Installing solid motor mounts
Thread Starter
Burning Brakes
Joined: May 2014
Posts: 884
Likes: 128
From: Rhine Georgia
Installing solid motor mounts
After much deliberation I'm installing solid motor mounts with a energy suspension trans mount. My 383 has 470 torque and I've broken 1 set of parts store mounts and I think my second set are on the out as well. I'm hoping for not too much vibration. If I do I'll switch to energy suspension all around. I will post back after install with results. Also hoping for a little more HP to the ground with the less flex. Any guesses on outcome?
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Solid motor mounts are just the natural progression as power goes up. When my stock mounts failed I went to the locking poly Energy S. When they melted and failed i went to Morroso solid.
Melting Slicks
Joined: Sep 2004
Posts: 2,655
Likes: 19
Solid motor mounts with my 6.0 LS swap.
Not much effect with noise or vibration, but then again, I'm running sidepipes.
Not sure if any effect on my convertibles frame flexing. Thinking a spreader bar might help with that.
Not much effect with noise or vibration, but then again, I'm running sidepipes.
Not sure if any effect on my convertibles frame flexing. Thinking a spreader bar might help with that.
Safety Car
Joined: May 2004
Posts: 4,363
Likes: 1,588
From: los altos hills california
Why is that? These things have always scared me. While they transmit the same torque to the frame welds, any shock transmitted is far quicker. If the bolts through the frame are loose, the motor is going to bang them hard.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
Jeese, solid motor mounts are the way to go, been running them for years. Helps with frame flex and I don't notice any vibration over stock motor mounts. 
Last edited by MotorHead; Mar 9, 2016 at 01:26 PM.
Safety Car
Joined: May 2004
Posts: 4,363
Likes: 1,588
From: los altos hills california
I know, I'm a big baby, but I've had broken motor mounts and the downside is pretty bad.
Race Director
Joined: Apr 2000
Posts: 17,676
Likes: 201
From: Who says "Nothing is impossible" ? I've been doing nothing for years.
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Burning Brakes
Joined: Dec 2003
Posts: 1,004
Likes: 7
From: Adelaide South Australia
Only a slight noticeable vibration on cold start with my solid mounts.After a few minutes, there is no discernable increase in vibration from stock mounts.
Now when I blip the throttle, instead of the engine, the whole car torques over!
Last edited by OzzyTom; Mar 9, 2016 at 03:10 PM.
Drifting
Joined: Jun 2002
Posts: 1,620
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From: Orlando Florida
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
On the other hand wimpy motor mounts scare me. I was driving my vette home at night (fast) on a mountain road........ I floored the gas at the apex of a turn and the steering bound up. I let of the gas and the steering came back. I floored it and the steering bound up again. The ES poly had melted and then broke allowing the header tubes to TQ over into the steering shaft before the box.
Running around a 4.2 mile road racing track my headers get so hot that they glow like on the long straightaway. That is what melted my Energy suspension Red poly locking motor mounts. They were a PITA to remove because the red poly melted over the motor bolts. so I had to grind and chisels the ploy away to get to the bolt heads.
Then days later they broke while driving.
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
I had a left-side solid motor mount develop a 3/4 crack with about 6 months of usage. I'll never go that way again and am sticking to the newer rubber mounts with the safety interlocking feature.
Safety Car
Joined: May 2004
Posts: 4,363
Likes: 1,588
From: los altos hills california
Thanks for the reply later but I wanted to go back to your original supposition as to why, with a more powerful motor, you said that solid mounts were a "natural progression". I think it is exactly the opposite. And that the problems you later described were with heat and not torque.
I look at the welds on my frame and I think to myself - is that all there is? - wishing when I had the body off I'd beefed it up a lot. My thinking was with an LS376/515, maybe I should go easy on things? Also with an aluminum motor, maybe I don't want it to be part of the frame?
I have previously had my share of motor mount issues, motor torquing over to full throttle in a parking lot, fan slicing a radiator hose. Bought the best mounts I could for this car and then put some additional heat shielding between the manifolds and the mounts. So far so good, nothing has melted.
The downside has been with adapter plates and stock mounts the motor sat high enough that none of the standard hoods would fit. A custom welded up adapter would have fixed that but I really wasn't up to the risk.
Other than the one negative response seems like it's not a big deal and has worked out for most folks.
I look at the welds on my frame and I think to myself - is that all there is? - wishing when I had the body off I'd beefed it up a lot. My thinking was with an LS376/515, maybe I should go easy on things? Also with an aluminum motor, maybe I don't want it to be part of the frame?
I have previously had my share of motor mount issues, motor torquing over to full throttle in a parking lot, fan slicing a radiator hose. Bought the best mounts I could for this car and then put some additional heat shielding between the manifolds and the mounts. So far so good, nothing has melted.
The downside has been with adapter plates and stock mounts the motor sat high enough that none of the standard hoods would fit. A custom welded up adapter would have fixed that but I really wasn't up to the risk.
Other than the one negative response seems like it's not a big deal and has worked out for most folks.
