Cam degree results...I have 3 degrees above spec on the cam card...
Point is its a good option to get the timing back!
02-21-2007, 10:46 AM
#17
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02-21-2007, 10:52 AM
#19
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Thanks a bunch guys.
So how hard is it to pull that crank key off, I have the short block built and dont really want to pull the pistons. What is the best way to do this.
If this will get my timing to just 1 degree over spec that will be worth the trouble. The Mr. Gasket Key is only $10.00 or so and trimming is no problem.
So how hard is it to pull that crank key off, I have the short block built and dont really want to pull the pistons. What is the best way to do this.
If this will get my timing to just 1 degree over spec that will be worth the trouble. The Mr. Gasket Key is only $10.00 or so and trimming is no problem.
The only draw back was the price and the fact that the adjustment bushing has to slightly modified to work with an opti.
02-21-2007, 11:03 AM
#21
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Pick up 2 of them if they're not local in case you mess up while grinding. Pay attention as that key can advance or retard depending on which direction it goes in.. you have to grind the correct side. If you're retarding the cam like I was, just grind based on my picture.
Getting the key out requires a hammer and a narrow punch. Just beat on the backcut side of the key in the crank with the hammer/punch and you'll notice the back of the key start to come out of the slow.. keep at it until it pops out.
Getting the key out requires a hammer and a narrow punch. Just beat on the backcut side of the key in the crank with the hammer/punch and you'll notice the back of the key start to come out of the slow.. keep at it until it pops out.
02-21-2007, 11:10 AM
#22
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Did he degree all 8 cylinders or did he just do one?
Did he degree both intake and exhaust?
Did he compare the reading at .005 and at .050?
Did he check cylinder 1 and 6 and average the variance?
Did he degree the cam on the bench before he installed it?
Crank indexing from one journal to the next can easily be off a degree or 2 on a reground crank shaft depending upon how the grinder indexed each journal...
If I want to get real serious about degreeing a cam I index off the number 1 intake and work from there.
degree it on the bench and see how consistent each lobe is.
Then degree each cylinder. Then see what the variance is from one cylinder to the other. Then take the average and set the cam on that.
It depends on how serious you want to get on degreeing and how important you thing the cam timing should be. Is it worth the level of effort?
I think for your app just run it like it is.
Greg
Did he degree both intake and exhaust?
Did he compare the reading at .005 and at .050?
Did he check cylinder 1 and 6 and average the variance?
Did he degree the cam on the bench before he installed it?
Crank indexing from one journal to the next can easily be off a degree or 2 on a reground crank shaft depending upon how the grinder indexed each journal...
If I want to get real serious about degreeing a cam I index off the number 1 intake and work from there.
degree it on the bench and see how consistent each lobe is.
Then degree each cylinder. Then see what the variance is from one cylinder to the other. Then take the average and set the cam on that.
It depends on how serious you want to get on degreeing and how important you thing the cam timing should be. Is it worth the level of effort?
I think for your app just run it like it is.
Greg
02-21-2007, 11:23 AM
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He did check the #6 intake vs. the #1 intake and they were dead on each other.
.050" and centerline methods were used.
Did not touch the exhaust.
Cam was not checked on the bench prior to install.
Crank was ground and I feel confident it was done right, but who knows.
Regarding if its worth the effort, I am not experienced enough to say. From what I am hearing you guys are about 4 to 1 for getting a tad closer to the spec. I was told that the engine might make a tad more lower end torque at the expense of top end HP but again I am not an expert here.
I understand what specs mean and what they are for, I would consider it worth the trouble to pull that key and install a modified one if it will put me within 1 degree of spec. I really do not want to touch the cam pin.
.050" and centerline methods were used.
Did not touch the exhaust.
Cam was not checked on the bench prior to install.
Crank was ground and I feel confident it was done right, but who knows.
Regarding if its worth the effort, I am not experienced enough to say. From what I am hearing you guys are about 4 to 1 for getting a tad closer to the spec. I was told that the engine might make a tad more lower end torque at the expense of top end HP but again I am not an expert here.
I understand what specs mean and what they are for, I would consider it worth the trouble to pull that key and install a modified one if it will put me within 1 degree of spec. I really do not want to touch the cam pin.
02-21-2007, 01:16 PM
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He checked it two ways:
Checked at .050" it was advanced 3 degree above cam card spec.
Checked at centerline it was advanced 1 degree above cam card spec.
All that being said, It appears that this is a problem?
Possibly your cam is DNO dead nuts on.
You mentioned he used quality dial indicator with the lifter bore tool and dead stopped the piston
I wonder if the lifter bore tool he used was one of those "cam checking" tools. They have a flat bottom that rides the cam lobe and I'm pretty sure you should have a round bottom to match the profile of a roller lifter.
