Engine torque rod, cure for the torn motor mount?

[undy]

As I'd mentioned before elsewhere I'd torn the drivers side motor mount and the other side was in bad shape too. I could have made some solid mounts out of the old torn mounts but the thought of that didn't thrill me. Solid mounts can be problematic. So I elected just to replace the mounts and then come up with a limiting device that would control the engine's desire to "twist". This is what I came up with. Parts totaled about 26 bucks, including the moly tubing at the local speed shop. I little welding and I was set.



I just drilled through the boxed frame and ran a thru-bolt capturing the bottom Heim joint. The assembly tightened up well.




You can see from below where the bottom heim joint bolts up.



Top view where it bolts to the head..



I've taken a test drive and it seems to work well. Time will tell.

Dave

[392cobra]

Looks like and connected the same on my Lone Star....It works.

[madmaxx]

Polyurethane motor mounts would have solved the problem, I lilke your idea, and if it works, different ways to skin a cat!!!

[undy]

Originally Posted by madmaxx

Polyurethane motor mounts would have solved the problem, I lilke your idea, and if it works, different ways to skin a cat!!!

Lone Star uses motor mounts for their FEs that fit a 65 through 68 Galaxie with a 390 or a 427 in it. Finding them in polyurethane is practically impossible, save a few $200+ one-off manufacturers. The heim joint rod was the lesser expensive of the fixes.

Dave

[RICK LAKE]

undy Dave the easy way is running a bolt through the motor mount with double large flat washers on each side. Niloc nuts work great. This allows the motor vibration to be absorbed throught the motor mount and not passed on to the body and frame. You don't tighten the nuts after both sides contact the mount. This also saves the motor from snapping out of the mounts. If you where not doing so many burnouts this would not be happening. Rick L. Ps make sure that the trans mount has no suffered the same ordeal as the motor mounts. If you go to a poly mounts for the motor the trans mount need to be changed too. That link may cause cracks in the body or frame. It works great but there is a down side. We where cheap in the old days and used chain. Rod is more adjustable but you can rip a hole through the frame over time. Been there done that. The bolts worked the best for me with a chain and adjustable shackle in the middle of the motor and trans. Having one in the front only, breaks parts. Live and learn Rick

[undy]

Rick,

There's not enough clearance on the back of the mount (engine side) for the bolt head and washer. I was going to do this. I might have enough clearance if I grind the "retainer" bolt head a little thinner. But ... I will lose bolt structural integrity doing so. It was a consideration about "wallowing out" the bolt hole in the frame. I honestly don't think it will happen though. I lot of engine bolts use a similar "through bolt" through their motor mount bracketry and they suvive for 100K miles and beyond with the same forces working on them. The elasticity of the motor mount will serve to minimize torque on the bolt/frame too. The wall tickness of the frame is substancial. I will monitor the though bolt and frame for movement/wear though.

The tranny mount's fine.. looked at that (along with putting a wrench on every known nut/bolt on the car) while I was doing my "winter overhaul".

Rick, the eternal pessimist..

Keep me honest buddy. You're talking to a guy that welded a Datsun rear differential mounting strap spring to the back of a cast iron Corvette diff housing to mount it in his Datsun 240Z (behind a 406 Bowtie small block motor)... and .... it held thru many 1/4 mile runs and as a daily driver.

Dave

[patrickt]

Originally Posted by undy

Rick,

There's not enough clearance on the back of the mount (engine side) for the bolt head and washer. I was going to do this. I

Dave, you don't have enough room for something like this?

[undy]

I don't think so Patrick, I don't have as much offset/clearance on my motor mount in the rear, next to the block. My motor mounts significantly different. I will take a closer look at the old mounts I took off though.

Dave

[vettestr]

Undy,
I think your set up will work fine Dave. I have used a couple short lengths of chain between the front and rear of the engine then down to the frame rail with great results . If the chain length possible can not be placed to be a little taught I weld two of the links together to adjust the length.

[Jerry Clayton]

I wouldn't worry about wallowing out the frame holes as you'll break that nice aluminum head first( add it won't be long) when it does fail, youll be on the gas, and a heart beat from looping the car from the pressurized coolant that will be expelled---

If you don't or can't used thru bolts in your motor mounts, use either chain or cable with a resonable amount of slack. The direction your link is mounted will transmit vibrational plus torque forces into both the frame and head---and everything on your car is going to vibrate

If you want to use a solid link---mount it horizonal so gravity doesn't have an effect and choose a location that like yours is against rotational forces--of course then you will probably have a certain amount of throttle steer introduced

[RICK LAKE]

undy Dave I NEVER question your mig or tig welding ability. You should be a MASTER BLACKSMITH. You line of work has you mating anything to any thing and welding anything from Aluminum to cast iron to now plastic. Home depot sells carriage flat bolts that the head is only 1/8". This way you don't have to worry about the head hanging the mount from laying flat. You could also with a little more work drill a second hole in the frame mount and use a longer bolt on each side to limit the same thing. Just spit farting here. Rick L. How's the spring looking for the beach????? Rick

[undy]

I might re-attack the motor mount issue later on. The way she is now is the way she's gonna fly until ... something breaks or moves. I just got everything back together, the wheels polished, car waxed and down off the jack stands. My ambition is gone for the winter.. The mounts ain't but 18 bucks each from the local Napa anyway.

Here's the mount.



Shoot man, there's plants sprouting up everywhere.. gettin' ready to get there's little plant hearts broken (frozen) when the cold weather comes back.

[Michael C Henry]

I managed to bolt through my mounts countersunk screws and self locking nuts. not anymore than snug so mount can move a little as designed.
When I was running a full sized cars I made a bar that bolted to left head at front corner of engine. The bar extended outward a little past the head. I then attached another piece of metal that would take the pull to the frame inline with the head mounted bar. I then welded a short length of 5/16" chain to the end of the barr on the head and to the metal mounted on the frame. The chain was straight with no slack when at rest . When the engine was under a pull the chain was tight and held the engine from torqueing over. For the most part you would never know that there was any devise in use. Normally, No vibration was felt from engie to driver.

[RICK LAKE]

Undy Dave was looking at some of my old race parts and crazy things I did. I suggest this to help take the load off one spot of the head and spread it out over a larger area. Get a small piece of flat plate and bolt it to the front of the head. Some heads have 3 bolt holes some have 2. 3 is better, 2 works better than one. Then you can bolt the torque bar to the plate. The shear factor is still the same but without possible damage to the corner of the head. Something to think about? Rick L.

[bobcowan]

What you've done is create almost a solid motor mount. That's going to transfer a lot of vibration to the frame, and put stress on the head bolt.

Motor movement and torn mounts are a common problem with drag racers; has been for decades. The answer is essentially what you've done, except with a chain and turnbuckle. That allows a little slack for normal movements to prevent excessive vibration. But it will tighten up when under a load and prevent too much movement. Cover the chain with a piece of rubber hose and it will look good and not rattle.