Solid motor mount question...again
 

I want to change to a solid motor mount, mine is dead now.

I just want to know it can be made with only hockey puck?
like 3 puck with one washer each end.(to get 3 1/2 inch)
or i really need a metal or aluminium piece in the center?


Thx for any input.

Mike

I dont like hockey pucks cause the rubber is too hard and can break if it gets too cold and you stress the mount.
Neoprene gives a bit of flex and aluminum makes it rigid and strong.

You could use pucks in the short term but watch them closely.

Where can i found this kind of neoprene?

and what can i use for solid part? a aluminium rod? like 3 inch wide, but where the hell i can find that?


Theres practice puck that seem to be have more strenght, can it be solid enought?

I did a little test with a practice puck(those heavy 10 oz)

I put one in the freezer yesterday, i just get outside and hit it with a hammer as hard as i could. Trying to get it sideway to "break it" in 2. Never broke, it only have dent on it.
and hammer mark.


So, i think the best way to know is to try it.

Anybody have an opinion on this?

Give it a try Mike, but just watch it over the next while.
Practice pucks are tougher than regular pucks so you maybe on to something?

Yes, ill give it a try before the end of the week end, i just need to find 2 washers big enought to cover all the puck. Wich will be the harder to do.

Do you know the exact size of the hole i have to drill?
:?
Thx

Just to make sure....

Do i will feel the engine vibration like i was in a dragster?

If yes, do the OEM motor mount will handle for a couple of year the added power of a 3.4,rocker and PCM?

Sorry I did not get back to you sooner Mike. I have been dealing with an ill parent. You can use the hockey pucks, or anything that can take up that space. I would suggest a 2 1/2" or 3" hole saw and cut a couple of disks out of the sidewall of an old tire, to put on top and bottom of the hockey pucks. The only weight on the spacer is when the motor is at rest. There is no weight on it when you are under power. When you are under power the engine torques backwards trying to tear the bolt in half. I suggest the use of the tire sidewalls so you can tighten the bolt down good and compressed on the hockey pucks to keep them from vibrating. Tell us how it all works out and if you like it or not. I do not notice any vibration but I have had mine on for three plus years. :D

ROD

Thanks rrounds, THAT was the info i needed ;)


ill let you know!

If the mount is on the cradle and not on the body then you will not feel a difference because you still have rubber mounts to the cradle.

Yes exactly. I really don't feel a vibration now after having the solid mount for two years.
You can see the entire cradle flex slightly under load but the solid mount doesn't have any give.
My engine only moves about 1/8" now whereas before it was moving about 1".

Sorry (not 100% bilingual) what is the cradle ?



Wich part of the entire mount is the cradle?

sorry to ask and thank you for the info!

It's the black rectangular box steel subframe that the engine and suspension is attached to. This drivetrain cradle is attached to the car body by rubber mounts.

ok, thank you ! :thumbup:

ill try to do it today.

i dont believ that vibration would be much of an issue at all... i was under the impression that bonneville engines have a tighter balance tolerance than that for the grandprixs, due to the more luxury car standards

There is no difference between the engines, internally speaking. Only difference is how they are mounted to the chassis.

I have been very interested in this for quite some time. In looking at how everyone has built their mounts, one question has cropped up in my mind... Why have the 2 neoprene/poly/whatever pucks below the motor bracket? To really effectively make a better mount, shouldn't you put a puck on either side of the top bracket, then bolt down through a spacer? This would isolate the engine completely instead of pulling against a solid bolt when under acceleration... Really, the way it has been done benefits in no way from having the 2 pucks where 1 would suffice... Correct me if I'm wrong, but the only reason for the puck in the current usage is to make for some give, but only in one direction, down...

I just think that having a puck on top and bottom of the motor bracket would provide a MUCH better vibration isolation, and pretty close to the same benefits of the current design...

Yes you are right Kyle. Much like how body mounts work. A cushion in either direction of movement.
There were practical reasons for doing it the way we did. Availability of materials and existing design. It's not easy to physically mount an isolating puck on the other side of the bolt, and as Blazin pointed out there are rubber subframe mounts that isolate vibration.
The little bit of vibration that does get through is hardly noticeable and it is only noticeable right after the mod. Given a couple of days of driving and experiencing the other benefits makes you forget all about it.
I don't notice it at all now. Neither does anyone else. ;)

If you do it and the little to no vibration that you get is a problem then just raise your idle a few 100 RPM and that vibration should go away.

Can i just put the puck with a washer at each end without putting rubber?(old tire side)

:?

edit: i am putting 3 puck, + 2 big washer and 2 smaller= 3 1/2 inch.

is it good enought?

I think you are good to go.

Where have you guys gotten your poly bushings from?

Oh and the idle speed isn't an easily changed parameter unless you've got a pcm editor...

I got mine from NAPA. Universal Body mounts. 3/4" thick x around 3" dia. I had to ream out the bolt hole to fit the bolt but they come is sets of two (another reason for using 2) and work perfectly.

