Degreeing Cam
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
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^Your a little further than I am right now. good luck. So I'm a little confused on finding TDC. I understand the concept and also have already tryied doing it on the motor with the heads off but I'm afraid I'm on the exhaust stroke. How do you find the TDC on the compression stroke. How can you verify that with your heads off? I've found some post saying you can find the compression stroke with the heads on. but nothing so much with the heads off. TDC is my first step. thanks
Hi guys, I'm in the middle of degreeing my cam as well and I'm a little lost, I can't seem to move forward with it.
I took my car to the dyno and it peaked way too early (228/228 114 LSA) - I don't recall the exact number, but my tuner told me to degree my cam, as it wasn't properly degreed.
Anyways, I understand finding TDC, aligning the degree wheel, but I don't get the next couple of steps:
1. I watched the Comp Cams video on Youtube and it told me to do it on the valve spring retainer with the lightened springs, and to multiply the measured lift by the rocker ratio (1.7) - so I get .085 - that's the number I shoot for, correct? So I turn the crank clockwise until the valve tops out, zero out my dial indicator, rotate it until the dial indicator starts moving (the valve starts going down) and until it hits .085 - and measure at the degree wheel, correct? Then I keep moving forward, and the lifter goes "over" the lobe, sets back, and hits .085 again - and measure again, add that to the other number + 180 and then that will give me the duration, correct? But when I do that, it tells me to advance the cam (reduce the RPM range - lower my peak, when I'm already peaking low) - but that was the whole problem in the first place - am I doing something wrong?
Also, when I do it the intake centerline method - I can only get low 100's - in the Comp Cams video they get 200+ and divide it by 2. What am I doing wrong?
I took my car to the dyno and it peaked way too early (228/228 114 LSA) - I don't recall the exact number, but my tuner told me to degree my cam, as it wasn't properly degreed.
Anyways, I understand finding TDC, aligning the degree wheel, but I don't get the next couple of steps:
1. I watched the Comp Cams video on Youtube and it told me to do it on the valve spring retainer with the lightened springs, and to multiply the measured lift by the rocker ratio (1.7) - so I get .085 - that's the number I shoot for, correct? So I turn the crank clockwise until the valve tops out, zero out my dial indicator, rotate it until the dial indicator starts moving (the valve starts going down) and until it hits .085 - and measure at the degree wheel, correct? Then I keep moving forward, and the lifter goes "over" the lobe, sets back, and hits .085 again - and measure again, add that to the other number + 180 and then that will give me the duration, correct? But when I do that, it tells me to advance the cam (reduce the RPM range - lower my peak, when I'm already peaking low) - but that was the whole problem in the first place - am I doing something wrong?
Also, when I do it the intake centerline method - I can only get low 100's - in the Comp Cams video they get 200+ and divide it by 2. What am I doing wrong?
Maybe this will help. to get ICL:
1) rotate crank clockwise to max cam lobe lift. zero your dial indicator
2) rotate crank counter clockwise to .100" from max cam lob lift
3) rotate crank clockwise to .050". Look at the pointer and degree wheel. write down the numbers on your note pad
4)rotate crank clockwise past max cam lobe lift to .050" (on other side of cam lobe). Look at the pointer and degree wheel. write down the numbers on you note pad (number on degree wheel should be less than 180)
5) add both #'s together and divide by 2 = lobe centerline
^Your a little further than I am right now. good luck. So I'm a little confused on finding TDC. I understand the concept and also have already tryied doing it on the motor with the heads off but I'm afraid I'm on the exhaust stroke. How do you find the TDC on the compression stroke. How can you verify that with your heads off? I've found some post saying you can find the compression stroke with the heads on. but nothing so much with the heads off. TDC is my first step. thanks
Thread Starter
TECH Apprentice
Joined: Oct 2007
Posts: 311
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If I'm not a the compression stroke wouldn't I be 180 out. I went a head and line up the dot to dot with the cam gear with it being at six o'clock and the crank being at 12. I'm assuming that is the compression stroke. The measurments I took (assuming I did it right) said my ICL was 113. I took measurments 4 times. out of the 4, three said 113 the other said 112. My LSA is 113. Am I 3 degrees out? and do I need to retard the cam?
If I'm not a the compression stroke wouldn't I be 180 out. I went a head and line up the dot to dot with the cam gear with it being at six o'clock and the crank being at 12. I'm assuming that is the compression stroke. The measurments I took (assuming I did it right) said my ICL was 113. I took measurments 4 times. out of the 4, three said 113 the other said 112. My LSA is 113. Am I 3 degrees out? and do I need to retard the cam?
113 ICL on a 113LSA means that your camshaft has zero ground in advance. If you wanted to advance your camshaft 2* and re-check your ICL you would then have a 111 ICL on a 113 LSA = 113LSA +2 (camshaft advanced 2*)
Thread Starter
TECH Apprentice
Joined: Oct 2007
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I should of clarified on the my cam a little bit, it is supposed to be 110 ICL i came out with 113. If I retard it or set the crank gear key to -2 or -4 (the crank gear key goes by 2's) from 0. Will this get me to my ICL or close to it? Cause thats what I did today. I moved it back to -2 from 0. Do I verify and go through the entire process of degreeing again?
