Degreeing a Cam Shaft

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carfreak6970

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I have some issues when it comes to degreeing a cam and I think I know what is wrong, but would like to ask anyway.

I have a 67 dart with a 383 that I installed a Crane Cam H-278-2. Other than that it is the stock rotating assembly, with stock iron 4 barrel and a stock 440 holley. It has TTI headers. I believe I degreed it properly before when I initially installed it. I did follow their break in procedure of running the engine at a mid range RPM for 30 minutes. That was a couple years ago. This past summer I finally got it out on the road and was trying to drive it but couldnt make it far due to the temperature climbing and if you got on it would start to back fire out the tail pipes. When I tried to put it away for the winter I had to back it up the driveway which is on a hill and it kept stalling. I finally got it in and I thought I must have screwed up installing the cam. When I tried to tune it after I got it inside I noticed there was a pretty big fuel leak and thought that must have been the issue with it stalling going up the driveway, but still wanted to check out if I degreed the cam shaft incorrectly due to the backfiring. So today while at my folks place I tried to do just that.

I got it so the drivers side rocker cover was off and the timing cover was off. I set the engine to TDC, installed a degree wheel on the crank, rotated the crank counter clockwise and installed a piston stop. I rotated the crank clockwise until it stopped. I wrote down that number. I rotated the engine counterclockwise until it hit the piston stop again, I wrote that number down. I took the difference of those two numbers, divided that by two and either added it or subtracted it so that which ever direction I rotated the engine the degree readings were the same once it hit the piston stop. Which tells me I am at TDC CORRECT!?!?!?!?

I installed a measuring device from the cam degree kit on the number one intake valve (which is on the drivers side 2nd one back from the front of the engine, RIGHT?!?!?). I left the rockers on so I would have the force from the valve springs pushing down on the lifters so I would be able to measure the .050 distance on the closing side of things. I placed the measuring rod on the portion of the rocker that is contacting the push rod. I did my best to align that measuring rod on that gauge so the center lines from both were lined up. Took awhile to do that.

From there I rotated the engine in the clockwise direction until I saw the dial read .050 and wrote that degree down (first time was 33 ATDC). I continued rotating the engine until I saw the .050 for the last time and that was 9 ABDC. I thought to myself "damn, that is really far off" below is the cam card:

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It is suppose to be at 2 BTDC at .050" open, not 33 ATDC. The timing set is a clyodes adjustable one so I set it at the 8 degrees advance, found TDC the same way as described above and re did the measurements to see when the intake was opening... it opened to .050" at 39 ATDC and closed at 14 ABDC. wrong direction so I installed the timing set at the 8 degrees retarted position, redid my TDC measurement and tried the intake opening measurements again.... it now opened at 41 degrees ATDC... needless to say I was pissed because none of this is making sense. Until I did some math....

The cam card above says I should have 222 intake duration when measuring at the .050 measurement. according to my initial measurements of opening .050 at 33 ATDC and closing to .050 at 9 ABDC I am only getting 156 degrees of duration. Am I doing my math right?!? and if so does that mean I have at least one wiped cam lobe...? I am beyond disgusted...

How do I determine if one or more cam lobes have be wiped? does that mean removing the rockers and lifters. remove the cam and take some measurements? or would there be some pretty clear indicators if something is wrong? If I do have wiped lobe(s), does that mean the entire engine needs to be disassembled...?
 
Ok, looking at your cam card it looks like that cam is on a 114 Lobe Separation Angle and they want it installed on a 109 Intake Centerline. That would be 5 degrees advanced.

So let’s talk about what you are doing. You have found TDC and now you have the dial indicator on the valve. Is that correct?

If so, you will get wonky numbers doing that. That’s because your cam card says that at .050 LIFTER RISE your intake opening will be degrees BTDC.

If you are checking that at the valve, you have to multiply that .050 lift by your rocker ratio. If that’s 1.5 you have to read the degree wheel at .075 VALVE LIFT to get the right numbers.

If you have 1.6 rockers you need to be at .080 VALVE LIFT. That’s why it’s easier to check your timing at the lifter. If you can’t do that then you have to add in the rocker ratio.
 
Ok, looking at your cam card it looks like that cam is on a 114 Lobe Separation Angle and they want it installed on a 109 Intake Centerline. That would be 5 degrees advanced.

So let’s talk about what you are doing. You have found TDC and now you have the dial indicator on the valve. Is that correct?

If so, you will get wonky numbers doing that. That’s because your cam card says that at .050 LIFTER RISE your intake opening will be degrees BTDC.

If you are checking that at the valve, you have to multiply that .050 lift by your rocker ratio. If that’s 1.5 you have to read the degree wheel at .075 VALVE LIFT to get the right numbers.

If you have 1.6 rockers you need to be at .080 VALVE LIFT. That’s why it’s easier to check your timing at the lifter. If you can’t do that then you have to add in the rocker ratio.
Lol I was writing @ Rat bastid
 
You need to put a solid lifter in when you do your measurements. You need to take measurements off a solid point. Your dial indicator and gravity will make sure the lifter follows the cam profile. What is your installed centerline supposed to be?
 
The only true accurate way to degree is to pony up for the lifter bore tool that holds the dial indicator. Other than that, you're very likely to be off on your measurements.
 
