[RLM66SS]

http://i1215.photobucket.com/albums/cc503/ronmoye/IMG_0635.jpg[/IMG][/URL]

I am having trouble setting this cam up based on the cam card provided. I am trying to use the intake valve open degree but it seems off. I just start to get lift at 49 degrees and don't see the 35 the card says until about .007 lift. Clay smith told me this cam should have an ICL of 103 /104 and I do get 104.5 so it seems close buy Chris wanted me to use the Valve events as my guide. What gives.... ?
Let me just say that YES my TDC is acuurate and repeatable. I have a e- mail into Chris but since it is the weekend I am not expecting to hear from him until Monday which is completely understandable. I was just hoping to get this thing dialed in this weekend. Any thoughts or suggestions are appreciated!!

 

[RB69SS396Conv]

If the ICL is where it's supposed to be, then .... it's degreed right. That's how it's done, not by the flanks of the ramps.

Most cam mfrs "rate" the beginning and ending of their valve action at .006" of lobe lift. If you're seeing the "rated" duration at .007" lobe lift, I'd say that's PLENTY close enough.

There comes a time when it turns into "measure with micrometer, mark with chalk, cut with axe". Sounds like you're there.

Time to put the timing cover on.

 

[RLM66SS]

If the ICL is where it's supposed to be, then .... it's degreed right. That's how it's done, not by the flanks of the ramps.

Most cam mfrs "rate" the beginning and ending of their valve action at .006" of lobe lift. If you're seeing the "rated" duration at .007" lobe lift, I'd say that's PLENTY close enough.

There comes a time when it turns into "measure with micrometer, mark with chalk, cut with axe". Sounds like you're there.

Time to put the timing cover on.

The problem I have is the card doesn't list the ICL. Guy at Clay Smith just rattled off the 103/104 numbers. He didn't ask for the grind number or info about the cam. How do I know what he is saying is correct? Is it just me or does that card I have the link to seem like it lacks info?

 

[Dave Birdwell]

I think it should say "degree intake lobe to xxx", but most of chris's stuff is on a 103 icl anyway. What does the cam read at the other three degree points??
I like the bullet cam cards, they give the events at .050 lift. No guessing there.

 

[RLM66SS]

I think it should say "degree intake lobe to xxx", but most of chris's stuff is on a 103 icl anyway. What does the cam read at the other three degree points??
I like the bullet cam cards, they give the events at .050 lift. No guessing there.

The a link to the card is in my first post. it gives intake open / close and Exhuast open / close but doesn't state if at .xxx lift or anything...?

 

[Bluegoose1970]

Off their site your 103/111 centers with a 107 LSA.
As far as I know, lift should be at 0.050 same as the duration for timing events.
I will post a pict, will not upload from my phone.


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[Bluegoose1970]

This is off Clay Smith Cams for your cam #. And pretty sure lift is at .050" run it and see what your center is.

 

[RB69SS396Conv]

It's right there on the card, clearly written in all that white space.

Int opens at 35° BTDC, closes at 69° BTDC. Obviously it's open for 180° in between that: it opens as the piston approaches TDC, stays open for the whole int stroke as the piston goes all the way from TDC to BDC (half a rev, or 180°), and closes shortly after the piston starts coming back up. So:

35° + 180° + 69 = 284

This is the total duration between "lash" points. That would be the cam's "advertised" duration.

Divide by 2 (this makes the assumption that the lobes are symmetrical, which may or may not be true, so there is a possibility that it's not perfectly accurate) to figure out what one half of the lobe is. That's 141°. Subtract the part of it that's before TDC, which is 35°. That leaves you with 106°.

That's the ICL, right straight off the cam card.

To degree the cam, find the peak opening, then find the points at which the lift is some small amount less than that; say, .015" less. Exact # you use doesn't matter as long as it's something you can easily find, see, and measure repeatably. You could use .010", .015", .030", etc.; whatever works best in the exact situation at hand. The true ICL is halfway between those 2 points. You should be able to read your degree wheel with sufficient precision to verify that.

Now: what happens to timing chains after they've been running for awhile? Think hard. They "stretch", right? Now when that happens, which way does the cam timing go? Does it advance itself? No. It retards itself. That means, whatever you measure today on the engine stand, is the farthest advanced the cam will ever be for all eternity; for the rest of time, it will always be retarded from there. Since the ICL is measured as ATDC, smaller #s correspond to "advance", larger #s to "retard". Meaning, if you install it at 104.5° TODAY, then when the chain "stretches" (wears, actually) 1.5°, the cam will be right exactly where the card says it is. But of course, how much does a chain "stretch"? Right: I don't know either. So no matter how much "measure with micrometer" you put into this process, the numbers IN REALITY are still "fuzzy" to that extent; that's the "cut with axe" part.

I'd say you're about as close as you can realistically get, and CERTAINLY closer than you need to be to predict the engine's long-term behavior. Time to put the timing cover on.

 

[RLM66SS]

This is off Clay Smith Cams for your cam #. And pretty sure lift is at .050" run it and see what your center is.

Chris wanted me to use the valve events for my set up. Card says intake opens at 35 and closes at 69. Is 35 from just off the base or at some lift?? can't tell by card.

 

[Bluegoose1970]

I think it should say "degree intake lobe to xxx", but most of chris's stuff is on a 103 icl anyway. What does the cam read at the other three degree points??
I like the bullet cam cards, they give the events at .050 lift. No guessing there.

X2 You are going to degree at the lift stage of the cam. Every cam I degree is at .050 to give you a readable lift to dial it in, lift is under this point is spread out too much and in smaller increments. Measuring at .006" lift would give a chance of too many degrees error with the type of measuring tools most people have.

