Write-Up: Hockey Puck & Casting Front/Side Motor Mounts

I did the hockey puck engine mount mod this past weekend (in addition to a filled rubber rear mount). I decided to try a slightly different version, which only requires two pucks, a piece of black iron pipe as a sleeve (5/8" OD, 1/2" ID, 3.9" L) - no Bonneville mounting bracket required. Two stacked pucks is exactly the thickness of the PEM mount, and the puck diameter is a perfect fit for the OEM bracket, with slight modification.

Old front mount:






Pressing sleeve into pucks:




"Slight Modification":


Press new mount into OEM bracket:




After installing, there is definately a lot less movement in the engine bay, and more vibration in the cabin. It felt odd at first, because I can now feel the cylinders fire individually, which makes the engine seem less smooth, but more responsive. It feels like a sports car now, not an old Buick. It didn't take long before I started appreciating it. Feeling the engine through the wheel and floor and seat keeps me updated with feedback at low RPM and under heavy throttle, but at cruise it's not very noticeable. Before I was isolated from the engine, giving the illusion it ran smooth. If something's off, you might not have detected it as easily before, but you'll know it for sure with these mounts!

Looks nice and neat, great result! So correct me if I'm wrong, but I assume the need for this mod is because the OEM are discontinued or because you prefer the improved strength of the pucks?

Oh, also, how did you determine the location of the pipe?

My priority for this mod would be in this order:

1) Price: dealer price for front mount is $316 + tax, GM parts direct: $187 + shipping, Rockauto: $55. Price of two hockey pucks and pipe: $5

2) Durability: the denser material of the pucks should last longer than a new OEM soft rubber mount. It's easy to see how the OEM rubber gets torn - there's not much material for support.

3) Performance: I wanted to stop the engine from shifting around in there, delivering more torque. The pucks are strong enough to handle this, while the OEM mounts really aren't. Locked in 1st gear between 20-35 MPH, the throttle response is just scary.

Hole for pipe is 5/8" drilled on center.

Nice! Looks like a simple solution! and no messing around with window weld either...

Thanks. I did add window weld the rear mount - an OEM replacement I found for cheap at Rockauto. I think if I did the rear with pucks it would made some VERY harsh vibration in the cabin, but would have saved about $50.

The front mount was in bad shape, completely fractured one of the webs (see above). The pucks should keep this from happening in the future.

Thats exactly what i did, i just didnt use a pipe. Im going to put pucks in the rear mount soon and ill let you know how it turns out.

I like that. I'm gonna take my spare front mount and do it sometime soon even. My only concern with it is I wonder if it will end up putting more stress on my current rear mount that's getting by for now but pretty much on it's way to being bad already..?

Probably, yes. You haven't changed your rear mount yet? Maybe can use pucks all around.

AA wrote:

Probably, yes. You haven't changed your rear mount yet? Maybe can use pucks all around.

I bought new Anchor's for the front and rear mounts. I never got around to 3M'ing them in time for the cradle job though so I'm working on them now to install this summer while I have the engine out again.

AA wrote:

Probably, yes. You haven't changed your rear mount yet? Maybe can use pucks all around.

Definitely yes, my rear mount was on the way out when i did the front and theres nothing left of the rear now

AA wrote:

a piece of black iron pipe as a sleeve (5/8" OD, 1/2" ID, 3.9" L)

I'm making mine. I went to the store and I got the 1/2" ID black pipe. Turns out the ID and OD of my pipe is too big. It's too big for my 5/8" hole that I drilled into the pucks and the bolt is really loose in it. I measured the OD of the pipe to be just a hair over 3/4". What kind of pipe did you get?

3/4" is too big - you probably bought 5/8" ID. I used a 5/8" spade bit and had to ream out the hole in the pucks a bit to get the pipe to fit - pressed it in with the vise. The pipe I used is 5/8 outside dia (OD), which is 1/2" inside dia (ID). It's called black iron, used for residential gas & plumbing, and comes threaded on each end. The mounting bolt was slightly loose in the pipe, but just a tiny bit.

http://www.lowes.com/pd_28021-185-308+L38X12_4294821999_4294937087_?productId=3360846

AA wrote:

3/4" is too big - you probably bought 5/8" ID. I used a 5/8" spade bit and had to ream out the hole in the pucks a bit to get the pipe to fit - pressed it in with the vise. The pipe I used is 5/8 outside dia (OD), which is 1/2" inside dia (ID). It's called black iron, used for residential gas & plumbing, and comes threaded on each end. The mounting bolt was slightly loose in the pipe, but just a tiny bit.

http://www.lowes.com/pd_28021-185-308+L38X12_4294821999_4294937087_?productId=3360846

I'll try another store if Ace doesn't have what I need. These pipes didn't have ID and OD, just one measurement and they had black or galvanized for 10c more.

