Mostly noise and vibration.

Bogie

 

Isn't it a sign that the engine moves too much, or, looking at it differently, that the engine makes more torque than the engine mount can support? Some people use a strap on the driver side of the engine to limit its movement, should you look into this?
You say you drive the car a fair amount, and I do not know what is acceptable to you, but the vibrations of a solid mount can also mean loose screws all over the car...

 

The loose screw issue is something that I haven't considered. And I don't see anything that's a 'sign'. I guess that was the point of my question. I inderstand about a strap on the driver side, but that mount on the other side is the one that takes all of the abuse, which has me puzzled.

Bogie - so you're saying there is no real benefit?

 

Here's a motor mount fix I've used for years. Take the rubber or urethane mount off and drill a 3/8" hole thru in place you can put a bolt without interfering with engine block, frame, etc. Put in a 3/8 Grade 8 bolt with a lock nut. Tighten down the nut, then back off the nut about 1/8". The bolt will be a tight fit in the rubber so it won't rattle. Use a lock nut so it doesn't vibrate looser. The motor mount will still absorb vibration but movement will be limited by how much you tighten the bolt.

 

Solid motor mounts are great for all out race cars. On the street, the vibrations drive me crazy and just don't make sense.

 

If you decide to go solid mount, address the transmissin mount as well. The trans case can crack at the bellhousing if the chassis to trans and chassis to engine to aren't tied together. Either remove the trans mount, or make it solid too. So basically all rubber, or all solid.

 

I'd agree if the vehicle was not a G body Based car.
His problem is most likely 2 fold.
The engines power output and the G body's chassis/frame flex.
The frames in these cars were weak from the factory , Remember they downsized from the earlier cars to make them lighter and the vehicles frame got this, make it lighter process.
The thread starter did not say if anything has been done to his vehicle to stiffen up the chassis.
Solid mounts in a g body with the power he is claiming would stress the transmission case and break it just from the frame/chassis flex.
I've heard the g body flex issue called the "g body shuffle" by those at the track with these cars.
I would hold off till I was able to talk to others with g body cars , I would venture to say there are forums for that vehicle family. and ask questions.
If he has addressed the chassis/frame flex That those g body vehicles were born with , then Solids would be an option.
But I would not use them if the flex has not been addressed, but you know what they say about opinions. So your mileage may vary.

The thread author Also stated that the passenger side mount is the one showing more stress/wear/failure.
He also stated the car is boosted, My question for him to ponder is, is it boost coming from a turbo? and if so, is the turbo and /or the exhaust pipe out of turbo passing near the passenger side engine mount? Cooking it.
I heat shield might be what the doctor ordered.

 

I once had a 86 chevy s10 with welded solid mounts for the engine and used the clamshells on the side and I used a regular transmission mount on my 350 turbo transmission and I can say I never had any issues with bolts coming loose and as far as vibration goes I have never really noticed any difference for the most part between it and my 96 chevy s10 which has the regular 2.8 v6 mounts that comes with most kits of the v8 conversion kits using the 2.8 engine mounts and brackets and I have not really felt any difference as far as vibrations goes. That is just my exoerience.

I like other posted above that running solid motor mounts with a regular tranny mount is a no no and can lead to breakage of the transmission housing. How often and easy that is I don't know if you don't race it and just maybe get on it once in a while I don't know the risk factor at that point. I was never really hard on my rides.

 

You're correct about the heat issue as well as flex. We are in the process of moving this drivetrain from one car to another, but the new car is getting prepped for a 10 point cage. In terms of amount of HP output, it running 80-84% DC for a set of Deka 80's + 20 gallons of meth per hour. The meth should be equivalent to another 10-15lb of fuel per hour - it will make 800whp on a Mustang dyno.

I understand about the G-body shuffle as well, the car referenced in this thread is my son's, but I have one as well with an 8 point cage that I'm making about 750 or so whp. At the top end of 3rd gear at the track I have to steer the car - it was a little nerve racking the 1st time I put a full run onto it.

I'm very much considering using one solid and one poly on the engine, and then the poly trans mount.


Thanks for the input

 

With our 4 speeds, we like a urethane mount under the tailhsg over a solid mount. Our tail will eventually develop crack with a solid mount.

 

This has worked well for me for a few decades.
Torque rod bolts hard to frame and has bushings from a shock absorber at L bracket on engine.

New item by Ray Davison

photos.app.goo.gl