Degreeing a big block cam

furyus

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I am trying to learn to degree my cam, but it's making my head hurt. It's a 505 engine, not that it matters. I am working with the short block that already has the rotating assembly, done by the machine shop. I asked if they would degree the cam, but he said no. HMMM.
anyway, I did the finding tdc with a piston stop. it says it's at 35 degrees rotated each way untill it hits the piston stop. I used the dial indicator to verify tdc is good. That seems fine, but when I got to the part of using the dial indicator on the cam, the numbers were way off(I think). my main question is Is it ok to use a flat tappet lifter on a hydraulic roller cam to check the cam figures? second, where is the best printed instructions to do this? watching youtube is helpful, but having to keep stopping, and rewinding to try to understand adds another level of stress for me.
TIA.
 

GTX JOHN

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I use a solid Flat tappet on a flat tappet and a solid roller
on a roller cam. I know the profiles are different and the ramps.
However, I would call the cam Manufacturer because I do not
logically see why it would matter. Many cam companies have instructions
on their web site
 
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Outsider

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I have single solid lifter I store with the degree wheel that I use. And for what its worth, in the past when I've been asked to help friends when they were having degreeing problems, the most common issue I have seen is that they were lining up the gears on the crank key instead of the line-up pip on the crank gear.
 

Ray70Chrg

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I am trying to learn to degree my cam, but it's making my head hurt. It's a 505 engine, not that it matters. I am working with the short block that already has the rotating assembly, done by the machine shop. I asked if they would degree the cam, but he said no. HMMM.
anyway, I did the finding tdc with a piston stop. it says it's at 35 degrees rotated each way untill it hits the piston stop. I used the dial indicator to verify tdc is good. That seems fine, but when I got to the part of using the dial indicator on the cam, the numbers were way off(I think). my main question is Is it ok to use a flat tappet lifter on a hydraulic roller cam to check the cam figures? second, where is the best printed instructions to do this? watching youtube is helpful, but having to keep stopping, and rewinding to try to understand adds another level of stress for me.
TIA.
Hey Furyus, I know the feeling. I've done this only one time, but the good news is that my engine has 2K miles on it and all seems well. If you visit Lunati Cams, they have a pretty good write up and that's what I used to degree my new cam. What they say in the instructions is to use a "mechanical lifter" for a flat tappet cam. I took that to mean a solid lifter. I was putting in new lifters, so I used 2 of old ones and converted them to solid by taking them apart and inserting a small nut to take away any travel in the lifters. I learned this by reading everything I could find here on site. I don't know exactly how you are doing this and I'm no expert by any measure, but take your time to get it right. Once I understood what I was doing, I did it 3x and came within 1 degree of the centerline each time. Remember, you are only checking that the cam is what it's supposed to be. I knew their cam was exactly at 106 degrees and my 1 degree discrepancy was do to my inability to be as exact as they are. Good luck.
 

Geoff 2

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No, you have to use a roller lifter on a roller cam. You might be able to use a hyd roller, depending on design, such as using the extension on the lifter that holds the tie bar as the measuring point. Measure two lifters with calipers to make sure they are the same overall length.
If the cam is a single pattern, here is trick that saves a lot time. Most cams have 4-6* of advance ground into them [ unless custom ground, then not always ].
Get #1 or #6 cyl on overlap, at TDC. Install the int & exh lifter & put a straight edge across the top. The int lifter should be higher than the exh by 0.005 - 0.020".

I always laugh at these threads. Extremely rare for a cam to be ground incorrectly these days. People go to great lengths to dial in a cam to some pre-determined ICL, say 106*, & not having any data that this would be best for THIS engine. Buggarise around with offset cam keys/bushes, multi slot sprockets etc to get it 'right'. So that is #1 cyl done. If a V8, nobody checks the other 7 cyls which could be way off!!!!!!
 

BSB67

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my main question is Is it ok to use a flat tappet lifter on a hydraulic roller cam to check the cam figures?
No. You cannot use a flat tappet lifter for degreeing a roller cam. And you should use the correct diameter wheel as well.

Comp Cams used to have the centerline method in a pdf online.
 

zyzzyx

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Keep repeating the procedure, and once you have it figured out you will be amazed at how
accurate the cam card is as far as opening and closing the valves!
 

furyus

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I have single solid lifter I store with the degree wheel that I use. And for what its worth, in the past when I've been asked to help friends when they were having degreeing problems, the most common issue I have seen is that they were lining up the gears on the crank key instead of the line-up pip on the crank gear.
I didn't do that. I put the 0 on the keyway, and the other 0, by the teeth in line with the cam dot. So i think I'm good there.
 

furyus

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Thanks everyone for your input. I will go back at it again. It helps to know that I need to use the roller lifter. And I will go on the cam websites and get their directions.
I called bullet cams, and they were able to straighten me out. Thanks for all the help.
 
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