Ben Taylor

I was under my car today and noticed a giant red blob hanging down from the engine compartment. I have the Energy Suspension red poly mounts, and it looks like the heat from my headers destroyed them. Is this a common problem with headers? Is there a different brand that doesn't melt?
I probably got these 6 years ago, but I hadn't been driving it much. I'm planning on making this my daily driver again. I really liked the poly compared to the old rubber ones, but I don't want to have to replace them all the time.

jackson

First, verify ignition timing & fuel mix are correct.

Failing that, suggest fab simple small sheet-metal shields attached around poly mounts.

Ray Y

I have the same mounts on my big block car with headers and no issues. I agree with timing check post above.

MN80Vette

I had the same problem with stainless steel block hugger headers that were about 1/2" from the Energy poly motor mounts. I switched to fully length ceramic coated headers that are much further from the motor mounts, and I have not had any motor mount-heat problems since. My engine is better tuned now (including timing), so I can't attribute the solution to either the headers or timing exclusively...both changes probably helped solve the problem.

straub18045

i have those mounts, no problems but my headers are ceramic coated.

Ben Taylor

I'll check my timing, but I don't think I can change the fuel mixture on my 81, I'm pretty sure that's controlled by the computer. I do have the Dynomax ceramic coated headers and they are about 1-1/2 inches from the mounts. If I change to solid mounts would those eventually cause something to crack? The engine I put in there has about 300 hp.

I do remember the engine overheating because I had air in the coolant a while ago, maybe that caused it, I was driving it a lot at that time.

OzzyTom

I have seen quite a few threads regarding molten poly mounts in the past...
even with heat shields fitted!

What's wrong with rubber mounts? If you have a lot of torque twist, you can limit the strain on the left mount by using some old hot rodder tricks...
... use a chain bolted low on the chassis to a left side header mount bolt ...
or fit a bolt through left mount plates to limit the extension distance....

both methods work.

Vibration insulation under normal driving, but limited torque twist under full load.

Grumpy 427

I went with solid mounts, no issues and no real vibrations to complain about.

turtlevette

solid mounts. Cheap and they'll last forever.

TheSkunkWorks

I've had solid mounts on my shark for ages without complaint.
Moroso # 62530 fits all SB & BB C2/C3 applications.

babbah

I have them on my BB with headers - no issues!

Ben Taylor

Timing is set correct, I think the poly melted when I had an overheating problem last year, and I just never noticed it. The solid mounts are cheap enough that I'm willing to give them a try.

Truck490

Grumpy 427

Put a set of Moroso solid mounts on and call it a day.

ignatz

You guys recommending solid mounts, are you also running a spreader bar?

HeadsU.P.

I agree. Moroso Solids, ARP bolts, Loctite Blue and never look back. Very, very, slight vibration in the steering wheel, but I can live with that.

Some of the older fellas & gals may remember the notorious, history making GM motor mount failure of the 70's. Thousands sheared apart, usually under acceleration. The recall fix was a steel cable to harness any separation.

Jebbysan

Same here.....the first holeshot I pulled with my 406 broke the factory mount.
My friend had those Energy Suspension mounts and they melted....32' Ford with block huggers....went Moroso and called it a day.

Jebby

v2racing

I run the solid motor mounts also and I have a spreader bar. It eliminates the broken motor mount problem and tightens up the car. I also have my frame solid welded and gusseted, so the the overall difference from stock is stark.

Mike

rpoL98

on a C3, remember that the body is isolated from the frame: the body has rubber bushings for mounting to the frame. this means that vibration, noise on the frame is not transmitted into the cabin. So in the case of the C3, use of steel motor mounts does not result in a whole lot of engine noise, vibration being heard or felt in the interior of the cabin.

totally different story on uni-body cars, though, where the frame is integrated into the body.

I also put the Moroso steel motor mounts on my 78 with a BBC, and was surprised that there wasn't much noise/vibration difference. That then inspired me to install solid motor mounts on my 1990 Camaro (unibody). Whoa, big difference, totally, like night and day. But I got used to it, and now revel in the experience. Don't need no stereo in the IROC any more. total engine-sound, surround-sound "immersion".

ignatz

I had headers on my car for years with no heat shields and my energy suspension mounts never melted. But suppliers do change materials, often without notice. My new setup now includes a shield just for insurance.

The scientist in me would put the remains in the oven and see at what temperature they became mushy!

Also if you replace the mounts with equivalents, you should make sure they have a travel limit.