T25 Tappet Orientation

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Lance
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T25 Tappet Orientation

Post by Lance »

T25 manual says the thinner end of the tappets face forward. I can't see any difference. The only thing that I can see is that there are 2 oil holes are drilled into the stem on one side. Would this be what dictates the way round the tappet is fitted? The top end of the engine is assembled, so I can't look into the tappet housing to see if there are any oil ways that might line up with the holes in the tappets.

Any guidance about this would be much appreciated.

Chris Lance
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madsundaysurvivor
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Re: T25 Tappet Orientation

Post by madsundaysurvivor »

Hello
if it is a pre oil in frame model, yes there is a small difference in thickness (I do not know if this is the same in oil in frame models), if you cannot see it use the vernier caliper
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Re: T25 Tappet Orientation

Post by twinshocker »

The thinner edge of the tappet ist always in front .
In the tapped guide there is no channel for the oil or so.
At full lift the top hole in the tappet gets out of the guide and a little amount of oil can get in there and leaves at the lower hole. That lubicates the guide bore.
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SteveS
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Re: T25 Tappet Orientation

Post by SteveS »

.
The two oil holes in the cam follower stem align with the thicker end of the foot, so when fitted the oil-ways will face to the rear.

I don't know if there is an engineering convention that dictates this orientation?
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Lance
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Re: T25 Tappet Orientation

Post by Lance »

Thank you for your replies they were very helpful

For the record my bike is a T25SS 1971 O.I.F.
The inner tappet (exhaust) foot is thinner one end which I have put facing the front.
The outer tappet is symmetrical
I understand the tappet lubrication now

I always thank people at the end of a thread for information given is this the correct way? Only against my name I noticed it says I have never thanked anyone.

Chris Lance
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Re: T25 Tappet Orientation

Post by twinshocker »

SteveS wrote: Wed Apr 22, 2020 8:19 am ...........
I don't know if there is an engineering convention that dictates this orientation?
I think as the cam rotates counter-clocwise this angle gives the tappet a smoother lift or so..... thats my theory :roll:
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Re: T25 Tappet Orientation

Post by minetymenace »

lance wrote: I always thank people at the end of a thread for information given is this the correct way? Only against my name I noticed it says I have never thanked anyone. 
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Just because you say "thankyou" in words in you post, dosent mean the internet is clever enough to recognise you sincerity, however those you thank will appreciate your thanks none the less.
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