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wow you guys are really quick, holy hell. lol So after I had a swig of Jack and Coke I thought of how this car is using hydraulic lifters and that by contacting the back of the rocker arm at the point right above the push rod I was not accounting for the collapsing of the hydraulic lifter since they are not pressurized. Which I guess since I dont have a solid lifter or a fancy lifter bore tool, I will have to remove the intake to be able to contact the edge of the lifter with my dial indicator. Which I didnt want to do, but given the tools I have I dont have any other way. Thank you! Ill keep everyone posted on what I find.
 
wow you guys are really quick, holy hell. lol So after I had a swig of Jack and Coke I thought of how this car is using hydraulic lifters and that by contacting the back of the rocker arm at the point right above the push rod I was not accounting for the collapsing of the hydraulic lifter since they are not pressurized. Which I guess since I dont have a solid lifter or a fancy lifter bore tool, I will have to remove the intake to be able to contact the edge of the lifter with my dial indicator. Which I didnt want to do, but given the tools I have I dont have any other way. Thank you! Ill keep everyone posted on what I find.
You need to the lifter bore tool. Coming off the lifter with the dial indicator.....how will you make sure the indicator is DEAD PERFECT straight with the center line of the lifter? You cannot. If it's not perfectly parallel with the lifter, your reading will be inaccurate. You're askin for help. I'm just tellin you the right way. Plenty of people will come on here arguing with me sayin "I've done it this way for 175 years and it's always worked, blah blah blah" and maybe they have, but if the dial indicator is not dead perfect, they've done it wrong for 175 years.
 
What’s sad is I KNEW this was a hydraulic grind and I forgot to mention he needs a solid lifter or better yet the lifter bore tool.

I use so few hydraulics I forget about that.
 
Most Crane shelf grinds have 5* of advance ground into them. That means if you install the timing chain set on the '0' mark & all the machining is accurate, the ICL will be 109*.
 
He's not building the space shuttle.

You could take the rockers off and rig up the dial indicator on the tip of pushrod. That would get rid of your springs collapsing the lifters and get a good reading to do the math.

How come women in new england were never happy when the revolutionary war was going on... too many minutemen
 
I don't see how the engine could run well and then not due to cam issue. If it sat for 2 years it could well have carb or fuel issues. You can degree using your hydraulic lifters at least with pushrod removed so lifter doesn’t compress. After finding TDC you should be finding max lift point on the intake lobe and rotating 0.050 cw and ccw from max lift. Add the 2 numbers and divide my 2. Just in my google degreeing using the intake centreline method to find the YouTube video. I followed this procedure last week with repeatable results.
 
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Also it sounds to me like you’re leaving the piston stop in after rotating back and forth, which would keep you from ever reaching true TDC.
 
Hang on guys;
33 +9+180= 222 and the cam card says it's a 222@.050 Tappet rise.
So then, while his method is obviously wrong, he was, if nothing else, meticulous....... lol.
From these results, I submit that his lifter, if bleeding down, it ain't by much.
So then, I would say; just repeat the procedure, and if the results are the same, then I would assume that, even if not 100% accurate to the cam card, it is still preaching an accurate centerline.
 
You need to the lifter bore tool. Coming off the lifter with the dial indicator.....how will you make sure the indicator is DEAD PERFECT straight with the center line of the lifter? You cannot. If it's not perfectly parallel with the lifter, your reading will be inaccurate. You're askin for help. I'm just tellin you the right way. Plenty of people will come on here arguing with me sayin "I've done it this way for 175 years and it's always worked, blah blah blah" and maybe they have, but if the dial indicator is not dead perfect, they've done it wrong for 175 years.

So I thought with the intake off I could get the measurement tool lined up via the magnetic base... Yea I was wrong...lol. Oh well. So I do need the lifter bore tool. I appreciate everyone being patient with me as I work through this.

I was on Mancini racing website and they have a couple of lifter bore tools, however I was hoping to find a tool I could use where I would not have to remove the head. So essentially one that is long enough. Any ideas?

Also it sounds to me like you’re leaving the piston stop in after rotating back and forth, which would keep you from ever reaching true TDC.
Apologies I did not mention that I do indeed take the piston stop out after I have found TDC. Sorry for the confusion.
 
I would just make something which is what I did although the head was off. I just had some flat bar with a hole in it bolted to the deck to support the rod. I used a long bolt that sat in the lifter bore. An adjustable ball/cup type pushrod length checker might be better. It was good enough and gave repeatable results.
 
You need to the lifter bore tool. Coming off the lifter with the dial indicator.....how will you make sure the indicator is DEAD PERFECT straight with the center line of the lifter? You cannot. If it's not perfectly parallel with the lifter, your reading will be inaccurate. You're askin for help. I'm just tellin you the right way. Plenty of people will come on here arguing with me sayin "I've done it this way for 175 years and it's always worked, blah blah blah" and maybe they have, but if the dial indicator is not dead perfect, they've done it wrong for 175 years.

Say your dial indicator is 5° off from the direction of the pushrod. The cosine of 5° is 0.996 or 99.6%. Your dial indicator at lifter lift of 0.050" will read 0.0498". Since most dial indicators read to the nearest thousandth this small error won't even be detected.
 
Say your dial indicator is 5° off from the direction of the pushrod. The cosine of 5° is 0.996 or 99.6%. Your dial indicator at lifter lift of 0.050" will read 0.0498". Since most dial indicators read to the nearest thousandth this small error won't even be detected.
....and you "know" you're off 5 degrees HOW? For me, it's not open for debate. I based my recommendation on my opinion and personal experience. In other words, how I would do and have done it. So an argument here is pointless, although I certainly appreciate you breakin your cherry to point it out.
 
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