Yesterday's Tractor Co. Parts for Farm Tractors - Compare our Prices!
Click Here or call 800-853-2651 
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

higher compression ratio?


 
Post new topic    
View previous topic :: View next topic  
Author Message
Mr. T. Minnesota
Regular


Joined: 17 Jan 2012
Posts: 460


Report to Moderator

PostPosted: Thu Dec 13, 2012 11:27 am    Post subject: higher compression ratio? Reply to specific post Reply with quote

Forum Members,
Curious if it is possible to increase the compression ratio when rebuilding an 8N engine to higher than 6:1? Any thoughts are appreciated!

Mr. T. Minnesota
 
Back to top
View user's profile
HCooke
Tractor Guru


Joined: 29 Sep 2006
Posts: 4122
Location: Missouri

Report to Moderator

PostPosted: Thu Dec 13, 2012 12:03 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Sherman made a 'high' compression head - it was made out of aluminum. 8Ns have a compression ratio of 6.5:1. Many times these heads get trimed (decked) to correct a warp. Caution there is not much room before the piston begin to contact the head.
 
Back to top
View user's profile
Dean
Tractor Guru


Joined: 29 Jan 1998
Posts: 12547


Report to Moderator

PostPosted: Thu Dec 13, 2012 12:20 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Only slightly without the NLA pop-up pistons.

The late 8N engine CR is nearly maximized.

Dean
 
Back to top
View user's profile
Dell (WA)
Tractor Guru


Joined: 21 Sep 1998
Posts: 24106


Report to Moderator

PostPosted: Thu Dec 13, 2012 1:27 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Mr T..........take yer sleeves OUT and run bigger pistons. By definition, you have increased yer compression ration. (ratio of swept volume to combustion chamber volume)

As the flathead V-8 guys have found out, It is really difficult to increase compression. Since ALL cylinder heads are interchangeable, Buy a NEW 8N cylinder head and gitt 6.5:1 compression.

Howsomevers: you want more power? Gitta 454 Chevy smog pump and NAA carb and SUPERCHARGED yer engine. You doubt? Google "Dirt cheap supercharger by Steven Richmond" ........Dell
 
Back to top
View user's profile
kylemorley
Regular


Joined: 02 Aug 2010
Posts: 345


Report to Moderator

PostPosted: Thu Dec 13, 2012 2:27 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

6.5 to 1 is pretty much the limit because above that everything is too crowded to let the valves and heads breath effectively - you can't run a piston right up to the valves like an OHV can do, when they are off to the side.

Harley Davidson put huge amounts of effort into developing the flathead long after it was obsolete, well into the '60s, due to a loophole in the US racing rules that let HD run 45 c.i. sidevalves against 30 c.i. OHVs. While stock sidevalve Harleys ran compression ratios similar to the 8ns, the fastest racers usually had even LOWER compression ratios, 5.5 or so, since there was no way to port them without lowering the ratio, and good breathing was found to be more important than compression ratio.

It's likely some 8ns are now nibbling at the upper limits of compression without benefit of trick heads due to the heads and/or blocks having been resurfaced.
 
Back to top
View user's profile
souNdguy
Tractor Guru


Joined: 20 Aug 2002
Posts: 53851


Report to Moderator

PostPosted: Thu Dec 13, 2012 3:13 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

shave an 8n head a lil.. then check valve clearance with putty and no head gasket.. then relieve as needed and bolt on.. that's about it.. as dean and the others said. other goodies not so available.

and the merc pistons in the parent bore.. well.. it works.. bat can cause issues later and requires overbore to correct.

also don't give you much more hP.

if you have an 8n and want more hp.. get a naa or 6xx ( or 8xx and have near 2x hp )
 
Back to top
View user's profile
Mr. T. Minnesota
Regular


Joined: 17 Jan 2012
Posts: 460


Report to Moderator

PostPosted: Thu Dec 13, 2012 3:31 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Forum Members,
Thanks for the info. Reason for the question is the 8N I purchased this summer had been newly overhauled. The seller said he had added special pistons, shaved the head and decked the block. He said the compression "may be an 8:1 ratio" ?? Even as a novice to mechanics the math just did not seem to work out. There is only so much space to work with.
With that being said, the 8N seems to be a lot more powerful than my not so worn out 2N. Had to change the 33 to a 243 carb to make it run right which may also add to the power.
Again, any other thoughts are appreciated. In retirement my goal is to learn something every day.
Mr. T. Minnesota
 
Back to top
View user's profile
Bob Harvey
Tractor Guru


Joined: 18 Jan 2003
Posts: 4908


Report to Moderator

PostPosted: Thu Dec 13, 2012 3:39 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Or go the Baumann way and install a turbine/V-8/Valkirie !!
 
