Surfriding Idea for beefing up / repairing stock motor mounts

Dustin Mustangs

Dustin Mustangs

uʍop ǝpıs dn
Location
Holland, MI
The new aftermarket motor mount offering got me thinking about easier ways to make a bullet proof mount. I don't have any experience with broken mounts (knock on wood) but it seems that most fail with the rubber portion ripping in half from upside down landings. Correct?

Well, why not just through bolt them? There would need to be a dampener between the top of the bedplate and the bolt to allow a small amount of vertical movement for vibration (say mmc pn 60525K21). Don't weld the nut on the bottom of the mount and you can adjust how much dampening is provided laterally by how tight you torque the bolt.

You would have to clearance an area between the motor mount hull inserts for the nut sticking off the bottom but that would be pretty easy. The motor would have to be pulled/installed with the mounts still attached but that doesn't seem like a big deal either. As an added bonus, I imagine a failed mount would be just as effective as a good one when set up like this.

Any thoughts on why this wouldn't work? It just seems too easy...


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tom21

tom21

havin fun
Location
clearwater FL
I thought about this awhile ago and in the end I just let it go. I think you are right about the way it would stop the mount from tearing away in an inverted landing, but both ends need to be isolated not just the top. when the vibrations transfer down the thru bolt they will wallow out the mount, so that end needs a bushing, in the end it just seemed easier to keep new mounts in there. at least to me.

what I would think would be a better way to go is to find a way to rebond the mount together. huh? now that would be a money saver, you could keep rebonding the mount til there was no rubber left. lol hopefully by then you would be past inverted landings but you still have the saltwater corrosion to deal with.
 
Dustin Mustangs

Dustin Mustangs

uʍop ǝpıs dn
Location
Holland, MI
tom21 said:
...both ends need to be isolated not just the top. when the vibrations transfer down the thru bolt they will wallow out the mount...
Click to expand...

Good point on the wallow. You could stick another dampener down there but man that would require a lot more material to be removed between the inserts.
 
227

227

Its all about the surf!
Location
Oceanside, CA
A good thought but I'm thinking they're suppost to rip! That's there purpose, to dampen the stress on the hull inserts from engine vibration and general surf riding mayhem. Like already stated, I'd rather lose a $25 dollar motor mount than ruin a hull because the inserts got ripped out
 
CarterB

CarterB

X
Location
orlando
couch mounts will stretch like a mofo (without breaking), so def run keepers or you will get your motor seperated from the midshaft coupler and still be temporarily immobile in the surf. i tried the through bolt idea even though it got shot down on here quick and i found that the vibrations and hard upside downers will ruin the hull inserts :(
 
blaster800

blaster800

Location
sunbury ,ohio
glass in 2 more mounts!!! .... when i installed the 66e in my b-1 i glassed in 2 mounts that needed moved and left the old ones in place right next to them , a person could easily tandem the mounts with a thin plate ! '' just an Idea ''
 
Dustin Mustangs

Dustin Mustangs

uʍop ǝpıs dn
Location
Holland, MI
CarterB said:
couch mounts will stretch like a mofo (without breaking), so def run keepers or you will get your motor seperated from the midshaft coupler and still be temporarily immobile in the surf. i tried the through bolt idea even though it got shot down on here quick and i found that the vibrations and hard upside downers will ruin the hull inserts :(
Click to expand...

Now that's what I am talking about, some real world experience with this. Thanks for the post!

blaster800 said:
glass in 2 more mounts!!! .... when i installed the 66e in my b-1 i glassed in 2 mounts that needed moved and left the old ones in place right next to them , a person could easily tandem the mounts with a thin plate ! '' just an Idea ''
Click to expand...

Good idea but I imagine you'd have to either redo all the mounts and double them up or move your engine in the process. Otherwise the loading wouldn't even be close to symmetrical between the two at each corner and you wouldn't get double the strength. That is quite the added bonus for that pv motor though.
 
227

227

Its all about the surf!
Location
Oceanside, CA
CarterB said:
couch mounts will stretch like a mofo (without breaking), so def run keepers or you will get your motor seperated from the midshaft coupler and still be temporarily immobile in the surf. i tried the through bolt idea even though it got shot down on here quick and i found that the vibrations and hard upside downers will ruin the hull inserts :(
Click to expand...

Carter what couch mounts are compatable with a SJ? Will any of them work?
 
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