Instructor
Joined: Dec 2004
Posts: 228
Likes: 3
From: Tampa FL
I have Moroso solid motor mounts in my 72. It has a ~500HP solid lifter small block. Frame is fully seam welded with Borgeson steering box and big hole for power steering ram welded up. Frame still twists around a bit on bumps and turns. Motor does not move at all watching the air cleaner through an l88 hood. I was more worried about cracking the block than the spaghetti frame.
I had to pull the 4-speed. Those sold mounts are not that solid. The back of the motor still moved up and down several inches to help install and remove the transmission.
I had poly mounts. They were melted after 10k miles with the old l48 and long tube headers. I notice no difference in vibration between the solid and poly mounts even with double the horsepower. I do still have the poly transmission mount. I would not go solid there.
I had to pull the 4-speed. Those sold mounts are not that solid. The back of the motor still moved up and down several inches to help install and remove the transmission.
I had poly mounts. They were melted after 10k miles with the old l48 and long tube headers. I notice no difference in vibration between the solid and poly mounts even with double the horsepower. I do still have the poly transmission mount. I would not go solid there.
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Thanks for the reply later but I wanted to go back to your original supposition as to why, with a more powerful motor, you said that solid mounts were a "natural progression". I think it is exactly the opposite. And that the problems you later described were with heat and not torque.
.
.
TQ broke the melted poly
Not all solid mounts are created equally. The older Morroso were thicker metal than their new items.
I have not broken my my thicker morroso with solid with my 5 speed and the TQ of my 434 road racing and drag racing with big slicks
Race Director
Joined: May 2003
Posts: 10,956
Likes: 409
From: California
I run these, with a 650hp 427 hitting the track about 10 times a year, and the canyons about another 15 times a year... had them now about 2 years... no problems, and yes, I work my vet very hard.
1 7/8" headers, no melting yet:-)
http://www.summitracing.com/parts/en...make/chevrolet
Brand:Energy Suspension
Manufacturer's Part Number:3-1120R
Part Type:Motor Mounts and Inserts
Product Line:Energy Suspension Motor and Transmission Mount Kits
Summit Racing Part Number:ENS-3-1120R
UPC: 703639277002
Motor Mount Style: Complete mount
Bushing Material: Polyurethane
Bushing Color: Red
Bracket Included: Yes
Bracket Finish: Zinc plated
Transmission Mount Included: Yes
Quantity: Sold as a kit.
Notes: Kit includes early style "short and wide" motor mount that measures 2 5/8 in. between the ears and 1 3/4 in. tall to the center of the through bolt hole and polyurethane mount for automatic transmissions.
In-Store Pickup:Choose In-store pick-up (OH, GA, NV) on our web site.
These Energy Suspension performance polyurethane motor and transmission mount kits feature the best of both worlds--they're smooth running for the street and are strong enough for the track. Torque-resistant, yet comparable in strength to solid metal mounts, they'll give you the performance you're looking for.
1 7/8" headers, no melting yet:-)
http://www.summitracing.com/parts/en...make/chevrolet
Brand:Energy Suspension
Manufacturer's Part Number:3-1120R
Part Type:Motor Mounts and Inserts
Product Line:Energy Suspension Motor and Transmission Mount Kits
Summit Racing Part Number:ENS-3-1120R
UPC: 703639277002
Motor Mount Style: Complete mount
Bushing Material: Polyurethane
Bushing Color: Red
Bracket Included: Yes
Bracket Finish: Zinc plated
Transmission Mount Included: Yes
Quantity: Sold as a kit.
Notes: Kit includes early style "short and wide" motor mount that measures 2 5/8 in. between the ears and 1 3/4 in. tall to the center of the through bolt hole and polyurethane mount for automatic transmissions.
In-Store Pickup:Choose In-store pick-up (OH, GA, NV) on our web site.
These Energy Suspension performance polyurethane motor and transmission mount kits feature the best of both worlds--they're smooth running for the street and are strong enough for the track. Torque-resistant, yet comparable in strength to solid metal mounts, they'll give you the performance you're looking for.
Last edited by pauldana; Mar 10, 2016 at 02:16 PM.
Thread Starter
Burning Brakes
Joined: May 2014
Posts: 884
Likes: 128
From: Rhine Georgia
UPDATE: I just got car back home. Engine is very steady no shaking like before. Car seems overall more stable and tight. 700r4 shifts smoother at low speeds. Only extra vibration I can feel is in my feet/floor. Its very slight, but noticeable. She seems to respond better through the gears but that can be my imagination. I'm very pleased with the results.
Just to recap. I changed from parts store rubber motor and trans mount to solid motor and energy suspension trans mount.
Just to recap. I changed from parts store rubber motor and trans mount to solid motor and energy suspension trans mount.
Racer
Joined: Dec 2008
Posts: 297
Likes: 19
From: arlington TX
Hi, Glad you got it figured out!
Just FYI - I drag raced the yellow 74 (in my pic) for over 10 years with just a solid left mount (that's what takes all the abuse on a launch) and a stock right motor mount and stock trans mount. No breakage, no problems.
Anyway, have fun!!
walt z.
Just FYI - I drag raced the yellow 74 (in my pic) for over 10 years with just a solid left mount (that's what takes all the abuse on a launch) and a stock right motor mount and stock trans mount. No breakage, no problems.
Anyway, have fun!!
walt z.