cam swap done... BIG PROBLEMS
03-30-2010, 11:21 AM
#63
Correct, but it does not matter when taking the engine apart. It will help insure/make it easier for you to put it back together if you are going right back in with a new cam like when doing a cam swap. It’s tough enough to do the swap in the car, and any little thing that helps make it easier and helps keep you from making a mistake is an excellent idea in my book. But it does not mean that if you did not line up the dots before you disassembled the chain/sprocket you are going to have problems or are doing it wrong.
If you plan on doing several cam swaps on different cars in your life time, or might want to shift the peak power point up or down the rpm range, then it would be very advantageous to you to purchase a degree wheel/kit and learn how to degree a cam in. It is not hard, and with the correct tools you can do this with the heads still on the car. You will know without a doubt were the cam is. Take my current cam, it has 6 degrees of advance ground into it and I installed it at a 105 degree intake centerline, so I installed it another 6 degrees. Did this to bring the NA power down real low to help make more power down low in the rpm before the turbo spools up and takes care of the top end power, and to help get the 88 turbo spooling faster/sooner.
You would be surprised how many cams are not timed exactly were you want it to be. Have you ever wondered why some factory cars or just faster then another car just like it? This is one of the reasons. By just lining up the dots you are assuming the cam was ground perfectly on the numbers. I have never seen a cam ground far enough off to cause a malfunction, but it is not uncommon for them to be 2-4 degrees off one way or the other. I would venture to say most if not all of the sponsors here degree the cams they install.
If you plan on doing several cam swaps on different cars in your life time, or might want to shift the peak power point up or down the rpm range, then it would be very advantageous to you to purchase a degree wheel/kit and learn how to degree a cam in. It is not hard, and with the correct tools you can do this with the heads still on the car. You will know without a doubt were the cam is. Take my current cam, it has 6 degrees of advance ground into it and I installed it at a 105 degree intake centerline, so I installed it another 6 degrees. Did this to bring the NA power down real low to help make more power down low in the rpm before the turbo spools up and takes care of the top end power, and to help get the 88 turbo spooling faster/sooner.
You would be surprised how many cams are not timed exactly were you want it to be. Have you ever wondered why some factory cars or just faster then another car just like it? This is one of the reasons. By just lining up the dots you are assuming the cam was ground perfectly on the numbers. I have never seen a cam ground far enough off to cause a malfunction, but it is not uncommon for them to be 2-4 degrees off one way or the other. I would venture to say most if not all of the sponsors here degree the cams they install.
03-30-2010, 01:02 PM
#64
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You guys are freaking me out. I put a cam in 2 days ago and I did not line up my dots before removal of the old cam. I did put the new cam back in the same relative position as the old one (dowel pin at 9:00). EDIT- actually I didn't- I spun the cam to set the lifters so I lost the relative position. Anyway, the dots were certainly line up when the new cam went back in. I even cranked it over 360 degrees (by hand) to make sure the dots were still lined up. I'm okay, right? I did a previous cam swap on my Z28 a few years ago and had no problems. Sorry, no hijack intended.
you're fine. and you did good by turning it over 360.
03-30-2010, 01:20 PM
#67
Did the OP ever get it figured out? I can't believe no one said the reason the engine could be tough to turn is because of compression till Merv. Everyone jumps on the bandwagon, "the valves are bent the valves are bent!" and no testing has been done. Hell just tear it apart and don't even do any checking. 
Could the valves be bent? Yes. To the OP, make sure your dots are lined up, turn it over by hand once or twice to make sure the dots line back up. Do a compression check and go from there.
Oh, smack your buddy that said the injectors are to small for it to start. Find a buddy that knows what that the $%^& he is talking about and maybe he could have caught the timing mark problem.
Could the valves be bent? Yes. To the OP, make sure your dots are lined up, turn it over by hand once or twice to make sure the dots line back up. Do a compression check and go from there.
Oh, smack your buddy that said the injectors are to small for it to start. Find a buddy that knows what that the $%^& he is talking about and maybe he could have caught the timing mark problem.
