Degreeing Cam by Measuring Overlap @ Lifters

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seabee

seabee

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Hi folks, I am degreeing a cam for the first time and after devouring a ton of videos and articles I am confused about the method where you check the overlap at lifters to TDC.

Here's a great video by a member here to explain what I mean.


Is aligning the overlap with TDC method as accurate as degreeing the intake lobe method?
 
Forget overlap. Install the cam at the intake centerline on the cam card. Then you can look at the lifters if you want to. All that will tell you is how advanced or retarded it is, not how much. Unless of course it’s in straight up. Then you’ll know it’s straight up.
 
He is completely incorrect on this point, because lots of modern cams when degreed 'where you want them' are not at "split overlap." (This is the design of the cam) It IS a quick and dirty way on old school cams but that does not mean that cam is optimum for performance for that particular cam and your particular engine/ and driving purpose
 
67Dart273 said:
He is completely incorrect on this point, because lots of modern cams when degreed 'where you want them' are not at "split overlap." (This is the design of the cam) It IS a quick and dirty way on old school cams but that does not mean that cam is optimum for performance for that particular cam and your particular engine/ and driving purpose
Click to expand...

Some guys here have "degreed" new engine installs by cranking pressure. In other words adjust the cam timing for max cranking pressure on a cylinder.

Actually degreeing a cam is just not that hard. I've done it 3x now, and every time, I have to go watch a few videos to refresh my brain and take notes.
 
Thanks for the replies and clarification. My timing chain was stretched enough to knock against the fuel pump arm so I figured since I am replacing it might as well go further and learn about degreeing. I have only put together a few engines and always did a dot-to-dot and go which worked but I have never been able to really dial this engine in. Excited to see if it makes a difference.
 
Well, and with a used cam, "if you don't know" what the cam "is" you may not be able to intelligently degree it. If it was in there with a "dot to dot" cam drive, that might be all you can do. "Generally" since most of us run "torque" engines without extensive headwork, etc, the generaly trend is to advance a cam, which moves the power curve down in RPM. On the other hand if you are building a high RPM rip-snorter with high compression, porting, etc, you might want to "lean" the other way.
 
Rat Bastid said:
Forget overlap. Install the cam at the intake centerline on the cam card. Then you can look at the lifters if you want to. All that will tell you is how advanced or retarded it is, not how much. Unless of course it’s in straight up. Then you’ll know it’s straight up.
Click to expand...
If you watched the video, I explained this also. The damper or harmonic balancer will tell you the degrees it's off with the timing cover once all is verified that TDC is actually TDC.
 
67Dart273 said:
He is completely incorrect on this point, because lots of modern cams when degreed 'where you want them' are not at "split overlap." (This is the design of the cam) It IS a quick and dirty way on old school cams but that does not mean that cam is optimum for performance for that particular cam and your particular engine/ and driving purpose
Click to expand...
This system works for me. This particular video was done on a "modern split cam" from Oregon Cam Ginders. Some don't like it, that's all cool. I won't debate or dispute it. Those that like it can use it, those that don't won't. I couldn't be happier with the way the engine performs. Actually, I couldn't be happier with the way ALL my engines perform :)
 
Buy a degree wheel and follow the instructions. It’s another tool in your toolbox. Buy a decent one and you’ll have it for many years.
 
I've got the degree wheel kit and everything ready to go, just hung up on this overlap versus intake lobe method in my head. Before I remove the old timing set I am going to degree and write down where everything is so I can compare it later. I already know the overlap is not at TDC using 318WillRun's method. This kind of stuff is really fun for me, thanks for bearing with my newby questions.
 
seabee said:
I've got the degree wheel kit and everything ready to go, just hung up on this overlap versus intake lobe method in my head. Before I remove the old timing set I am going to degree and write down where everything is so I can compare it later. I already know the overlap is not at TDC using 318WillRun's method. This kind of stuff is really fun for me, thanks for bearing with my newby questions.
Click to expand...
I don't see how any test can possibly be accurate with a timing chain as sloppy as the one you described. Also, remember, if you are using a quality timing set, and if the cam manufacturer did their job dot to dot should be where the cam manufacturer wants it installed.
 
seabee said:
I've got the degree wheel kit and everything ready to go, just hung up on this overlap versus intake lobe method in my head. Before I remove the old timing set I am going to degree and write down where everything is so I can compare it later. I already know the overlap is not at TDC using 318WillRun's method. This kind of stuff is really fun for me, thanks for bearing with my newby questions.
Click to expand...
I had a wheel, someone liked it more than me, never got to use it.. that being said, even I learned from Your Post... makes me wonder. How much more fun could have been squeezed out
 
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Simply put, I use the harmonic balancer AS THE DEGREE WHEEL (it's on the crank just the same), and the timing cover "0" as the indicator. Once verified, it's accurate. Timing cover "0" as indicator, I have 10* of timing either way.
 
