Hush up.
Degreeing a Cam Shaft
- Thread starter carfreak6970
- Start date
a70duster
Member
That was a piss poor apology kinda like saying "I'm sorry you feel that way". It is a very ungenuine apology and more like a fnck you in disguise.
I don't want you to put need pads on, just in the future please act like a rational person and be open to discuss topics. If it bothers you that much and you can't have a rational discussion then just ignore it.
I think you should continue to hide under the kitchen table and play the victim. You're on the list.
a70duster
Member
I PMed you.
ultimatejay
Well-Known Member
JUST SET IT 0-0 AND BE DONE WITH IT. ITS NOT A RACECAR.
Rat Bastid
Dunamis Metron
Bad advice. Lining up the dots means you have no clue where the cam is timed.
Tolerance stack up is real.
I don’t care if it’s dead stock, the cam gets degreed. Every time.
carfreak6970
Well-Known Member
Gentlemen (and ladies), I finally got the tools and a set up that can produce repeatable results. However I still have some questions.
It took me a little longer than Id like to admit, but initially I dont think I was matching the crank pulley's keyway marking with the indicated one that should match up with the "O" mark (there are no other indicator markings on the cam shaft gear) on the camshaft gear. But once I figured that out I determined through following my process mentioned in the beginning of this thread I needed to have the key way in the 4A slot (4 degrees advance) and the crank gear marking 4A line up with the "O" mark on the cam shaft gear. That produced the following results:
Opening at 3 degrees BTDC (cam card says .050" lift at 2 deg BTDC)
Closing at 37 degrees ABDC (cam card says .050" lift at 72 deg ABDC)
max lift coming in at 108-109 degrees ATDC (cam card says max lift at 109 deg ATDC)
Now, my timing set only allows the flowing adjustments:
8, 6, 4, 2 degrees retarded
0 to 0
2, 4, 6, 8, degrees advanced
So my question now is, where do I set it up? It appears my opening is almost within spec and the max lift is coming in at where it should, but my exhaust is closing 35 degrees before it should. so what is more important? intake opening? max lift? or intake closing? it would appear the duration of this cam lobe is off from what the cam card states.
Now, if (thats a big "IF") I initially installed the cam shaft correctly the markings were originally 0 to 0, which means my cam was 4 degrees retarded.
It took me a little longer than Id like to admit, but initially I dont think I was matching the crank pulley's keyway marking with the indicated one that should match up with the "O" mark (there are no other indicator markings on the cam shaft gear) on the camshaft gear. But once I figured that out I determined through following my process mentioned in the beginning of this thread I needed to have the key way in the 4A slot (4 degrees advance) and the crank gear marking 4A line up with the "O" mark on the cam shaft gear. That produced the following results:
Opening at 3 degrees BTDC (cam card says .050" lift at 2 deg BTDC)
Closing at 37 degrees ABDC (cam card says .050" lift at 72 deg ABDC)
max lift coming in at 108-109 degrees ATDC (cam card says max lift at 109 deg ATDC)
Now, my timing set only allows the flowing adjustments:
8, 6, 4, 2 degrees retarded
0 to 0
2, 4, 6, 8, degrees advanced
So my question now is, where do I set it up? It appears my opening is almost within spec and the max lift is coming in at where it should, but my exhaust is closing 35 degrees before it should. so what is more important? intake opening? max lift? or intake closing? it would appear the duration of this cam lobe is off from what the cam card states.
Now, if (thats a big "IF") I initially installed the cam shaft correctly the markings were originally 0 to 0, which means my cam was 4 degrees retarded.
Indeed. Lined up dot to dot on new everything and the cam was around 10* retarded. Just run it. Nope.
It's easy to verify and takes little time to do so. 1* off meh... more than that and start looking to move it, especially if retarded. JMO
@carfreak6970 If the crank keyway isn't inline with the #1 cylinder on a LA or BB mopar, something is off with the set up. I had a customer put a 3 way gear on crank in the +4 position, then lined up the 0 mark with the cam. The key went from 1:30 looking at a clock to 5:30ish. The valves met pistons and totalled a fresh build in seconds. He mentioned it was "hard" to turn over with a socket... yeah no kidding. Obviously, no degreeing done.
Something went wrong with the closing event. Dial indicator slightly moved on tappet? I usually only go .050 before and after MAX lift and do the math. The cam appears to be close enough to run it with your 3* opening point. Max lift inline.
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carfreak6970
Well-Known Member
Just did the exhaust side and this is what I got:
Open at .050 was 57 deg BBDC (cam card says 56 deg BBDC)
Close at .050 was 5-6 deg BTDC (cam card has 2 deg BTDC)
Max lift at 123-116 deg BTDC (cam card has max lift at 119 BTDC)
So I am good?