03-30-2010, 01:20 PM
#68
Did the OP ever get it figured out? I can't believe no one said the reason the engine could be tough to turn is because of compression till Merv. Everyone jumps on the bandwagon, "the valves are bent the valves are bent!" and no testing has been done. Hell just tear it apart and don't even do any checking.
Could the valves be bent? Yes. To the OP, make sure your dots are lined up, turn it over by hand once or twice to make sure the dots line back up. Do a compression check and go from there.
Oh, smack your buddy that said the injectors are to small for it to start. Find a buddy that knows what that the $%^& he is talking about and maybe he could have caught the timing mark problem.
Could the valves be bent? Yes. To the OP, make sure your dots are lined up, turn it over by hand once or twice to make sure the dots line back up. Do a compression check and go from there.
Oh, smack your buddy that said the injectors are to small for it to start. Find a buddy that knows what that the $%^& he is talking about and maybe he could have caught the timing mark problem.
03-30-2010, 01:40 PM
#69
Did the OP ever get it figured out? I can't believe no one said the reason the engine could be tough to turn is because of compression till Merv. Everyone jumps on the bandwagon, "the valves are bent the valves are bent!" and no testing has been done. Hell just tear it apart and don't even do any checking.
If you have one of them little Snake Cams that will be the perfect thing to use and see if the Valves are hammered..a friend of mine has one and it comes in handy to look at anything inside the Cylinders.
03-30-2010, 02:11 PM
#70
I guess this genius is ASE certified. Do you not know the difference between talking to a mechanic and a person thats a do-it-yourselfer?? How are you gonna try and talk to a guy that hasnt ever done this with nothing but technical terms that is jibberish to him. Instead the easy way to tell someone, that has never done this before, is to assemble and disassemble in the exact same way he took it off. Really dude, really?? Its like you coming to my job trying to do my work and all I say is pure technical terms. 
with that ****!!
with that ****!!
03-30-2010, 02:15 PM
#71
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I guess this genius is ASE certified. Do you not know the difference between talking to a mechanic and a person thats a do-it-yourselfer?? How are you gonna try and talk to a guy that hasnt ever done this with nothing but technical terms that is jibberish to him. Instead the easy way to tell someone, that has never done this before, is to assemble and disassemble in the exact same way he took it off. Really dude, really?? Its like you coming to my job trying to do my work and all I say is pure technical terms. with that ****!!
with that ****!!why the **** would it matter if you dissasemble dot to dot?
i'll say it again,
03-30-2010, 03:11 PM
#78
This is not entirely correct. IF the cam or timing set is machined improperly and the VE's are off by enough, then it can/will affect your peak power and where the powerband lies. HOWEVER, not all are wrong, and more often than not when you degree a combo in it is just as ordered (within 1º typically) and there is nothing to adjust for and nothing left on the table.
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Last edited by Sales2@Texas-speed; 04-01-2010 at 10:09 AM.
03-30-2010, 03:32 PM
#79
Back to our little discussion(maturley this time)! I went back and freshened up on cam installs and it really doesnt matter if you line up the dots before or after. Bottom line is that at the end, they will have to be lined up. If you line them up before you take the cam off, you dont have to worry about it TOO much at the end cuz they will be pretty close to being lined up. Of course you may have to make minor adjustments. On the same token, you can just line them up at the end too. Either way is fine. As far as time efficiency, give or take a minute or two on either one.
03-30-2010, 05:45 PM
#80
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This is correct!
This is not. IF the cam or timing set is machined improperly and the VE's are off by enough, then it can/will affect your peak power and where the powerband lies. HOWEVER, not all are wrong, and more often than not when you degree a combo in it is just as ordered (within 1º typically) and there is nothing to adjust for and nothing left on the table.
This is not. IF the cam or timing set is machined improperly and the VE's are off by enough, then it can/will affect your peak power and where the powerband lies. HOWEVER, not all are wrong, and more often than not when you degree a combo in it is just as ordered (within 1º typically) and there is nothing to adjust for and nothing left on the table.
i agree. IF its off enough, of course if its spot on nothing will change. but tolerance stacking does happen.