NEED HELP DEGREEING CAMSHAFT

New engine build has hit a wall as I am having trouble degreeing my camshaft. I would appreciate any advice. First some background. The camshaft is supposed to be a H264/274 112 lobe center from CI although there was nothing on/in the box to indicate that it is. Does anyone know if there should be a particular part number on the cam to identify it? I have installed the cam staight up with an adjustable double roller timing set also from CI. I installed the crank sprocket on the 0 degree slot and positioned the cam sprocket dot to be as lined up as possible with the crank key. I followed both cam degreeing procedures. For the centerline method, I got between 108 and 109 degrees. For the duration at 0.05" lift I got the following:

Intake opens: 5 degrees BTDC (0.05")
Intake closes: 137 degree BTDC (223 ATDC, 43 ABDC) also at 0.05"
Max Lift: 0.469"

If I add 223 and 5 that gives me a duration of 228 degrees at 0.05" lift. I am using higher ratio roller tipped rockers (bought from private party on this forum no documentation) that I have read can increase duration by about 3 degrees and lift by about 0.030" although my max lift is only 0.019" more than the advertised lift of 0.450". If that is the case I am wondering if I have a 274/274 cam since the duration at 0.05" for that cam is 224 degrees (add 3 degrees for the roller rockers and I'm at 227) instead of 214. Also if I index the cam sprocket one tooth either way, I don't get any closer to a 112 lobe center (more like 127) so I am now thinking that the cam might be a H274/274 108 LC. I did lightly oil (oil not assembly lube) the cam lobe and solid lift from the cam degree kit but I wouldn't think that would add 10 degrees of duration. I am also using an adjustable pushrod and low tension checker valve spring from JEGS. I've spent all weekend and probably a dozen attempts but none of the numbers are making any sense unless I have the wrong cam. I haven't checked the exhaust yet because I'll need to pull the head and switch the lifter over since I the kit only had one. Any help/advice would be greatly appreciated.

I found that when I degreed mine it appears that the initial lift was measured from .010.

Was it a clay smith cam? If I understand you correctly, if I measure at 0.01" instead of 0.05" I should get 264 degrees indicating that it is atleast a 264 on the intake not a 274? Also, if I degree it properly with no advance (straight up) then the opening and closing measurements at 0.01" lift should match the cam card (intake opens 20 degrees before TDC and closes 64 degrees after BDC, 20+180+64=264)? Once I advance it 4 degrees, the intake should then open at 24 degrees and close at 60 degrees right? I'm still concerned about the effect of the higher ratio roller rockers as far as getting the right numbers. The adjustable pushrod I have also has a ball end so I guess I could install the original non-adjustable standard ratio rocker arms long enough to get the cam degreed.

Most cams are intended to be measured at lifter rise rather than at the valve. Even trying to do this at the pushrod end of the rocker will be problematic.
Joe

oz,

Go to this site:
http://www.pirate4x4.com/tech/billavist ... %20cam.pdf

This should help you. The head should not be on to initially degree the cam.

Forget the center line stuff. It's too confusing with no good way to check your work or theirs. Use the events.

Also forget about your additional rocker ratio to degree your cam in. It will simply give you a little more cam. Don't go changing things around to make something work.

Lazy is right, go off the push rod like the link shows. Work with it a little bit. If you have any questions, come back and we'll figure things out.

There should have been a stamping on the end of the cam, IIRC the back end, with something along the lines of 264HDP12. Mine did, anyhow.

I couldn't find my cupped pushrods, so I ground the top flat on an old ball ended one.
I also put some masking tape on the hole in the head where the pushrod exits to help stabilize it.

Thanks for all your help. I will remove the rocker arms and try to degree it at the pushrod. If it still seems like the duration is 274 instead of 264, I will pull the cam and check for markings.

Ok, I tried degreeing the cam once again, this time taking my measurements at the end of the pushrod rather than at the valve retainer. The durations at 0.050" lift for the intake and exhaust appear to be right for an H264/274 cam but since the cam cards from CI specify when the valves should open and close but don't specify at what lift this should ocurr it is proving difficult to verify. My measurements seem to indicate that it is somewhere between 0.008" and 0.010" of lift (see second set of measurements below). Also, I am trying to verify my lobe center. My car is an automatic and I want to make sure the LC is 112.

