Yesterday's Tractor Co. Low Prices, Parts Ship Fast!
Click Here or call 800-853-2651 
   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 
Marketplace
Classified Ads
Photo Ads

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
Enter your email address to receive our newsletter!

subscribe
unsubscribe
  
Ford 9N, 2N & 8N Discussion Forum
Show Parts for Model:

Re: Need advice re ring/crank bearing replacement

[Show Entire Topic]  

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

04-09-2013 08:23:26
108.184.35.167



Report to Moderator

Always understood that most of the journal wear occurs at start up rather than at normal operating conditions.

Ok, so why does the flatheat N have the 0-50 psig oil pressure gauge and the OHV NAA have the 0-80 psig oil pressure gauge?

Both engines have equal rated 2000 rpm and nearly equal 6.6/6.7 CR after 85000 serial #.
The oil pump capacity was increased at some point on the N series?

Larger capacity oil pump would increase the back pressure at the journal at equal RPM?

Maybe the larger capcity pump was incorporated to increase the longevity of the engine and not to increase the oil pressure on a new or new rebuilt engine?

So what is the concern about oil back pressure, since the oil pressure is not in the equation for oil film thickness?

In my opinion the N series engine needs to have minimum of 15 psig oil pressure @ 1500 rpm.

Maybe the NAA needs more oil back pressure than the N, since the gauge has a greater range or with a larger capacity pump than the N, the oil pressure is higher.

The tire mfg's are always researching & testing to come up with the ultimate thread pattern to reduce the chance of hydroplaning, which creates a thin film of water between the tire and road in heavy rain conditions. The water film supports the "gravity" weight of the vehicle, which is basically the same physics as the engine journal. Michelin Tire has a great video on U-Tube.

Oil pressure issue seems to be one of the most frequent FAQs on the N forums.

AKA "raven" on the NTC forum

[Log in to Reply]   [No Email]
TheOldHokie

04-09-2013 09:56:53
74.110.74.117



Report to Moderator
 Re: Need advice re ring/crank bearing replacement in reply to Bulldozer, 04-09-2013 08:23:26  
Always understood that most of the journal wear occurs at start up rather than at normal operating conditions.



That is normally the case since that is the transition from boundary to hydrostatic regime. Luging an engine alsl contributes to accelerated wear since increased load at lower RPM equates to a reduced oil film thickness and mixed mode lubrication.

Ok, so why does the flatheat N have the 0-50 psig oil pressure gauge and the OHV NAA have the 0-80 psig oil pressure gauge?

WAG - the engineers wanted a higher pumping pressure and increased flow rate to accomodate the greater demands of the OHV design. A flathead doesn't need top end lubrication but an OHV does and it needs it nearly immediately on startup. The oil pressure gauge on my 1963 Triumph equipped with a similar size and vintage Standard engine is 100 PSI and the Leyland specification is a minimum idle hot oil pressure of 30 PSI hot. With an OHV you have to move more oil, move it further, and get it there faster. An OHC is even more demanding in that regard.

So what is the concern about oil back pressure, since the oil pressure is not in the equation for oil film thickness?

It is a easily collected performance metric. The issues I just mentioned are part of that performance but pump oil pressure is also a very good indirect measure of bearing clearances. Bearing clearances ARE a factor in oil film thickness and a low pumping pressure indicates increased clearances and a reduction/loss of the protective oil film.

In my opinion the N series engine needs to have minimum of 15 psig oil pressure @ 1500 rpm.

A fresh engine with good oil clearances will easily make 40 PSI at 1500 RPM. I would say that an engine with 15 PSI @ 1500 RPM is telling you it has wide clearances and/or a worn oil pump and is nearing the end of it's service life. It's those widened clearances that will cause accelerated engine wear - not the low oil pressure.

TOH

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

Hop to:

TRACTOR   PARTS TRACTOR   MANUALS
Same-Day Shipping! Most of our stocked parts ship the same day you order (M-F).  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. [ More Info ]

Home  |  Forums


Copyright © 1997-2014 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