Also I spoke with a freind and he said that comp cams usually have 4* ground in. Should this be considered even though my cam is a 110 ICL with a LSA of 113?
Also I spoke with a freind and he said that comp cams usually have 4* ground in. Should this be considered even though my cam is a 110 ICL with a LSA of 113?
Last edited by oxblood!z28; Apr 14, 2012 at 07:53 PM. Reason: more questions
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Verdad Gallardo if at 0* on the crank gear your cam is at 113 ICL then you have no ground in advance on you cam (if cam is 113LSA). if you want to advance your cam 2 degrees you would remove your crank gear and replace it back on the crank key way at the +2 position. Then re-degree your cam. you should now be at 111 ICL which on a 113LSA would be +2 advanced (113LSA +2). if you ICL is less than your LSA then your cam is advanced by that difference. If your ICL is more than your LSA then your cam is retarded by that difference
so if you have cam with a icl111 and lsa 112 is it safe to advace it +4 bc the cam just pulls way too high. its on a single plane app the specs are 244/244 612/612 112 lsa. i need the power band to come down. it picks up real hard at 7300-7600 tooo many rpms. 346cui on stock heads
help please!!!
thanks dustin
help please!!!
thanks dustin
TECH Fanatic
Joined: Jun 2011
Posts: 1,343
Likes: 8
From: Katy, TX
I probably didn't make my questions clear enough... Without an adjustable timing set you can't change anything if the cam is not the exact specs you ordered/wanted, right? At that point, knowing the exact ICL/ECL would be just a few more specs in your head that you couldn't change, right?
Joined: Nov 2006
Posts: 707
Likes: 1
From: Right across the river from Huntington, WV
I'm getting ready to degree my cam but I'm wanting to do cam only so I'm wanting to degree it with the heads on method. How would I check piston to valve?
Hi guys, I'm in the middle of degreeing my cam as well and I'm a little lost, I can't seem to move forward with it.
I took my car to the dyno and it peaked way too early (228/228 114 LSA) - I don't recall the exact number, but my tuner told me to degree my cam, as it wasn't properly degreed.
Anyways, I understand finding TDC, aligning the degree wheel, but I don't get the next couple of steps:
1. I watched the Comp Cams video on Youtube and it told me to do it on the valve spring retainer with the lightened springs, and to multiply the measured lift by the rocker ratio (1.7) - so I get .085 - that's the number I shoot for, correct? So I turn the crank clockwise until the valve tops out, zero out my dial indicator, rotate it until the dial indicator starts moving (the valve starts going down) and until it hits .085 - and measure at the degree wheel, correct? Then I keep moving forward, and the lifter goes "over" the lobe, sets back, and hits .085 again - and measure again, add that to the other number + 180 and then that will give me the duration, correct? But when I do that, it tells me to advance the cam (reduce the RPM range - lower my peak, when I'm already peaking low) - but that was the whole problem in the first place - am I doing something wrong?
Also, when I do it the intake centerline method - I can only get low 100's - in the Comp Cams video they get 200+ and divide it by 2. What am I doing wrong?
I took my car to the dyno and it peaked way too early (228/228 114 LSA) - I don't recall the exact number, but my tuner told me to degree my cam, as it wasn't properly degreed.
Anyways, I understand finding TDC, aligning the degree wheel, but I don't get the next couple of steps:
1. I watched the Comp Cams video on Youtube and it told me to do it on the valve spring retainer with the lightened springs, and to multiply the measured lift by the rocker ratio (1.7) - so I get .085 - that's the number I shoot for, correct? So I turn the crank clockwise until the valve tops out, zero out my dial indicator, rotate it until the dial indicator starts moving (the valve starts going down) and until it hits .085 - and measure at the degree wheel, correct? Then I keep moving forward, and the lifter goes "over" the lobe, sets back, and hits .085 again - and measure again, add that to the other number + 180 and then that will give me the duration, correct? But when I do that, it tells me to advance the cam (reduce the RPM range - lower my peak, when I'm already peaking low) - but that was the whole problem in the first place - am I doing something wrong?
Also, when I do it the intake centerline method - I can only get low 100's - in the Comp Cams video they get 200+ and divide it by 2. What am I doing wrong?
make sure your dial indicator is mounted solid,even the slightest movement will throw off your measurements.
No it's faster if you're degreeing the cam with the heads on. Everything is pretty much already set up. You just put the cylinder you're checking at TDC on overlap and measure the distance until the valve hits the piston with the dial indicator in increments of a couple degrees until the clearance starts to increase. You should find your minimum PTV somewhere between TDC and 15 before or after TDC depending on which lobe you're checking.
