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

Cam Timing

Welcome Guest, Log in or Register
Author 
mshultz

08-24-2005 16:53:13




Report to Moderator

Got the cam for my tractor and went to degree the camshaft at .050 lift specs. On the intake valve at about 5-6 degrees before the "big" lift begins, the dial indicator jumps about .010, then stays put until the big lift up. My understainding was that you go from the "base circle" before the small .010 jump for the .050 reading. Problem is, that the closing degree reading that I get at .050 is about 5-6 degrees off too - if I use my .010 from the base circle as my 0.000 point I'm pretty close to right on on the closing side of the cam..... what gives?

Haven't tried the exhaust to see if it's the same way - just wondering if there are any pros out there at this that could give me a heads up before I move stuff around to check another one.

[Log in to Reply]   [No Email]
Gary Baker

08-26-2005 05:34:09




Report to Moderator
 Re: Cam Timing in reply to mshultz, 08-24-2005 16:53:13  
Use the intake cam lobe centerline. From my experience the base circle is not reliable on most reground camshafts, thus throwing off .050ths
lift points.



[Log in to Reply]  [No Email]
Goldsburg

08-25-2005 17:53:59




Report to Moderator
 Re: Cam Timing in reply to mshultz, 08-24-2005 16:53:13  
You need to take your measurements from the 0.000" of lift point. The little .010" of lift that you are seeing is built into the profile. This little bump before the big lift prevents valve train slap as the clearances are taken up and the little "step off" at the end of the ramp (if I understand your description correctly) is to decelerate the valve train prior to close so as not to have valve slam shut.

This is nothing unusual, just go with your gut and don't overthink it...

Good Luck,

Goldsburg

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

08-27-2005 18:38:37




Report to Moderator
 Re: Cam Timing/Goldsburg in reply to Goldsburg, 08-25-2005 17:53:59  
what is your opinion about advancing cam with an off-set key, when stroking a crank and maintaining stock rod length ?
Do you have an opinion on when the exhaust valve closes on power stroke ?

bud barenie



[Log in to Reply]  [No Email]
Goldsburg

08-28-2005 14:25:05




Report to Moderator
 Re: Cam Timing/Goldsburg in reply to B Barenie, 08-27-2005 18:38:37  
Bud -

I wouldn"t say that there is a hard and fast rule for advancing the cam after stroking. It would really depend on the cam profile and the profile"s lobe center(s).

I have seen the exhaust opening on "good cams" range from 28 to 43 BBDC, depending on the size of the engine, RPM range, and flow capability of the head.

I know that this probably didn"t help much, but generally speaking the bigger the engine, the earlier before BBDC you will need open the exhaust valve to adequately clear the cylinder. Similarly, the better the cylinder head flow, the later you can open the exhaust and still properly scavenge the cylinder.

Regards,

Goldsburg

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

08-29-2005 17:11:09




Report to Moderator
 Re: Cam Timing/Goldsburg in reply to Goldsburg, 08-28-2005 14:25:05  
ON A MEDIUM BUILD UP APROXO 100CUBES, OPENING THE EXHAUST VALVE EARLIER, (CAM IN ROTATION WITHOUT CHANGING DEGREE SEPERATION) WILL ACTUALLY HELP LOW END TORQUE, i'M NOT UNDERSTANDING THE MIDDLE OF THEE MOTOR AT ALL. PERIOD !



[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