Question about solid dogbone engine mount. (Page 2/3)
Kevin87FieroGT JUL 01, 07:56 PM
On the GT the other 3 mounts, if stock, would be rubber. Two on the trans(manual), and one under the front of the engine. Guess you might want to go poly all the way around if trying to get more power to the wheels. With a poly dog bone the torque twist goes elsewhere considering the other mounts are stock rubber.
Kevin87FieroGT JUL 01, 08:11 PM
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[This message has been edited by Kevin87FieroGT (edited 07-06-2018).]

Blacktree JUL 02, 08:58 AM

quote
Originally posted by Kevin87FieroGT: With a poly dog bone the torque twist goes elsewhere considering the other mounts are stock rubber.


Yep. The next component to look at would be the rear tranny mount. It's compressed under acceleration. So a mount with better compression resistance would reduce drivetrain movement. That should also balance out the torque twist under acceleration.

[This message has been edited by Blacktree (edited 07-02-2018).]

crashyoung JUL 02, 11:45 AM
I plan on solid mounts for my engine swap. I like engine vibration...
My 63 Nova had solid mounts all around, the vibration was great from the 350 mouse motor!
theogre JUL 02, 12:39 PM

quote
Originally posted by Patrick:

...and the ability to increase vibration to the cab.

I noticed when I installed the poly dogbone in my Formula that the added engine vibration at idle from the 1.6 rockers became quite evident. I don't mind it, but I suspect I wouldn't like even more vibration being transmitted through a solid dogbone.

Not only vibration you feel...
Solid engine/trans mounts and "dog bones" can break the car. Is like hitting w/ a sledge hammer to entire car. Something has to give from torque/suspension/etc loads and if not then will break whatever is weakest... Sheet metal or spot welds, aluminum trans case, even cast iron/steel engine blocks.

And that's ignoring everything expanse/shrinks at different rates for heat cycling for engine heating, weather, etc.

ETA--> Many use chain/cable to limit loads on engine/trans mounts. They go tight only for launching to protect the mounts. Many mounts are built so this is not needed for most cars.
polly mounts/dogbone and auto trans can shake the car at idle too. I hate polly DB in duke w/ auto but saves breaking exhaust and intake parts and that's w/ solid rubber engine and trans mounts. See my Cave, Torque Strut (OE engine mount is liquid filled and doesn't last more then 2-3 years.)

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 07-02-2018).]

RayOtton JUL 02, 12:50 PM

quote
Originally posted by theogre:

[Not only vibration you feel...
Solid engine/trans mounts and "dog bones" can break the car. Is like hitting w/ a sledge hammer to entire car. Something has to give from torque/suspension/etc loads and if not then will break whatever is weakest... Sheet metal or spot welds, aluminum trans case, even cast iron/steel engine blocks.




Sledgehammer?

The 2.8?

It doesn't seem likely this engine has the cojones to break anything.
Bruce JUL 03, 04:26 PM
I had the poly (TFS) dog bone to replace the rotted rubber stock one. I decided to replace the polyurethane dog bone back to stock, since I was worried that too much vibration would be transferred back to the engine and mounts. At least, that's what I learned from following PFF.
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Raydar JUL 03, 05:18 PM

quote
Originally posted by RayOtton:


Sledgehammer?

The 2.8?

It doesn't seem likely this engine has the cojones to break anything.



I know some people who can tear up a crowbar in a sandbox.

All kidding aside, there are cases of people tearing the front tranny mount out of the cradle with a 2.8. 88s seem to be especially susceptible to this, due to the lighter cradle.
RayOtton JUL 06, 09:57 AM
True. Try hard enough and you can break anything.

But man, I think you'd have to try pretty hard with the 2.8.
Patrick JUL 06, 11:35 AM

quote
Originally posted by RayOtton:

But man, I think you'd have to try pretty hard with the 2.8.



Tell me Ray, have you driven a duke? Makes the 2.8 seem like a powerhouse!