These first set of measurements are for the intake with the cam set at 0 degrees advanced:

Lift Angle
Opening
0.010" 19 BTDC
0.050" 2 ATDC
Closing
0.050" 34 ABDC
0.010" 60 ABDC

For my cam, the intake should open at 20 BTDC and close at 64 ABDC so something is a little off. The duration at 0.010" indicate a total duration of 259 (19+180+60) instead of 264 (20+180+64). The duration at 0.050" lift should be 214 but mine is 212 (180-2+34). I also used the centerline method and came up with a LC of 108 not 112. Next I adjusted the timing set so that the tooth on the 4 degree advanced keyway slot on the crank sprocket was lined up with the dot on the cam sprocket, reinstalled it and the degree wheel and found TDC again using a piston stop in the #1 spark plug hole. I went through the process agian this time for both the intake and exhaust, taking measurements every 0.002" up to 0.010" lift.

Intake
Lift Angle
Opening
0.002" 46 BTDC
0.004" 35 BTDC
0.006" 29 BTDC
0.008" 26 BTDC
0.010" 23.5 BTDC (with 4 degrees advance IV should be opening at 24 degrees so this looks right)
0.050" 2 BTDC
Closing
0.050" 30 ABDC (This again gives a duration at 0.050" of 212 (2+180+30) not 214)
0.010" 56 ABDC (with 4 degrees advance IV should be closing at 60 degrees not 56)
0.008" 60 ABDC
0.006" 67.5 ABDC
0.004" 78 ABDC
0.002" 91 ABDC

Using the centerline method here, I get a LC of 104 (I want 108 with 4 degrees of advance on a 112 cam).

Exhaust
Lift Angle
Opeing
0.002" 98.5 ATDC
0.004" 104 ATDC
0.006" 108 ATDC
0.008" 111 ATDC
0.010" 113 ATDC(with 4 degrees advance, EV should open at 73 degrees BBDC not 67 (180-113)). Cam card says should open at 69 with no advance.
0.050" 134 ATDC
Closing
0.050" 3.5 BTDC(This gives a duration at 0.050" of 222.5 (360-134-3.5) not 224 for an H264/274 cam)
0.010" 24.5 ATDC(with 4 degrees advance, EV should close at 21 degrees not 24.5). Cam card says should close at 25 with no advance.
0.008" 29 ATDC
0.006" 33 ATDC
0.004" 36 ATDC
0.002" 44.5 ATDC

Without knowing the lift that the valvle events should be ocurring at, I am unable to convince myself that I have the correct cam and that it is properly advanced 4 degrees. The intake numbers look close but the exhaust numbers are confusing me as they seem to be closer to the numbers for a cam with no advance. Also, I am not sure how to verify that this cam has a 112 LC. This is important to me as I have an automatic and do not want a rough idle and need vacuum for both the automatic and power brakes.

I also measured total lift on the inake at 0.290" (this would give a lift with stock 1.52 rockers of 0.441 not 0.450). The lift on the exhaust was 0.294" which would be pretty close. After getting back to the base circle I was about a half a thousandth (0.0005") off 0 so I know there is at least some small error in my numbers. Would appreciate any help from someone who has done this before.

Thanks,

Jason

The numbers to verify are the ones stamped on the cam, printed on the card, and what you get off the degree wheel.
First the easiest thing to check is total CAM LIFT.
Then go to the Timing events @ .050 tappet lift.

FORGET trying to degree a cam @ .010, and .008 and.... Go with the numbers @ .050 and FORGET About your rocker arm ratio .
Degreeing the cam is phasing it to the crank.

The rocker ratio of course dictates the total lift. it has NOTHING to do with phasing the cam to the crank. and neither do the valves.

I would do what you suggest, however, no information came with the cam and the info on the CI website only gives the duration at 0.05" lift and the valve events but not at 0.05" lift. The duration at 0.05" lift that I have measured is 212 intake 222 exhaust. They should be 214 and 224. The valve events given by Mike at CI are for the full duration (264 and 274) not the duration at 0.05" so I have no way of knowing what they should be.

ozconv":1j5rjk57 said:

..... The duration at 0.05" lift that I have measured is 212 intake 222 exhaust. They should be 214 and 224....

