|
This is the modern view of the Yesterday's Tractors Forums. Just login with your YT Userid and password to post. If you have trouble logging in, contact us by email to support at ytmag.com, or through the Reader Form, and we will get you going right away.
| View previous topic :: View next topic |
| Author |
Message |
boler76
Regular
Joined: 07 Apr 2005
Posts: 275
Report to Moderator
|
 Posted: Sat Oct 13, 2012 12:09 pm Post subject: cam lobe height |
  |
|
What is the proper valve lift for a '49 8N Thanks
|
|
| Back to top |
|
 |
JMOR
Tractor Guru
Joined: 13 Aug 2007
Posts: 12660
Report to Moderator
|
| Posted: Sat Oct 13, 2012 1:13 pm Post subject: Re: cam lobe height |
|
|
| boler76 wrote: | | (quoted from post at 16:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
You are not likely to find that number.. From those who really should know, it is said that the cam wears very little due to small spring pressure and the fact that lobes are flame hardened. I would measure all & compare to one another & if all are about same, call it good.
|
|
| Back to top |
|
|
TheOldHokie
Tractor Guru
Joined: 08 Apr 2005
Posts: 5871
Location: Myersville, MD
Report to Moderator
|
| Posted: Sat Oct 13, 2012 2:30 pm Post subject: Re: cam lobe height |
|
|
| JMOR wrote: | (quoted from post at 17:13:47 10/13/12) | boler76 wrote: | | (quoted from post at 16:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
You are not likely to find that number.. From those who really should know, it is said that the cam wears very little due to small spring pressure and the fact that lobes are flame hardened. I would measure all & compare to one another & if all are about same, call it good. |
Here is an interesting little graphic. FWIW a high performance Crane cam for a V8 Ford flatty is pushing .400 lift.
This source is a treasure trove of information and says a stock flatty was .307: Camshaft Design History
TOH
Last edited by TheOldHokie on Sat Oct 13, 2012 2:50 pm; edited 2 times in total |
|
| Back to top |
|
|
JCinKY
Regular
Joined: 01 Aug 2012
Posts: 280
Location: Glendale KY
Report to Moderator
|
| Posted: Sat Oct 13, 2012 4:42 pm Post subject: Re: cam lobe height |
|
|
| boler76 wrote: | | (quoted from post at 13:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
Intake=0.3553
Exhaust=0.3370
|
|
| Back to top |
|
|
JMOR
Tractor Guru
Joined: 13 Aug 2007
Posts: 12660
Report to Moderator
|
| Posted: Sat Oct 13, 2012 6:06 pm Post subject: Re: cam lobe height |
|
|
| JCinKY wrote: | (quoted from post at 20:42:29 10/13/12) | boler76 wrote: | | (quoted from post at 13:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
Intake=0.3553
Exhaust=0.3370 |
Source?
|
|
| Back to top |
|
|
JCinKY
Regular
Joined: 01 Aug 2012
Posts: 280
Location: Glendale KY
Report to Moderator
|
| Posted: Sat Oct 13, 2012 7:08 pm Post subject: Re: cam lobe height |
|
|
http://www.oldfordtractors.com/oftspecs.htm
Not sure if it's 100%, but seemed close enough to rebuild my engine. The "original" copy was soaked in oil in the tool box so it took me awhile to find it again.
|
|
| Back to top |
|
|
JMOR
Tractor Guru
Joined: 13 Aug 2007
Posts: 12660
Report to Moderator
|
| Posted: Sat Oct 13, 2012 7:16 pm Post subject: Re: cam lobe height |
|
|
| JCinKY wrote: | (quoted from post at 23:08:49 10/13/12) http://www.oldfordtractors.com/oftspecs.htm
Not sure if it's 100%, but seemed close enough to rebuild my engine. The "original" copy was soaked in oil in the tool box so it took me awhile to find it again. |
Cool! I looked there, but obviously not close enough! Thanks.
