Yesterday's Tractor Co. Shop Now
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 
Marketplace
Classified Ads
Photo Ads
Tractor Parts

Community
Discussion Forums
Project Journals
Tractor Town
Your Stories
Show & Pull Guide
Events Calendar
Hauling Schedule

Galleries
Tractor Photos
Implement Photos
Vintage Photos
Help Identify
Parts & Pieces
Stuck & Troubled
Vintage Ads
Community Album
Photo Ad Archives

Research & Info
Articles
Tractor Registry
Tip of the Day
Safety Cartoons
Tractor Values
Serial Numbers
Tune-Up Guide
Paint Codes
List Prices
Production Nbrs
Tune-Up Specs
Torque Values
3-Point Specs
Glossary

Miscellaneous
Tractor Games
Just For Kids
Virtual Show
Museum Guide
Memorial Page
Feedback Form

Yesterday's Tractors Facebook Page

Related Sites
Tractor Shed
TractorLinks.com
Ford 8N/9N Club
Today's Tractors
Garden Tractors
Classic Trucks
Kountry Life
  
Ford 9N, 2N & 8N Discussion Forum
Show Parts for Model:

2N Rebuild: Low Compression

Welcome Guest, Log in or Register
Author  [Modern View]
Breese

01-03-2014 01:03:37




Report to Moderator

I checked compression on my rebuilt 6V system 1945 Ford 2N engine: only 40 PSI at each cylinder. This is after new sleeves/pistons/rings/valves. I used the original connecting rods, cam-timing shaft, and drive shaft since all gear teeth & journals looked great & measured in spec. The 40PSI is consistent but far from the 95 PSI target. The ring gaps were all in-spec prior to installation of the pistons with the new sleeves. All 8 new valves were lapped and seals verified prior to adjustment.

My initial concerns are with the head-gasket & would like feedback on these 3 next steps. 1) I installed a head gasket (the type with metal rings around each cylinder) and have seen other bloggers complain about this design. Has the type of head-gasket really been an issue for others? Now is the time for me to try another type.
2) I installed the head-gasket dry: others claim to use copper spray for a better seal. I have a can of the Permatex copper gasket-seal spray: does this stuff really help to improve compression?
3) Lastly, I torqued the nuts on the head stud bolt to 55 ft/lbs: that seems low given the diameter of these grade 8 stud bolts. I've seen conflicting (higher) stud bolt nut torque specs but don't want to go above 55 ft/lbs unless others have.

My thinking is perhaps a consistently under-torqued head gasket (or poor-design, or without sealant) loses compression equally across all 4 cylinders. I have a running 2N (12V system) also 1945. For reference, I'm going to use my torque wrench and see where my 2nd 2N tractors head stud bolt nuts are set (where my torque wrench trips). Compression readings on two of the four cylinders on my running tractor are 90/92PSI so the compression gauge seems to be working.

Any other ideas/suggestions would be appreciated. Clearly, I don't want to start pulling new pistons/rings unless I absolutely have to. Thanks!

[Log in to Reply]   [No Email]
Hobo,NC

01-14-2014 04:52:42




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to kornfused, 01-03-2014 01:03:37  
Quoting Removed, click Modern View to see

If I were a gambling man I would feel good doubling down my wager rite now...Even with those leakage #' it should start and I would guesstimate 70 lbs of compression...

I have only run a leak down test on one fresh engine. Leakage ran 20/25% on the engine stand the best I remember... I did suspect leakage # to be on the high side till the rings broke in... Its normal for the rings to break in on the initial test drive if not I have always found you are in deep do-do...

[Log in to Reply]  [No Email]
R Geiger

01-13-2014 20:02:00




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
Did you hone the cylinders? maybe the rings are not seating as they should.



[Log in to Reply]  [No Email]
Breese

01-12-2014 19:40:29




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
Follow-up to the “put air pressure to each cylinder” advice from teddy52food...

I researched leak down testing and bought a tester. As you may recall, my symptom is only 40 PSI of compression across all cylinders on my rebuilt 1945 Ford 2N engine (6V system). New sleeves, pistons, rings, and valves. The tractor does not start. Here are the (cold) leak down results; 2 readings for each cylinder, taken one day apart:

Cyl # & leak% result 1/2
1 – 35/35
2 – 35/30
3 – 40/35
4 – 25/30

All the relative leak down % values show up in the 'green' region of the tester gauge. I don't know how accurate the readings really are. However, it's a great troubleshooting tool. I did not detect any major leaks: a very faint flow from the oil breather. Vales seating looked good. No leaks until I intentionally cranked each cylinder into the exhaust/intake phases: then tons of air passing through raised valves.