Click to expand...

Measuring from the end of the pushrod as you are doing will induce a slight error due to the fact that won't travel perfectly straight, sounds like you are pretty close; just find the .050" lift point on both opening and closing, halfway between is the Centerline. Go with that.
Joe

JW, measuring the @.050" lifts will only give you the centerline of the lobe, if it is a symetrical lobe design. You need to measure and the graph the lobe closer to the nose to be as accurate as you can, like .050 either side of max lift, not off the heel of the cam. That would be like trying to find TDC with the piston at the bottom of the cylinder, instead of at the point of peak travel. You are just inducing too much potential for error that far away from where you need to be checking it. It seems from the readings he is getting on his exhaust lobe C/L, that it might be a non symetrical profile, thats is why he is getting a little skewed centerline # besides what he should be getting.

Ozconv, can you give us the short version how you are finding TDC, and determining how you are measuring and finding the C/L of both the intake and exhaust.

CNC-Dude":8lmbc71f said:

JW, measuring the @.050" lifts will only give you the centerline of the lobe, if it is a symetrical lobe design....

Click to expand...

Agreed.
But his stated purpose was to find the centerline. (I was assuming symmetrical lobes )
Joe

If wsa111 (BILL) was still able to post on the forum, the problem would be solved. The guy helped me and numerous amounts of people on this forum with problems like this. He was a big help to Mike from classic inline also... I wish the guy was still around... Anyone give this poor guy any info to email wsa111 (Bill) directly...to help him with degreeing the cam...


Wcol

To find TDC I am using a piston stop in #1. I go to 15 degrees before TDC rotating CW, screw in the stop till it hits the piston and then rotate ccw until I hit the stop again. If it isn't 15 degrees, say 10 degrees, I move the degree wheel until it reads 12.5 degrees and then rotate cw to make sure that it reads 12.5 degrees either direction. The big problem seems to be that there just isn't enough information on the clay smith cams on Mike's website. I have verified the duration at 0.05" lift (within 2 degrees) but can't verify if the valves are opening and closing at the right times because the lift for those events (or better yet the degree values that the valves open and close at 0.05" lift) aren't specified by Mike. The degrees for opening and closing that are given seem to be between 0.008" to 0.010" lift. For lobe center I have taken measurements 0.05" either side of max lift for the intake lobe. This is what is confusing because if it is a 112 LC then I am thinking that I should get 112 with the timing chain set at 0 advance but I get 108 indicating that it is already 4 degrees advanced if it is a 112 LC. The valve events, however don't agree but are close (at least for the intake) if I do advance the timing set 4 degrees. When I do this and then use the centerline method, I get 104, not 108. Therefore using the centerline method, I wouldn't advance the cam because it appears that I am already there but when trying to match the valve opening and closing events, it seems that I should. To me it seems that the cam cards on the web site don't give nough information to properly degree the cam. I have searched for previous threads on the topic and it appears that I am not the first person to have this issue. In these previous posts Mike indicated that he had aquired the additional information from Clay Smith and posted it on the CI site but I have been unable to find it if it is there.

Oz,

I tried to figure your problem out. I think there's some error being introduced. To me it looks like if you check the cams at .009, you should get the correct duration. As long as the duration checks out, and you use the same check height for the intake and exhaust, that's what the checking height is, just adjust it accordingly. A few degrees can really throw things off. Are you turning the crankshaft in the same direction that the engine runs without backing up at all. I think the timing chain play is causing your error. Maybe you can preload it somehow or be careful that the cams not running forward or backward on you when you take your measurements. Also, is your cam used? What about the lifter? That can also throw the measurements off. Don't assume that 0 degrees on your timing chain is 0 degrees and 4 degrees is 4 degrees. Just use it as a guide to get the cam positioned right. Manufacturing tolerances throw things off. Good luck. Try everyone's tips and let us know.

ozconv":2pyisn9n said:

