Compression

Farmall Cub Forum -- Questions and answers to all of your Cub related issues.

Moderator: Team Cub

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.
Cbecker
Posts: 3
Joined: Thu Sep 03, 2015 6:59 pm
Zip Code: 62675

Compression

Postby Cbecker » Tue Sep 15, 2015 9:01 am

I recently purchased a 1952 Cub. It has not had much use the past several years. It smokes a fair amount when running. Planning to pull the hood and tank this evening to check compression, and was wondering how much compression a tight nine should have.

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 16256
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: Compression

Postby Eugene » Tue Sep 15, 2015 1:13 pm

Report back with the dry then wet test readings.
I have an excuse. CRS.

User avatar
Stanton
Team Cub Mentor
Team Cub Mentor
Posts: 4274
Joined: Mon Jun 22, 2009 6:56 am
Zip Code: 64070
Tractors Owned: 1942 Farmall AV, serial #87025
1945 Farmall H, serial #213,651
1947 Farmall Circle Cub, serial #2116
1948 Farmall Cub, serial #46066
Circle of Safety: Y
Location: Lone Jack, MO

Re: Compression

Postby Stanton » Tue Sep 15, 2015 2:03 pm

Welcome to the forum. It's tight, but you don't have to remove the hood to do a compression test. Have done several with hood intact.

Let us know what you find out. The GSS-1008 Specifications Manual (available via the links across the top of the screen) states that 120 PSI is the approximate compression mark. But engines will start/run with a lot lower numbers.
Stanton
Image Circle of Safety

Cbecker
Posts: 3
Joined: Thu Sep 03, 2015 6:59 pm
Zip Code: 62675

Re: Compression

Postby Cbecker » Tue Sep 15, 2015 6:34 pm

All cylinders are between 100-110 dry, and 115-120 wet. Those sound like good numbers to me. Maybe this weekend I will pull the head and see what the valves look like. Or I may just change oil and run it some and see if it clears up. This tractor belonged to my cousin who recently passed away. He had a total of 41 tractors, with 9 Cubs. So, I pretty sure it hasn't been run much lately.

Eugene
Team Cub Mentor
Team Cub Mentor
Posts: 16256
Joined: Fri Jul 02, 2004 9:52 pm
Zip Code: 65051
Circle of Safety: Y
Location: Mo. Linn

Re: Compression

Postby Eugene » Tue Sep 15, 2015 6:50 pm

I wouldn't remove the head. Compression numbers are close to excellent.

Suggest some Sea-Foam in the oil and fuel. Operate the tractor for some time, under load. I have the feeling that the smoke will clear up.
I have an excuse. CRS.

Cbecker
Posts: 3
Joined: Thu Sep 03, 2015 6:59 pm
Zip Code: 62675

Re: Compression

Postby Cbecker » Tue Sep 15, 2015 7:40 pm

Thanks for you input.

User avatar
Stanton
Team Cub Mentor
Team Cub Mentor
Posts: 4274
Joined: Mon Jun 22, 2009 6:56 am
Zip Code: 64070
Tractors Owned: 1942 Farmall AV, serial #87025
1945 Farmall H, serial #213,651
1947 Farmall Circle Cub, serial #2116
1948 Farmall Cub, serial #46066
Circle of Safety: Y
Location: Lone Jack, MO

Re: Compression

Postby Stanton » Wed Sep 16, 2015 6:53 am

Eugene wrote:I wouldn't remove the head. Compression numbers are close to excellent.


Agreed. If you did want to look at the valves, you wouldn't pull the head. The plate behind the manifold on the side of the block is where the valves are located. Owner's and Service Manuals are available for free download that cover procedure on this...have you downloaded them yet?
Stanton
Image Circle of Safety

Matt Kirsch
10+ Years
10+ Years
Posts: 4456
Joined: Tue Jun 08, 2004 3:04 pm
Zip Code: 14559
Circle of Safety: Y
Location: Rochester, NY

Re: Compression

Postby Matt Kirsch » Wed Sep 16, 2015 1:58 pm

Seafoam does its best work when introduced directly into the intake manifold, either through the vacuum port or by spraying into the air intake of the carburetor.

All putting it in the oil does, in my experience, is make the oil pressure scary low.


  • Similar Topics
    Replies
    Views
    Last post

Return to “Farmall Cub”

Who is online

Users browsing this forum: John *.?-!.* cub owner and 8 guests