My first question: for “cold” values – are these numbers OK?

My next step is to do a wet oil test & re-measure leak down %. Other input/questions welcome...

[Log in to Reply]  [No Email]
Breese

01-04-2014 11:46:18




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
First time posting to any tractor forum: I greatly appreciate everyone's response. Most of them were quite helpful.

I really like teddy52food's suggestion of pressurizing each cylinder and checking for leaks.
I'll look for a 1/4" quick-release to spark-plug thread adapter later today: I assume that's the most effective way to pressurize cylinders.

Additional background: a) no - the tractor does not start
b) compression checked with all plugs removed

I'll post my findings in the next week or so: thanks again!

[Log in to Reply]  [No Email]
Bob

01-04-2014 12:00:00




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-04-2014 11:46:18  
Buy or borrow a "cylinder leakdown tester".



[Log in to Reply]  [No Email]
teddy52food

01-03-2014 07:45:00




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
If you try to torque on the other tractor, it will tell you nothing as they are (set) and will take a lot to break loose unless you back them off first.. Pull the plugs and put air pressure to each cylinder & see where it goes. Crank breather is rings, carb is intake valves & tailpipe is ex valves.



[Log in to Reply]  [No Email]
Breese

01-13-2014 19:51:43




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to teddy52food, 01-03-2014 07:45:00  
My next step is to check leak down with ~2ml of engine oil in each cylinder.
Any preference between 5W, 10W, and 20W weights?



[Log in to Reply]  [No Email]
Ultradog MN

01-03-2014 06:42:12




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
I gotta agree with Hobo;
First of all does it run?
If so then your compression readings are wrong.
Secondly, if it wont run it's likely your cam timing.



[Log in to Reply]  [No Email]
soundguy

01-03-2014 14:22:33




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Ultradog MN, 01-03-2014 06:42:12  
without knowing more..and a new rebuild.. I'd have to third you and hobo's advice as well.

bad test or bad cam /valve timing.



[Log in to Reply]  [No Email]
Britcheflee

01-03-2014 08:11:14




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Ultradog MN, 01-03-2014 06:42:12  
If rings were not offset would that cause low compression? Also wondering if installed without a generous oiling of everything then pressure would be less? - after running a bit maybe everything will seat properly and pressure increase?



[Log in to Reply]  [No Email]
Hobo,NC

01-03-2014 05:15:55




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
I would wager your cam trimming is off a tooth are so... Check valve overlap... This would affect every cylinder... I seriously doubt its a head gasket issue at this time... Stop and confirm the root cause and quit treating the symptom...

Does it run :?:



[Log in to Reply]  [No Email]
ASEguy

01-03-2014 03:58:15




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
Compression tests are not always conclusive. Since the numbers are consistent, with all due respect, was the compression test done with WOT, all plugs out, sufficient cranking speed, fuel off and five "hits" per cylinder on the gauge. Is it a known good gauge? I would address these issues, and if ok and compression is still very low, it's time for a cylinder leakage test.



[Log in to Reply]  [No Email]
ASEguy

01-03-2014 04:04:10




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to ASEguy, 01-03-2014 03:58:15  
Sorry, went right past the part about the good gauge.



[Log in to Reply]  [No Email]
TOM N MS

01-03-2014 03:44:13




Report to Moderator
 Re: 2N Rebuild: Low Compression in reply to Breese, 01-03-2014 01:03:37  
"new valves were lapped"-----valves not sealing are most likely some, if not all, of the problem.



[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop to:


TRACTOR PARTS TRACTOR MANUALS
Fast Shipping!  Most of our stocked parts ship within 24 hours (M-Th). Expedited shipping available, just call! Most prices for parts and manuals are below our competitors. Compare our super low shipping rates! We have the parts you need to repair your tractor. We are a company you can trust and have generous return policies. Shop Online Today or call our friendly sales staff toll free (800) 853-2651. [ About Us ]

Home  |  Forums


Copyright © 1997-2018 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters