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

Shop Now

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

Tractor Pulling Discussion Forum

Where did the pull down and lug go ?

Welcome Guest, Log in or Register
Author 
Old Puller

03-01-2008 15:46:03




Report to Moderator

This one bugs me and looking for answer. Talking about a bored and stroked engine with higher compression. Why is it most of the time you loose the pull down and lug that the engine had when it was stock. I see this over and over and I just don't understand why. I'm not talking big cam change ect. ect. IH, JD, or whatever stroker engines run like a bear but don't pull down and just flat lug, most of the time they drop like a rock. I could understand if you built a big cam RPM engine. Unless I'm missing something if you extend the stroke, increase the compression and bore you are increasing the HP, Cu.In. and torque. So what happens to the ability to pull down and lug ?

[Log in to Reply]   [No Email]
caseguy

03-04-2008 13:26:17




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
also something not mentioned is when stroking an engine it takes more force for the piston to come back up on the compression stroke due to higher compression and the leverage effect



[Log in to Reply]  [No Email]
Gary in da UP

03-02-2008 09:53:39




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
I think the reason a hi compression engine falls flat in lugging ability is the lack of a healthy spark , hi comp ratio"s have the tendancy to " put out the fire". Just a thought. gh



[Log in to Reply]  [No Email]
ChadS

03-02-2008 04:37:36




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
Id add that I belive that fuel can be a huge part of having no torque curve,,, race fuel,,, gets in, burns up and gets out,, designed to get in, burn up as fast as it can and exit out the exhaust. the explosion is not a long lasting explosion,,, it fizzles out before any thing can be done. Aviation fuel does the same thing,,, runs good, smells good, but it aint worth a darn to make torque. thats alot of cyl pressure in a JD 2 cyl,,,, I imagine that it took alot of octane to run it,,,, by the time you found the high octane fuel,, its way too much octane, makes it too hard to ignite,,, then the timing curve suffer to make up the difference. JMHO,, but I belive the fuel crapped out on it when you ran the higher compression,,, seen it many times,,,,
slow burning, high octane, cooling fuel helps,,,
race fuel,, its fast burning, hotter in temperature, and is high octane,,, one is for high rpm, one is for low rpm,,,,, ChadS ChadS3@hotmail.com

[Log in to Reply]  [No Email]
Like the topic.

03-02-2008 03:37:36




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
Ive been watching this debate. My take on this is. I built a engine stroked it 1 inch to 7 total and bored it a 1/4 inch. It ran great untill i pulled it. I compression checked it at 265 pounds. Thats all i got before it would pop the seal at the plug. So i dont know how high it actually was. I tried to pull 1 gear higher than i had been when stock wouldnt do it not even close. We played and messed with it for most of the summer to no good. Changed the head to a lower compression chamber one and gained my gear and would lug good. It ran this gear really good on any track. Compression checked it 200lbs or so. Thats me take.

[Log in to Reply]  [No Email]
B-maniac

03-01-2008 19:52:56




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
Another thing that hasn't been mentioned here is the issue of intake air velocity. The bored and stroked tractor more than likely has been set up with a lot more port , manifold and carb flow to fill the increased cylinder volume at an increased rpm level. Once the rpm falls , so does the volume that needs filled , but the throttle probably stays wide open and because of the enlarged intake passage the intake charge has just slowed up too much to effeciently fill the cylinders and the torque drops quickly. My opinion has always been that on a sticky track you need low-midrange torque and on a slick track you need one of those "other" tractors with all it's wheel spinning horsepower produced in a narrow 2-300 rpm span over 2000rpm. I've allready been "hung" for the "torque" line of thinking on this forum so remember this is just my uneducated "cabin fever" opinion.

[Log in to Reply]  [No Email]
770

03-02-2008 11:32:20




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to B-maniac, 03-01-2008 19:52:56  
The bored and stroked tractor more than likely has been set up with a lot more port , manifold and carb flow to fill the increased cylinder volume at an increased rpm level. Once the rpm falls , so does the volume that needs filled , but the throttle probably stays wide open and because of the enlarged intake passage the intake charge has just slowed up too much to effeciently fill the cylinders and the torque drops quickly. THAT"S IT IN A NUTSHELL!

