Bill Ball

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.

SeanR

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.

ROG100

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.

GregBBRD

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.

ROG100

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

Bertrand Daoust

Greg,

Mine were done - and well done - after 16 on the car and 14 years on the road with about 45K. The car is a 1991 but sold new in 1993.

Lizard928

And what of those who have fitted stock mounts and had them fail in less than 1 year and you are stuck going back in there on your dime?
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.

jeff spahn

It must be all the ozone in the smog eating the rubber causing a failure

Sab

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

Rob Edwards

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.....

ROG100

Sab,
Please take some pictures if you can.
This has me puzzled. Wish you were closer as I would come and help out.
Roger

Sab

Thanks Roger, I will snap some pictures tomorrow.
cheers,

Mrmerlin

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

Sab

Got another replacement set overnighted and the car is fixed.
Mounts where faulty. Thanks for your help Roger.
Cheers

Don Carter

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.