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318willrun said:
Simply put, I use the harmonic balancer AS THE DEGREE WHEEL (it's on the crank just the same), and the timing cover "0" as the indicator. Once verified, it's just as accurate. Timing cover "0" as indicator, I have 10* of timing either way. IF the cam is out more than 10*, I say get another camshaft !! And, many aftermarket balancers (like the one in the video) shows 60* of advance timing, should your cam need to be degreed to that :D :D
Click to expand...
I checked out one of yer videos a Lil while back. It was cool. I'll watch this one now..
 
318willrun said:
I don't see how any test can possibly be accurate with a timing chain as sloppy as the one you described. Also, remember, if you are using a quality timing set, and if the cam manufacturer did their job dot to dot should be where the cam manufacturer wants it installed.
Click to expand...
I want to see if there is a difference between the timing marks between sets. For example: if the comp cams set I am replacing with the Howards set is at a different degree of overlap when dot to dot. Not because I have to but just curious.
 
67Dart273 said:
Some guys here have "degreed" new engine installs by cranking pressure. In other words adjust the cam timing for max cranking pressure on a cylinder.

Actually degreeing a cam is just not that hard. I've done it 3x now, and every time, I have to go watch a few videos to refresh my brain and take notes.
Click to expand...
How would ya do that? Keep pulling it down, after a comp check, adjust, reinstall, measure again? Sounds labor intensive, maybe there is a short cut I'm missing? Or maybe it's just old school work ethic, where if you want every bit of performance out of that mother you're Going to keep into it, till you just get it right!
 
318willrun said:
This system works for me. This particular video was done on a "modern split cam" from Oregon Cam Ginders. Some don't like it, that's all cool. I won't debate or dispute it. Those that like it can use it, those that don't won't. I couldn't be happier with the way the engine performs. Actually, I couldn't be happier with the way ALL my engines perform :)
Click to expand...
Well, IF it is a "split overlap" cam, then no problem
 
Ironracer said:
How would ya do that? Keep pulling it down, after a comp check, adjust, reinstall, measure again? Sounds labor intensive, maybe there is a short cut I'm missing? Or maybe it's just old school work ethic, where if you want every bit of performance out of that mother you're Going to keep into it, till you just get it right!
Click to expand...
I've never done this but I assume you just jig it up with a bell and starter, and just put in the no1 pushrods and go to it. I can see you could do it fairly quickly. I don't know enough about cam design to know whether or not it is a definitive marker, but I've read of guys doing that and claiming so.
 
seabee said:
I want to see if there is a difference between the timing marks between sets. For example: if the comp cams set I am replacing with the Howards set is at a different degree of overlap when dot to dot. Not because I have to but just curious.
Click to expand...
If the old one is worn, you might not be able to tell very much. Sprockets wear, and chains stretch...........
 
67Dart273 said:
I've never done this but I assume you just jig it up with a bell and starter, and just put in the no1 pushrods and go to it. I can see you could do it fairly quickly. I don't know enough about cam design to know whether or not it is a definitive marker, but I've read of guys doing that and claiming so.
Click to expand...
Now that makes sense! See how narrow my pointy Lil skull is? But it ain't narrowed left! Lol
 
I helped a local guy some time back. He/ I had asked here, about his specific cam, where it should "be." The opinions were to wind it ahead. Turns out the sprockets were off (retarded) from where the grinder said it should be. So between the recommended advance, and correcting the retard in either the cam or the drive, we wound that thing ahead something like 6 or 8 degrees. "Night and day" difference in this case

In his case he had a drive set with several keyways in the crank gear, so it would go a ways................
 
67Dart273 said:
I helped a local guy some time back. He/ I had asked here, about his specific cam, where it should "be." The opinions were to wind it ahead. Turns out the sprockets were off (retarded) from where the grinder said it should be. So between the recommended advance, and correcting the retard in either the cam or the drive, we wound that thing ahead something like 6 or 8 degrees. "Night and day" difference in this case

In his case he had a drive set with several keyways in the crank gear, so it would go a ways................
Click to expand...
This is the most I've learned in a minute...and reason stands to Degree it, just to check the gears, ect..and I know you're an electronic Genius, didn't know you are a cam install tech! Thanks Dell!
 
67Dart273 said:
Some guys here have "degreed" new engine installs by cranking pressure. In other words adjust the cam timing for max cranking pressure on a cylinder.

Actually degreeing a cam is just not that hard. I've done it 3x now, and every time, I have to go watch a few videos to refresh my brain and take notes.
Click to expand...
I've degreed a BUNCH and I still get my notes out. I also incorporate a compression gauge.
 
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