T140 inlet guide oil seals.

Having just stripped the head from my T140 project, I was shocked at the amount of debris, presumably solidified /burnt oil that was attached to the lower side of the inlet valve. There was so much debris on the valve and in the port, I'm sure that the engine performance must have been compromised? As I haven't heard this bike run (it was bought as a none running project) I wouldn't know.

The question I would like to ask is, how effective is the original "O" ring oil seal at keeping oil consumption down through the valve guide on the T140? I've nominated a Triumph Bonneville specialist to do the valve work for me and I discussed fitting some Norman Hyde valve guides, his inlets coming machined for and with valve stem oil seals that look very similar to the Norton Commando, and although the nominated repairers said if I supplied the N/Hyde type that they would fit them, they went on to say that they just stuck to standard production design products i.e. the small "O" ring. I don't understand how this can be effective when fitted as it is not held onto the top of the guide and I assume just finds its resting location on the valve stem after the valve has been depressed and remains there? Can anybody explain?

https://normanhyde.co.uk/meriden-triump ... seals.html

Reggie said:

Having just stripped the head from my T140 project, I was shocked at the amount of debris, presumably solidified /burnt oil that was attached to the lower side of the inlet valve. There was so much debris on the valve and in the port, I'm sure that the engine performance must have been compromised? As I haven't heard this bike run (it was bought as a none running project) I wouldn't know.

The question I would like to ask is, how effective is the original "O" ring oil seal at keeping oil consumption down through the valve guide on the T140? I've nominated a Triumph Bonneville specialist to do the valve work for me and I discussed fitting some Norman Hyde valve guides, his inlets coming machined for and with valve stem oil seals that look very similar to the Norton Commando, and although the nominated repairers said if I supplied the N/Hyde type that they would fit them, they went on to say that they just stuck to standard production design products i.e. the small "O" ring. I don't understand how this can be effective when fitted as it is not held onto the top of the guide and I assume just finds its resting location on the valve stem after the valve has been depressed and remains there? Can anybody explain?

https://normanhyde.co.uk/meriden-triump ... seals.html

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Whatever you do Martin, a Triumph will always eat its valve guides rather sooner than they should (by today's standards).

So my guess would be that yours were already worn, and that wear allowed excessive oil to be drawn down the guides.

I never fitted seals to any of my Triumphs (4 valve twins that is. My triples and 8 valves had seals).

The guides Degens uses have a kind of scraper built in to the top to scrape off oil as the valve descends. I used these often and never had any issues.

All that said, for normal use, and as they are proven and available off the shelf, in your position I would fit the Hyde guides.

Thanks again for your advice Nigel.
I have a friend who is a retired engineer and I've spoken to him tonight and he concurs with you that the N/Hyde guides are the best option (I try not to bother him too much in case I become unpopular. He's done quite a few small jobs for me over the years). He has reassured me about a local engineer shop who are very competent and have all the latest equipment for this valve job and that they will for example vapour blast the guides before removal etc etc so as the initial shop that I nominated is an hour and a half's drive away and a bit demeaning about the N/Hyde valve guides, I'll go and talk to the local shop probably tomorrow.

I have read about the "knife edge" guides but have never seen one in the flesh.

I fitted those Hyde guides (and valves) to my T140.

I've had no problems.

Edit: It seems those inlet valve O-rings were only fitted to the Harris Bonnevilles.

LAB wrote;

Edit: It seems those inlet valve O-rings were only fitted to the Harris Bonnevilles.

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Just after I posted last night, out of curiosity I looked on ebay at valve guides / seals for the T140 (not my usual supplier) and I saw that there were inlet valve seals for the T140 and they were also suitable for the Commando apparently which had the same design, and this started me wondering if some or all of the T140s had the Norton type valve guide oil seals.

So I've looked at my parts book for the Meriden 1982 T140 and they are the same/similar to the Norton Commando design. I also have a Les Harris T140 Bonneville parts book circa1985, and they do show the small oil seal which in the case of my engine has not been effective at all, and if it ever was effective, it certainly wasn't towards the end usage by the former owner, but they are apparently correct for this engine when built.

So Les you are correct as usual, thank you. This also helps to explain why the Triumph dealer I was speaking to didn't see the inlet valve oil seal as an issue.

Reggie said:

So I've looked at my parts book for the Meriden 1982 T140 and they are the same/similar to the Norton Commando design.

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Yes, according to the parts books, the '81-on Meriden Triumphs had 'proper' 70-7363 inlet stem seals-although the 71-7506 inlet guides as advertised on ebay and elsewhere don't always seem to be machined to take the seals? :?