A flat bottom cam checking tool will move up the cam lobe quicker and show advanced readings at the .006 and .050" etc. BUT it will show correct for the intake centerline method.
Maybe? ? ?
Karl
Checked at .050" it was advanced 3 degree above cam card spec.
Checked at centerline it was advanced 1 degree above cam card spec.
All that being said, It appears that this is a problem?
Possibly your cam is DNO dead nuts on.
You mentioned he used quality dial indicator with the lifter bore tool and dead stopped the piston
I wonder if the lifter bore tool he used was one of those "cam checking" tools. They have a flat bottom that rides the cam lobe and I'm pretty sure you should have a round bottom to match the profile of a roller lifter.
A flat bottom cam checking tool will move up the cam lobe quicker and show advanced readings at the .006 and .050" etc. BUT it will show correct for the intake centerline method.
Maybe? ? ?
Karl
02-21-2007, 01:28 PM
#25
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FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam.
I also haven't been happy with the Cloyes stuff either, just too many times they are way dam off. A Hex-A-Just works really well, you just have to modify it to work with the newer Optis. I personally like the ProGear stuff on most builds where I don't use a Hex-A-Just.
Karl is right on the lifter deal, you gotta run the rounded tool....
As you can see most kits come with both now.
Bret
02-21-2007, 01:41 PM
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That is the exact same tool he used, it had the rounded over profile so that aint the problem either.
I agree that the cam could be DNO and something else might be off. At this point I dont know what to blame.
I agree that the cam could be DNO and something else might be off. At this point I dont know what to blame.
02-21-2007, 02:35 PM
#27
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Have him do it this way....
"FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam."
That will fix your issue and give you the real centerline.
Bret
"FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam."
That will fix your issue and give you the real centerline.
Bret
02-21-2007, 02:36 PM
#28
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Have him do it this way....
"FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam."
That will fix your issue and give you the real centerline.
Bret
"FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam."
That will fix your issue and give you the real centerline.
Bret
Thanks bret
02-21-2007, 05:14 PM
#29
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Yep, I use the big dog. I guess CV now has one like 24-36" or something retarded now. I spent enough on the 16" version.
FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam.
I also haven't been happy with the Cloyes stuff either, just too many times they are way dam off. A Hex-A-Just works really well, you just have to modify it to work with the newer Optis. I personally like the ProGear stuff on most builds where I don't use a Hex-A-Just.
Karl is right on the lifter deal, you gotta run the rounded tool....
As you can see most kits come with both now.
Bret
FWIW I degree the cam and find the centerline by going +/- .005-.010" from peak lift. Any other way and you just play around with the ramps and BS of maybe a asymetrical lobe. Most times the lobe is placed by it's centerline by the peak lift of the cam.
I also haven't been happy with the Cloyes stuff either, just too many times they are way dam off. A Hex-A-Just works really well, you just have to modify it to work with the newer Optis. I personally like the ProGear stuff on most builds where I don't use a Hex-A-Just.
Karl is right on the lifter deal, you gotta run the rounded tool....
As you can see most kits come with both now.
Bret
Time to invest in a bigger one! Well, at least they a pill for that now.
Rich
02-21-2007, 05:31 PM
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We did this again with the below method and taking the reading at .010" just like Bret said:
After mounting the wheel to TDC, 0 your indicator at maximum lobe lift. Reverse the rotation until the lifter has dropped about .050 before maximum lift. Slowly rotate the engine until the indicator is .020 before max lift and record the reading on the degree wheel. Continue past maximum lift until you are back at the .020-point on the other side of the lobe. If your degree wheel is marked properly you can add the 2 figures together and divide by 2. This will give you the intake centerline.
The first reading was 134
The second reading was 89
The final number was 107.5 degrees
The cam centerline is 108 degrees so I am not sure if it is +.5 or -.5 degrees.
This is what we got last night too and the .050" method has not changed a bit in terms of readings.
The way I am seeing it, one method says to run that sucker and the other method says to drop back and punt and put in the crank 2 degree offset . Thoughts?
After mounting the wheel to TDC, 0 your indicator at maximum lobe lift. Reverse the rotation until the lifter has dropped about .050 before maximum lift. Slowly rotate the engine until the indicator is .020 before max lift and record the reading on the degree wheel. Continue past maximum lift until you are back at the .020-point on the other side of the lobe. If your degree wheel is marked properly you can add the 2 figures together and divide by 2. This will give you the intake centerline.
The first reading was 134
The second reading was 89
The final number was 107.5 degrees
The cam centerline is 108 degrees so I am not sure if it is +.5 or -.5 degrees.
This is what we got last night too and the .050" method has not changed a bit in terms of readings.
The way I am seeing it, one method says to run that sucker and the other method says to drop back and punt and put in the crank 2 degree offset . Thoughts?
Last edited by wrd1972; 02-21-2007 at 06:39 PM.