poly or rubber spool motor mounts

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bbab3

bbab3

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I just finally installed the motor in my '67 barracuda yesterday. And had more than a few problems with the cheap [or should I say Chinese] spool motor mounts.
I have done some searching here on FABO and most people recommend poly mount vs. rubber.
Are they as quiet and vibration free as rubber?
 
I’ve had rubber ones since 1997.

But, I filled the voids in the with clear silicone caulking. Was a trick Rich Eherenberg wrote about once.

what was your issues?

In 1997, I just replaced the rubber insert and they fit loose even after I swayed the end over. So I had a friend tack weld the inserts to the bracket.... been 23 years like that.
 
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I take it you replaced your '67 K frame with one from a '73+ car?

When I installed the 340 in my '74 Duster I replaced the rubber inserts with poly bushings. I used a bench vise to "press" them in, they were a tight fit into the old mounts. Same on the engine, the poly inserts definitely take some of the play out of the mounts, so there was a little more wrangling involved with getting the engine down and bolted in. As for noise and vibration, I haven't noticed any noises. But Poly is harder and more dense than rubber, so, you will get more vibration than with a rubber insert. And less than you would with a solid mount. Just the nature of the material.
 
The main problem I had was one just keep falling out of the factory bracket. Also they are way to tight for the bolts and did not fit into the K member well. I have run both poly and solid mounts in offroad cars for years. The noise was the biggest issue with solids along with metal fatigue of the chassis mounts, polys helped to a point. Obviously a street car is a different beast. What brands poly and rubber mounts do you recommend?

i forgot to mention I am using Doug's headers and have the '67 steering column with power steering.
 
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Urethane does transmit a little more vibration, but they'll likely be the last mounts you buy. I like the silicone caulk idea too though.
 
bbab3 said:
The main problem I had was one just keep falling out of the factory bracket. Also they are way to tight for the bolts and did not fit into the K member well. I have run both poly and solid mounts in offroad cars for years. The noise was the biggest issue with solids along with metal fatigue of the chassis mounts, polys helped to a point. Obviously a street car is a different beast. What brands poly and rubber mounts do you recommend?

i forgot to mention I am using Doug's headers and have the '67 steering column with power steering.
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I'm just using these ones from Energy Suspension. Pretty much all the poly stuff I run is from them, all of it has fit and held up well.
1974 PLYMOUTH DUSTER Energy Suspension 5.1106G Energy Suspension Motor Mounts/Motor Mount Inserts | Summit Racing

I definitely didn't have any issues with the inserts being loose, as I said before I had to "press" mine in with a bench vise. But the mounts themselves can vary a bit. I use poly grease on the install, so I haven't had any issues with noises and they've held up well. They will transmit more vibration than rubber, but the rubber seems kinda sloppy and the reproduction rubber seems to be pretty short lived/poor quality these days, especially the stuff that's been coming out in the last couple years.
 
72bluNblu said:
I'm just using these ones from Energy Suspension. Pretty much all the poly stuff I run is from them, all of it has fit and held up well.
1974 PLYMOUTH DUSTER Energy Suspension 5.1106G Energy Suspension Motor Mounts/Motor Mount Inserts | Summit Racing

I definitely didn't have any issues with the inserts being loose, as I said before I had to "press" mine in with a bench vise. But the mounts themselves can vary a bit. I use poly grease on the install, so I haven't had any issues with noises and they've held up well. They will transmit more vibration than rubber, but the rubber seems kinda sloppy and the reproduction rubber seems to be pretty short lived/poor quality these days, especially the stuff that's been coming out in the last couple years.
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Do you know if all of the spool mount inserts are the same across the board for the slant, big and small blocks? I think they might be, but I'm not sure. Thank you drive through.
 
RustyRatRod said:
Do you know if all of the spool mount inserts are the same across the board for the slant, big and small blocks? I think they might be, but I'm not sure. Thank you drive through.
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Hmm. According to the "applications" list the set I linked appears to be good for all V8's, it list's 318's all the way up to 440's. And that matches what I know, I've seen the BB spool mounts and they look the same.

