How to fix a broken adjustable tappet

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TonyB
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How to fix a broken adjustable tappet

Post by TonyB » Sat Oct 24, 2020 7:28 pm

The speedster wasn’t running good when I went to it a couple of weeks ago in preparation for the annual speedster run. There didn’t seem too much compression on a couple of cylinders. So I removed the head and I wasn’t too happy as there was lots crud in a couple of cylinders which settled under a couple of the intake valves. Then I realized that #3 inlet hardly opened ???
So pulled off the valve cover and started to check the valves and sure enough a couple of the intakes needed a little grinding but still #3 inlet hardly moved. Closer inspection yield this picture
Broken adjustable tappet
Broken adjustable tappet
Yes, the end has broken off the adjustable tappet.
Now in the past on a different T I have all eight come loose which resulted in lots of noise and very little performance. But now I guess I did them too tight☹️
The only solution I can see is to remove the camshaft☹️☹️
Does anyone see a simpler solution?
Tony Bowker
La Mesa, California
1914 Touring, 1915 Speedster, 1924 Coupe.


Jerry VanOoteghem
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Re: How to fix a broken adjustable tappet

Post by Jerry VanOoteghem » Sat Oct 24, 2020 7:35 pm

If you can remove the broken off end from the tappet without removing the tappet, then it's just a matter of putting a new adjuster bolt in place. Since you've already got the head off, maybe you can remove the valve, grind a makeshift screwdriver slot in the broken off end of the bolt, and slip a screwdriver down the valve guide hole to unscrew the broken end?

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TonyB
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Re: How to fix a broken adjustable tappet

Post by TonyB » Sat Oct 24, 2020 7:53 pm

Great idea.
I’ll give that a try when I get more enthusiastic.
Tony Bowker
La Mesa, California
1914 Touring, 1915 Speedster, 1924 Coupe.


Adam
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Re: How to fix a broken adjustable tappet

Post by Adam » Sun Oct 25, 2020 12:00 pm

It’s broken off in a way that the remainder in the tappet should be fairly loose. A left handed drill bit thru the valve guide from the top should turn it right out. You will, of course, have to fabricate an “extension” for the drill bit, but that’s an easy “creative” task.

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TonyB
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Re: How to fix a broken adjustable tappet

Post by TonyB » Sun Oct 25, 2020 7:43 pm

Jerry’s idea worked just fine. I had a couple of spare tappets so I even had the correct screw and nut. So I replaced the valve, adjusted the tappet, not too tight, and buttoned it all up. It runs but now has an exhaust leak. I can fix that another day. 😊
Thanks Jerry
Tony Bowker
La Mesa, California
1914 Touring, 1915 Speedster, 1924 Coupe.


Jerry VanOoteghem
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Re: How to fix a broken adjustable tappet

Post by Jerry VanOoteghem » Sun Oct 25, 2020 7:45 pm

TonyB wrote:
Sun Oct 25, 2020 7:43 pm
Jerry’s idea worked just fine. I had a couple of spare tappets so I even had the correct screw and nut. So I replaced the valve, adjusted the tappet, not too tight, and buttoned it all up. It runs but now has an exhaust leak. I can fix that another day. 😊
Thanks Jerry

Tony,

Very happy to see that it worked out! You are welcome :)


D Stroud
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Re: How to fix a broken adjustable tappet

Post by D Stroud » Wed Oct 28, 2020 6:20 am

Almost always if a bolt or screw is broken off due to something other than being twisted off, they can be removed very easily, as Jerry pointed out. BUT, if they have been twisted off due to over tightening or rusted in tight when trying to remove them, THAT'S a whole different ballgame. Jerry had a very good solution to the problem, glad it worked out for you. Thanks for the follow up, I'm sure that will help many others in the future, and PLEASE, if any of you have those worthless spiral "easy outs", throw them away, they cause MANY more problems than they cure. JMHO Dave
1925 mostly original coupe.


Allan
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Re: How to fix a broken adjustable tappet

Post by Allan » Wed Oct 28, 2020 5:27 pm

That job may even be easier. If the valve spring is removed the valve can be pushed up out of the way. A Dremel cut-off disc could be used to make a screwdriver slot in the remainder of the broken bolt. A sacrificial small screwdriver could be bent at right angles to hold the broken bolt and the tappet rotated to screw it out. That should mean that the cylinder head need not come off to remove the valve and with the current shortage of copper head gaskets, that is a good thing.
I have never had to do this though, so it is just an idea. The one broken one I had to fix had left enough of the bolt proud of the tappet that I could just hold it enough to start screwing it out.

Allan from down under.

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