Dog Bone mount options

I removed the rubber and replaced with polyurethane 90. I also replaced the rod with a tube welded 20mm lower than stock to fit my UT engine. Making a mold is not necessary. I used clay in the bottom to keep it sealed, and the center tubes in position, then poured the polyurethane. It is a good idea to use a vacuum pump to remove all air from the poly mixture before pouring to avoid air bubbles.

Will be interesting to see how well it holds up - with the rod off the centerline I expect it will alter the load characteristics - however since you used a solid fill perhaps it makes no difference?
 
I did the same thing that Bjorn did. I used Urethane Casting Compound, 80A Hardness, 1 lbs. PN 8644K11 from McMaster-Carr. https://www.mcmaster.com/casting-compounds/
80A is pretty firm, 90, or 95 may be a better choice because I've heard that the softer urethane is too soft and will not work.

I made some very simple molds as you can see in the pics. They were very easy to make because I had the original part to use as a template. I drilled out a bit of the wood to allow the bushing to sink in to the proper depth. The hardest part of doing the mod was getting the old rubber out.

One thing that I found helpful was to use candle wax to seal my simple molds. I simply fabbed up the mold, then dripped some candle wax where the metal part of the mount contacts the wood. Then I heated up the metal before sliding it onto the mold. That formed a pretty good seal. The candle wax worked well but it's not the end of the world if a little urethane leaks out.

Obviously you need two different molds to do a 1300 and 1500 dog bone. And, the side of the bushing that's up will look a bit better than the side that's down against the mold, but - oh well - you can't see it when it's mounted anyway. I found that the 1 pound can was more than I needed. I didn't attempt to cast a lower/trans mount because I think the mold would be a lot more difficult to make.
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I made an adjustable solid mount with a 1/2 inch bolt. It transmitted way too much vibration for me. So I uses Dr. Jeff's method of inserting a
rubber bushing, with a much larger steel internal bushing that expanded the rubber to fill the dog bone. Works great, with minimal movement.

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I made an adjustable solid mount with a 1/2 inch bolt. It transmitted way too much vibration for me. So I uses Dr. Jeff's method of inserting a
rubber bushing, with a much larger steel internal bushing that expanded the rubber to fill the dog bone. Works great, with minimal movement.

View attachment 34983
So Paul, is your solid engine mount for sale? I could be interested. I'm already using a solid engine mount and I'm living well with it.
 
I did the same thing that Bjorn did. I used Urethane Casting Compound, 80A Hardness, 1 lbs. PN 8644K11 from McMaster-Carr. https://www.mcmaster.com/casting-compounds/
80A is pretty firm, 90, or 95 may be a better choice because I've heard that the softer urethane is too soft and will not work.

I made some very simple molds as you can see in the pics. They were very easy to make because I had the original part to use as a template. I drilled out a bit of the wood to allow the bushing to sink in to the proper depth. The hardest part of doing the mod was getting the old rubber out.

One thing that I found helpful was to use candle wax to seal my simple molds. I simply fabbed up the mold, then dripped some candle wax where the metal part of the mount contacts the wood. Then I heated up the metal before sliding it onto the mold. That formed a pretty good seal. The candle wax worked well but it's not the end of the world if a little urethane leaks out.

Obviously you need two different molds to do a 1300 and 1500 dog bone. And, the side of the bushing that's up will look a bit better than the side that's down against the mold, but - oh well - you can't see it when it's mounted anyway. I found that the 1 pound can was more than I needed. I didn't attempt to cast a lower/trans mount because I think the mold would be a lot more difficult to make. View attachment 34966View attachment 34967View attachment 34968View attachment 34969View attachment 34970View attachment 34971View attachment 34972View attachment 34973
That’s awesome! Thank you for sharing! I think I’ll end up doing the same this winter!
 
You're welcome. I outlined what I did several years ago.
Be sure you observe the cure time, it's pretty long.
Good luck, I found that it was pretty easy to do. I didn't do the vacuum thing to remove the air bubbles, but it couldn't hurt.
I would imagine that there might be some buyers out there for urethane motor mounts.
 
I would imagine that there might be some buyers out there for urethane motor mounts.
Agreed. Given that someone went to the trouble of producing urethane suspension bushings (offered by VAS), I'm a bit surprised they didn't also make urethane engine mounts (all three).
 
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