Back to top
View user's profile
souNdguy
Tractor Guru


Joined: 20 Aug 2002
Posts: 53851


Report to Moderator

PostPosted: Thu Dec 13, 2012 4:06 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

yep.. jet engine HP Smile
 
Back to top
View user's profile
Dean
Tractor Guru


Joined: 29 Jan 1998
Posts: 12547


Report to Moderator

PostPosted: Thu Dec 13, 2012 5:12 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

It's not 8:1.

Probably closer to 6.5:1.

Your 2N most likely has flat-topped pistons in it while the 8N almost certainly has late 8N domed pistons, which are good for a noticeable increase in torque and power vis-a-vis the flat-topped pistons.

Dean
 
Back to top
View user's profile
HCooke
Tractor Guru


Joined: 29 Sep 2006
Posts: 4122
Location: Missouri

Report to Moderator

PostPosted: Thu Dec 13, 2012 5:25 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

8:1 seems like an exaggeration, but my '51 8N does seem stronger than any of my 5 9Ns.
 
Back to top
View user's profile
HCooke
Tractor Guru


Joined: 29 Sep 2006
Posts: 4122
Location: Missouri

Report to Moderator

PostPosted: Thu Dec 13, 2012 5:25 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

8:1 seems like an exaggeration, but my '51 8N does seem stronger than any of my 5 9Ns.
 
Back to top
View user's profile
Dean
Tractor Guru


Joined: 29 Jan 1998
Posts: 12547


Report to Moderator

PostPosted: Thu Dec 13, 2012 6:39 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

It will be if everything is as manufactured. Late 8Ns do have higher CR and more HP than 9/2 Ns.

Dean
 
Back to top
View user's profile
Hobo,NC
Tractor Guru


Joined: 14 Jun 2007
Posts: 12169


Report to Moderator

PostPosted: Thu Dec 13, 2012 7:10 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Mr. T. Minnesota wrote:
(quoted from post at 03:31:36 12/14/12) Forum Members,
Thanks for the info. Reason for the question is the 8N I purchased this summer had been newly overhauled. The seller said he had added special pistons, shaved the head and decked the block. He said the compression "may be an 8:1 ratio" ?? Even as a novice to mechanics the math just did not seem to work out. There is only so much space to work with.
With that being said, the 8N seems to be a lot more powerful than my not so worn out 2N. Had to change the 33 to a 243 carb to make it run right which may also add to the power.
Again, any other thoughts are appreciated. In retirement my goal is to learn something every day.
Mr. T. Minnesota


My guess if you save the head and deck the block its possible to gain a pony are 2....

No guess the difference in a 2N and a 8N engine is the head that's it,,, the difference is in the valve pockets... Put a 2N head on a Very good running 8N and the power lose very noticeable.. A 8N head is very close to the Hot Rod aluminum head that was offered for a N... You can shave a N head all you want to the valves will never hit ( write that down )... The piston is a different story but can be over come... A """"NEW"""" reproduction head has the same valve pockets as a 2N head and will cost you a pony are 2 so don't go their.....

If you are power hungry bump the RPM up if you can hang on Theirs 40 of'em their waiting to be turned loose Laughing
 


Last edited by Hobo,NC on Thu Dec 13, 2012 7:12 pm; edited 1 time in total
Back to top
View user's profile
Ken(Ark)
Long Time User


Joined: 17 Feb 2007
Posts: 1479


Report to Moderator

PostPosted: Fri Dec 14, 2012 9:13 pm    Post subject: Re: higher compression ratio? Reply to specific post Reply with quote

Mr. T. Minnesota wrote:
(quoted from post at 15:27:47 12/13/12) Forum Members,
Curious if it is possible to increase the compression ratio when rebuilding an 8N engine to higher than 6:1? Any thoughts are appreciated!

Mr. T. Minnesota


Angle mill an 8n head and or Mill the block .

New Valves and seats . ( Thicker for Static Compression , Larger w/ swirl polished stems for Dynamic Compression )

Oversized pistons .

Offset weld the crankshaft

Dual Exhaust manifold & port work ( Dynamic Compression ) I think a custom tube header would be the cats meow .

A custom ground Cam from ??? could knock the heck out of the Dynamic Compression as would a forced induction system .

Low impedance air filter , gas cool can , electric fan , genny cut off switch (H.P.)

Let's not forget NO2

Run the 9/16 pump with light weight full synthetic oil .

Polish connecting rods and balance the rotating assemble .



Or go buy a 226 flat six , get crazy and rip all the guts out of the drive train .

A properly built N motor has the best high ratio of power at the lowest risk of drive train damage .
 
Back to top
View user's profile
Display posts from previous:   
Post new topic    Yesterday's Tractors Forum Index -> Ford 9N, 2N, 8N All times are GMT - 8 Hours
Page 1 of 1

 
Jump 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.

YT Home  |  Forums Home

Copyright © 1997-2014 Yesterday's Tractor Co.

Powered by phpBB © 2001, 2005 phpBB Group

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