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One only has to look at the Trident, where the original engineering for this change was done, to see what the problem with the way Triumph, and Meriden workers after them, manufactured the rocker shaft and placed the the shim and thackary washers. Before one can discuss this with some insight one needs to look at a Trident rocker box assembly, the trident parts and workshop manuals.

This change came out of Umberslade Hall, which was under their direction. In in the mid-1969 model year Triumph introduced the new rocker arm, supplied from buyers at BSA, they did not make the change to the rocker shaft (which they made in house) or the washers. If one puts a clear hose on the rocker oil feed line on one of these 1969-1972 models you will immediately see the lack of oil flowing to the head. Finally in 1973 Triumph finally put a groove in the shaft to free up the flow of oil to the rocker box, but never made the change on the shop floor placing the flat washer against the side of the rocker... The flat washer allows the cut on the end of the rocker to direct the flow of oil away from the rocker toward the valve tip and push rod cup. With the thackeray against the rocker the end finds its way into the cut leaving the oil to dribble down the face of the rocker.
 

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This is getting worrying now.After 42,000 miles and the rocker shafts have not been removed from new,i might have it assembled wrong.I must say,if mine is wrong it is doing very well.I do have a very good flow through the oil feed pipe so i assume the oil is getting to all the bits OK.Must remember to check the rockers in a few years time.My USA 71 parts book also shows the thrust washer against the rocker.
 

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Thanks for the clear explanation Johntioc. It makes perfect sense when explained like this, but otherwise, we're left wondering what on Earth you could mean!

I reckon your dash of 2 stroke oil might be the key to longevity for your T120's top end Rambo. I've got plenty of that around all the time, so I'll start adding a splash to every tankful. Certainly can't do any harm.
 

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Someone said their drop of 2T oil in the petrol lubricated the throttle slide and that made sense.


Any benefit to the head, valves or whatever sounds like it may well be imaginary.
 

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Although the parts book show the flat washer against the side of the rocker the workshop manual for the 1971-72 and 1973-up models has them against the side of the rocker box. When you do get around to checking your rocker shafts you will most probably find them worn more than usual. You will also find your rocker shaft has no groove to deliver the oil out to the sides of the rockers as designed. The shaft seems to get enough oil to survive, but where these shafts seemed to last forever the bike without the grooved shaft the shaft and rockers seem to suffer more wear.
 

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Someone said their drop of 2T oil in the petrol lubricated the throttle slide and that made sense.

Any benefit to the head, valves or whatever sounds like it may well be imaginary.
Can't see why you'd think that when on a two stoke it gets all the way from the tank, through the carbies, into the crancase and main bearings and then goes on to lubricate the pistons and then finally almost all gets burnt in the combustion chamber, the remainder getting pushed out the muffler.

On my Daytona it only has to get from the tank to the carbies and slides and then onto the inlet valve stems and into the combustion chambers to do some good.
I'm currently using only 500:1 (10ml/5L) and I know, not imagine it's working.
I was using 250:1 then 300:1 but it was more than needed.

davy
 

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Someone said their drop of 2T oil in the petrol lubricated the throttle slide and that made sense.


Any benefit to the head, valves or whatever sounds like it may well be imaginary.
I agree. No manufacturer today of 4 stroke engines advises placing oil in the petrol. Waste of time and money! Years ago Vanguard cars (same engine as the famed Fergie tractor) had an oil injection system factory fitted, their engines lasted no longer than those that were not fitted. It was quite common some years ago to fit oil injection to LPG powered vehicles, the rational being that LPG was a 'dry' fuel and would cause valve seat recession trouble was, LPG will not mix with mineral oil!
Inlet valve stems and guides will last for 1000's of miles, as designed without the addition of oil into the fuel as long as scheduled maintenance is undertaken.
The only way to disprove/prove of any of this to the letter would be to have two identical engines run over a period of many hours, one with oil in the fuel, the other running as designed, have them both stripped down and the parts that some believe would be more/less worn measured. My bet is the addition of oil to the fuel would prove meaningless.
 

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Hi John,

Thanks for the clear explanation Johntioc. It makes perfect sense when explained like this, but otherwise, we're left wondering what on Earth you could mean!
The trick is not to depend on this Forum for information about Triumphs. ;) I've yet to see anything worthwhile on here - particularly John Healy's knowledge - that hasn't been on the BritBike Forum for years.

Regards,
 

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Hi John,


The trick is not to depend on this Forum for information about Triumphs. ;) I've yet to see anything worthwhile on here - particularly John Healy's knowledge - that hasn't been on the BritBike Forum for years.

