First time cam degree

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turbovan

turbovan

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I'm running a craigslist 360 which had very little history other than stock bottom end, "small cam," and 2.02 stainless valves. The engine ran pretty strong, but would nose over HARD after 5200 rpm. I took it to 6k one time, but even in first gear it barely made it.
It sounded healthy at idle, but needed 1100 and 22" initial to pull 11 inches of vacuum, and if I set the idle lower it would stall in gear. Performed a compression check and although the numbers were a little spread, everything was within 10%.
Decided to swap in a new cam, and was surprised at what I pulled out; xe262h.
So I'm installing a summit 480/480 cam(cam card attached) using the existing double roller set. I've checked the cam timing about 8 times so far, checking tdc with a piston stop each time, and am coming up with 110-111 each time.

First question- Am I right to assume that this timing set may be retarded, and contributed to the xe262's idle and rpm issues?

Second question-I've ordered the summit billet timing set. Should I install the cam
At 107 per the manufacturer or advance it? I don't plan to take the motor past 6k.
The engine will be turbocharged.

IMG_8013.PNG
 
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Who sold you that cam for a turbo? I think I'd stop and get something different.

Straight up would be 112 by that card. I'm not a big fan of advancing the cam to make up bottom end. You are better off with the correct cam instead of crutching it.

I would not advance the cam if you are trying to get it to RPM.
 
yellow rose said:
Who sold you that cam for a turbo? I think I'd stop and get something different.

Straight up would be 112 by that card. I'm not a big fan of advancing the cam to make up bottom end. You are better off with the correct cam instead of crutching it.

I would not advance the cam if you are trying to get it to RPM.
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Forgive me I'm new. How did you arrive at 112? I'm doing something wrong because I thought I was trying to be at 107.

http://www.compcams.com/Technical/Instructions/Files/145.pdf
I used these directions
 
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When I looked at your cam card, I added up the 107 and 117 and divided by 2. Never seen a cam card like that.

If it is on a 107 LSA that is way to tight for a turbo. My numbers come up at 114-115 installed at 112-113.

Is there more to the cam card?
 
yellow rose said:
Just looked it up on the summit web site. It is on a 112 LSA. I would install it at 110 and let it go.
Click to expand...

I'm having a rough time and I feel like I'm missing something...
The number I'm arriving at on my engine through the intake centerline method as described by comp is 110 degrees. But the cam card says the intake lobe center should be 107. Does this not mean I'm 3 degrees retarded if I leave it this way?
 
turbovan said:
I'm having a rough time and I feel like I'm missing something...
The number I'm arriving at on my engine through the intake centerline method as described by comp is 110 degrees. But the cam card says the intake lobe center should be 107. Does this not mean I'm 3 degrees retarded if I leave it this way?
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No, the cam card doesn't say it goes in at 107. If you add the 107 and 117 and divide by two to get the intake centerline.

That is a piss poor cam card. Summit should do better. If you google the cam number you'll find all the specs and it's ground on a 112. If you get 110 you are right on. There's where I'd put it, and where I'd expect it to be.

Again, summit gives a Shitty cam card. You should be golden.
 
yellow rose said:
No, the cam card doesn't say it goes in at 107. If you add the 107 and 117 and divide by two to get the intake centerline.

That is a piss poor cam card. Summit should do better. If you google the cam number you'll find all the specs and it's ground on a 112. If you get 110 you are right on. There's where I'd put it, and where I'd expect it to be.

Again, summit gives a Shitty cam card. You should be golden.
Click to expand...

THANK YOU!
 
Your dropping out in gear is probably from needing a little extra fuel for idle/transition. Give her a little more (idle mix screws).
 
yellow rose said:
No, the cam card doesn't say it goes in at 107. If you add the 107 and 117 and divide by two to get the intake centerline.

That is a piss poor cam card. Summit should do better. If you google the cam number you'll find all the specs and it's ground on a 112. If you get 110 you are right on. There's where I'd put it, and where I'd expect it to be.

Again, summit gives a Shitty cam card. You should be golden.
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Nonsense, there is nothing wrong with the cam card. You add the 107 and the 117 and divide by 2 to get the 112 degree lobe separation angle (LSA). The cam card says 107 intake Lobe Center. It is to be installed at 107 intake centerline.

Nothing wrong with installing it at 110 ICL as you suggest.

Like my Dad would say, "Jimmy, you need to smarter than your cam card."
 
IQ52 said:
Nonsense, there is nothing wrong with the cam card. You add the 107 and the 117 and divide by 2 to get the 112 degree lobe separation angle (LSA). The cam card says 107 intake Lobe Center. It is to be installed at 107 intake centerline.

Nothing wrong with installing it at 110 ICL as you suggest.

Like my Dad would say, "Jimmy, you need to smarter than your cam card."
Click to expand...

Nothing wrong with installing it at 110, but it is to be installed at 107...?