Sorry about the confusion. I provided the ID & OD assuming you might measure it in the store before you bought it. Didn't consider you might ask them for 5/8, but that would make perfect sense!

Pipe specs make absolutely no sense to me. There are different systems, and the specs used in stores do not accurately reflect the actual dia, because it's based on older specs that have changed over time. I believe the correct size for our black or wrought iron threaded pipe is 3/8" Nominal Pipe Size (NPS). The 3/8" NPS size has an internal dia of .493" and an outside dia of .675", so that's where I got my measurements from. I don't know why they call it 3/8".

Check this link and scroll down to "Wrought Iron Pipe" to see what I'm talking about: http://www.gizmology.net/pipe.htm

Note that with other materials (copper, PVC), the 3/8" NPS size pipes have different ID dimensions!

I exchanged it and got a 3/8" x 5.5" long. It's about 5/8" OD and the M12 bolt size fits snug so looks like I got the right one now.

Got it done - just like AA's prototype with the exception of my hole being offset 1/4" from center for reasons not related to this thread.
Not very hard to do. It looks like AA used a bench grinder to trim down the pucks - I used a bench mount sander. Same difference.


just gotta get the final position for the sleeve


new anchor mount on the left, HP mount on the right





I'm not noticing a dramatic difference in vibration after putting this thing in so I'm guessing the tired stock rear mount is just getting all the torque now Good thing that's getting changed this summer.

I noticed that the Anchor mounts are beefier than the OE mounts, to begin with. Any comments. My new (Anchor) mounts transmit some vibration to the cabin at idle, not so much it's a hassle (and none while moving) but makes me wonder if rigging a set of liquid-filled mounts might be a better idea.

Comments?

I didn't notice the difference, but you could be right. I assume they could have noted how the OEM design wore out and added some thickness to compensate.

AA wrote:

I didn't notice the difference, but you could be right. I assume they could have noted how the OEM design wore out and added some thickness to compensate.

It also could be they were mis-installed (I did not do the install) - might have to crawl under there and basically, use a floor jack and some wood blocks to put the engine in right position while loosening and then re-tightening the mount bolts to relieve stresses.

I *MIGHT* look at it Saturday if I finish the must-do's (mowing) early enough.

Albertj

albertj wrote:

I noticed that the Anchor mounts are beefier than the OE mounts, to begin with.

YUP!

Only have to look once to see the difference.


Albertj

Well, I tried this out on the wife's 98 this weekend. The front mount was fairly beat-up, and the engine would roll quite a bit. The hockey pucks worked quite well. Not too much extra vibration, but now the engine doesn't roll around. I'm very happy with the results.

I did it a little different: I used a bit of 1" steel stock, and turned a hole through it to match the bolt exactly. I would have just used some 5/8 pipe like AA, but I couldn't find any around. I figured the extra surface area of the 1" steel might add some durability to the mount. I also cut the hole in the pucks using the lathe, though it really doesn't make any difference. It would have been just as easy to drill it out. I also used a bench sander to make the two flat parts, and pressed it into the mount.

Now I'll have to look at doing the rear sometime.

3/8" pipe (for reference; it still doesn't make any sense to me!)

Glad to hear you like the mod. The only time I notice a bit of vibration is the very first start in the morning. It really jumps to life when I turn the key! Btw, I am really loving tight corners and hard braking after the mounts and cradle insulators. I can still remember how the engine felt rolling around up front, but that memory is fastly fading.

I made a rear. We'll see how it goes. I need to finish cleaning up and paint the new bracket. There's more rust than paint on my current one. What's a good paint to use that'll keep up and what about primer?


I looked at the original insert and made the hole about 1/4" lower to account for resting position under weight and make sure I have the extra hood clearance I'll need later. I figured the OEM mount pin probably comes down about 1/8" under weight. A window-welded OEM mount insert probably wouldn't fall down any measurable amount (which is actually kinda not good for me looking for hood clearance)

I need to get this thing in. I would say our speculations about the hard front mount killing a weak rear mount quickly was right.

A good tough paint you could use would be por-15 or something similar. Pretty tough and helps stop the rusting. I painted some parts on the bottom of my car last year with something similar. Don't let it dry on your skin otherwise you have to let it wear off.