Attempting to degree the cam...

[2Luke2]

Hello Everyone! I hope you're having a great weekend so far! Lisa and I are since we are putting our engine together.

So anyway Lisa and I are trying to degree our camshaft, but we are getting some numbers that are way off of what they should be... hoping someone can point us in the right direction.

We have installed the crank, pistons, cam and timing chain. We installed the gears/chain heads up or dot to "O" according to the instructions in the timing chain box.

We then proceeded to find true TDC. We put a stop on piston 1(no heads are installed. We then rotated the engine clockwise until it hits the stop and we record the number on the degree wheel which lets say it was 13. We then rotate the engine counter clockwise until the piston hits the stop at 11. We then loosen up the degree wheel and adjust one degree. We then retest and get 12 going clockwise and 12 going counter clockwise. So we now have true TDC ( or so we think).

So now we are trying to validate some cam card specs. According to the cam card at .006 lift the intake should be 37. Well... this is where shit hits the fan... We are getting 155 degrees... No idea, but we have retried to make sure we were getting the right TDC numbers, but it keeps coming out very close the same and no where near the 37.

We are using an dial indicator on the top of the lifter in the intake bore which is the 2nd one from the front on the number one cylinder ( or so we think?).

Anyway hopefully we gave enough information for someone to point out what the heck we are doing wrong.

We have also tried to do the .050 before and after max lift and then take the two numbers and divide by 2, but that isn't coming anywhere near the duration @ .050 like we think it should.

Any help would be greatly appreciated.

Oh btw... cam card specs.
We are using an XE285HL-10 hydraulic flat tappet.

Grove Valve Lift .545/.545
Duration @ .006 tappet lift 285/297
Duration @ .050 241/247
Lob Sep: 110
ICL: 106

Thanks
-Lisa and Luke

[heyoldguy]

The first lobe on the camshaft from the front of the engine is #1 exhaust, 2nd is #2 exhaust and the 3rd lobe is #1 intake.

[ws23rt]

Just to be clear. The indicator is set loaded on zero with cam lobe at max lift.
Rotate engine clockwise (engine rotation) till cam lobe is approaching max lift again and stop at .050 on indicator before max lift. Note degrees
Continue to .050 indicated after max lift. Note degrees.
Add the two degree numbers and divide by 2.
This is the cam center line not the duration.
Your spec. says it should be 106.
If your number is different that means you need to adjust the cam one way or the other to get 106.
Example--If you come up with 110 you need to advance the cam 4 degrees.
BTW if you are within one degree either way you are done.

[2Luke2]

Thanks for responding Oldguy. We are using the 2nd lifter hole from the front of the engine going back on the number one cylinder.



Ws23rt: We tried it loaded as well and came up with  way low numbers. It should be 106 like you said, but we got 35 at @.050 after max lift and 45 @ .050 after max lift. Which is obviously way off. Since it was pretty late we are going to try again and see if we were just tired and misding something basic, but the procedure seems pretty straight forward so I'm doubtful.

Thanks for trying to help out! We greatly appreciate it!

[2Luke2]

Ok so we found true tdc again by placing a stop over the piston. We then rotated the crank clockwise until the piston hit the stop. It was at 9, then we turned the crank counter clockwise and it came up at 14. So we moved the degree wheel 2.5 degrees towards the 9. After we got true tdc we then zeroed the dial indicator at max lift of the number one cylinder's intake lifter. We then turned the engine clockwise until the gauge read .050 we recorded a number of 35. We then turned the engine counter clockwise until the dial went past max lift and back to .050 and recorded 61. So we are supposed to add those two numbers and divide by 2 in order to get our duration at .050. Or so we think.

We also tried to zero our indicator on the heel of the lobe, then we turned the engine clockwise until the lifter started to come up and the gauge reads .006 our intake is supposed to read 37 at this point, but instead the wheel was pointing at 155.

So there has to be something we are doing completely wrong here. Clockwise to the right and counter clockwise to the left.... The comp cams timing chain said to align the dot of the camshaft gear to the "O" not zero on the crankshaft gear. Does this sound right?

[ws23rt]

I am missing something in what you said. "at .006 lift the intake should be 37" ?
At .006 opening until .006 from closing should be a total of 285/297
You got 155 at .006 open and as you continue till .006 before closing that number should add to the 155 and be close to the 285-297 (291)

[ws23rt]

I think I see it. Or at least part of it. You are turning the crank shaft back and forth.

Start at the max open indicator zero.
Turn engine clockwise (almost two turns) till the cam comes up to .050 before max. Record deg.
Continue clockwise until .050 after max open. Add this deg. to the first deg. and divide by two

[2Luke2]

Sorry what we meant was that after we zeroed the indicator on the heel of the intake lobe we turned the engine clockwise until the indicator read .006. According to the cam card @.006 open the intake should read 37 degrees BTDC. Unless we are just misunderstanding the card?

We will try to measure from .006 open to .006 closing to see if we come up with the 285.


We just saw your next reply while writing this one. We will try that and see what happens. Thanks a ton for helping us out.

[2Luke2]

Ok so we turned the engine until we were at max lift and then zeroed the indicator. We then continued to turn the engine clockwise until the dial read .050 before max lift and the degree wheel read 34 and then we turned the engine clockwise until the indicator hit 0 or max lift and then started to drop we then recorded the degrees at .050 after the gauge started to drop which was 60. So 94/2= 47? What number should that reference on the cam card?

[2Luke2]

I think I see some of our issue. We lined up the dot and the "O" like the timing chain said to do, but we didn't put the crank keyway into the 0 slot. Going to see if that gets us closer.

[ws23rt]

    Hmm  the degree wheel is on the crank shaft?  

[2Luke2]

Ok now the numbers are a lot closer and actually mean something.

We got 112.5, but that could us going a bit over or under .050 before and after max lift. Going to try to get it again. and get with in 1 degree like you mentioned. Since it's already ground with 4 degrees of advance it should read 110 to be on target correct?

[ws23rt]

Your target is 106. So if you advance 6 deg that should be it. That is if I am thinking the right direction.
You will see if you went the right way when you re check it.

BTW we don't need to tell anyone about that key in the crank

I am not familiar with the what you say is a 4 degree advance grind I would follow the cam instructions as to the center line set up.

[2Luke2]

Ok... so we did it again and this time we got 106.75...  Being over 6 degrees off is a bit much... but 106 would suggest we are going in the right direction. Though I was thinking that since it's already ground with 4 degrees advance we should see that and our number should be closer to 110.

But I guess we don't know much about this so we could be totally off in our understanding of the numbers.

About the crank... yea I won't tell anyone else haha.. That's what we get for trying to work until 2am on putting everything together.



Thanks so much!!!

[ws23rt]

You are welcome.  I do like these puzzles though

[2Luke2]

You are welcome.  I do like these puzzles though

You can bet there will be more soon haha!!! 

[firefighter3931]

Here's a good step by step tutorial from Comp Cams : http://www.compcams.com/technical/instructions/files/145.pdf

I like this method because it's relatively easy once you get organized 

Luke, if you're at 106.5 with the crank sprocket in the "straight up" key then you're good to go. Comp does grind in 4* of cam timing advance so with the timing set lined up in the straight up position you should be reading a 106* intake centerline    I wouldn't worry about half a degree 


Ron

[Kern Dog]

This stuff sucks. I'm dealing with similar crap with my engine. There are some procedures that people enjoy doing and others that are totally annoying.
Good luck to us all.