Solid motor mounts....any problems?
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,843
Likes: 99
From: Orrtanna Pa.
Solid motor mounts....any problems?
I took the Vette out for a run yesterday, and during one of my "take off's" I had a bit of a scare. I started off in first pulling out onto the highway, gradually feeding the gas till I got to the end of the entrance ramp. At 4000 rpms, I nailed the throttle, tached to 7000 rpms like usual, and hit second. I saw the hood on the drivers side jump about two inches, which at the time I thought I'd broke a mount.
As it turns out, I guess the last time I had it open, the hood wasn't latched fully. But the whole incident got me thinking about solid mounts for the insurance.
I did a quick looksy, and found Moroso 62530 mounts at Summit. Is anyone using these, and have you had any issues with them? Fit, vibrations, etc..............
As it turns out, I guess the last time I had it open, the hood wasn't latched fully. But the whole incident got me thinking about solid mounts for the insurance.
I did a quick looksy, and found Moroso 62530 mounts at Summit. Is anyone using these, and have you had any issues with them? Fit, vibrations, etc..............
Le Mans Master
Joined: Apr 2000
Posts: 5,202
Likes: 10
From: cincinnati ohio
St. Jude Donor '09
I switched to solid mounts when I did the blower install. The close proximity of the linkage to the hood won't allow for any movement. To tell the truth, I noticed no additional vibration etc.
Team Owner
Joined: Aug 2006
Posts: 24,125
Likes: 15
From: Columbia Missouri
I have solid mounts on my '77, and I installed them on Curt's 355 in his '74. I can only tell a slight difference in vibration in the steering wheel, and the throttle response is great compared to the old feel of the rubber mounts. I believe Curt is a huge fan as well.
Le Mans Master
Joined: Jun 2004
Posts: 6,231
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From: Seattle WA
St. Jude Donor '14
Keep in mind that solid mounts make the engine block part of the frame/suspension - meaning it's now a 'stressed member' (no jokes 
IMHO, I don't recommend solid mounts for a variety of reasons - better bet are the Performance Suspension or other poly-type mounts. Just one guy's opinion.
IMHO, I don't recommend solid mounts for a variety of reasons - better bet are the Performance Suspension or other poly-type mounts. Just one guy's opinion.
Race Director
Joined: Apr 2000
Posts: 17,676
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From: Who says "Nothing is impossible" ? I've been doing nothing for years.
I had solid mounts with my 406ci and I liked them but I went with Energy Suspension poly mounts on my 427ci, the engine runs very smooth so I like the poly mounts too, probably get a spreader bar to stiffen up the front suspension now 
Pro
Joined: Jun 2005
Posts: 581
Likes: 60
From: USA
I've used the solid mounts on 2 C3's and on my other non-Corvette daily driver. I have no vibration problems on the C3's, actually I was kind of surprised at how little the increase in noise was, and we're talking 540ci BBC with headers, etc in one case. As required, I use the polyurethane transmission mount in all cases. On the C3, the body is insulated from the frame with the rubber body mounts so this minimizes the noise, vibration transmitted to the cockpit, cabin area.
On my other daily driver, it is of the marvelous cost-cutting "unibody" design, so there's a whole lot of engine "audio", surround-sound-effects being transmitted to the interior. I don't need a stereo anymore on that car. But still, not a problem, I've gotten used to it and wouldn't have it any other way.
On my other daily driver, it is of the marvelous cost-cutting "unibody" design, so there's a whole lot of engine "audio", surround-sound-effects being transmitted to the interior. I don't need a stereo anymore on that car. But still, not a problem, I've gotten used to it and wouldn't have it any other way.
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Race Director
Joined: Dec 1999
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From: Forked River NJ
The poly mounts should be enough. They are locking also so even if the poly let go it would not allow the motor to move to much. I am running the Energy Poly mounts after breaking a rubber one in about a year. 
Team Owner
Joined: Apr 2002
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From: All humans are vermin in the eyes of Guru VA
Cruise-In IV Veteran
Cruise-In V Veteran
I forget where, but I was reading somewhere that if you have solid motor mounts you should have a solid transmission mount.
But everybody says to have a poly transmission mount.
But everybody says to have a poly transmission mount.
Racer
Joined: Apr 2005
Posts: 259
Likes: 45
From: Columbus Mn
I run solid mounts on my 73' with a 6-71 blower. (686HP 662trq). I'd say there is a bit more shake to the body at idle. No noise. transmitting through to the interior. The shake gives my Vette more attitude. The engine and my foot seem like one. I kept tearing rubber mounts. I love my solid mounts. Oh, another benefit is that the collector gaskets aren't constantly blowing because the motor stays in one place. Just my two cents.
