Rootes1725cc

I need a new Timing Chain Rubber Tensioner, as the old one, had bits come off it from the chain.
It then bubbled up like a balloon, and clogged the oil pan filter in the sump.
The mechanic said DO NOT BUY that same rubber, it's obviously faulty and reacts with the oil.

So, has anyone had a similar problem?
Or have you bought one recently from someone with no problems?

Yes, Aubrey pointed this out in his Sceptre column in the club mag - these pattern parts are a pain, same as the dreaded fuel T pieces which crack when exposed to petrol.

You need to try and find an original if you can, possibly a good used one.

Unfortunately I can't find Aubrey's write up.

I did however manage to speak to a professional, who had actually done some testing on the rubber tensioner.
They found that the rubber disintegrates, softens and expands when exposed to 'modern' additives.
Products such as Synthetic Oils, Slick 50, Oil Stop Leak etc.
If the proper 20/50 classic oil is used there are no problems.

One well known shop recently sold 100 units in the last year! That's an extraordinarily large amount considering the small amount of cars.
It suggests to me that 100 car owners have added a synthetic product to their engine in some way, and had to replace the unit.

I feel that the rubber , should be converted to a polyurethane composition instead, as this would be more durable, and less prone to being chemically degraded.
I am currently looking what the manufacturing costs would be to make such a product.

Yes, Aubrey had a pattern one fail on him in the same manner, replaced it with a genuine part if I recall correctly. I don;t believe he was using anything unusual in his engine
Were you using any additives, do you think?

I would have used Slick 50. I'll give Aubrey a shout tonight.
Apparently the new ones are made to the exact specifications as the original ones.

Hi Chaps,

As you say I've been there done it, wrote it. Only get an original and they are available from greenwood_auto_uk on ebay under Hillman Hunter Commer PB
Humber Sunbeam Alpine Timing Chain Tensioner for the phenomenal price of £6.20 inc post. its almost worth getting 2 at that price.

Aubrey

Hi Aubrey,
What issue was your article in?
I spoke to Paul at Greenwood yesterday, they are not Original, they are manufactured in Iran.
He said there a lots of Rootes 1725 engines being used over there, on a different named vehicle, called the Hillman Arrow and Iran Khodro Paykan so there is a market for spares.

It disintegrated because of the additives in the synthetic oil, Oil Stop Leak or Slick 50.
If the correct oil 20/50 classic oil (with no additives) is used, it will be fine.

If these ones are seeing a lot of use on Paykans, they should be ok then, and like you say, avoid the additives.