|
|
| Back to top |
|
|
boler76
Regular
Joined: 07 Apr 2005
Posts: 275
Report to Moderator
|
| Posted: Sun Oct 14, 2012 2:21 am Post subject: Re: cam lobe height |
|
|
Thanks that is the info I was looking for
|
|
| Back to top |
|
|
TheOldHokie
Tractor Guru
Joined: 08 Apr 2005
Posts: 5871
Location: Myersville, MD
Report to Moderator
|
| Posted: Sun Oct 14, 2012 3:33 am Post subject: Re: cam lobe height |
|
|
| JMOR wrote: | (quoted from post at 23:16:17 10/13/12) | JCinKY wrote: | (quoted from post at 23:08:49 10/13/12) http://www.oldfordtractors.com/oftspecs.htm
Not sure if it's 100%, but seemed close enough to rebuild my engine. The "original" copy was soaked in oil in the tool box so it took me awhile to find it again. |
Cool! I looked there, but obviously not close enough! Thanks. |
Careful - look at the column dividers in that table. Those numbers are only for the OHV engines - not the L-head.
TOH
Last edited by TheOldHokie on Sun Oct 14, 2012 3:36 am; edited 1 time in total |
|
| Back to top |
|
|
JMOR
Tractor Guru
Joined: 13 Aug 2007
Posts: 12660
Report to Moderator
|
| Posted: Sun Oct 14, 2012 6:25 am Post subject: Re: cam lobe height |
|
|
| TheOldHokie wrote: | (quoted from post at 07:33:05 10/14/12) | JMOR wrote: | (quoted from post at 23:16:17 10/13/12) | JCinKY wrote: | (quoted from post at 23:08:49 10/13/12) http://www.oldfordtractors.com/oftspecs.htm
Not sure if it's 100%, but seemed close enough to rebuild my engine. The "original" copy was soaked in oil in the tool box so it took me awhile to find it again. |
Cool! I looked there, but obviously not close enough! Thanks. |
Careful - look at the column dividers in that table. Those numbers are only for the OHV engines - not the L-head.
TOH |
Clearly still not looking close enough! 
And if trying to check cam for wear on those OHV engines, one would need to measure at the valve, not the cam lobes, unless he knew the rocker arm ratio, since the chart gives valve lift. That would be obvious to TOH, but maybe not for the world wide population. 
Last edited by JMOR on Sun Oct 14, 2012 7:03 am; edited 1 time in total |
|
| Back to top |
|
|
Ken(Ark)
Long Time User
Joined: 17 Feb 2007
Posts: 1446
Report to Moderator
|
| Posted: Sun Oct 14, 2012 12:19 pm Post subject: Re: cam lobe height |
|
|
| boler76 wrote: | | (quoted from post at 16:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
I have been looking for those numbers and have not found any .
I measured 6 USED front dizzy "N" cams and got .296 - .298 for a mean lift . They could all be worn .060 for all I know . I threw a quick digital caliper on them and will use a dial gauge down the lifter/valve bore this winter when I get around to building some N motors . I want to throw a degree wheel on it so I can post those numbers too .
They sell reground cams on this site but I have not talked to anyone who has purchased one .
I would bet these numbers have been measured 1000's of times over the years , but I can't find any posted .
I forgot to write it down , but the bearing journal was the same diameter as a 1937 - 21 stud flathead V8 cam I had in the shop . The V8 cam had a low lift of about .298 also .
I will measure the V8 block for an O.D. cam bearing diameter and post that someday ???
P.S.
These are front mount distributor cams , I think I have read that the side mount cams have a higher lift .
After WWII and the introduction of better fuel , the industry raised compression ratios and valve lifts . The cam was redesigned with the side dizzy so I assume the engineers pepped it up a little ????
