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Re: Degreeing a cam for the first time. What a PITA.
[Re: Dodgem]
#1473620
08/15/13 02:17 PM
08/15/13 02:17 PM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
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Striving for excellence
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Posts: 18,493
Granite Bay CA
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Quote:
yea but when your finding TDC your findng where the piston is not finding where the cam is! After is when you want to go Clockwise direction only!
I'm going from memory here since the directions are out in the shop, but I'm sure they wrote that I am to turn the engine CW to maximum cam lobe lift then set the dial indicator to zero. Turn engine CCW to .100 then CW to .050 and record the number on the degree wheel. Continue rotating the engine CW until I reach .050 on the closing ramp and record that number. Add the 2 numbers and divide by 2.
If that is correct, that first switch to CCW would give me an inaccurate .100 point, right?
Maybe I am worried over nothing.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473622
08/15/13 11:09 PM
08/15/13 11:09 PM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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Quote:
I am to turn the engine CW to maximum cam lobe lift then set the dial indicator to zero. Turn engine CCW to .100 then CW to .050 and record the number on the degree wheel. Continue rotating the engine CW until I reach .050 on the closing ramp and record that number. Add the 2 numbers and divide by 2.
If that is correct,
Correct Yes, that number will be the intake lobe centerline (the # of crank degrees the centerline is away from piston TDC such as 102 or 105 degrees which is the final # you're after when degreeing a cam. The only other thing you need is to first before that is to find exact piston TDC with the piston stop (CW & CCW) then set the degree wheel to TDC (zero) at that piston position then the above lobe centerline. (1) piston at its' exact TDC (2) set degree wheel at that piston position to TDC zero (3) find peak intake lobe height (centerline) location on the degree wheel. That # (before + after divided by 2) is your final answer. A centerline at 102 degrees away from TDC is more advanced (closer to TDC) than a centerline that is 105 degrees away from TDC. EDIT wouldn't hurt to in addition check that the dampener slit is at zero (TDC) on the timing tab when the piston is at EXACT TDC at the top of the cyl. Make a new mark with white paint across the dampener if need be. You need that to be accurate so when you time it so that 36 degrees on the light is actually 36 degrees of advance. but some timing lights ain't accurate, another story...
Last edited by RapidRobert; 08/16/13 09:48 AM.
live every 24 hour block of time like it's your last day on earth
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Re: Degreeing a cam for the first time. What a PITA.
[Re: BSB67]
#1473623
08/15/13 11:09 PM
08/15/13 11:09 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
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master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
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Quote:
CW and CCW to find TDC. CW only for degreeing the cam.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Cab_Burge]
#1473626
08/16/13 01:07 AM
08/16/13 01:07 AM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
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Posts: 18,493
Granite Bay CA
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Quote:
I always check every cam at .200 before max lift, .100 BML and at .050 BML and after on all three
Do you do this like the .050 method? ( Take the .200 numbers, add them, then divide by 2)
Is this a more accurate method than measuring at .050?
I have found that once all the tools are out and the setup is done, the actual degreeing of the cam doesn't take that long.
I will clearly admit here and now that I am converted. Since I have all the stuff, I will degree the cam in future engine builds.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473627
08/16/13 09:44 AM
08/16/13 09:44 AM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
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master
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Ontario, Canada
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I often like to use .200 add numbers divide by 2 .100 same and .050 most times all the same. Then there is the actual .050 opening method where you turn till it is at 0 lift then turn till lifter lift is .050 off seat and check the number. So a 261 @ .050 cam you divide by 2 so 131.5 then subtract the 106 installed centerline gives you 25.5 so you should have .050 lift at 25.5 before TDC. That would be installed at a true 106 centerline. so if it comes in at 21.5 that would be 4 degree retarded from suggested install or 110 intake centerline if it comes in at 27.5 that would be two degrees advanced from the suggested install of 106 or in at 104. You can also check the total duration @ .050 by checking the .050 before closing which at 106 install should be 180 - 106 = 74 then 131.5 - 74 = 57.5 After bottom dead center. again 4 retarded from 106 (110) would be 61.5 and 2 advanced from 106 would be 55.5 I like to use this and max lift (.050/.100/.200 methods) right at the top of your pad paper .200 .100 .50 and record the numbers at each stop .200 .100 .50 .50 .100 .200 ad and divide by 2. 
