Lower engine mount...once more.

[workaholic_ro]

Originally Posted by T-Cut

workaholic_ro, will the PU bush be an 'all engines' part or will it be necessary to create different bush 'tempers' for diesels and petrols? I understand the OEM bushes are made using different rubbers, is that correct?

TC

The natural way would be to follow the MGR designer's policy; if they made three different 'tempers', then to make three and, respectively, if they only made one, renamed for each engine model, to make one.
There are two ways to make dampers with different stiffness grades: changing the shape or changing the rubber composition and therefore the hardness (Shore A).
Now, trying to put myself in the manufacturer's skin, due to logistical and economical reasons, I would change the shape or the width of the damper rather than the rubber. Which they did not. That's why I strongly believe that all three part numbers are actually sharing the same part. But, of course, I may be wrong. One more argument is that the rubber from the suspension bushes looks very much the same.
There is only one way to tell precisely, comparing all the three parts (unused and not aged) with a shore meter. No problem with the shore meter but I don't know who has the completely new parts. No one, I'd guess

[Jules]

Did no one see my previous notes on this!!?
We have 2 Brand new OEM engine mounts here

One is for Diesel and one is for KV6

I can confirm there is a very big difference in the rubber hardness between them.
Pics to follow

Because the Diesel type are out of stock there are some unscrupulous distributors out there advising owners that the petrol Bush will fit a Diesel.............yes it will but believe me, it will only last a few 1000 miles!

[workaholic_ro]

Originally Posted by Jules

Did no one see my previous notes on this!!?
We have 2 Brand new OEM engine mounts here

One is for Diesel and one is for KV6

I can confirm there is a very big difference in the rubber hardness between them.
Pics to follow

Because the Diesel type are out of stock there are some unscrupulous distributors out there advising owners that the petrol Bush will fit a Diesel.............yes it will but believe me, it will only last a few 1000 miles!

Can you detail a bit on the following:
1. how do you estimate the big difference ?
2. apart from an eventual inefficient vibration damping why would they fail? the inner metal bush play is limited by the rubber profile; if not aged, the rubber should be able to permit a side to side movement without breaking.

BTW, thanks for blowing the mystery; now we know they are different!

[workaholic_ro]

Originally Posted by workaholic_ro

Can you detail a bit on the following:
1. how do you estimate the big difference ?
2. apart from an eventual inefficient vibration damping why would they fail? the inner metal bush play is limited by the rubber profile; if not aged, the rubber should be able to permit a side to side movement without breaking.

Secrets are everywhere... ....Therefore we have to experiment, compare, calculate when we can and, the most painful part, think. A different poly composition for a diesel, that will try to destroy it starting from tomorrow. The small bush will be left out, it doesn't pay the effort to install it, AFAIK the original one never fails.

[Jules]

Originally Posted by workaholic_ro

Can you detail a bit on the following:
1. how do you estimate the big difference ?
2. apart from an eventual inefficient vibration damping why would they fail? the inner metal bush play is limited by the rubber profile; if not aged, the rubber should be able to permit a side to side movement without breaking.

BTW, thanks for blowing the mystery; now we know they are different!

Here you go Fidel, and the other sceptics!!
Here's a very DIY scientific test i did
You can see the different displacements of the rubber for the equal amounts of forces applied

Brand new OEM Teardrop mounts

[HarryM1BYT]

Interesting thread and more interesting because I think my M47 is bouncing about more than it really should as I drop the clutch.

I wonder if some measured comparisons between the two new rubber bushes could be made by applying a known weight and and measuring the deflections in two plains - thrust in line with the rubber webs and thrust where the air space is in the web? Just to give workaholic_ro some better clues as to what is needed. Judging by the photos, the diesel looks around half the deflection of the petrol version.

[lukefree233]

Do you have any information on the material you are casting for the new bush?

Material spec or even the name on the product would be great.

Regards

Luke

[red mist]

Just finished reading this thread and would be interested to know whether the replacement rubber is working in the KV6?

Also if Xpart or rimmers have now received any OEM parts?

Cheers
Phil

[Jules]

Yes we just received a few OEM,s from Rimmers

[mantianak]

Is this part similar to anything else, say on a BMW? Would be interesting to see how it compares against other makes.