Last edited by Ken(Ark) on Sun Oct 14, 2012 12:49 pm; edited 1 time in total |
|
| Back to top |
|
|
TheOldHokie
Tractor Guru
Joined: 08 Apr 2005
Posts: 5871
Location: Myersville, MD
Report to Moderator
|
| Posted: Sun Oct 14, 2012 1:29 pm Post subject: Re: cam lobe height |
|
|
| Ken(Ark) wrote: | (quoted from post at 16:19:30 10/14/12) | boler76 wrote: | | (quoted from post at 16:09:48 10/13/12) What is the proper valve lift for a '49 8N Thanks |
I have been looking for those numbers and have not found any .
I measured 6 USED front dizzy "N" cams and got .296 - .298 for a mean lift . They could all be worn .060 for all I know . I threw a quick digital caliper on them and will use a dial gauge down the lifter/valve bore this winter when I get around to building some N motors . I want to throw a degree wheel on it so I can post those numbers too .
They sell reground cams on this site but I have not talked to anyone who has purchased one .
I would bet these numbers have been measured 1000's of times over the years , but I can't find any posted .
I forgot to write it down , but the bearing journal was the same diameter as a 1937 - 21 stud flathead V8 cam I had in the shop . The V8 cam had a low lift of about .298 also .
I will measure the V8 block for an O.D. cam bearing diameter and post that someday ???
P.S.
These are front mount distributor cams , I think I have read that the side mount cams have a higher lift .
After WWII and the introduction of better fuel , the industry raised compression ratios and valve lifts . The cam was redesigned with the side dizzy so I assume the engineers pepped it up a little ???? |
The stock valve lift and profile for the flathead cams varied (all numbers taken from original Ford prints):
- 1932-38 Ford V8 used a 6 arc profile with a .307 lift. Camshaft numbers 18-6250 and 78-6250
- 1949-51 Ford V8 used a triple curve profile with a .307 lift. Camshaft number 8BA-6250
- 1949-50 Mercury V9 used a triple curve profile with a .380 lift. Camshaft number 8CM-6250.
- The 1937-48 Ford six cylinder used a triple curve profile with .350 lift. Camshaft number 7HA
The 120 CID 4 cyl camshaft journal diameters are the same as for the V8's. Clevite camshaft bearing set SH-21S fits the V8 and has OD of 1.9275/1.9285. You would need to punch the 120 CID L-head out .131 over to use them in that motor - should be plenty of meat to accomodate that.
TOH
|
|
| Back to top |
|
|
TheOldHokie
Tractor Guru
Joined: 08 Apr 2005
Posts: 5871
Location: Myersville, MD
Report to Moderator
|
| Posted: Sun Oct 14, 2012 1:34 pm Post subject: Re: cam lobe height |
|
|
| JMOR wrote: | (quoted from post at 10:25:15 10/14/12) | TheOldHokie wrote: | (quoted from post at 07:33:05 10/14/12) | JMOR wrote: | (quoted from post at 23:16:17 10/13/12) | JCinKY wrote: | (quoted from post at 23:08:49 10/13/12) http://www.oldfordtractors.com/oftspecs.htm
Not sure if it's 100%, but seemed close enough to rebuild my engine. The "original" copy was soaked in oil in the tool box so it took me awhile to find it again. |
Cool! I looked there, but obviously not close enough! Thanks. |
Careful - look at the column dividers in that table. Those numbers are only for the OHV engines - not the L-head.
TOH |
Clearly still not looking close enough!
And if trying to check cam for wear on those OHV engines, one would need to measure at the valve, not the cam lobes, unless he knew the rocker arm ratio, since the chart gives valve lift. That would be obvious to TOH, but maybe not for the world wide population. |
Or one could determine the rocker ratio and simply compute the cam lift needed to get the specified valve lift 
TOH
|
|
| Back to top |
|
|
Ken(Ark)
Long Time User
Joined: 17 Feb 2007
Posts: 1446
Report to Moderator
|
| Posted: Sun Oct 14, 2012 3:41 pm Post subject: Re: cam lobe height |
|
|
| TheOldHokie wrote: |
The stock valve lift and profile for the flathead cams varied (all numbers taken from original Ford prints):
- 1932-38 Ford V8 used a 6 arc profile with a .307 lift. Camshaft numbers 18-6250 and 78-6250
- 1949-51 Ford V8 used a triple curve profile with a .307 lift. Camshaft number 8BA-6250
- 1949-50 Mercury V9 used a triple curve profile with a .380 lift. Camshaft number 8CM-6250.
