Aftermarket Motor Mount NVH

[XCRN]

Could anyone share some first hand experience with aftermarket motor mounts that utilize OEM Clevite rubber control arm bushings and if there was a significant increase in NVH or if it mostly remained the same? How well have the bushings been holding up. Some examples of these types of mounts are MORE Bombproof mounts, Rustys, and Iron Rock Offroad. I am only asking this as I am designing mounts for a not Jeep engine and want to try and keep down the NVH but still handle moderate off road use.

https://mountainoffroad.com/product...fQTsqdep26jcxOTYDhQlRXA-tGOgg9r0aAlfDEALw_wcB

https://www.rustysoffroad.com/produ...5yEM4zGVUhlv6FMWaGQe5miD048ReyQTYmE3p-tB7oxGD

https://www.ironrockoffroad.com/product/motor-mount-kit.html

 

[mrblaine]

Could anyone share some first hand experience with aftermarket motor mounts that utilize OEM Clevite rubber control arm bushings and if there was a significant increase in NVH or if it mostly remained the same? How well have the bushings been holding up. Some examples of these types of mounts are MORE Bombproof mounts, Rustys, and Iron Rock Offroad. I am only asking this as I am designing mounts for a not Jeep engine and want to try and keep down the NVH but still handle moderate off road use.

https://mountainoffroad.com/product...fQTsqdep26jcxOTYDhQlRXA-tGOgg9r0aAlfDEALw_wcB

https://www.rustysoffroad.com/produ...5yEM4zGVUhlv6FMWaGQe5miD048ReyQTYmE3p-tB7oxGD

https://www.ironrockoffroad.com/product/motor-mount-kit.html

I wish there was a definitive way to figure this out other than testing. All I know is I've used many different iterations of control arm style and tube and sleeve style bushings over the years and have never been able to predict the outcome and the outcome several times was fully contrary to what I expected. Good luck and if anyone tells you different, they have a very narrow band of experience.

 

[XCRN]

I wish there was a definitive way to figure this out other than testing. All I know is I've used many different iterations of control arm style and tube and sleeve style bushings over the years and have never been able to predict the outcome and the outcome several times was fully contrary to what I expected. Good luck and if anyone tells you different, they have a very narrow band of experience.

Thats a fair point. I was mostly hoping to see if it was even a difference enough to even bother worrying about it. I did consider the idea of flipping a factory mount at 45 degrees for this project but it does not look like it would have enough rubber support where the weight will be at nor fit in the narrow window I am working with. My hope is it will almost be a none issue with the 4.3 LVx engine seems to run real smooth in the trucks/vans that come factory with them.

 

[mrblaine]

Thats a fair point. I was mostly hoping to see if it was even a difference enough to even bother worrying about it. I did consider the idea of flipping a factory mount at 45 degrees for this project but it does not look like it would have enough rubber support where the weight will be at nor fit in the narrow window I am working with. My hope is it will almost be a none issue with the 4.3 LVx engine seems to run real smooth in the trucks/vans that come factory with them.

I've related this before but I typically keep a few AutoFab bushing kits around for crossmembers and such. I was doing one and forgot to check the inventory for the large ones and only had the small ones in stock. I cleared it with the owner with the promise that I would convert to the "lower" NVH large one on my dime when he returned from his impending trip we had to get finished for.

Surprise, the little bushings were butter smooth and better than any of the larger ones.

 

[XCRN]

I've related this before but I typically keep a few AutoFab bushing kits around for crossmembers and such. I was doing one and forgot to check the inventory for the large ones and only had the small ones in stock. I cleared it with the owner with the promise that I would convert to the "lower" NVH large one on my dime when he returned from his impending trip we had to get finished for.

Surprise, the little bushings were butter smooth and better than any of the larger ones.

I didn't think of the option for a trans cross member either. I was planning on using a stock GM trans mount that stick fairly low and making a rigid cross member that would need to dip down a bit. But using these bushing I can make a low profile channel cross member and move the bushings higher and possibly get a lower profile skid plate than intended. Not sure what I am going to do yet but definitly some food for thought when I get to that point.

 

[mrblaine]

I didn't think of the option for a trans cross member either. I was planning on using a stock GM trans mount that stick fairly low and making a rigid cross member that would need to dip down a bit. But using these bushing I can make a low profile channel cross member and move the bushings higher and possibly get a lower profile skid plate than intended. Not sure what I am going to do yet but definitly some food for thought when I get to that point.

It wasn't a suggestion for you but an illustration of how easily I've been fooled by trying to predict the final results of various bushing solutions.

 

[XCRN]

It wasn't a suggestion for you but an illustration of how easily I've been fooled by trying to predict the final results of various bushing solutions.

I know it was an example you brought up of your experience at the subject at hand, but it is still something I had not considered this as an option for another problem. Either way I do appreciate your input and figured you would be one of the best people that would have some firsthand knowledge on the subject. Turns out the subject does not have a black and white answer like I was hoping would exist, but thats just how it is sometimes.

 

[GoldenGorilla]

I have a sample size of one, but my stock motor mounts with my 4.0 had sagged around 1/4" and I was doing work in the area that made sense to replace them. I went with an OMIX set initially which were a failure. Now have the MORE and they are alot stiffer and transmit some vibration through at the factory idle rpm. Bumped idle up to 824 and never noticed them again.