Motor mount question.

[retired ralph]

Iam going to put a chain on the motor mount to save my fan should if it breaks. I did it on my Mustang(Sorry to mention that word). What side of the engine rises if it breaks? Thanks Ralph

[idvette]

I' sure it's the driver's side that lifts. I put solid mounts in when I built my 383. Then again, I also did an electric fan conversion.........

[Vettehead Mikey]

What side of the engine rises if it breaks? Thanks Ralph

Neither- the stock engine mounts are the 'locking' type which prevents the movement you're worried about.

[Hib Halverson]

What "Vettehead Mikey" says is correct, but to elaborate.

Back in the 1970s GM's engine mount design was changed such that even if the rubber part of the mount breaks, the locking feature prevents the engine from moving up more than about 3/8-in.

Simply replace your existing old-style mount with a new-style OE replacement, such as the Anchor brand mounts RockAuto sells for about 7 bucks each, and you'll be set.

[Vettehead Mikey]

The OP has a '74 which came stock with locking mounts. Unless they're worn out, no reason to change them.

[Hib Halverson]

Couldn't remember the break points.

The locking mounts are, no doubt, a safety "must' but, strangely, I've found it's harder for people to realize the rubber part is broken.

Guess it makes sense to, once in a while, stick a big-assed pry bar underneath the engine near a mount and pull up. If you see the rubber separate, time for a new mount.

Speaking of mounts...while, for obvious reasons, I'd never use a solid mount on the street (learned a hard lesson about that when I was a wee tike) but I might consider polyurethane mounts.

Anyone here use poly engine mounts?

[idvette]

Curious about the hard lesson........... I've run mine for about 2 years now with no obvious adverse affects, what happened for you?

[LLC5]

Iam going to put a chain on the motor mount to save my fan should if it breaks. I did it on my Mustang(Sorry to mention that word). What side of the engine rises if it breaks? Thanks Ralph

Vettehead Mikey is right, if you have the OEM style motor mounts then they are not needed. If you feel that you still need them for any reason, then the left side (driver) is the place to install the cable or chain. Good luck with it.

[Hib Halverson]

Curious about the hard lesson........... I've run mine for about 2 years now with no obvious adverse affects, what happened for you?

Three problems I had. One was self-inflicted in that I used solid engine mounts and a rubber trans mount. Big mistake. There was still enough powertrain movement with that set-up that one of the metal mounts finally cracked then broke. As they are not the "locking" mounts, you know what happened next. The throttle stuck at an inopportune time.

Second, I hated the vibration and noise. It was freakin' terrible and not near worth the small amount of "coolness" I thought "racecar engine mounts" would bring.

Last, I ran them for a year or so and when I went back to rubber, I noted that the frame welding had cracked in one place between the right frame rail and the front x-member. Now, I can't say with 100% confidence that crack was due to the sold mounts, but I believe it was contributory.

With solid mounts:
1) On a C3, all three mounts must be solid otherwise the powertrain moves enough to crack and possiblyi break metal engine mounts.
2) On street and race cars w. solid mounts, periodic inspection of engine mounts and transmission mount are necessary
3) Periodic inspection of frame welds near engine mounts may be a good idea.

Lastly, I learned later in life, in talking with people who built real race cars that, on a production-based, street performance car, there's little or no performance gain in switching to solid mounts.

[idvette]

2) On street and race cars w. solid mounts, periodic inspection of engine mounts and transmission mount are necessary
3) Periodic inspection of frame welds near engine mounts may be a good idea.

"Solid" info, thanks. Points that have never been brought to my attention before. All 3 mounts are solid in my car, and maybe it's because I might still be a bit of a young buck, but I haven't been bothered by the harshness. This coming year will (hopefully) be the first to spend some real time on the highway, so that may change when I can't feel my hands anymore lol.... Thanks again for the heads up!

[Hib Halverson]

If your powertrain balance...engine, trans, driveline...are perfect, the vibration won't be too much of an issue--problem is, with cars that old, it seldom is even close to "perfect"--but the noise at certain rpms, you may find annoying.

[Dad]

Iam going to put a chain on the motor mount to save my fan should if it breaks. I did it on my Mustang(Sorry to mention that word). What side of the engine rises if it breaks? Thanks Ralph

Of interest to me is where you found a Mustang that could break a motor mount?

Mine are still original and I've had it over 23 years without it breaking one.

[minifridge1138]

The driver motor mount on my 1982 was the safety locking type.
When it broke, the fan did hit the shroud and the belt cut a very small hole in the upper radiator hose.
I don't want to know what would have happened without the locking mount.

The first replacements i bought at autozone and they were not the locking ones, so I took them back and order a set online.

I think they switched to the locking type in 1969, but I could be wrong.

[GRAND SPORT #12]

i would go for a good locking mount the chain looks real back yardish was cheap insurance in the old days because not only did bank one side rise it many time caused a full throttle application. if you want to go that way for extra security i would look into a catch rod instead of the chain

[terry82]

in 1968 chevy put cables on some cars as a safety for broken motor mounts.when my motor mount broke i replaced it with a poly motor mount .it has worked fine .