- The 1937-48 Ford six cylinder used a triple curve profile with .350 lift. Camshaft number 7HA
The 120 CID 4 cyl camshaft journal diameters are the same as for the V8's. Clevite camshaft bearing set SH-21S fits the V8 and has OD of 1.9275/1.9285. You would need to punch the 120 CID L-head out .131 over to use them in that motor - should be plenty of meat to accomodate that.
TOH |
Just adding info .
Ford Flathead Cam Lobe Designs
TThe Ford Flathead engine used various cam designs. Among these were the Model T cam, Model A/B cams, and the V-8 cams. Camshaft performance was usually described in terms of a number of terminologies in relation to the timing of the valve movements. These include the Top Dead Center (TDC), Bottom Dead Center (BDC), Before Top Dead Center (BTDC), After Top Dead Center (ATDC), Before Bottom Dead Center (BBDC), and After Bottom Dead Center (ABDC).
Model T and Models A/B Cams Specifications
The Model T cam BTDC, ABDC, BBDC, and ATDC were -12, 52, 39 degrees and one degree. Its duration was 220 degrees for both the intake and exhaust. The Lift was 0.250 inches and the Lobe Separation was 115.5 degrees. Model A/B cams BTDC, ABDC, BBDC, and ATDC were 8, 56, 56, and degrees. The duration was longer than that of the Model T cam at 244 degrees. The Lift was also higher at .334 inches during intake and 0.341 inches during exhaust. Lobe Separation was 114.0 degrees.
Flathead V-8 Cams
The Flathead V-8 camshafts came in four versions from 1937 up to 1952. These were the 78-6250 cams from 1937-1948, 8Ba-6250 cams from 1949-1951, 8CM cams from 1949-1950, and the 7HA cams from 1946-1952.
The 78-6250 cams BTDC, ABDC, BBDC, and ATDC were 0, 44, 48, and 6 degrees. It was 5, 44, 48, and 3 degrees for the 8BA-6250 cam, 10, 50, 50, and 10 degrees for the 8CM cam, and 11, 41, 48, and 10 degrees for the 7HA cam. The duration was 224 degrees for the 78-6250, 229 degrees for the 8BA-6250, 240 degrees for the 8CM, and 22 degrees for the 7HA. The 78-6250 and 8BA-6250 had Lifts of 0.307 inches. The 8CM's Lift was .338 inches, while the 7HA measured 0.350 inches. The Lobe Separation for the models ranged from 107.0 degrees for the 7HA up to 111.5 degrees for the 78-6250 cam.
|
|
| Back to top |
|
|
Ken(Ark)
Long Time User
Joined: 17 Feb 2007
Posts: 1446
Report to Moderator
|
| Posted: Sun Oct 14, 2012 3:49 pm Post subject: Re: cam lobe height |
|
|
http://www.tildentechnologies.com/Technical/CamHistory.html
http://www.tildentechnologies.com/Technical/FlatheadPerformance.html
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
|
|
Discount Prices for Parts! You can help support this extensive website by purchasing your tractor parts, manuals and merchandise from our [ Antique Tractor Store ] or call our friendly sales staff toll free (800) 853-2651. [ More Info ]
|
YT Home
| Tractor Manuals
| Tractor Parts
| Forum Home
Copyright © 1997-2013 Yesterday's Tractor Co. - A Washington State Corporation
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
|
|
|
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