It does not include slant 6's though. Which is weird, because I'm pretty sure the inserts are the same for them too. They looked the same on the set that originally was on the /6 in my Duster. But I didn't hold onto those mounts and I didn't try to fit them with poly inserts, so I don't know for sure.
 
Thanks, I will give the Energy Suspension bushings a try. The ones I have are rubber and are small compared to the holes in the factory brackets and I had to run a drill bit thru them to just get the bolt in.
 
72bluNblu said:
Hmm. According to the "applications" list the set I linked appears to be good for all V8's, it list's 318's all the way up to 440's. And that matches what I know, I've seen the BB spool mounts and they look the same.

It does not include slant 6's though. Which is weird, because I'm pretty sure the inserts are the same for them too. They looked the same on the set that originally was on the /6 in my Duster. But I didn't hold onto those mounts and I didn't try to fit them with poly inserts, so I don't know for sure.
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I may have some slant spool mounts out in the shop to compare. I have some big block spool mounts so I can see if they're the same. I will report back with my findings.
 
bbab3 said:
Thanks, I will give the Energy Suspension bushings a try. The ones I have are rubber and are small compared to the holes in the factory brackets and I had to run a drill bit thru them to just get the bolt in.
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Yeah the rubber bushings really seem to have fallen off a cliff lately for quality. I know Moog has moved their factories around again in the last year or two, and the result has been terrible quality.

RustyRatRod said:
I may have some slant spool mounts out in the shop to compare. I have some big block spool mounts so I can see if they're the same. I will report back with my findings.
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Nice! I'm sure somebody probably wants to know!
 
72bluNblu said:
Yeah the rubber bushings really seem to have fallen off a cliff lately for quality. I know Moog has moved their factories around again in the last year or two, and the result has been terrible quality.



Nice! I'm sure somebody probably wants to know!
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Nope, they are not the same. The mounts on the slant are oval, like the big and small blocks, but the oval is bigger. The mount bracket I have has the shell of an insert in it and the big block mount insert shell and all just falls right into it. That figures. lol
 
RustyRatRod said:
Nope, they are not the same. The mounts on the slant are oval, like the big and small blocks, but the oval is bigger. The mount bracket I have has the shell of an insert in it and the big block mount insert shell and all just falls right into it. That figures. lol
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Right? Slant 6 stuff is different again. So, the slant 6 inserts are larger? I suppose with a welder one could down size the /6 mount to use the V8 poly insert. Especially if you had the old shells for a V8. If one were so inclined anyway. I didn't see poly mounts offered for the /6, but I didn't look very hard either.

Some of that stuff just blows my mind. Like, why not design it to use the same insert? It would have to cost less money for production to have all the inserts be the same. Same thing for the SBP stuff. Why not use the same brakes across all platforms? I mean, that's what they did later for that exact reason, but why ever do it the other way?
 
72bluNblu said:
Right? Slant 6 stuff is different again. So, the slant 6 inserts are larger? I suppose with a welder one could down size the /6 mount to use the V8 poly insert. Especially if you had the old shells for a V8. If one were so inclined anyway. I didn't see poly mounts offered for the /6, but I didn't look very hard either.

Some of that stuff just blows my mind. Like, why not design it to use the same insert? It would have to cost less money for production to have all the inserts be the same. Same thing for the SBP stuff. Why not use the same brakes across all platforms? I mean, that's what they did later for that exact reason, but why ever do it the other way?
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I don't know, man. You know Chrysler. lol This guy here is the only one I know of offering them.

polyurethane spool mount slant 6
 
That silicone idea is genius! Wish I knew about that years ago... I had a 61 impala, 409-4speed that would constantly blow out the driveshaft carrier bearings from the housing. That may have saved me hundred of dollars on spare bearings.
 
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