Engine mountings

[stuartgb100]

Looks like my n/s engine mounting is shot. The rubber appears to have debonded from the metal on one side, along all 4 edges.

Surely that's not right?

If it's to be replaced, I think replacing both is best.

So where's best to get them from, please? I've only found TTR's price of ?65 per pair + carriage + the dreaded VAT.

Regards,

Stuart.

[stuartgb100]

Oops ..... can't read !!

That's ?65 for a pair of race mounts,
or ?35 for strengthened road mountings.

Regards,

Stuart.

[steveww]

I have just replaced the carb side engine mount on my S4 for the third time this year. I got the first two mounts from Paul Matty. These failed again after only a couple of hundred miles. The third mount that I have just used I got from Sue Miller, this looks to be from a different supplier however the holes do not align with the engine properly and it needed a bit of adjusting. The mounts from PM and SM are about ?15 + VAT each. May it is worth paying the extra to TTR if they are better quality.

[stuartgb100]

TTR's site seems to say that they're dissatisfied with the quality of many of the 'rubber' components being made today. They seem to have developed their own polyurethane versions.

Don't want to open up the plastic v rubber debate, but I'd have thought that polyurethane mountings/bushes would be ideal for engine, gearbox and differential mountings/bushes, and I wouldn't have thought they would affect ride etc issues.

Will talk to them tomorrow and post back any findings.

I take it that there should be no debonding between the rubber/metal interfaces, anywhere on the mounting?

It seems to me that once debonding has started, it will just accelerate.

Regards.

[stuartgb100]

Just an update:

Talked to Tony at TTR. They were dissatisfied with the quality of rubber components being produced. So in league with Powermax (who I think he said do all Subaru's poly bits) developed a series of poly bushes over a period of time to suit the elan and +2, in a way that does not really affect ride and handling characteristics, but does give significant improvements in terms of longevity.

He wouldn't recommend changing just one engine mount, (and if going from rubber to poly, you'd change both anyway), but he'd also always change the gearbox mountings at the same time. Presumably a duff engine mount will put excess strain on the other mount, and because there's a direct metal to metal contact between engine and box, some additional stress must transfer to the box mountings.

I know he's got product to sell, but there seems a logic there.
My thoughts, FWIW.

Regards.

[M100]

Just an update:

Talked to Tony at TTR. They were dissatisfied with the quality of rubber components being produced.

The story of this "substandard" rubber has been flying round for a few years with regard to the rotoflex's and apparently "banned" rubber additives, but despite that, and because of the lack of visible legislation detailing these compounds (someone elsewhere online mentioned sulphur!!!), I can't help thinking we are getting lumbered with the current low quality of engine mounts and other rubber parts because the know-how and/or original specifications have probably disappeared from the usual (UK based?) suppliers and back street copies on an Eastern European "it will fit but bugger the longevity basis" have become the norm.

In years to come expensive funny coloured copies done in another material might be the only option for small scale production like the diff/rear end but for the front end at least there must be tens of thousands of cars worldwide that could justify someone producing a few thousand proper OEM spec rubber bushes that realistically last a long time. Maybe these TTR urethane bushes will be ok but some of the alternative bushing material suppliers are well known for turning out crap for other cars that is dimensionally very inaccurate - I've re-machined some MG ones for a friend that were out by a mile and they also tend to wear the pivots and/or the inside of the bush as they are in effect "loosely assembled" rather than moulded as one.

Since the late 80's at least Lotus have tended to source rubber components (engine and suspension) from outside the UK and despite some like the 90's Elan Raft and wishbone bushes being infinitely more complex in formulation/construction than the ones used on the 60's cars, they tend to last quite a long time, hence one reason why I don't completely buy the banned rubber additives argument!

Also, this current problem begs the question, are all new engine mounts still being manufactured dimensionally out of limits and with what would appear to be substandard rubber, yet are still being deliberately sold by parts suppliers who do (not should!) know better?

[rgh0]

Martin

I agree completely with your comments. I worked for 15 years in synthetic rubber manufacturing up until recently and over that period the rubber compounds and formulations for rubber curing continually improved. This was mainly driven by tyre manufacturing technology but the same applied to other rubber components.

I source my Lotus bushes where I can from industrial supply catalogues as many of the Lotus source components were standard industrial bush sizes and orginally came from these same manufacturers and you can still get high quality parts from the major manufacturers.

While the performance of things like the Elan engines mounts may be worse in recent years this is due to low quality small run manufacturing by the current new back yard manufacturers for parts such as this that are not standard industrial components.

Rohan

[triumphelan]

I have changed all 3 mounts with ones from CN I still get judder on take off I have always thought that as I have "new mounts" they cannot be the cause .This topic has give "food for thought" ,I have checked all the mounts several times and they "seem" fine but are they ??Has anyone any experiance with anything other than the ones supplied by the usual sourses?
Regards John

[stuartgb100]

Just to correct my earlier post... Powerflex NOT Powermax.

Regards.

[mark030358]

Hi there,
I posted a picture on the yahoo elan site of an origional mounted bolted to a "new" mount and the difference is incredible. I then drove to another local supplier and when tested as per the picture gave the same problems. So I refitted the 32 year old one till I can find a better item.
cheers
Mark

[steveww]

I could not find your picture of the engine mounts??

When I was at TTR picking up some rear suspension bits I had a chat with Stuart about engine mounts. They are currently working on their own design that will be "fast road" types. Given the quality of their other bits looks like these will be the ones to fit in the future.