To find TDC I am using a piston stop in #1. I go to 15 degrees before TDC rotating CW, screw in the stop till it hits the piston and then rotate ccw until I hit the stop again. If it isn't 15 degrees, say 10 degrees, I move the degree wheel until it reads 12.5 degrees and then rotate cw to make sure that it reads 12.5 degrees either direction. The big problem seems to be that there just isn't enough information on the clay smith cams on Mike's website. I have verified the duration at 0.05" lift (within 2 degrees) but can't verify if the valves are opening and closing at the right times because the lift for those events (or better yet the degree values that the valves open and close at 0.05" lift) aren't specified by Mike. The degrees for opening and closing that are given seem to be between 0.008" to 0.010" lift. For lobe center I have taken measurements 0.05" either side of max lift for the intake lobe. This is what is confusing because if it is a 112 LC then I am thinking that I should get 112 with the timing chain set at 0 advance but I get 108 indicating that it is already 4 degrees advanced if it is a 112 LC. The valve events, however don't agree but are close (at least for the intake) if I do advance the timing set 4 degrees. When I do this and then use the centerline method, I get 104, not 108. Therefore using the centerline method, I wouldn't advance the cam because it appears that I am already there but when trying to match the valve opening and closing events, it seems that I should. To me it seems that the cam cards on the web site don't give nough information to properly degree the cam. I have searched for previous threads on the topic and it appears that I am not the first person to have this issue. In these previous posts Mike indicated that he had aquired the additional information from Clay Smith and posted it on the CI site but I have been unable to find it if it is there.

Click to expand...

Ok, looking at your methods, you are right on with your installation procedures. What are you getting for the LSA. You might be confusing the C/L and LSA, they are not the same. And on the cam spec sheet on the Classic Inlines page, most cam companies use the 108 or 110, etc. in the cam specs to represent the LSA, not the intake or exhaust C/L. No matter how much you advance or retard the cam, the LSA will never change, this is the difference in degrees between the intake C/L and the exhaust C/L. Since that cam is available in a 108, 110 and 112 LSA, that would be a quick way to verify which cam you actually have in case it was shipped or packaged incorrectly. Once you can verify this, that might explain a lot in case it is the wrong cam.

It was slow at work today so I went to the CI website and copied down the valve events for the H264/274 108, 110, and 112 cams. I then figured out to arrive at 108,110,or 112 by using the angle values for that cam. For the 112 cam The half way point between the intake opeing (20BTDC) and closing (64 ABDC) is (264/2)-64ABDC(intake closes)=68degrees BBDC. For the exhaust it is(274/2)-69 BBDC (exhaust opens)=68 degrees ABDC. You then add the 2 together, subtract from 360 and divide by 2, or (360-(68+68))/2=112. This same approach worked for the 108=(360-(72+72))/2 and 110=(360-(70+70))/2 values so it should work with my measurements at 0.05" lift.

When I used my measured values at 0.05" lift, I got (214/2)-30ABDC=77 BBDC for the intake and (224/2)-46 BBDC=66 ABDC. (360-(66+77))/2=108.5 so I now suspect that Mike sent me the wrong cam (H264/274 108 instead of an H264/274 112). The calculations I made for the 108 cam with 0 advance using the website numbers came out to 72 and 72. If you adjust my measurements for the 4 degrees of advance, 77 becomes 73 and 66 becomes 70 which is pretty close to the 72 and 72 values so I suspect that I may have advanced the wrong cam about 5 degrees. I am going to triple check everything and retake my measurements one more time but I suspect that I am going to have to pull the cam and send it back. If I have to pull it I will check to see if it is marked.

You have run so many numbers by us its a cluster to even try to figure out.
With a 112 L/C cam advanced 3-4 degrees.
264 intake @.050 will be close to 36 abdc & open 2 atdc.
274 exhaust @ .050 will open 48 bbdc & close at 4 btdc.
These numbers if close would be a 112 L/C camshaft advanced 3-4 degrees.
Another approach is get the intake lobe center & the exhaust lobe center & it should be 112 degrees between them regardless if the camshaft is advanced or retarded. Good luck. Falcon Man