Last edited by Dodgem; 08/16/13 09:46 AM.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Dodgem]
#1473628
08/16/13 09:52 AM
08/16/13 09:52 AM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
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master
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Ontario, Canada
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PS if you want to try the .050 opening method it is best done on lifter (or in pushrod cup) but if you do want to check at valve retainer you must use rocker ratio so if you have 1.5 rockers it's .075 at the spring retainer solid lifter 0 lash. Max lift does not mater as that is all about average from arbitrary points. 
Last edited by Dodgem; 08/16/13 09:53 AM.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473630
08/16/13 02:10 PM
08/16/13 02:10 PM
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Joined: Aug 2003
Posts: 43,263
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,263
Bend,OR USA
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Quote:
Quote:
I always check every cam at .200 before max lift, .100 BML and at .050 BML and after on all three
Do you do this like the .050 method? ( Take the .200 numbers, add them, then divide by 2)
Is this a more accurate method than measuring at .050?
I have found that once all the tools are out and the setup is done, the actual degreeing of the cam doesn't take that long.
I will clearly admit here and now that I am converted. Since I have all the stuff, I will degree the cam in future engine builds.
The main reason I check them at all three locations is to make sure what the lobe grind is like, I've seen a cam have 105 at .200, 106 at .100 and 107 at .050    I'll usually check the cam timing on the lobes first, both of them ,and then when I get ready to check piston to valve clearances I will check at the retainers due to finding so many rocker arm sets not haveing the correct ratio on all of them  I go ahead with the light checking springs and verify what the valves are seeing as far as cam lobe centers and intake lobe position  As far as the math I make my sheet up with .200 first,.100 and then .050, find max lift and back the cam up to .300 or a little less befome max lift and then move the crank to get .200 BML, write it down, then do .100 and then .050, go to .050 after max lift and write it down under the .050 BML and do the math, same thing on the other two
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Cab_Burge]
#1473631
08/16/13 10:48 PM
08/16/13 10:48 PM
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Joined: Feb 2005
Posts: 4,318
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,318
Prospect, PA
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Quote:
....I've seen a cam have 105 at .200, 106 at .100 and 107 at .050
That is because it is an asymmetrical lobe.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Cab_Burge]
#1473633
08/17/13 09:46 AM
08/17/13 09:46 AM
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Joined: Feb 2005
Posts: 4,318
Prospect, PA
BSB67
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Prospect, PA
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Something not right there.
More often than not, posters seem to get lost on why you degree a cam. First, it is to make sure that the stack up of tolerances of all the parts is about right and something is not screwed-up. It almost seems like the advent of the multi-keyway timing set was an excuse to make junk quality. Second, to put the ICL where YOU want it, and to have a baseline for future cam timing adjustments.
The cam manufacturer has simply given a recommended ICL. Measure it how you like, but be consistent, as the ICL will change on most modern lobes based on the method you use. Then install it where you want.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473634
08/17/13 12:52 PM
08/17/13 12:52 PM
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Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
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Ontario, Canada
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Quote:
How the heck do you know all of this stuff?
Very impressive!
You learn this stuff as you go along trial and error lots of error and it's what you want or need to learn as you go.
I had to learn the .050 off the seat the first time i did a milodon gear drive on a hemi there are no marks on the BB milodon gear drive You 0 your degree wheel turn crank to say 24 BTDC my current roller then you turn the cam by hand to .050 lifter lift and then the top gear that has 7 non concentric bolt holes is put together where it will line up and done. well then you run through all your checks other checks max lift -.050, -.100 and so on but usually it's bang on. (i now have two milodon gear drives myself)
My first time degreeing a 533/320 mopar cam had watched the mopar cam degree video talked with people and decided to retard my cam as i wanted more top end (pull better in third out the end) well it was in at 106.75 i drilled a hole in the top gear and using an offset bushing and put it in at 109.5. off to the track and wow more than three tents slower. So I go back and put 0 offset bushing in but since hole and bushings are not 100% it went back in at 106.25. well then it was always .05 to .075 faster than it had been before for certain weather after a few years i had a good feel plus in the fall my PB went to .075 faster than before.
so what i learned was when the talk retarding a cam for more top end power they mean in the 7000 to 10000 rpm range it works good not out the top end of the 1/4. and advancing a cam kicks ass 0 to 7000 rpm.
