Timing Cover Stiffener

[pgp001]

I was at a loose end waiting for parts to arrive in the post so to keep myself busy I decided to see if I could persuade a timing cover stiffener to reveal itself from a piece of 1/4" thick Duralumin plate I had been saving.
I saw a laser cut mild steel one on an ebay advert, but being a Yorkshireman could not bring myself to spend over £20 on one.

Here is the raw material with a few rough shapes marked out.


Then cut out on the bandsaw and holes drilled.


And finally cleaned up and fitted to the lower half of the timing cover.


Phil

[Murrayminor]

Forgive my ignorance, but why fit this stiffener?
The only thing I can think is to spread the load of the securing bolts, is this a leakage point?

Nicely made anyway, well done.

[philthehill]

BMC/BL introduced the timing chain stiffener (Pt No: 12A666) to reduce the possibility of leakage from the bottom of the early timing chain covers which suffered badly from oil seepage past the gasket.
The stiffener was only introduced for use with the early type timing chain cover without tensioner.
The later type simplex timing chain cover with tensioner is not prone to leakage. BL adopted a better quality rubberised material gasket for use with the simplex tensioner type cover.
http://www.minispares.com/product/Class ... o%20search

Phil

[Murrayminor]

BMC/BL introduced the timing chain stiffener (Pt No: 12A666) to reduce the possibility of leakage from the bottom of the early timing chain covers which suffered badly from oil seepage past the gasket.
The stiffener was only introduced for use with the early type timing chain cover without tensioner.
The later type simplex timing chain cover with tensioner is not prone to leakage. BL adopted a better quality rubberised material gasket for use with the simplex tensioner type cover.
http://www.minispares.com/product/Class ... o%20search

Phil

Thanks for the explanation.
I take it the duplex cover it not prone to the same issue.

[philthehill]

Just for reference:-

https://www.ebay.co.uk/itm/Classic-Mini ... SwUIletp6I

'A' Series engines fitted with duplex chains tend to have a later type timing chain cover, for example the Cooper S with duplex chain set up Pt No: 12G2506 with better strengthening/rigidity around the rim..

Here is a later timing cover with the stiffener attached and not separate.

https://www.ebay.co.uk/itm/Classic-Mini ... Swmyle0PXv

[pgp001]

Nothing much more to add really, Phil TH has described its purpose perfectly.

I did not really NEED it, I just WANTED it.
I do a lot of model engineering as my main hobby and have a well tooled up workshop, so I quite enjoy making odds and ends like this.

Phil

[philthehill]

Because of the raised portions between the holes of the timing cover make sure that there are spacers around the bolts (equal in height (or just under) to the raised portions) between the stiffening plate and the timing cover otherwise the cover will distort when you tighten the bolts and you will be back to square one with leaks.
The strengthening plate was originally for those timing covers without the raised portions between the holes. The raised portions alleviated the need for the strengthening plate.

[pgp001]

Mine does not have those raised ribs between the holes, it has very slight depressions into the outer face, so my additional plate actually sits nice and flat over the whole area around the holes.

It looked like this one when I got it, I had to remove the sensor bracket and beat out the small clearance bulge from the inside, and remove an internal protruding lip.


I think they did all sorts of different variations, this one shows the raised strengthening ribs you are talking about on the standard cover.


Phil

[philthehill]

Phil

Thank you for clearing that up.

Phil

[Monty-4]

I have a simplex chain with tensioner and a cover like the above, with this gasket if I recall correctly. Still manages to leak the odd drip.

These cars really are good at rust-proofing themselves in particular places.

[ampwhu]

don't forget the 'ribbed' timing cover has a rubber seal and the early 803/948 cover has a felt seal. the difference is very noticeable in my book.

[philthehill]

Just to add to the above - the rubber/neoprene seal can be fitted from either the inside or the outside of the timing cover dependent upon which timing cover is fitted and to which vehicle.