Burning Brakes
Joined: Feb 2000
Posts: 1,246
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You should NOT unless you want to crack the case. See, the frame still distorts and the torque effect end up in the tranny case if you use a solid mount.
Team Owner
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From: All humans are vermin in the eyes of Guru VA
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Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,843
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From: Orrtanna Pa.
I already have a coffee spilling shake at idle, ......this should be interesting now.
I have the spreader bar acrossed the upper control arms, poly bushings throughout the suspension, and tranny mount, and 550 lbs springs. I'm guessing it's going to take a lot of motor to twist the frame enough to worry about cracking a tranny case.
Solid mounts are on order,....
I have the spreader bar acrossed the upper control arms, poly bushings throughout the suspension, and tranny mount, and 550 lbs springs. I'm guessing it's going to take a lot of motor to twist the frame enough to worry about cracking a tranny case.
Solid mounts are on order,....
Le Mans Master
Joined: Dec 2003
Posts: 5,727
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From: Fremont CA
Yes EVERYBODY including me says you should have a rubber/poly transmission mount or you will chance cracking the tailhousing of the transmission when the frame flexes and there is no "give" at the weakest link (thin aluminum casting verses the cast iron block.)
Tech Contributor
Joined: Jun 2004
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From: I tend to be leery of any guy who doesn't own a chainsaw or a handgun.
No, pretty much any vehicle with a frame that will twist under road inputs such as bumps, etc. If you tie the engine and trans solidly to the frame, you are asking the transmission housing (cast aluminum) to act as a torsion bar when the frame flexes. Cast aluminum transmission housings make an inefficient (and costly) torsion bar.
Le Mans Master
Joined: Apr 2006
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If you use solid front mounts solid rear mount you have created a solid triangle in the frame when the frame twists from torsion (make no mistake C2/C3 ladder frame is very weak on torsional stiffness) it will put a twisting force on your trans, aluminum belhousing. The solid front mounts are great but you use rubber or poly for the trans mount this alows the flexi flyer lol frame to do the twisting its going to do without twisting on your trans belhousing. My brand new C3s never twisted on frames when I would drive them over a railroad track the T-tops would squeak a little from the frame twisting. Personally if I were going to
do it again I would still use a factory rubber mount for the trans, poly is getting stiffer more like a solid mount factory rubber will last a long time for just a trans mount be a little more flexible.
do it again I would still use a factory rubber mount for the trans, poly is getting stiffer more like a solid mount factory rubber will last a long time for just a trans mount be a little more flexible.
Last edited by Little Mouse; Oct 14, 2008 at 04:23 PM.
Thread Starter
Melting Slicks
Joined: Jun 2002
Posts: 2,843
Likes: 99
From: Orrtanna Pa.
Just got the solid mounts yesterday, and may try to swap them in this weekend. Would it be something possible with the motor in, just jack it up a bit,pull the old mount, and replace with the solid?
I realize it'd easier with the motor out, but I'm not really wanting to pull it till cam swap time in a year or so..............
I realize it'd easier with the motor out, but I'm not really wanting to pull it till cam swap time in a year or so..............
Burning Brakes
Joined: Dec 2007
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Team Owner
Joined: Aug 2006
Posts: 24,125
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From: Columbia Missouri
Just got the solid mounts yesterday, and may try to swap them in this weekend. Would it be something possible with the motor in, just jack it up a bit,pull the old mount, and replace with the solid?
I realize it'd easier with the motor out, but I'm not really wanting to pull it till cam swap time in a year or so..............
I realize it'd easier with the motor out, but I'm not really wanting to pull it till cam swap time in a year or so..............
I installed mine with the engine in the car. It's not that bad.
Getting the car up on jack stands is the first step. Then use a floor jack and lift the engine taking the pressure off the barrel pin bolts. Once they are loose you can remove the prevailing torque nuts, and slide the bolts out.
This is where you'll want to jack the engine up further, watching carefully the fan shroud and distributor...and you'll have access to get an extension and a wobble up to get the mounts unbolted from the block.
Then you install the new mounts, but leave the bolts all finger loose to the mount can move a bit. Lower the engine slowly until the holes line up with the barrels, and to where you can slide the bolts back through.
Install the nuts, to where they are almost snug, and drop the engine down until the mounts hold their weight. Now tighten the block bolts, and finally the nuts on the barrel pin bolts.
That's all there is too it.