Open at .050 was 57 deg BBDC (cam card says 56 deg BBDC)
Close at .050 was 5-6 deg BTDC (cam card has 2 deg BTDC)
Max lift at 123-116 deg BTDC (cam card has max lift at 119 BTDC)
So I am good?
You need to correctly follow a procedure like the intake centerline method. All you check is that your degree wheel is in the correct position indicating TDC and that your intake centerline (max intake lift) is at the correct position relative (109 degrees in your case). I would expect the cam timing to be close or right on lining up the dots. All the cams I have done except the last one were within 1 degree (the last one from Oregon Cams had to be advanced 2 degrees). There are some good videos out there like this one
carfreak6970
Well-Known Member
So the method you describe is the centerline method, the method I am using is the duration at .050” lift.
Wouldn’t it be easier/more accurate to do the duration at .050 since you would be able to see when the cam hits and leaves the .050” mark easier as opposed to the centerline method where it could be at max lift for more than 2 degrees of rotation?
The videos I have seen (like the one you posted) really don’t go into where to find the centerline of the lobe. Just that it’s at max lift, but they don’t address how it’s at max lift for more than one degree. And being that it is at max lift for more than one degree, I don’t see how you can find the true centerline. Unless I am missing something?
MOPAROFFICIAL
Well-Known Member
This reminds me how some people will find the middle of TDC and degree from that.. While others find the first degree of TDC and degree to that.
Rat Bastid
Dunamis Metron
The reason I don’t do the .050 lifter rise timing is because 1) There are way too many variables that affect it. Lifter bank angle variations is a big one and 2) You can have 10 lobes with the exact same .050 lifter rise and all of them will have different intake center lines.
IMO where that valve is relative to the piston at max lift if far more critical than where the valve is at .050 lifter rise (which is .075 valve opening with a 1.5 rocker and .080 at the valve with 1.6 rockers).
carfreak6970
Well-Known Member
First of thank you.
secondly I’d like to apologize for my misunderstanding. I had to reread this thread 3 more times to understand what’s going on. I swear I’m dyslexic.
But most importantly is where the center line (max lift) is in relation to crankshaft. I don’t know why I didn’t gather that from the beginning. Stay tuned.
I don't have a problem with this method. Check everything twice and make sure you get the same result.
Does that match the cam card?
carfreak6970
Well-Known Member
Okay so when I took the degrees at the .050" lift, found the duration, took the duration and devided that by 2, and add that to my .050" opening I was getting 107 for the centerline, which is wrong, the card says 109 degrees. So I moved the crank sprocket to the 2A position, lined up the corresponding 2A mark with the "O" mark on the cam gear and found TDC again. I decided to mark down the degrees at .050", 100" and .150" lift and I got the following information:
@ .050" lift - opens at 2 BTDC, closes at 40 ABDC (matches the cam card)
@ .100" lift - opens at 28 ATDC, closes at 9 ABDC
@ .150" lift - opens at 62 ATDC, closes at 155 ATDC
The duration between the opening and closing lift points:
@ .050" lift - 222 (matches the cam card)
@ .100" lift - 161
@ .150" lift - 93
The centerline according to those lift measurement points:
.050" lift - 109 (matches the cam card)
.100" lift - 108.5
.150" lift - 108.5
Id say I got it!! thank you for all your help and sticking with me through this! and again I apologize for my misunderstanding.
@ .050" lift - opens at 2 BTDC, closes at 40 ABDC (matches the cam card)
@ .100" lift - opens at 28 ATDC, closes at 9 ABDC
@ .150" lift - opens at 62 ATDC, closes at 155 ATDC
The duration between the opening and closing lift points:
@ .050" lift - 222 (matches the cam card)
@ .100" lift - 161
@ .150" lift - 93
The centerline according to those lift measurement points:
.050" lift - 109 (matches the cam card)
.100" lift - 108.5
.150" lift - 108.5
Id say I got it!! thank you for all your help and sticking with me through this! and again I apologize for my misunderstanding.
Yep, When max lift is covered by 6+ degrees, where is the true centerline. Then throw in assymetrical lobes... ugh.
That's why I like the Find max lift, then get readings coming up to the top and down the backside at .050 before and after max lift. Makes the math easy. Add two numbers together and divide by 2. Done. Don't have to worry about adding/subtracting opening and closing events, btdc or after tdc +180 nonsense. KISS method.
mopowers
Well-Known Member
Yep, that's how I've always done it. Max lift, then 0.100", 0.050", and 0.020" before and after just to make sure they all agree.