 

[Bluegoose1970]

Chris wanted me to use the valve events for my set up. Card says intake opens at 35 and closes at 69. Is 35 from just off the base or at some lift?? can't tell by card.

You are trying to verify you are on center, according to their site, 103 is your center. You can use any lift point you want to find center. Most lift points on cam cards are at .050 , run your cam, at .050 record the degrees. If it is to your card, you are on center. Another way is at the degrees on the cam card 35 and 69 record your lift, they should be the same, if not you are off.

 

[Wolfplace]

The problem I have is the card doesn't list the ICL. Guy at Clay Smith just rattled off the 103/104 numbers. He didn't ask for the grind number or info about the cam. How do I know what he is saying is correct? Is it just me or does that card I have the link to seem like it lacks info?

Yes it lacks info. No offense to Clay Smith but that cam card sucks.
It is damn near impossible to use seat to seat timing to degree a cam the movement at the seat is to small per degree, very easy to make a mistake

Also that card is showing a 107 ICL with no advance in the seat to seat numbers which is kind of stupid if they want it advanced to a 103

If you want to use open & close use .050 lift numbers.
In your case subtract 29.5° from the open & close numbers or intake 5.5 open & 39.5 close for 107 & 9.5 open / 35.5 close for 4° advance.
Personally I would just use 103 ICL ±1° if it were me

The other thing you want to be real sure about is your TDC start point, check it a couple of times because if this is off,,, everything you do from here is screwed up

 

[Bluegoose1970]

FYI, that is the back of a bullet cam card, surprised Clay Smith does not have degree instructions on back.
Sorry, front side of card is a secret.

 

[Wolfplace]

You are trying to verify you are on center, according to their site, 103 is your center. You can use any lift point you want to find center. Most lift points on cam cards are at .050 , run your cam, at .050 record the degrees. If it is to your card, you are on center. Another way is at the degrees on the cam card 35 and 69 record your lift, they should be the same, if not you are off.

The numbers on that card are seat to seat & it shows no advance so why would he use 35 & 69? That is a 107 ICL
Also no mention of .006 or whatever they are using as "advertised" duration, no mention of ICL for those numbers which are not at 103,,,,,,,,
I do this every day & had to think about it a couple of times,,,
I can see why Ron is confused

 

[Bluegoose1970]

The numbers on that card are seat to seat & it shows no advance so why would he use 35 & 69? That is a 107 ICL
Also no mention of .006 or whatever they are using as "advertised" duration, no mention of ICL for those numbers which are not at 103,,,,,,,,
I do this every day & had to think about it a couple of times,,,
I can see why Ron is confused

That why you are the man:thumbsup:, I never ran his card, that is confusing. On their site it shows 103 center, but Chris told him to do timing events which are 107 center.
I am sorry, did not run it, but it is obvious, now that I did. Running around with my head cut off.
I would run it at .050 , see what the ICL is at, if 103 +-1 then its good or wait for Chris to answer.

 

[Bluegoose1970]

Ron, I have been confused before too. Billet adjustable timing set, had to jump a tooth to make ICL. If you look at the bolts, I adjusted them to death. Finally realized either the cam or gear set was off. Everything went smooth and used timing set to advance 4 deg. J was a mistake, Y is the correct. JOY is being done after that. Good Luck!

 

[RLM66SS]

Yes it lacks info. No offense to Clay Smith but that cam card sucks.
It is damn near impossible to use seat to seat timing to degree a cam the movement at the seat is to small per degree, very easy to make a mistake

Also that card is showing a 107 ICL with no advance in the seat to seat numbers which is kind of stupid if they want it advanced to a 103

If you want to use open & close use .050 lift numbers.
In your case subtract 29.5° from the open & close numbers or intake 5.5 open & 39.5 close for 107 & 9.5 open / 35.5 close for 4° advance.
Personally I would just use 103 ICL ±1° if it were me

The other thing you want to be real sure about is your TDC start point, check it a couple of times because if this is off,,, everything you do from here is screwed up

Wolf,

I was hoping you would see and chime in on this. Granted this is my first time degreeing a cam. I understand the proceddure and have the tools to do it. I just couldn't figure out what the heck to set it to based on the info provided. So I will try for 103 ICL. I have checked my TDC too many times to count and It repeats so I think I am good there. I got 104.5 ICL now with it straight up. I think I might advance the crank sproket 2deg and see how well that does. Any suggestions on how much "pre-advance" if any for chain strech? Rollmaster Gold series. Does anyone do that? Try and build in some advance for strech??

 

[Wolfplace]

Wolf,

I was hoping you would see and chime in on this. Granted this is my first time degreeing a cam. I understand the proceddure and have the tools to do it. I just couldn't figure out what the heck to set it to based on the info provided. So I will try for 103 ICL. I have checked my TDC too many times to count and It repeats so I think I am good there. I got 104.5 ICL now with it straight up. I think I might advance the crank sproket 2deg and see how well that does. Any suggestions on how much "pre-advance" if any for chain strech? Rollmaster Gold series. Does anyone do that? Try and build in some advance for strech??

Try it two advanced & see what you get. If it actually moves only 2° that is where I would leave it.
I do not lead it for chain stretch, you have an excellent chain so it should be a long time before this is a worry but your thinking is correct, if you want it at 103 running with a good chain 102 is not a bad place to be,,,

 

[RLM66SS]

Well I played around with it and have it at 102. That seems better than my origion 104.5. Might just have to leave it alone...

 

[Wolfplace]

Well I played around with it and have it at 102. That seems better than my origion 104.5. Might just have to leave it alone...

:thumbsup:

Now if you wish you can go back & check the .050 open & close numbers
They should be very close to 10.5 & 34.5