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"Chaining" the engine down
I have torn off the mounts for both mufflers due to excessive movement of the engine. I have new mounts on the engine and the tranny but the engine appears to move too much under severe acceleration.
One option is to chain the engine to the frame on the driver's side which will limit it's movement. Has any one done this? What are your thoughts? Is noise and vibration much greater? Wayne |
What kind of motor mounts are you running? I switched to solid motor and trans mounts and didn't gain any appreciable vibration. NO sidepipe movement now! :D Poly mounts might be a good compromise if you don't want to go full solid. Some folks use a turnbuckle type arrangement to limit the movement under full torque.
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What are you using for mounts at the mufflers? What is the interface between the primary and side pipes? Flange or slip-fit?
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Re chaining engine down
I have a safety chain on my engine that has just a little slack in it. But my motor mounts hold my motor. The chain is just there in case a mount breaks and it will stop the motor from torquing up and through the hood until I can shut it off.
Ron61 Ron widener |
Wade,Bob
I am using standard Ford motor mounts, steel and black rubber. Same for the tranny mount. I tried to buy urethane mounts but couldn't find any. The side pipes are mounted to the headers with a flange so there is no give there at all. I used rubber bushings between the side pipe brackets and the frame bracket but the engine (and pipes) simply move too much. I have rewelded the broken side pipe mounts and bent the mount a bit to allow for more room between it and the frame and I have now used slightly longer bolts on the rubber bushings to allow them to move more but I think it is probably just a matter of time until I break the pipes again. Does someone make urethane motor mounts for the 351W? I assume they would limit the engine movement quite a bit. Wayne |
Wayne,
We have several guys down here that have installed torque straps on our cars....what we found out with our ERA's was that when we got on it the torque from the engine was actually making 2 half moon impressions in the body where the exhaust exits the engine compartment...no problems now Matt |
Torque chains will stretch. A turnbuckle works better. Avoid the solid mounts, they will rattle everything on the car. An aluminum flywheel will help this problem more than you could imagine.
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Maybe the Excalibur is different? I have my motor BOLTED solidly down on both sides but left the tranny mount with the original rubber. I can't tell the difference in vibration or noise. First thing was cracks in my headers followed by side pipe mount problems. All gone now!
Ernie |
I ran solid motor mounts on my chevelle for 9 years. At first, they didn't seem all that different. After years however, eveything on the car began to rattle. Oh well, at least I'm not tearing motor mounts anymore, allowing the engine to torque over and smash the headers against the control arm cross shaft. Tried the chain setup, but I had to add a twist to it every other week cause it would stretch. Had a turnbuckle arraingement recommended, but went for the solid steel mounts instead. Don't run solid motor mounts and a solid tranny mount, one of them must have some give to it. Solid motor mounts, than run a ruber tranny mount. The solids work great, but transmit alot of vibration to the car. Back to cobras, steel flywheeled motors torque over way more than aluminum flywheeled motors. Even when the alum equipped motor makes twice the torque. Just a good excuse to buy that aluminum flywheel you've always wanted.
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Matt
I also had to slightly "modify" the body with my Dremmel tool to remove a bit more glass where the pipes had been touching the body. That was the first sign that the engine was moving more that I expected. Mr. Fixit I am running a brand new billet steel flywheel so I don't think I want to spring for an aluminium one right now, but thanks for the idea. I have been looking at my setup and this winter I am going to fabricate a bracket that will attach to the front of the left head. This will be the upper mounting point for a radius rod that will have rod ends, LH one end, RH the other. The lower end will mount on the frame of the car. This LH,RH thread arrangement will allow for adjustment, similar to a turnbuckle. I will let you know if this works well. Wayne |
Wayne, I think Finish Line has what you are looking for if you don't want to fabricate anything. I was going to order one to replace my stretching chain, but a friend said he would make one for free. Can't beat that.
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Since the topic is chaining the driver's side head to the frame, I though I would bring this up. A friend of mine builds 9 second, all steel, untubbed, 3600 pound, naturally aspirated drag chevys. It takes a motor that would go alot quicker in the quarter mile if it was installed in a proper chassis. These torque monsters ofter wear a third motor mount attaching the driver's side cyl head to the frame. He runs solid mounts, so I asked why the turnbuckle style third mount. He claims that the stress on the block where the motor mounts bolt up can be great enough to distort the block, even tear away the mounting pad off the block. That's why drag racers like motor plates soo much. He is into stealthy drag cars, so the turnbuckle style mount is preferred over the motor plate. Just thought it was interesting.
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Why would you want to chain the driver's head to the frame? Would this not impair rearward vision? Woudn't a HANS device be more effective? cb
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Since this thread went somewhat off topic and started discussing flywheels, can someone explain to me the what the seat of the pants difference would be with an aluminum flywheel v. steel in a 428 with lots of torque? I understand the physics of less rotating mass, faster rpm with aluminum, but is there a noticable difference on a street driven car?
Is it worth spending the extra $$ for aluminum on a very light, high torque, street driven car?? Thanks in advance, Mike |
Wayne........
I fabicated an adjustable bracket just as you described for my car. Uses heim joint ends with LH threads on one and RH threads on the other. Certainly made a noticable difference and hopefully no more broken side pipe attachment brackets.
Jim :3DSMILE: :3DSMILE: :3DSMILE: |
Anticipating just this kind of problem with OEM Ford rubber motor mounts, used Energy Suspension polyurethane motor and trans mounts. Summit has them.
Poly mounts soak up high end engine vibrations, but the motor doesn't move around at all. Instead of engine rocking, whole car rocks at idle. Sidepipes don't move around either. Nearly 11,000 miles on car now and no problems. E.S. Poly mounts are only made for late (83 - up) Mustangs. Uses single 14mm through bolt, and locating tab. Classic Roadsters now uses late Mustang frame mounts that use these. Other brands may need fabrication of motor mount-to-frame mount to use the E.S. late Mustang poly motor mounts. But they solve all the problems listed above if you have a 302, or 351W block. |
Chaplin - assumeing they are the same size and weight not much from a performance standpoint. Aluminum wheels do dampen vibration better and cool off faster than steel so aluminum wheels tend to have a little less clutch fade. Steel is more stout and will last longer and when it come time to resurface, steel usially needs less cut to clean it up. They both have a steel inserts most times where the pressure plate makes contact. (later style wheels) I know of no truely lightweight steel wheels out there. Oh yes, when a aluminum wheel lets go they make less mess in that explosion proof bellhousing that no one uses.
On the rest, I run both a engine plate and mid plate. In the past I used a turnbuckel setup on BOTH sides of the engine. cobrashock |
jwoodward
Thanks, sounds like I maybe on the right track. Please look at my questions below to MrFixit. Have you had any similar problems? Jack21 I have the old style Ford engine mounts. I couldn't find them in polyurethane. MrFixit I only have room to do this on the driver's side since it is very tight on the other side with the alternator being there. Do you think it will be OK to only restrain the engine on one side. I realize that the engine block goes up on the driver's side so all I have to do is hold it down but what happens on deceleration? Do you think there maybe a problem with this arrangement? Does the engine torque the other way? I have a very nice spot to attach the bottom end to the frame so this should work well, but only on one side. Wayne |
The two factory engine mounts plus one torque strap on the driver's side. If it is a solid strap (turnbuckle style), not an actual chain, loading will be consistant in both directions.
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Mr.Fixit
Thanks. I will let you know how it works out. Wayne |
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