Reggie, not familiar with the triumph oring but any good desiegn wouldn't just sit on the valve stem as it will act like a pump and push oil down the guide, oring are normaly fitted under the split collets in the retainer to stop the oil flowing straight down the stem, they jam between the stem and the retainer. They work ok in a none flooded application.
As the shop will probably have to machine the outside down to get the interference right it isn't hard to also do the end of the guide to fit a seal, the Norton seal is adequate as the guides will never last to long. You could always try the old ROVER method oring in the guide absolute arse to fit and usless to

Martin,
You've gone quiet on us!
How is the rebuild going?
And WHERE ARE THE PICTURES ??

Fast Eddie wrote;

Martin,
You've gone quiet on us!
How is the rebuild going?
And WHERE ARE THE PICTURES ??

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Rebuild is going OK if slowly.
I sent the crank off to Basset down the first week in January and am waiting for it all to come back. It's due in theory sometime next week apparently.
I've had the alloy barrel top face dressed as well as the cylinder head and rocker box joints on the head and the rocker boxes in preparation for the rebuild.

This week I've spent quite a while completely stripping every bearing, removing the intermediate pinion spindle and anything that "stuck out" etc before making panels out of .75mm aluminium to cover all openings into the engine and bolting them on. I also used washers and bolts of appropriate size to block of bearing holes. This was done prior to having the head and crankcases blasted with "media" by my friend. My rationale behind this was that the media would only "hit" the appropriate areas and any that got past my panels would loose inertia and not embed into the internal walls especially as I packed rags behind the panels to catch any that got past. I would show you some pictures of the engine "panelled up" but I can't get photobucket to work tonight. They may follow?

So today I have been airlining the engine bits, washing in cold water, then power washing said parts before putting the bits in the oven at 100*C and then into boiling water and brushing/scrubbing to release any embedded debris/ I'm even considering having them steam cleaned just to make sure but maybe I'm becoming irrational and paranoid that there is some media left embedded that will release itself into my engine??

Norton is very close to being fired up following its rebuild............................so all is well. I've ordered some adjustable pushrod tubes tonight from Dave Madigan to help me compensate for the trimming of certain faces on the T140 that I've mentioned above.

I'll see if I can sort some photos for tomorrow.

Martin

Here's some pictures of the protection applied to my engine prior to media blasting. These pictures are after the parts have been cleaned but before I took the covers off..












The covers weren't 100% successful at keeping the media out, but hopefully stopped it embedding itself into the internal engine aluminium. The gearbox cover was 100% successful, and the one I've used has a dent in it and I have a replacement cover.
The tacho drive is an old damaged one from my T160 so glad I didn't chuck that one.

The T140 was completed at the end of June and I'm pleased to say, is running well.
First impressions are that it's quite enjoyable to ride, a few vibrations coming in at 4K, but I haven't revved it above this as I'm still running it in.
I've enclosed a few photos of the rebuild and completed bike including a very short (poor quality) video in the link below.

https://1drv.ms/f/s!AglWa7LPA-KxlDFrAfBKC-Sl_rnR

This T140 came to me with T120 rocker boxes fitted and was approximately the 15th from the last Les Harris Bonneville built (whilst Les Harris was building them under licence). I have a photo of the bike with the first and only previous owner when it was about a year old and the T120 rocker boxes were fitted then so I must assume that they were fitted in the factory? Also this bike came with alloy barrels with the UNC threads in the cylinders also fitted from new.

This bike hadn't been run for about 18 years and there were a lot of oil leaks all over the motor evident from its previous use and lots of rust in the fuel tank.

I suppose you hadn't heard of blasting with a water soluble medium.

That looks great, well done Martin.

Don't forget, you've not had a bored etc, so no need to be too much of a fairy with the running in. Give it its head and tell us what its like.

Those TSS cranks are good for 9,000rpm by the way. The rest of it isn't though...

I have two 1079 140D US models. Mind telling us what year that lovely bike is? The side covers looks like they are the newer style than mine. Also, are those the Veglia dials. (only came on the D, the Bonnies had the Smiths) And the non specials had the luggage rack instead of the plain grab rail. I'm just wondering if the US/Brit models varied a little or was it a year to year difference. Love the double front disc, by the way.

Britfan60 said:

I have two 1079 140D US models. Mind telling us what year that lovely bike is? The side covers looks like they are the newer style than mine.

And the non specials had the luggage rack instead of the plain grab rail. I'm just wondering if the US/Brit models varied a little or was it a year to year difference. Love the double front disc, by the way.

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Reggie's is a Harris Bonneville. These were manufactured by L F Harris after Meriden closed and therefore many components differ even from the late Meriden Bonnevilles.

http://www.classic-british-motorcycles. ... illes.html
http://www.lfharris.co.uk/about_us

Britfan60 said:

Also, are those the Veglia dials. (only came on the D, the Bonnies had the Smiths)

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Veglias were increasingly fitted to all models of Meriden T140 from around mid-1978, not just T140D.