Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Attention Forum Users: On the 28th of December 2023 at 9:00am Central Time, we will be taking the forums down for maintenance while we prepare the new forums for your use. Please click here for more information.

Tractor Pulling Discussion Forum

long and short of piston speed

Welcome Guest, Log in or Register
Author 
mlpankey

03-21-2007 23:32:44




Report to Moderator

ok a shorter rod puts a steeper angle and introduces more side loading .resulting in skirt wear and some friction loss. a short rod will decrease dwell timing near top dead center .which means its moving to and away from top dead center faster. it is also beneficial in a motor with poor port flow as the peek piston speed occurs earlier in the intake when the pressure is greatest acroos the valves. the smaller rod ratio also pulls the piston deeper in the cylinder opposed to a long rod .as a result torgue at lower rpms goes up.maximum piston speed is 5,000fpm . do not go over it or failure will occur . the formula for piston speed is as follows STROKE X RPM / 6 HOPE B BARINIE AND OTHERS FIND THIS USEFULL

[Log in to Reply]   [No Email]
Ebbsspeed

03-23-2007 08:39:22




Report to Moderator
 Re: long and short of piston speed in reply to mlpankey, 03-21-2007 23:32:44  
I don't quite agree with your statement that "the smaller rod ratio also pulls the piston deeper in the cylinder opposed to a long rod". IF the engine is built right, a short rod motor will have a different piston pin height (lower than a long rod version) in order to retain the proper combustion chamber volume and compression ratio. It is true that if you simply replace a long rod with a short rod the piston will go deeper into the cylinder at bottom dead center, but there will also be an identical lowering of the piston at TDC, and this will absolutely kill performance.

[Log in to Reply]  [No Email]
LW

03-22-2007 18:02:38




Report to Moderator
 Re: long and short of piston speed in reply to mlpankey, 03-21-2007 23:32:44  
Every test I have ever read or reviewed showed a lower ratio or shorter rod engine making a gain at high rpm. Go to ISKY's website there are results from there trail and error that they feel like they proved. Sorry opposite of your claim.



[Log in to Reply]  [No Email]
mlpankey

03-22-2007 20:07:38




Report to Moderator
 Re: long and short of piston speed in reply to LW, 03-22-2007 18:02:38  
resources i use was from stahl header and jim kasse he is the leading engine builder of the westech engine build off . i also prefer ultradyne cams. there very hard on valve springs but make power . i have yunicks publishings technology is like time always changing stay up or become ripp vanwinkle .snoozers are loosers. and as i said before all builders are intiteled to different oppinions this toppic has been hashed out more times than this web site wiill ever. so there is no right and wrong its a matter of where you like your torque curve to be.

[Log in to Reply]  [No Email]
mlpankey

03-22-2007 17:56:42




Report to Moderator
 Re: long and short of piston speed in reply to mlpankey, 03-21-2007 23:32:44  
every engine builder has there opinions. yunick is old school just ask grumpy if his engines from yunicks era made the power his pro stocks make today. yunick was a round track man if i remember correctly . i kinda thought tractor pulling was 300 ft straight but im rethinking it because i do turn to get to the scales . maybe its somewhat of a oval. yeah always thinking no time for sleeping if want to keep being competitive.

[Log in to Reply]  [No Email]
skip 33652

03-22-2007 06:22:25




Report to Moderator
 Re: long and short of piston speed in reply to mlpankey, 03-21-2007 23:32:44  
all rules made to be broken. every prostock will break 5000fps on warm up . one thing is for certain you are making way too much of rod stroke ratio . sometimes in really big cube motors all rules like rod stroke ratios must be thrown out.
smokey yunick said it best and first put the longest rod you can in the engine and go racing. and hot rod did an article with some dyno runs on a327 chevy one time with 5.5" vs 6.5" rods there was basically an unmeasureable difference in hp or torque and there was nothing that would have kept them from tuning difference away cam profile ect.ect.Paul

[Log in to Reply]  [No Email]
B Barenie

03-27-2007 17:50:03




Report to Moderator
 Re: / paul in reply to skip 33652, 03-22-2007 06:22:25  
Paul:

Good to here your voice !

Hope all is well !
And I'm not fishing,could this be Paul M.


Bud Barenie



[Log in to Reply]  [No Email]
B Barenie

03-22-2007 18:29:43




Report to Moderator
 Re: long and short of piston speed in reply to skip 33652, 03-22-2007 06:22:25  
smokey !
An awsome engine builder, a must read of anything he has published !

Mr Mlpankey ! The board qets educated, when people start digging !

Thank's to all !
I will close (skipwhat ever)!
When I ask question's, remember this thing ?

In tractor pulling, less is more and more is less !

Please all have an awesome evening !

Bud Barenie !



[Log in to Reply]  [No Email]
Captainhookerus

03-22-2007 19:47:08




Report to Moderator
 Re: long and short of piston speed in reply to B Barenie, 03-22-2007 18:29:43  
Here lies Less Moore Shot with a 44 No Less No More



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

Hop to:


TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

Home  |  Forums


Copyright © 1997-2023 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

Website Accessibility Policy