TKRIV Posted January 14 Share Posted January 14 Does anyone know what are the tell tail signs that an after market cam has not been properly degreed or not dialed in at all? I have been told that degreeing a cam serves as a second check for assembly errors, even in a stock replacement cam. Link to comment Share on other sites More sharing options...
JZRIV Posted January 15 Share Posted January 15 Lower performance in rpm range vs what it was designed for. Vacuum can also be affected. Many variables play into it though. Typically on a stock cam installed straight up you may not notice in seat of pants feel if its off a couple degrees. The more one is seeking high horsepower, the more important it is to degree it. In my opinion its wise to take the time to check/verify it when assembling the engine no matter what. If you get the engine together and have a problem, you will always wonder if cam setup is the root cause. If it was degreed, then that can be crossed off. Its no fun pulling engine back apart after the fact. 1 Link to comment Share on other sites More sharing options...
NTX5467 Posted January 15 Share Posted January 15 Consider . . . in earlier times AND at the dealerships, parts were/are installed "as is", no more no less. Cam degreeing is generally in the realm of machine shops and such where racing engines are built. Not to say that anybody can't degree-in a cam if they want to. It does become more important in a high-power race engine than on a stock street car (even a higher-horsepower street engine). IF done at a machine shop where the engine is being built, always good to see "where everything is" so it's known rather than "where things should be" according to supplier specs. The OTHER thing about a machine shop doing it is that they generally are capable of correcting things with an offset bushing in the cam sprocket, like up to about 4 degrees variation. Otherwise, a multi-keyway'd crank sprocket should be used. Usually, some customers need to bleed-off a bit of low rpm torque so they can get the rear tires hooked up sooner, with the 4 degree retard also making for more top end power to compensate, for example. Or if the engine will be for a "pulling" vehicle, then advancing the cam 4 degrees might get a bit more low end torque, but a bit less top end power. These differences would show up on an engine dyno run, but you'd probably be hard pressed to noticed it unless you knew what you were looking for in general street-driving performance. Not to forget that any power gained will have 15% or it absorbed with the remaining 80+% getting to the ground. So, is it worth it? IF you like numbers, it can be. Will it make the car run better/faster? Not necessarily, unless the two vehicles are exactly-matched, which is also when "driver abilities" can come into play. Now, at an engine shop or with the engine on an engine stand, you an get a degree wheel and attach it to the crankshaft. Verify TDC by #1 piston position, and then roll the engine over to check for when the valves open and close, to compare to the cam card, or to see what's there. THAT type of quality check is normal for any engine builder, I believe. Take care, NTX5467 2 Link to comment Share on other sites More sharing options...
XframeFX Posted January 15 Share Posted January 15 48 minutes ago, JZRIV said: Typically on a stock cam installed straight up you may not notice in seat of pants feel if its off a couple degrees. "Straight Up". So, that's it. Degree'ing a camshaft will tell you if it has built-in advance or not. Do you have the Cam-Card for 'said' camshaft? it may or may not indicate advance. If it doesn't, look at .050" data. Are Lobe Separation Angle (LSA) and CL to to intake the same? If so, likely 0° advance but some Cam-Cards are inconsistent and no way of knowing without doing the degree procedure. No other way to tell unless you have before/after "in-the-seat-of-your-pants" feel. I have a DynaSlow. No seat in my pants feel, regardless. Link to comment Share on other sites More sharing options...
TKRIV Posted January 15 Author Share Posted January 15 I enjoy the banter when I hear mechanics talk about diagnostic/problem solving. But I have NEVER heard a discussion that concludes the Degreeing was off therefore rebuild required. Always learning. Yes, agree that Cam-Cards can be inconsistent and/or confusing. Link to comment Share on other sites More sharing options...
arnulfo de l.a. Posted January 15 Share Posted January 15 15 hours ago, XframeFX said: "Straight Up". So, that's it. Degree'ing a camshaft will tell you if it has built-in advance or not. Do you have the Cam-Card for 'said' camshaft? it may or may not indicate advance. If it doesn't, look at .050" data. Are Lobe Separation Angle (LSA) and CL to to intake the same? If so, likely 0° advance but some Cam-Cards are inconsistent and no way of knowing without doing the degree procedure. No other way to tell unless you have before/after "in-the-seat-of-your-pants" feel. I have a DynaSlow. No seat in my pants feel, regardless. John lobe separation angel ( LSA ) is measured in camshaft degrees and cannot be changed. Its ground into the cam. Intake centerline angel( CL ) is measured in crankshaft degrees relative to the crankshaft being at top dead center. Intake centerline angel can be changed by removing the camshaft and rotating for either more advance or retard. 1 Link to comment Share on other sites More sharing options...
