New motor mounts - bad grinding vibration...???
#16
Under the Lift
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Which mounts are you supposed to use washers to put the motor higher? I've done cars with the solid mounts and not had vibration UNTIL the most recent one using a set of mounts the owner provided (not Roger's mounts). I sure hope it doesn't need washers. With new mounts there should be at least a finger between the oil pan and crossmember, but I didn't recheck this after the mounts were installed.
#17
Can't answer that with any certainty Bill. When Rog started to supply them with the mounts I just put them on. On the last few sets I opted to not put them in to see if there was a difference. There wasn't.
I think the only reason the washers are provided was due to someone having a clearance issue with the PS line. I've never seen that on any I've done, but doesn't mean it didn't happen.
I think the only reason the washers are provided was due to someone having a clearance issue with the PS line. I've never seen that on any I've done, but doesn't mean it didn't happen.
#18
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Actually I added the washers because the general concensus was that they were required.
Due to the fact that the tolerances on the MM's are pretty open I personally feel they are a waste of time.
Never fitted them and never had a problem.
It was felt as Mr Merlin said that they brought the engine height back to stock.
Who defined stock? Does this take into account manufacturing tolerances in the MM's?
As we cut the bottom stud down clearance is not an issue.
Need more info from Sab please.
Due to the fact that the tolerances on the MM's are pretty open I personally feel they are a waste of time.
Never fitted them and never had a problem.
It was felt as Mr Merlin said that they brought the engine height back to stock.
Who defined stock? Does this take into account manufacturing tolerances in the MM's?
As we cut the bottom stud down clearance is not an issue.
Need more info from Sab please.
__________________
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
Does it have the "Do It Yourself" manual transmission, or the superior "Fully Equipped by Porsche" Automatic Transmission? George Layton March 2014
928 Owners are ".....a secret sect of quietly assured Porsche pragmatists who in near anonymity appreciate the prodigious, easy going prowess of the 928."
#19
Former Vendor
The original, perfect fitting, stock mounts lasted 20 years....
No cutting, no washers, no vibration.
Sure, they might cost more...but it's a Porsche, not a Ford.
No cutting, no washers, no vibration.
Sure, they might cost more...but it's a Porsche, not a Ford.
#20
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Greg,
I wish they did last 20 years.
Mine were as flat as a pancake on my 93 back in 2003.
They looked as if they had been that way for some time.
Never seen a 928 with good original set of Porsche MM's.
Must be something special about the CA air 8>).
Roger
I wish they did last 20 years.
Mine were as flat as a pancake on my 93 back in 2003.
They looked as if they had been that way for some time.
Never seen a 928 with good original set of Porsche MM's.
Must be something special about the CA air 8>).
Roger
#22
Nordschleife Master
I have never seen a stock MM that actually worked as well/lasted as long as the anchor mounts.
Sometimes some parts are better than stock parts.
#23
Rennlist Member
It must be all the ozone in the smog eating the rubber causing a failure
#24
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Thread Starter
Ok,
I will work on it tomorrow again. But we looked at it and the motor rests on the crossmember and exhaust is touching the heatshields.
When jacking the motor up, it will take almost an inch before the motor lifts off the mounts, so they seem to compress a lot. It seems that adding the washer will not make enough of a difference.
My motor was sitting much higher with the old collapsed stock mounts and was not touching the crossmember and or heatshields.
So something must be different, as the same mounts work for everyone else.
One of the mounts had a defect noticeable prior to install, but I had to complete the job even with the broken mount as the car needed to come off the lift.
Roger promptly replaced the part and I have to do it over now anyway.
I would like to find out however, why the motor sits too low, before having to do it over twice again...
Thanks
I will work on it tomorrow again. But we looked at it and the motor rests on the crossmember and exhaust is touching the heatshields.
When jacking the motor up, it will take almost an inch before the motor lifts off the mounts, so they seem to compress a lot. It seems that adding the washer will not make enough of a difference.
My motor was sitting much higher with the old collapsed stock mounts and was not touching the crossmember and or heatshields.
So something must be different, as the same mounts work for everyone else.
One of the mounts had a defect noticeable prior to install, but I had to complete the job even with the broken mount as the car needed to come off the lift.
Roger promptly replaced the part and I have to do it over now anyway.
I would like to find out however, why the motor sits too low, before having to do it over twice again...
Thanks
#25
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Just as a data point, I put a pair of Roger's solid mounts in the GTS prior to installing the stroker this weekend. Greg was adamant that new mounts go in due to the presence of the pan spacer, we'd need all the height we could on the mounts. I did not install any fender washers at all and ended up with plenty of clearance below. If anything, since Greg repaired the wiring harness to the temp sensor with a stiff piece of shrink wrap that's sticking straight up, it's going to be interesting getting the crossbar into place. I hope the hood closes.....
#28
Team Owner
The reason for the 2 fender washers a side is to add about 3 MM to the installed height as the Rock auto MMs are about this much shorter compared to new Porsche MMs.
This was verified at Motorsport in Utah, so adding these washers to the top position keeps the pan flush with the crossmember when using the Rock auto MMs I suggest to use full size washers they are about 2 in in OD and with 2 of them should give approx 3MM of additional clearance lift
This was verified at Motorsport in Utah, so adding these washers to the top position keeps the pan flush with the crossmember when using the Rock auto MMs I suggest to use full size washers they are about 2 in in OD and with 2 of them should give approx 3MM of additional clearance lift
#30
Rennlist Member
I wonder if that's my problem too. I thought I had my noise fixed, but it came back. More of a popping/knocking noise than a grinding. Waiting to get my lift installed (hopefully next week) to dig deeper.