member

    Nov 8, 2004
    Patterson, NY
    Mary, I agree with you on the solid mounts, but the poly mounts have some give. In theory they should be fine.
    That being said, I know the theory-have you got the experience? Did you see the problems with poly or solids?
  4. m pozzi

    m pozzi Moderator Staff Member

    I personally saw the broken threads inside of the block and also saw the progression of thread stretch, metal crush, and the supporting evidence leading up to eventual metal fatigue.

    Poly does have some flexibility; just make sure the engine is balanced. And keep the transmission mount rubber. Any flex there will probably break the case or tailshaft housing.

    Mary Pozzi
  5. theflash

    theflash Veteran Member Lifetime Gold Member

    Feb 27, 2004
    Podunk, CT
    I highly recomend the poly mounts. I have had several years of good luck with them, and they are much stronger than the factory rubber mounts if you're considering it in a high hp application.
  6. jmgnpd

    jmgnpd Veteran Member

    Mar 8, 2005
    Nanticoke, PA 18634
    I just bought an Energy Suspension complete kit for my F150. What a POS the directions sent me in the wrong direction costing me money. I called the tech line and the tech totally admitted the directions were wrong but offered no recourse or correction. Two of the bushings for the front end were so stiff I couldn't even compress them for the nuts to fit. I went and purchased rubber replacements instead. The kit and product was just a lousy experience all the way around. I only bought the kit because it was complete. As to my Z, I'm using nothing but rubber replacement parts.
  7. ZS10

    ZS10 Moderator Staff Member Lifetime Gold Member

    Jan 18, 2003
    BC, Canada
    Engine/trans mounts, rear spring bushings, front swaybar, and body mounts, are all Energy Suspension, and worked out exellent. I don't read the diections though.
    Last edited: Mar 16, 2007
  8. GetMore

    GetMore Veteran Member Lifetime Gold Member

    Nov 8, 2004
    Patterson, NY
    Mary, I was asking if they were solid mounts or poly.
    While we're on the subject, do you know/think that breakage was from chassis flex or engine torque?
  9. m pozzi

    m pozzi Moderator Staff Member

    I can't remember if the mounts were solid or poly as I saw this several years ago. It involved something Rice and there was an insurance coverage question about the mounts and the engine damage. I do remember that the mounts were not OEM but aftermarket and possibly solid. I don't remember seeing any poly. If I could find the investigation photos, I could tell you more as I took good close-ups.

    The guy was trying to say he ran over something in the road which caused the engine to raise up and the mounts/engine to break. Didn't find any evidence of any impact to the underside but did see lots of progressive metal fatigue.

    This particular vehicle had all the canyon-racer bells and whistles and I'm sure the engine had been wound pretty tight and often. There was a bottle and spray so some pretty good horsepower got seen. As far as torque, probably not much since it was a 4-banger Ricer.

    In my opinion, for moderate horsepower/torque the stock Camaro mounts are pretty good by themselves. When Dave and I installed the ZZ383 a couple of years ago, I got a wild hair and wanted to replace the engine mounts. After looking closer, I realized it was a PITA to do. I then looked at the OEM mounts and they were fine. I guess some things do last 35 years . . .

    Hope this helps,
    Mary Pozzi
  10. Roadking

    Roadking Veteran Member

    Nov 20, 2004
    North Bend, WA
    I'm glad that I am not the only one that had those thoughts. I put the poly mounts back in the box and they are still sitting on the shelf!

Share This Page