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David Geach
Yet to post message
Username: davidgee

Post Number: 1
Registered: 02-2022
Posted on Sunday, 13 February, 2022 - 05:03:   Edit PostDelete PostView Post/Check IP

I am in the process of checking the valve tappet clearances on my 1933 20/25, Chassis No GGA60.

The Rolls Royce manual specifies 0.003" with the engine cold. I am getting between 0.004" and 0.006" across all 12 valves. I realise that the 0.003" allows for expansion when the engine is hot, and the importance of ensuring the valves close fully.

Bearing in mind how fiddly adjusting the clearances can be, is this range of 0.004" to 0.006" acceptable? If not, what is the allowable maximum/minimum clearance I should aim for?

David
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Dorien Berteletti
New User
Username: dorien

Post Number: 29
Registered: 01-2013
Posted on Sunday, 13 February, 2022 - 05:40:   Edit PostDelete PostView Post/Check IP

Well the engine will run perhaps a little noisy, but why not do it correctly? It's not that hard and i have no problems setting the valves.

Dorien
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Jeff Martin
Frequent User
Username: jeff_r_1

Post Number: 326
Registered: 07-2018
Posted on Sunday, 13 February, 2022 - 10:26:   Edit PostDelete PostView Post/Check IP

Are the rocker arm ends worn/cupped ?
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ChristopherCarnley
Unregistered guest
Posted From: 86.182.152.160
Posted on Sunday, 13 February, 2022 - 18:43:   Edit PostDelete PostView Post/Check IP

Being set within the cylinder block, the tappets are very fiddly to adjust especially with oily and perhaps burred nuts.
The main thing is to have the valves closed to prevent burning.

The handbook reads .004" when cold.

(Message approved by david_gore)
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Theo Whitmont
Experienced User
Username: old_mate

Post Number: 76
Registered: 04-2020
Posted on Tuesday, 15 February, 2022 - 19:54:   Edit PostDelete PostView Post/Check IP

Gents

This is a skill I would love to learn.

Are there any instructional videos or other methods to understand more?

Many thanks
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David Gore
Moderator
Username: david_gore

Post Number: 4068
Registered: 04-2003
Posted on Wednesday, 16 February, 2022 - 06:27:   Edit PostDelete PostView Post/Check IP

Theo,

"Ask and ye shall receive"

Long time contributor to this section of the Forum Christopher Carnley has asked me to post the the following information from his personal files:

Carnley

Chris has advised the following additional information:

"It is so fiddly and down in the engine, that it is not for anyone with a bad back and a lot of patience is required."

.
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Dorien Berteletti
New User
Username: dorien

Post Number: 30
Registered: 01-2013
Posted on Wednesday, 16 February, 2022 - 07:17:   Edit PostDelete PostView Post/Check IP

This is amazing, truly amazing!
I have the same illustration in my "owners manual".
Now on the home page of the Australian Rolls Royce club they have the same manual

https://rroc.org.au/wiki/index.php?title=Handbook_for_20/25

And the valve section is in part 3 I think.
It's a great club...suggest the interested party become familiar with it.
Dorien
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Theo Whitmont
Experienced User
Username: old_mate

Post Number: 77
Registered: 04-2020
Posted on Wednesday, 16 February, 2022 - 09:57:   Edit PostDelete PostView Post/Check IP

thanks all for the speedy reply and commentary. All well received.

Best wishes to all.

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