Regards,
I guess that depends on whether or not anyone on this Forum takes any notice

Further comments deleted by Mr.Pete
 

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Regarding the 2T oil.I have always added an upper cylinder lubricant to old vehicles and never had to replace valves or guides.That means all the old vehicles over the last 45 years.Of course,there will be theories of wether it makes any difference.It was only the number of people changing valve guides that made me believe that UCL or 2T was allowing my guides and valves to last since they left the factory.My T120 never has a slow ride and is generally running up to 6000 rpm every outing.
Seems to benefit mine and owners changing valve guides might have had poor quality parts fitted.
It is anyones choice,but i will be adding just a little to both my old bikes.Not,however,to any new engines.
A definate thumbs down for Castrol R in the fuel as that does certainly gum up the carb slides.
 

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Fair enough Rambo, and choice is a prized possession for us all. As Kids our dream cars were Mk3 Zephyrs and PB Vauxhalls (I was always in the Ford camp) after graduating from Prefects and Morris 8's. The six cylinder 'Pommie' cars were very strong in the bottom and top ends but not so in the ring/piston/ bore dept, especially around the 80-100,000 mile mark. A large group of us owned various marques of these vehicles and it was unheard of to replace valves, have seat problems or any head problems in general. They were thrashed, minimally maintained and had huge milages on them, only then could we afford to buy them. They ran cold due to their huge (in todays terms) radiators and condensated the rocker covers to hell and gone! But as said above, can never recall having any trouble with valves and guides (although valve grinds were undertaken).
 

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My AJS 500 single had an adjustable oil feed through the side of the inlet valve guide and a non-adjustable feed to the cylinder bore.

Like the oil in petrol trick, I've no idea if it helped.
 

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I agree. No manufacturer today of 4 stroke engines advises placing oil in the petrol. Waste of time and money! .
That is not proof of whether it could be beneficial or not, given today's Emission regulations and catalytic converters, obviously no manufacturer is going to suggest adding oil to the fuel. I think with the over zealous politically fueled EPA in the US, that would probably involve a custodial sentence :(

It does help lube the carb, prevent corrosion in the fuel tank and can help mufflers from rusting out too. On the same basis it must increase lubrication in the engine, whether it's necessary or makes any measurable difference is hard to say, but as I mentioned when the topic arose a while back, in the 80's OMC (Johnosn and Evinrude) went to running outboards at 100:1 fuel ratios for environmental issues. Ultimately they went back to 50:1 not because there was insufficient lube normally, but due to internal engine corrosion in storage where there was insufficient residual oil on parts. The other factor was that 100:1 didn't leave enough margin for user error if someone screwed up mixing their oil and fuel. My point is if a motor can be entirely lubricated by a 100:1 mixture then even very small amounts can provide a lubricative effect.

I've heard that the 10% ethanol in modern fuel drastically reduces the natural lubrication that petrol has, so perhaps a little extra lube is no bad thing. At the end of the day it's rather like an oil thread about which engine oil is best, without extensive testing of several bikes over a long period of time in different conditions etc. amassing any definitive data is impossible. My personal opinion is it does provide extra lubrication and is worth using, as I always have plenty of it lying around from my outboards and the fact I add it to diesel fuel to protect the injector pumps that were not designed for the low sulfur diesel, there's always some on hand. I'm not at all offended if others don't use it.
 

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During the heat and force of combustion in a 4 stroke engine, any oil in the fuel will be turned into a puff of smoke (carbon) and thus lose any lubrication qualities it formally had. Carbon will not save or be of any benefit to mufflers. Carbon in the combustion chamber(s) of a 4 stroke engine should be avoided like the plague.
 

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During the heat and force of combustion in a 4 stroke engine, any oil in the fuel will be turned into a puff of smoke (carbon) and thus lose any lubrication qualities it formally had. Carbon will not save or be of any benefit to mufflers. Carbon in the combustion chamber(s) of a 4 stroke engine should be avoided like the plague.
If you were right then all the black stuff in our mufflers would be hard dry carbon... but it isn't is it.
Just look at a fair sample of tailpipes and you'll see the truth to this
And on a 4 stroke it has already done it's lubrication duty on the induction stroke before the bang stroke.

davy
 

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If you were right then all the black stuff in our mufflers would be hard dry carbon... but it isn't is it.
Just look at a fair sample of tailpipes and you'll see the truth to this
And on a 4 stroke it has already done it's lubrication duty on the induction stroke before the bang stroke.

davy
No, you stated that, I was referring to 4 strokes that have had oil added to the fuel.
A fair sample of tail pipes that I would care to look at (which I don't make a habit of) would have very little carbon in them as their owners would not add oil to the fuel.
There is no need for 'lubrication duty' in the combustion chamber of a four stroke, if there was then I am sure it would be called a 2 stroke or, manufacturers would be sending out bulletins by the ream advising of their design mistake(s).
 
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