So would 107 be optimal? I have a brand new adjustable timing set on the bench if this is the case...
 
I'm just reading the cam card. If I have no experience with a particular cam and a particular combination, when the card says, "do it this way" I do it the way the card says.
 
IQ52 said:
I'm just reading the cam card. If I have no experience with a particular cam and a particular combination, when the card says, "do it this way" I do it the way the card says.
Click to expand...

I guess "optimal" somewhat loaded the question. I just want the cam installed where the manufacturer recommends which I also thought was 107 until yellow rose said otherwise. Again, this is my fist time degreeing a cam so I just want to know what is correct.
 
More research shows I'm using the wrong wording.
When I originally said "straight up" I meant dot to dot...which is wrong.

So straight up would be 112 like yellow rose stated when answering my original question.

"Dot to dot" or where the manufacturer recommends install is 107 as IQ52 stated.

Is this right? Or am I confusing myself further...
 
turbovan said:
More research shows I'm using the wrong wording.
When I originally said "straight up" I meant dot to dot...which is wrong.

So straight up would be 112 like yellow rose stated when answering my original question.

"Dot to dot" or where the manufacturer recommends install is 107 as IQ52 stated.

Is this right? Or am I confusing myself further...
Click to expand...
According to me you are correct. In a perfect world, if the cam manufacturer ground 5 degrees advance in the cam, dot to dot would be 107 Lobe Center (or ICL) right where the card says it should be. When a cam is installed @ 112 ICL on a 112 LSA, I call that straight up. Some people do not. Some people call dot to dot straight up. But at least when I'm talking you know what I mean.
 
IQ52 said:
According to me you are correct. In a perfect world, if the cam manufacturer ground 5 degrees advance in the cam, dot to dot would be 107 Lobe Center (or ICL) right where the card says it should be. When a cam is installed @ 112 ICL on a 112 LSA, I call that straight up. Some people do not. Some people call dot to dot straight up. But at least when I'm talking you know what I mean.
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I thought you said dot to dot was 110? This is why I detest cam grinders grinding advance into the cam. It screws everyone up.

And that cam card sucks ***. If I bought a cam with that cam card I'd send it back.
 
Dang that is a mighty duration wide cam for a turbo. LSA would be fialry typical. What will you be doing with this engine and car? Street only? Race only? If so, what racing format?

Will you be running it non-turbo for a while? If so and you are running on the street, I would install it with the cam at the 107 ICL.
 
yellow rose said:
I thought you said dot to dot was 110? This is why I detest cam grinders grinding advance into the cam. It screws everyone up.

And that cam card sucks ***. If I bought a cam with that cam card I'd send it back.
Click to expand...

With my current chain dot to dot is coming out at 110, but at the beginning of this thread I thought dot to dot was synonymous with straight up.
 
nm9stheham said:
Dang that is a mighty duration wide cam for a turbo. LSA would be fialry typical. What will you be doing with this engine and car? Street only? Race only? If so, what racing format?

Will you be running it non-turbo for a while? If so and you are running on the street, I would install it with the cam at the 107 ICL.
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Well...advertised numbers are big, but the valve events on this cam are actually extreamly close to a LS1 stage 1 turbo cam. This cam also seems to only measure out at 224 degrees as apposed to the 228 stated by summit. I'll be running either an on3 7875 or gt45 turbo and both have decent size (78mm) exhaust wheels so the overlap shouldn't be a huge concern. The car is just a toy, but it may see the track once a month or less for test and tune fun. I have zero problem pulling the cam for something custom in the future.

I will be running it non turbo for the next month or two, and will be installing it at 107-108.
 
turbovan said:
With my current chain dot to dot is coming out at 110, but at the beginning of this thread I thought dot to dot was synonymous with straight up.
Click to expand...


Well, technically it is.

Because if you wanted to advance a cam, say 4 degrees (which to Comp is the de facto number now) you had to use offset keys or bushing if you didn't have a GOOD gear drive or multi key way gears. To make it easier, cam companies started grinding the cams with the advance built it. This made it so guys who didn't have multi key way gears or offset keys or bushings would likely get the cam "straight up" by lining up the dots. All cams should still be degreed in regardless.

That's why I was confused by the cam card. If you have it dot to dot it should be at 107. Why they want it 5 ahead I have no idea. If at dot to dot it's at 110 it's possible you have 3 degrees of tolerance stack up in the system.

Me, I'd leave the thing at 110. With chain stretch it will run closer to 112 though. I'm not a fan of my cam grinder designing a cam with advance built in, or dual pattern cams (most of the time).

That's just me though.
 
OK, well on thing about turbo cams is the exhaust profile, and how fast it opens; higher pressure pulses typically get the turbo spinning earlier and help the lag. I don't really know what you are wanting and expecting from the turbo: coming in at low to mid range RPM's or just higher RPM's.

If I get the chance, I may look up those models just to see what they are.
 
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