To those that have switched did it cause any noticable increase in vibration while driving or minimal or just what? Reason I ask is because I was considering these but just wanted some input to those that have these and how they liked them. Thanks

Brian

 

I didn't notice much difference (in vibration)......it sure helped a good bit in keeping my exhaust pipe from hitting the bottom of the car..........they are a BIT*H to install (stock motor mount stuff sucks) but all things considered I would say they are worth the time/cost/work.....

Why are you considering them? If it's to solve exhaust problems, they will help some but you will probably still need a torque strap to keep the engine from torque over.


I have plate mounts (solid) now and wouldn't have anything else.....

 

More info to be had in the External Engine section.

I have poly mounts on both sides of mine. Right
afterward I did notice that the engine miss that
used to jerk the motor at idle, was now bumping
the whole car instead. Not a big deal, just something
you notice initially and forget about. Otherwise no
difference for NVH I could see. Not that I have a
really rough motor, it's still basically stock aside
from plumbing.

 

Did mine to eliminate y pipe banging on floor. IT ABSOLUTELY FIXED THAT. So far, it is the best $ I have spent and no increase in vibration at all. No negatives to this, except the crappy install.

 

Im with Nick D

 

Why put in poly? Solid mounts are lighter, and the vibration is hardly noticeable, even with my big cam. The LS1 is really a smooth running motor.

 

So what mounts to get? Thunder has the Urethane Mounts. What others are out there? They are only $50. To install them dont you lift the motor up enough to pull the stock mounts and then put the new ones in and lower it down? I know it prolly isnt JUST that simple but isnt that pretty much how it goes?

 

I felt a slight increase in vibration, but it also fixed my Y pipe banging.

 

stock location solid mounts + thin wall aluminum block = bad........they put a lot of stress into the block and over time WILL distort the cylinder bores and can crack the block...........


I have even seen iron block Big Block Chevys with distorted blocks as a result of solid mounts in the stock location........without rubber/poly, SOMETHING has to "give" and the block is usually the one that does the "giving".......

TO ME......if you want a solid mount then the ONLY way to have a solid mount is to do a front and mid plate as you spread the load over the entire block......

(now before I get flamed all the hell.......YES...people run solid mounts in the stock location and never see any problems...........I don't want the risk and personally would not suggest that route to anyone........)



I think there is only one company making the inserts (I think Prothane.....~$50 sounds right....I got mine from Summit back before really anyone was doing poly mounts on LS1s......).......you will still have to buy some stock mounts (get a "junk" pair from someone parting out.....by "junk" I mean the rubber is bad.....the case needs to be good....) and replace the rubber insert with the poly set.......

you drill the rivets in the mount "case" out, the steel halves fall "away", you stick the poly inside the halves, and then either tack weld or bolt them back together (I had the steel halves powder coated and then bolted them together).........

you will unbolt the mounts (pull the main two big bolts) and lift the engine with a jack until you can unbolt and slide the old ones out........then just slide the new ones in (why it's good to have bought another set and have the mounts "made" ahead of time)..........

 

yeah, put a section of 2/4 on your jack and stick it under the engine, unbolt the old ones... 4 bolts on K-member, 4 bolts on engine block, lift up engine. Whole mess comes out. Drill press if you got one to separate clamshell. bench vice to get the poly in. I used loc-tite on the clamshell bolts just to make sure those suckers never come loose.

Do one side at a time, when you're putting it back together, do as many threads as you can while on the jack, then lower it and then torque em down, you dont want to torque em wit the engine still on the jack for obvious reasons

 

nahhhhhh......the engine and tranny are only 500-700lbs .....your head can hold that up easy......