R Type Continental 1954

 
Post new topic   Reply to topic    BENTLEY DRIVERS CLUB FORUM Index -> Crewe Cars through S Type
View previous topic :: View next topic  
Author Message
Eddie Young



Joined: 13 Aug 2009
Posts: 5
Location: West Sussex, United Kingdom

Reply with quote

Replacement clutch needed.

Has anyone had recent experience in replacing the clutch on 4.9 engine and if so can you pass a recommendation on which type to consider and if a new fly wheel is needed?
Understand the failure rate on new clutches is becoming of concern with poorly made components.

Eddie
Back to top
View user's profile Send private message
Christopher Carnley



Joined: 16 Nov 2007
Posts: 2746
Location: Yorkshire, United Kingdom

Reply with quote

Eddie,

First post, eh!

The flywheel and clutch are the 11" R-R "heavy" pattern, with a 3 part flywheel and a friction plate and pressure plate borrowed from the Ferguson tractor. The Borg and Beck friction plate is unusual for, service reasons, in that there is no front nose on the 10 splined hub which is in effect pushed backwards.
There was only about 2 mm of fibre lining above the rivet heads and wear from the bored out R Type engines was quite rapid, with lower than expected clutch life.
The extended running of the flywheel inner on the rivets generated so much heat that the free graphite in the cast iron went into solid solution, creating very hard spots on the surface.
The consequence being that relined clutches wore out rapidly, as no attention was given to the state of the flywheel friction surface.

New three part flywheels are available.

As to the clutch plate and pressure plate there is a guy close to me, in Wakefield, who runs a business called tractorclutches.co.uk, and reconditions used friction plates and covers for most of the specialist suppliers. He is called Trevor Hanson, tel 01924 453140, and knows all about clutches.
Back to top
View user's profile Send private message
Stephen Blakey



Joined: 02 Feb 1995
Posts: 1337
Location: Derbyshire, United Kingdom

Reply with quote

Hi Eddie,

Welcome to the forum.

The most abused 4.9 clutch in the club must be that in Paul Forty's very successful race-car. Maybe you could ask him for some tips? He's a helpful chap.

It would be good if you could share your eventual conclusions with the forum.

Good luck

Stephen
Back to top
View user's profile Send private message Send e-mail
Eddie Young



Joined: 13 Aug 2009
Posts: 5
Location: West Sussex, United Kingdom

Reply with quote

As a new member to your forum I'm most grateful for your input Christopher and Stephen. Your depth of knowledge is remarkable. I regularly use a sailing boat forum that invariably 'drifts' off the point so this makes an interesting departure.
I will start by calling Trevor Hanson. Many thanks and will let you know the result in a few weeks.
Happy Christmas
Eddie
Back to top
View user's profile Send private message
John Robins



Joined: 01 Jan 1985
Posts: 1208
Location: Staffordshire, United Kingdom

Reply with quote

Welcome, and glad you have a good experience with your first posting.

Don't expect this forum to arrive at the mark on starboard every time though!
Back to top
View user's profile Send private message
Eddie Young



Joined: 13 Aug 2009
Posts: 5
Location: West Sussex, United Kingdom

Reply with quote

In follow up to Christopher's suggestion to contact Trevor/Tim Hanson of ACS Ltd, Wakefield who's recommendation is stay with a spring lever reconditioned clutch for later adjustment reasons. However, Padgett Engineering is recommending change to modern diaphragm clutch with a new flywheel. My engineer would rather go with the latter as a better clutch for the car's high ratio gearing.
Anyone had experience with Padgett clutches?
Eddie
Back to top
View user's profile Send private message
Christopher Carnley



Joined: 16 Nov 2007
Posts: 2746
Location: Yorkshire, United Kingdom

Reply with quote

Hi Eddie,

Racing Green Engineering incorporated several of Jeremy,s lightweight flywheels and diaphragm clutches into their various high quality "Specials", hoping for some overall improvement, but there was no appreciable difference. The front housing of the gearbox had to be modified to clear the new thrust bearing arrangement

As I rebuild gearboxes for both parties I cannot "afford" to be disparaging of the reasons, except to say that availability of parts and the thrust bearing were factors in the latters decision.

There is absolutely no reason to modernize the existing layout and I second the recommendation of Trevor Hanson.
I would suggest a new 3 part flywheel to eliminate the hard spot problems, as it can involve the removal of up to .100"of cast iron, twice the R-R recommended removal.
Even a small change in any of the Rolls-Royce designs involves a lot more modifications than expected.
Back to top
View user's profile Send private message
Eddie Young



Joined: 13 Aug 2009
Posts: 5
Location: West Sussex, United Kingdom

Reply with quote

Christopher, you earlier mentioned 'new' 3 part flywheels are available. Any idea where I might find one? Trevor/Tim of ACS Ltd do not have any and therefore suggest reconditioning ours.

Eddie
Back to top
View user's profile Send private message
Christopher Carnley



Joined: 16 Nov 2007
Posts: 2746
Location: Yorkshire, United Kingdom

Reply with quote

I will PM with details.
Back to top
View user's profile Send private message
Richard Munton



Joined: 19 Aug 2002
Posts: 1
Location: Rutland, United Kingdom

Reply with quote

Try Di who runs Truckfix at Cleckheaton - she knows more about vintage/classic Borg and Beck clutches than anyone else alive. Did a great job rebuilding the 50s clutch in my Speed Six and has all the spares.
Back to top
View user's profile Send private message Send e-mail
Christopher Carnley



Joined: 16 Nov 2007
Posts: 2746
Location: Yorkshire, United Kingdom

Reply with quote

I believe that the firm closed due to ill health, October 2016.
Back to top
View user's profile Send private message
Eddie Young



Joined: 13 Aug 2009
Posts: 5
Location: West Sussex, United Kingdom

Reply with quote

We have just completed the exercise of overhauling the clutch and gearbox.
As recommended by the Forum we kept original throughout using the spring and lever clutch and original flywheel with just .0500" taken off. Our problem came after re-fitting. On start up a rapid vibration at over 1500 rpm became evident and holding the steering wheel felt more like a buzz bar! Adjustments were made to all external mounts etc. until it was time to remove the gearbox and clutch again. Once removed the engine was started and showed no vibration. So the clutch and flywheel went off for dynamic balance testing. Result - 21g on clutch housing and 9 g on fly wheel. These corrected and once back and gearbox fitted, started up, 'Puurrrfect'. Amazing what 30g can do in the wrong place. Lessons learnt all round, balance each component, assemble and balance again, then fit back.

Eddie
Back to top
View user's profile Send private message
Stephen Blakey



Joined: 02 Feb 1995
Posts: 1337
Location: Derbyshire, United Kingdom

Reply with quote

Eddie,

Thanks for the post. These threads often don't come to much in the way of a conclusion which can be a little frustrating.

That's about an ounce in old money. Who'd have thought it would make such a difference?

Best wishes,

Stephen
Back to top
View user's profile Send private message Send e-mail
Al Coutts



Joined: 25 Sep 2016
Posts: 108
Location: Norfolk, United Kingdom

Reply with quote

Eddie - how was the balancing done?
Back to top
View user's profile Send private message
Christopher Carnley



Joined: 16 Nov 2007
Posts: 2746
Location: Yorkshire, United Kingdom

Reply with quote

The car was at Royce Services who had the individual parts dynamically balanced.

When the cars were made, the basic engine was balanced along with the flywheel and clutch assembly,and you may notice balancing holes drilled into the flywheel parts.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    BENTLEY DRIVERS CLUB FORUM Index -> Crewe Cars through S Type All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group