Valve Lapping Tip

The Cub Club -- Questions and answers to all of your Cub related issues.
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
User avatar
ricky racer
10+ Years
10+ Years
Posts: 6001
Joined: Wed Sep 12, 2007 8:40 pm
Zip Code: 49120
Circle of Safety: Y
Location: Niles / Buchanan, Michigan

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! :{_}:
1929 Farmall Regular
1935 John Deere B
1937 John Deere A
1941 John Deere H
1952 John Deere B
1953 Farmall Cub

Bob McCarty
Team Cub
Team Cub
Posts: 11534
Joined: Tue May 25, 2004 8:02 pm
Zip Code: 80501
Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
Circle of Safety: Y
Location: CO, Longmont

Re: Valve Lapping Tip

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

Great idea!
"We don't need to think more,
we need to think differently."
-Albert Einstein

User avatar
Cub Pro
Cub Pro
Posts: 7760
Joined: Mon Jun 22, 2009 6:56 am
Zip Code: 64070
Tractors Owned: 1942 Farmall AV, serial #87025
1947 Farmall Circle Cub, serial #2116
1948 Farmall Cub, serial #46066
Circle of Safety: Y
Location: Lone Jack, MO

Re: Valve Lapping Tip

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

Image Circle of Safety

10+ Years
10+ Years
Posts: 7388
Joined: Sat Jul 22, 2006 5:02 pm
Zip Code: 00000
Location: in northern usa

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.

Gary Dotson
Team Cub Mentor
Team Cub Mentor
Posts: 5353
Joined: Thu Aug 03, 2006 6:20 am
Zip Code: 43358
Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D
Circle of Safety: Y
Location: OH West Mansfield

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!

  • Similar Topics
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: Indy4570 and 2 guests