cam decreeing with the 50 method - Hot Rod Forum : Hotrodders Bulletin Board
Hotrodders.com -- Hot Rod Forum



Register FAQ Search Today's Posts Unanswered Posts Auto Escrow Insurance Auto Loans
Hot Rod Forum : Hotrodders Bulletin Board > Tech Help> Engine
User Name
Password
lost password?   |   register now

Reply
 
LinkBack Thread Tools
  #1 (permalink)  
Old 12-08-2012, 07:39 PM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: MD.
Posts: 46
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
cam decreeing with the 50 method

I'd like to degree a new camshaft with the opening and closing figures at .050 tappet lift off the base circle of the cam rather than the intake centerline method but i'm having trouble knowing what numbers to look for on my cam card. Can someone tell me what numbers on this card I should be looking at when I come off the base circle to .050?

I can't type this exactly how the card shows the numbers because the site left margins everything but hopefully someone will understand.




intake exhaust

Duration at .050 216 228

Lobe Lift .3533 .3350

Separation 109. OP - CL OP - CL

Timing Events .050 1 35 45 3

Duration at .006 270 283

Gross valve lift .530 .503

Degree intake lobe to 107
Reply With Quote
  #2 (permalink)  
Old 12-09-2012, 04:28 AM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 58
Posts: 4,203
Wiki Edits: 1616

Thanks: 86
Thanked 391 Times in 357 Posts
The 0.050" duration specs are probably IO BTDC/IC ABDC EO BBDC/EC ATDC, but to be sure post a link to the cam specs.

Last edited by cobalt327; 12-09-2012 at 04:33 AM.
Reply With Quote
  #3 (permalink)  
Old 12-09-2012, 07:57 AM
Old & Furious
 
Join Date: Oct 2012
Location: MD
Age: 40
Posts: 1,073
Wiki Edits: 0

Thanks: 6
Thanked 86 Times in 83 Posts
In this case i would use a degree wheel and dail indicator and make a map with a peice of graph paper. Its a pita but will tell you what the lobe actacully looks like not all cams and cam cards actually measure up. Best to map it out then you will know all the numbers you are looking for. Use the graph lines Running up and down as degrees and the ones running left to right as measure of lift at the degree. Then you can map the cam and make any calculations or data points you needs.

Last edited by hcompton; 12-09-2012 at 08:01 AM. Reason: Corrected grid lines.
Reply With Quote
  #4 (permalink)  
Old 12-09-2012, 12:28 PM
Registered User
 
Last photo:
Join Date: Jun 2009
Location: Camaro land
Posts: 349
Wiki Edits: 0

Thanks: 1
Thanked 1 Time in 1 Post
use your duration numbers @ .050, plug them into this calculator Wallace Racing - Cam Degree Calculator, then you will have your open/close figures that you need to look for when degree in your cam @ 50
Reply With Quote
  #5 (permalink)  
Old 12-09-2012, 03:25 PM
Registered User
 
Last photo:
Join Date: Jan 2011
Location: MD.
Posts: 46
Wiki Edits: 0

Thanks: 1
Thanked 0 Times in 0 Posts
Thanks guys I think I've got the idea now, the Wallace Calculator helped me to see the numbers I needed to looked for at .050 off the base circle. I'm going to give it a shot in the morning. I've always just done the dot to dot but I'm getting more particular in my old age. If I can't get it to match the numbers on the card {now that I know which ones to look for} I'll be back with more questions, thanks again.
Reply With Quote
  #6 (permalink)  
Old 12-12-2012, 07:05 PM
Infomaniac's Avatar
Twin Turbo Drag Boat
 

Last journal entry: Random In Progress Shots
Join Date: Nov 2002
Location: Locust Grove, OK
Age: 50
Posts: 372
Wiki Edits: 0

Thanks: 0
Thanked 0 Times in 0 Posts
Timing Events .050 1 35 45 3

Those @ .050 events are in order intake open intake close exhaust open exhaust close.

Those are the numbers you should read on the degree wheel. You have to measure a lifter with a dial indicator. When the intake lifter raises .050 the degree whell should read 1 and .050 before it lowers completely it should read 35. Etc.

I always use valve events to degree inn a cam. If the intake opens at 3 it's retarded 2 degrees
Reply With Quote
  #7 (permalink)  
Old 12-12-2012, 07:31 PM
cobalt327's Avatar
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 58
Posts: 4,203
Wiki Edits: 1616

Thanks: 86
Thanked 391 Times in 357 Posts
Transposed numbers

Quote:
Originally Posted by cobalt327 View Post
The 0.050" duration specs are probably IO BTDC/IC ABDC EO BBDC/EC ATDC, but to be sure post a link to the cam specs.
Exhaust should read: EO ATDC/EC BBDC.
Reply With Quote

Recent Engine posts with photos


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
which timing method is right sooper Engine 12 05-11-2010 06:28 PM
Another Flat Black method? Cracker Red Body - Exterior 8 09-08-2004 12:19 AM
best engine break in method NovaSS350 Engine 13 07-05-2004 05:19 PM
Best method of bleeding MC under floor Sweet-34 Suspension - Brakes - Steering 4 05-31-2004 10:08 PM
best cleaning method for heads? stfinney Engine 9 11-11-2002 11:19 AM


All times are GMT -6. The time now is 07:37 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2013, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0 PL2
Copyright Hotrodders.com 1999 - 2012. All Rights Reserved.