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MG TD TF 1500 - O-Ring on Valve shaft

Hi Guys, I have again a question for you.
Is it correct to install the little O-Ring Item 52 in the enclosed picture between Valve cotter and spring washer?
What is the function of this element? I believe it will be damage very soon or not ???



Guenter

Guenter, I've worked on engines most of my life, even built high horsepower modified race engines in the past, but I've never come across a setup where the valve stems have an "O" ring in that position. Maybe it's there to help lock the keepers, or (cotters) in place? I also would be curious as to it's purpose. PJ
Paul Jennings

I remember them being in the kit I dropped off at the machine shop?
gblawson(gordon)

The XPAG/XPEG o-ring you describe serves a very necessary purpose: it is the only seal to prevent oil from pooling on top of the spring washer, running down the valve stem, through the valve guide and into the combustion chamber. The o-ring is held tightly in position inside the top valve retainer, and is not destroyed - by the time a rebuild is necessary it will be brittle, but undamaged.

The proper way to install these o-rings is to compress the complete valve unit into the head with the proper tool, roll the o-ring over the end of the valve and slide it to the bottom of the machined groove on the valve stem, fit the two retaining cotters (which will be held in place by the tight rubber of the o-rings), and carefully release presure on the valve spring compressor, being sure the cotters seat correctly.

Racers often use modern Teflon valve seals, but the 'top hat' oil deflector (54 in the disgram) must be onmitted, and some seals require other machining work to modify the valve guides. The o-rings appear to work well on engines with guides and valve stems in good condition, fitted with proper clearances, at least from 1939 to 1955...

Tom
t lange

In my case I removed the o-rings and the metal deflector and replaced them with the "umbrella" type seal, which stop oil running down the valve stem. It can be done without removing the head if you have the right spring compressor. They are better than the o-rings which to me, serve very little. In the case of my engine the seals were not o-rings but more like square edged seals.
I have put together the whole process and instructions, but I have had difficulty in others trying to open the file attachment in MS Word.
I can try sending it if you are interested.
colin stafford

Colin, I would be interested in your write up as I need to do this on my TF.
Tnx
Terry in Oakland
Terry Sanders

me too Bob
Bob Jeffers

I'd be grateful for a copy, as well. Thanks. Tom
t lange

Sorry - tlange at acadia dot net
t lange

Be glad to send it, but it is 720mb file in MS Word. What happens when I try to send it as an attachment to an email, is that, it goes in 3 parts and then the receiver cannot open it.
Perhaps it can be save in a different file format and be sent.
Any of you cyber guys out there have any suggestions.

colin stafford

You might save it as 'text' and try...or save as 'html' and try sending?
Or, copy it and just paste it into an email and send...
gblawson(gordon)

Colin, I seem to recall that we've been through this before. What version of Word are you using? I may have a way around this. Bud
Bud Krueger

OK did a cut and paste and sent it to you all.
Have fun.
colin stafford

Colin -- Got it fine, thank you. Didn't have to cut and paste.
Bob
Bob Jeffers

As Tom Lange says:

"The o-rings appear to work well on engines with guides and valve stems in good condition, fitted with proper clearances..."

I used them, and they work great, no oil burning loss between oil changes, no blue smoke on start-up. The only loss of oil on my car is that which preserves my garage floor!

warmly,
dave
Dave Braun

Came through for me OK. Thanks Colin.
Cheers,
Bob
Bob Jeffers

Colin,

Would you please send me your write-up.
jneel43 at hotmail dot com

Thanks and Cheers,
Jim
James Neel

I'm interested too on Colins solution. Please can sombody send me the doc?
Thank you
Guenter
Guenter

Hi guys: I am also interested in receiving Colin's solution. Thanks a lot.

Stuart
Stuart J. Ramos

See http://www.ttalk.info/StaffordSeal.htm for a look at Colin's solution. Thanks Colin. Bud
Bud Krueger

Thank you Bud,
Looks nice but what's about valve shaft lubrication? I believe some little oil is needed between valve guide and valve shaft, isn’t it?
Cheers,
Guenter
Guenter

Guenther.......even with these seals you do not get complete closure around the valve seat and the valve, so you get plenty of lubrication. These are so called "umbrella' seals which act to prevent the bulk of the oil going down the valve shaft as the act like an umbrella.
I had Bud put it on his website so I did not have to send dozens of requests all the time.
colin stafford

This thread was discussed between 13/04/2010 and 17/04/2010

MG TD TF 1500 index

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