Valve Lapping Tip

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ricky racer
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Valve Lapping Tip

Postby ricky racer » Mon May 27, 2019 7:12 pm

I'm working on a Cub engine swap and I'm going through the donor engine to bring it up to snuff. The valves in general looked pretty good but I've owned the donor engine for a few years and hard telling how many years it's been since it last ran. Anyway, all the valves needed was a good lapping in to assure they seat properly. I used a hand lapping tool, you know the wooden stick with the suction cups on the ends. I was having a hard time getting the suction cups to adequately "grip" the valves to allow me to lap them in. After some frustration I stuck a little piece of double sided tape to the top of each of the valves and the problem was solved. It gripped the valve so good that I could run the lapping tool with my cordless drill motor greatly reducing the time and effort involved. So there you go, the tip of the day! :{_}:
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Re: Valve Lapping Tip

Postby Bob McCarty » Mon May 27, 2019 7:29 pm

Great idea!
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we need to think differently."
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Stanton
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Re: Valve Lapping Tip

Postby Stanton » Tue May 28, 2019 1:23 am

:Dito:
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Re: Valve Lapping Tip

Postby BigBill » Tue May 28, 2019 5:06 am

Did you grind the valves and the valve seats first before lapping them?
I'm technically misunderstood at times i guess its been this way my whole life so why should it change now.

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Re: Valve Lapping Tip

Postby Gary Dotson » Tue May 28, 2019 6:34 am

That's a good tip, Ricky, My method has been to spray the top of the valve with a bit of hi-tack gasket sealer. Do what works for you!


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