Engine Mounts...Poly vs Rubber

[YoungClayB]

Hey guys,
I have my Golen engine on order..should be here in about 2 weeks :D

Whats the difference between the rubber mounts and the poly ones? (disregarding the obvious $50 price difference for the set)

What are the benefits of the poly mounts?

Poly Mounts: http://www.bjsoffroad.com/cartgenie/prodInfo.asp?pid=42&cid=3

Rubber Mounts: http://www.teamgrandwagoneer.com/parts/Detailed/312.html

Thanks,
-Clay

[azwagoneer80]

I know poly mounts are impervious to most stuff that would destroy rubber mounts. They should be stronger too, I have broken a couple of stock mounts over the years. They may transmit more vibration though, they are stiffer.

[FSJ Guy]

You will have to drill out the mount holes for the poly mounts. At least that's what the instructions say. I have yet to install mine, yet.

[shimniok]

I've ripped apart a few rubber motor mounts. It's really common on these rigs, it seems like. I think it's more common if you do four wheeling. The poly mounts are supposed to hold together better but they definitely transmit a lot of noise/vibration into the cockpit. More than I expected. I'll stick to rubber mounts as long as I can.

[cajun_lad]

when my jeep still belonged to my buddy, he broke the stock rubber ones on the trail in URE. every time he gave it some gas it rocked the motor up into the hood and sucked the throttle cable in and accelerated faster. i don't recommend trying it on the trail. he picked up some heavy duty poly ones at the local parts store and haven't had any problems. didnt have to redrill anything either. i say if you plan on offroad use and any engine mods for hp gain, go with poly. just my .02

[nograin]

Advantage to poly is that it doesn't degrade when soaked in oil.
This has been an issue with the trans mounts on my car and particularly the wagoneer.
Disadvantages are that its not as elastic (and doesn't do the job of reducing the vibrations as well). Cost.

I don't wheel the wag - heck I'm lucky to find a dirt road and a stream crossing - and the motor is quite stock. But I think the motor mounts I bought would stop the problems you are describing (breaking due to engine torque). They are a rubber mount, but the metal plates interlock. This does two things, it limits the engine movement under extreme torque, and acts as a fail safe if the rubber seperates.

There's a pic on my wagoneer webpage (http://users.erols.com/mathewg/mggw.html#Engine). I think they were made by Anchor and I bought them from my local independent parts store.

FWIW. I looked into a similar after market product for my car by Schumacher. I was breaking motor mounts pretty regularly (trans too) even though I had a nylon web torque strap. But he suggested that for the application, I'd be better off with a solid torque strap and a normal motor mount. Less vibrtation transmitted and more effective. That's what I did and no broken mounts since then.

[YoungClayB]

Cool. Thanks guys. The engine that I have on order is a performance rebuild by Golen Engine Service and they claim it will produce around 300 hp, but since I am sticking with the stock manifold and carb setup, I suspect that it will top out around 275 - which is still 100 hp more than stock.

The wagon will be my wife's daily driver (i.e. no wheeling :cool: ), so I think the rubber mounts will be just fine - the last thing I want is more vibration or noise in the cab.

[jeepguzzi]

Don't mix poly engine mounts with rubber tranny mounts or vise-versa. I have heard of broken case mounts attributed to this.

[PlasticBoob]

JeepGuzzi is right, and don't forget to swap out your tcase bushings for poly too. BJ's has them.

I bought Daystar "Bombproof" poly mounts and I didn't have to drill anything. As far as vibration is concerned, I didn't notice much of an increase either? Slight, but not annoying. :huh:

One thing I DID notice was that the engine seems to sit much higher up than with rubber, and I now have limited clearance for any air cleaner with a carb. TBI seems to have fixed that issue though.

[shimniok]

They are a rubber mount, but the metal plates interlock. This does two things, it limits the engine movement under extreme torque, and acts as a fail safe if the rubber seperates.

Good point. Thats the kind I've been using. It still broke but after a few years, but definitely prevented the motor from popping up. Got mine at Napa.

Michael