What affect does advance ground into a cam have?
10-22-2003, 04:44 PM
#1
What affect does advance ground into a cam have? I have recently seen several cams advertised with 0, 2, or 4 degrees ground in them. What affect does this have? Does it affect P to V clearance, peak power or tq, rpm where peak hp or tq occurs, or what?
Thanks, Shawn
Thanks, Shawn
10-22-2003, 05:47 PM
#4
Re: What affect does advance ground into a cam have?
From what I have been told:
Advancing the Cam will....
1) Lower the RPM where motor makes peak HP
2) Increase cylinder pressure by changing the intake valve's closing point.
Advancing the Cam will....
1) Lower the RPM where motor makes peak HP
2) Increase cylinder pressure by changing the intake valve's closing point.
10-22-2003, 06:43 PM
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Re: What affect does advance ground into a cam have? So how is getting a cam on a 114+4 different from getting one on a 118? That's what I don't understand. Are they the same?
-Geoff
-Geoff
10-22-2003, 06:58 PM
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Re: What affect does advance ground into a cam have? Trending Topics
10-22-2003, 08:43 PM
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Re: What affect does advance ground into a cam have? A 114+4 gives an ICL of 110. Which would be like a 110LSA with no advance/retard. You can get the same Intake Center Line was a 110 without the negative affects of such a tight LSA.
10-22-2003, 08:54 PM
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Re: What affect does advance ground into a cam have?
A 114+4 gives an ICL of 110. Which would be like a 110LSA with no advance/retard. You can get the same Intake Center Line was a 110 without the negative affects of such a tight LSA.
10-23-2003, 06:14 AM
#10
Re: What affect does advance ground into a cam have? So, for example, a 230/230 110lsa, and a 230/230 114+4 would both idle the same? I thought that 110 would idle worse than a 114, you're saying that the +4 would make it idle as rough as a 110? 
Aren't ICL and LSA two totally seperate, unrelated things?
Aren't ICL and LSA two totally seperate, unrelated things?
10-23-2003, 09:29 AM
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Re: What affect does advance ground into a cam have? Spanky I was wonderin the same thing, as this was going way over my head. Check out that CC timing tutorial, helped me out quite a bit. Should be required reading!! 
10-23-2003, 01:49 PM
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Re: What affect does advance ground into a cam have?
So, for example, a 230/230 110lsa, and a 230/230 114+4 would both idle the same? I thought that 110 would idle worse than a 114, you're saying that the +4 would make it idle as rough as a 110? Aren't ICL and LSA two totally seperate, unrelated things?
Aren't ICL and LSA two totally seperate, unrelated things? im a little lost too. and gonna be really pissed if the cam i ordered 230/230/114 +3 idles like a 110lsa cause its going in my a4 car and i wanted a decent idle with a lower powerband. please tell me that this cam is not going to be comparable to a 110lsa....
10-23-2003, 01:54 PM
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Re: What affect does advance ground into a cam have? No, the a 114 with 4 degrees of advance will not idle the same as a 110LSA. All it means is that the intake centerline will be the same as a 110. Intake centerline is when the intake valve reaches max lift (in this case, 110 degrees). It just changes when the valve opens and when it closes, which affects cylinder pressure and how high the power peaks. By changing when the valve is open, it also changes P to V clearance. Read that link, it has some good info.
10-23-2003, 02:14 PM
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Re: What affect does advance ground into a cam have? Should the cam card say +4 on it somewhere??? MY cam card says 112lsa and 108icl but nothing about +4 advance and the place where I got the cam from said that Comp didn't grind the advance in and I should do it with an adjustable timing chain so I did.
10-23-2003, 02:25 PM
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Re: What affect does advance ground into a cam have? No, my cam is advanced 4 degrees and it is not on the cam card stating that. What size cam do you have, 2001 Pewter WS6? I might be wrong about all this, I am not a cam expert by any means, but that is what I always understood.
10-23-2003, 02:34 PM
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Re: What affect does advance ground into a cam have? I have a 236/240 .602/.608 112LSA 108ICL. I advanced the cam +4 via adjustable timing chain. So you are all saying that a cam with no advance would havd the same LSA and ICL???
10-23-2003, 02:38 PM
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Re: What affect does advance ground into a cam have? thanks qwick ws6 i was a little worried . i read the article but i didnt know that much about it to begin with so now it makes more sense .
10-23-2003, 02:48 PM
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Re: What affect does advance ground into a cam have? Don't confuse lobe seperation angle (LSA) with intake centerline (ICL). If your cams lobe seperation is 112 degrees, that is the physical space (in degrees of 360) that seperates the intake peak and exhaust peaks. This is ground into the cam at manufacture and cannot be changed. Intake Centerline is the angle in relation to piston top dead center (TDC) where the intake valve reaches its peak. If you set ICL to 112 atdc degrees on a cam with an LSA of 112 degrees it is said to be installed "straight up". Higher (>112) is cam retarded and lower (<112) is advanced. Decreasing the ICL means that the cam will arrive to its peak sooner with relation to TDC. Get it?
Adding advance lowers the peak and gives you more low end or off the line torque but sacrifices top end power as the peak will roll off sooner. It's not this simple but when you consider intake manifold, exhaust, gearing and stall you can determine where a cam ICL should be set. Most times, it's just trial and error and / or experience that determines the ICL.
Adding advance lowers the peak and gives you more low end or off the line torque but sacrifices top end power as the peak will roll off sooner. It's not this simple but when you consider intake manifold, exhaust, gearing and stall you can determine where a cam ICL should be set. Most times, it's just trial and error and / or experience that determines the ICL.
10-23-2003, 03:56 PM
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Re: What affect does advance ground into a cam have? So by looking at the cam card, how can you determine how much advance is actually groud in? Or do they always stamp the end of the cam???