XframeFX Posted January 15 Share Posted January 15 (edited) 36 minutes ago, arnulfo de l.a. said: Intake centerline angel can be changed by removing the camshaft and rotating for either more advance or retard. Yes this is the case. However, when degree'ing to concur with the Cam-Card at .050" Lift, you will soon find out if the Camshaft has BUILT-IN ADVANCE. The Schneider Cam-Card below shows an LSA of 112° yet the CL to intake is 110°. So, this is an indication of 2° built-in advance. If this is actually the case, then CL to exhaust will be 114° as everything is shifted 2° Some camshafts show equal LSA and CL to intake angle but when degree'ing, discover built-in advance is present. (Cam-Cards don't necessarily have a 100% standard convention as I've found at TDC and +/- degrees. Many have typos!) Edited January 15 by XframeFX (see edit history) 1 Link to comment Share on other sites More sharing options...
arnulfo de l.a. Posted January 15 Share Posted January 15 Great info John ! I just finished up degreeing a camshaft from a 430 buick engine. It is the original camshaft . Trying to figure out amount of advance ,if any, the cam has. With the info you provided im assuming i can subtract CL from LSA to get advance value.First I need to figure out what the LSA is. Still learning ! Thanks Link to comment Share on other sites More sharing options...
XframeFX Posted January 16 Share Posted January 16 8 hours ago, arnulfo de l.a. said: First I need to figure out what the LSA is. If you have valve timing data, wash up and run those two online calculators. Capture screen-shots into a Word.doc so you have your cam as a baseline. Again, one is for entering valve timing and spits out duration, centerlines and advance. The 2nd works in reverse. You enter duration, centerlines and advance. It then spits-out valve timing and plots on a graph. The latter good for comparing Cam-Cards before you spend $$$. You mentioned overlap earlier. I think that's more for the SAE/advertised/.002" method. It always seems to be 0° with the .050" method. 1 Link to comment Share on other sites More sharing options...
XframeFX Posted January 16 Share Posted January 16 http://www.wallaceracing.com/camcalc.php https://mgispeedware.com/camshaft-calculator/ 1 Link to comment Share on other sites More sharing options...
arnulfo de l.a. Posted January 16 Share Posted January 16 Thanks John! Link to comment Share on other sites More sharing options...
RivNut Posted January 16 Share Posted January 16 I don’t know if you’re trying to degree your OE cams to compare them to aftermarket cams, but if you are, then you need to realize that the nailhead cams are measured at 0.002 rather than 0.005 or 0.050. Here’s a chart that shows the 401/425 cams. This is a reprint of the information that Denny Manner supplied tot the ROA for printing in the Riview some time ago. It is reprinted in the Team Buick website. https://www.teambuick.com/reference/nailhead_cam_specs.php 1 Link to comment Share on other sites More sharing options...
arnulfo de l.a. Posted January 16 Share Posted January 16 9 hours ago, RivNut said: I don’t know if you’re trying to degree your OE cams to compare them to aftermarket cams, but if you are, then you need to realize that the nailhead cams are measured at 0.002 rather than 0.005 or 0.050. Here’s a chart that shows the 401/425 cams. This is a reprint of the information that Denny Manner supplied tot the ROA for printing in the Riview some time ago. It is reprinted in the Team Buick website. https://www.teambuick.com/reference/nailhead_cam_specs.php Thats exactly what im trying to do but with a 430 and 455 cam. Thanks for posting the nailhead chart! Link to comment Share on other sites More sharing options...
XframeFX Posted January 16 Share Posted January 16 22 hours ago, XframeFX said: (Cam-Cards don't necessarily have a 100% standard convention as I've found at TDC and +/- degrees. Many have typos!) When reading various Cam-Cards, and running those calculators, be aware of "Exhaust Closing" and "Intake Opening" convention which are both at TDC. Some will use ATDC, BTDC or combo of both. You may have to include a minus (-) when entering your values for these 2 pieces of data. It should all fall into place. Enjoy! 1 Link to comment Share on other sites More sharing options...
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