My next time was installing an ultradyne 263/271 108 talking with him he explained why i would want more cam advance 102 if we could get it as opposed to the 106 on the cam card. well the valves got as tight as we felt comfortable at 104 so we left it there. later with head changes and things i thought oh I have more room so went to 102 and gained a tenth.
But as with anything there is a ton of things in the mix as to where you degree your chosen cam. 1st the cam itself then compression, cubic inches, torque converter stall (or stick) final gears car weight
use and a lot of little things a couple cam degrees can make quite a difference.
Guys like cab have a ton more experience.
The internet is a great source for info lots of good stuff. Then opinions some good and some bad. 
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Re: Degreeing a cam for the first time. What a PITA.
[Re: BSB67]
#1473635
08/17/13 03:38 PM
08/17/13 03:38 PM
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Joined: Feb 2010
Posts: 18,493
Granite Bay CA
Kern Dog
OP
Striving for excellence
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OP
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Posts: 18,493
Granite Bay CA
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Quote:
Something not right there. I agree. The 7 degree spread between settings shows me either the slop in the degree wheel is a factor or the machining of the timing set is waaaay off.
More often than not, posters seem to get lost on why you degree a cam. I have a history to getting impatient and bypassing the details, but this time I am sticking with it.
The cam manufacturer has simply given a recommended ICL. Measure it how you like, but be consistent, as the ICL will change on most modern lobes based on the method you use. Then install it where you want.
Install it where I like it. There is the "problem". I don't have enough experience to know where I'll like it. Maybe you mean to race it at different settings and pick the one that results in the best ETs? My goals are to eliminate the detonation and at the same time, make more power. My cam card called for an installed C/L of 106. I would have left it if it came in at 108.
What are the opinions of timing chain stretch? Would it be better to err to the ADV side? If it calls for 106 and the 4* ADV keyway gets me at 104-105, is that better than starting off at 107-108? Just a newbie perspective, but as the chain stretches, the cam timing comes in later. Is this a factor than you consider when degreeing the cam?
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473636
08/17/13 04:09 PM
08/17/13 04:09 PM
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Joined: Feb 2005
Posts: 4,318
Prospect, PA
BSB67
master
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master
Joined: Feb 2005
Posts: 4,318
Prospect, PA
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Quote:
Quote:
Something not right there. I agree. The 7 degree spread between settings shows me either the slop in the degree wheel is a factor or the machining of the timing set is waaaay off.
More often than not, posters seem to get lost on why you degree a cam. I have a history to getting impatient and bypassing the details, but this time I am sticking with it.
The cam manufacturer has simply given a recommended ICL. Measure it how you like, but be consistent, as the ICL will change on most modern lobes based on the method you use. Then install it where you want.
Install it where I like it. There is the "problem". I don't have enough experience to know where I'll like it. Maybe you mean to race it at different settings and pick the one that results in the best ETs? My goals are to eliminate the detonation and at the same time, make more power. My cam card called for an installed C/L of 106. I would have left it if it came in at 108.
What are the opinions of timing chain stretch? Would it be better to err to the ADV side? If it calls for 106 and the 4* ADV keyway gets me at 104-105, is that better than starting off at 107-108? Just a newbie perspective, but as the chain stretches, the cam timing comes in later. Is this a factor than you consider when degreeing the cam?
Like your're doing, ask a couple people, people that you trust..... 
Starting with 2 to 4 degrees advanced is a reasonable starting point. If it still pings, you can back it up 4 degrees. If it does not ping, but the bottom end is too soft for your liking, add additional advance.
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Re: Degreeing a cam for the first time. What a PITA.
[Re: Kern Dog]
#1473637
08/17/13 04:10 PM
08/17/13 04:10 PM
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Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,041
Lincoln Nebraska
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installing it more retarded (IE 108 rather than 106) will reduce cyl psi & decrease detonation then you'd want to optimize the ign curve (I'm assuming more octane ain't an option) & as you know more octane would let you run a faster ign curve & adv or ret it to get the power band closer to where you want it. People have suggested setting it to where you get the most cranking compression. You might set it where the mfr want's it then adjusting the ign curve & see where you're at. #1 you mentioned detonation & it MUST be eliminated ASAP!
live every 24 hour block of time like it's your last day on earth
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) where I want it I then always check the exhaust lobe in the same three places, if the cam is ground on a 108 lobe center and you install the intake lobe 3 degrees advanced at 105 ATDC then the exhaust lobe max lift should be in at 111 BTDC 