Gents,
I will be reassembling the top end of my 46 model 18 soon and will need to lap my barrel and head...The engine had a gasket prior and I would like to assemble the correct way.
I am aware the spigot area should be "taller" to complete the seal so am I looking at a .001"-.005" difference and checking for a gap or light when torqued down?
Thanks much.
There should be about .001"…
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Nathan, I agree with John,…
Nathan, I agree with John, fine on the spigot and course on the head, put it on both at the same time and lap it like a valve turning it back and forth, lifting it from time to time and rotating it. It works for me and was how George Cohen showed me how to do it. The fun bit (not!) is getting rid of all the grit afterwards!
John, is that your plane? An Auster? I have a friend in BC with a 58 Cessna 170 and a cub.
Dan
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Thanks gents!! I have the…
Thanks gents!!
I have the lapping process down but wasn't sure of the gap difference.
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There should be about .001" difference, so you will see light through the joint before you tighten the nuts, but none when done up tight. Use coarse grinding paste on the wide face, and fine on the spigot and it should work ok.
John