[Log in to Reply]  [No Email]
jd b puller

03-01-2008 19:22:18




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to long hauler, 03-01-2008 15:46:03  

Old Puller said: (quoted from post at 22:49:09 03/01/08) Thanks for the replies, I have pulled and been involved with pulling since the sixties and my tractors have always done well. I just often wondered why for example JD G stroker ( sorry Chads ) run like a bear but put him on a hard pull and it would drop like a rock, basic stock G pull down and lug on through. Now I'm talking same class, about the same tires and except engine very near the same tractor. Had my own thoughts on the subject but that's like something else everybody has one. Looking at changing brands and couple friends keep saying if I do I should put togeather a stroker engine and that just brought my question back to surface in empty space between ears so that's why I placed question on the forum. Found out long time ago, thinking I'm right don't make me right so I get other views and then if it's wrong I can blame someone else ( LOL )


I'd think there'd be several factors.

1. The stroker tractor is likely running faster. HP required is directly related to the ground speed. Takes twice as much HP to go 4 MPH as 2, and 4 times more to go 8 than 2MPH.

2. A lot of pullers think they have bigger motors than they do and think they need a "pulling cam". There's a lot of people out there selling "pulling cams". Due to the PITA of changing a cam, most people replace the cam when they build the storker motor. Most don't dyno it with the stock cam and then tear it all apart and dyno it again with the "new" cam, so as far as they are concerned, everything is "peachy" with the new cam. I don't know much about cams, but depending on what you do, you might as well kiss low end goodbye. The lower the RPM's get, the lower they'll get.

[Log in to Reply]  [No Email]
Old Puller

03-01-2008 18:49:09




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
Thanks for the replies, I have pulled and been involved with pulling since the sixties and my tractors have always done well. I just often wondered why for example JD G stroker ( sorry Chads ) run like a bear but put him on a hard pull and it would drop like a rock, basic stock G pull down and lug on through. Now I'm talking same class, about the same tires and except engine very near the same tractor. Had my own thoughts on the subject but that's like something else everybody has one. Looking at changing brands and couple friends keep saying if I do I should put togeather a stroker engine and that just brought my question back to surface in empty space between ears so that's why I placed question on the forum. Found out long time ago, thinking I'm right don't make me right so I get other views and then if it's wrong I can blame someone else ( LOL )

[Log in to Reply]  [No Email]
ChadS

03-01-2008 18:11:16




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Old Puller, 03-01-2008 15:46:03  
Depends on what kind of sled your pulling. Thats the pulling aspect of that question. certain setups work differently, anything can affect it, from tires to fuel, most have done it for so long they forgot more than we will ever know. We ALL have seen what has come and gone, and still remain.
Pulling, is about taking a tractor, harnessing its power and creating a leverage thru the hitch by weights creating the counter balances. HP is a by product,, abundance is keen, they do better, they pull farther, faster, etc etc, but a puller, will see that a tractor has a certain amount of power, with a given tire, and a set of rules that favor all the rest,,,, its up to us to make it stick to the ground, and what you do, is what ever you wish, even if its bone factory stock,,,, a puller, a tractor puller will get it farther down the track,, no matter what the dang thing is with what he/she is dealt with,

Any engine will lug, some stronger than others, and at a cost, any thing has potential, even with what it has now, pull it, drive it, put it out in the yard looking pretty for all to see. Its what its all about, you might have a good one already,,, you tell me. Why does it not lug out? thats for the guy who built the darn thing to answer. and if he cant answer it, there are other options,,,,, ,,,,, ,,,,, ,, ChadS ChadS3@hotmail.com

[Log in to Reply]  [No Email]
MLPANKEY

03-01-2008 18:03:51




Report to Moderator
 Re: Where did the pull down and lug go ? in reply to Gary Baker, 03-01-2008 15:46:03  

Old Puller said: (quoted from post at 16:46:03 03/01/08) This one bugs me and looking for answer. Talking about a bored and stroked engine with higher compression. Why is it most of the time you loose the pull down and lug that the engine had when it was stock. I see this over and over and I just don't understand why. I'm not talking big cam change ect. ect. IH, JD, or whatever stroker engines run like a bear but don't pull down and just flat lug, most of the time they drop like a rock. I could understand if you built a big cam RPM engine. Unless I'm missing something if you extend the stroke, increase the compression and bore you are increasing the HP, Cu.In. and torque. So what happens to the ability to pull down and lug ?
:lol: every article i have ever found on engine building simply states that the higher compression the more mid range torque you have. mid and low range torque is what ive always been after granted higher duration cams do move you up in rpm but thats not an act of compression alone. cubic inches is free horsepower . in changing stroke you change piston to valve timing the piston may dwell longer or shorter at tdc. getting those timing changes ground back into a cam is hard to do seeing that cam grinds are set up on the oem specs. alos spectators have changed the sport some seams that nobody wants to stand around and watch a dieing tractor die. they rather see the drag race to the finish line, oh well thats my input.

[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