You can reuse the original mount lock nut or double nut for security.

just a tip, before having the solid mount fabricated (I used some turned aluminum) measure the height of your existing mount as it is in the car now. I found that mine needed to be a little taller than Silver Bullets and my not paying attention caused a small leak at the rear exhaust manifold gasket. You know what they say "haste makes waste". Do your due dilligence and enjoy the mount.

Sorry but I have to disagree with Zuluhead about the effect of +/- 1/4" really making any difference to affecting rear manifold seal.

Possibly the stock flex connection is not as flexible as the new TOG flex.

So thats even worst to have the stock mount? Its always moving and it stress that manifold seal? :?

Too bad, my mechanic is off for holidays, i got to wait till next friday...grr :)

edit: By the way, thank you silverbullet and rrounds for all the info and happy new year all !!

:beerchug:

The stock mount allows for an acceptable amount of movement to reduce the vibrations felt in the cabin. This works in conjunction with the flex pipe that's part of the exhaust. The stock mount is good for the purpose it was designed for, but most people can live with the slight vibrations created by the solid mount for the benefits it provides.

The problem I had was that my mount wasn't as tall as my original mount and when I tightened it down it put too much strain on the exhaust manifold and created a small leak.

Silver Bullet can disagree with me on this if he likes, I respect him and heartily thank him for the help he gave me when I did mine, but I haven't come up with another reasonable explanation (maybe my flex pipe isn't as flexible as it should be or the leak was already there and this just made it more noticeable) for why I developed the leak immediately after installing a mount that was smaller than the original.

Point is, I believe, as do many others, that a solid mount is a good thing. I will simply caution people to make an effort to create a solid mount that is approximately the same size as thier stock mount.

When you changed your mount, you may have over stressed the connection by overextending the engine. That is, it may have dropped too much and pulled on the manifold connection.
Remember that the stock mount moves a lot more than the difference in height between your two mounts.

WHY SOLID ENGINE MOUNTS ?

Didn't GM go through alot of trouble designing hydraulic mounts to keep the vibrations away from the occupants ? :shock:

as i can see, when you are accelerating there is no load on the mount, right now my mount is very bad, i can ear sometime a "TIC" when i accelerate, the engine is moving too much.

But when im on load, it is only hold by the bolt of the mount(if im not wrong) its like there is not mount at all, i feel no vibrations on load.

Everything is a compromise....performance vs luxury.
You see the difference between the not as luxury oriented GTP and the more luxury type Bonne engine mounts? GTP uses rubber while the Bonne uses an oil filled rubber dampener.
The downside of not feeling any engine vibration is an engine that flexes. This flex reduces drivetrain tightness ie. the reaction time getting power to the wheels. It also allows so much movement that it is hard on inlet and exhaust tubing.
Another benefit for me was it allowed me to use the GXP strut tower brace and not have the engine flex enough to contact the alternator.

Good God Gertrude ! I didn't know there was all that flexing going on up there. :shock: :shock: :shock:

If you really want to check out the flexing, pop the hood, leave the car in park and push on the front bumper to rock the car back and forth. You will see just how much that engine moves.

The new mount is in !!

I have some little vibration at light acceleration/load , nothing big , right now im on the puck only, ill let it like that for couple of days and if it continue ill replace one puck by something softer, like a universal mount like did 2000silverbullet.

But this is a very good "mod" it feel more like a sport car now! :D

I feel the torque instantly, any brutal acceleration in 1st gear result in a instant wheel spin.(road are cold)

:twisted:

Thx !

PS. the old mount was practicaly tear in half. I will post pic as soon as i get my hand a on a camera.

....and the power to the ground quicker. That's what I like about it. Much more positive response.

Glad you like it Mike. :D

here is how my old and new mount look :D

old: http://www.fileshack.us/files/782/badmount.jpeg

new: http://www.fileshack.us/files/782/IMG_0651.JPG

orange hockey pucks? :lol:

looks good... hows it working?

please tell me u have more pics!

yeah i know, the esthetic suck :lol: those are the heavier puck for "practice", they have more strenght.

I really love the solid motor mount, its a totaly different car, you can really feel the torque of the L67 (especially in 1st gear), the power is delivered instantly on the tire. :twisted:

I have slight vibrations, feeled in the steering and the pedal, (not on frame and seat..)

ill see if ill change one puck by something slightly softer, but i can live with that minimal vibrations.

And my tranny seem to shift better (but my mount was really bad)

I can take more pics tomorow, it was dark outside, ill make a vid to show how it look in action.


And for 55$ total i think its a good deal (if you do it yourself then its a cake)

I was amazed at how much the motor moves. I was changing plugs and dropped a ratchet extension down the backside of the motor, so I tried rocking the car to get it out. There's a good 2-3 inches of play there. :shock:

Now 1/8 inch 8)

Yup.
The solid mount reduces it to almost nothing.
Think of how much response is lost to this excessive movement.

The GM designers were concerned with vibration and harshness elimination for this Luxury version of the L67.