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Old 08-13-2018, 10:25 AM   #1
Firehawk321
 
Drives: 2010 SS Camaro
Join Date: May 2017
Location: Oklahoma
Posts: 34
I'm getting a new cam install, but I dont know much about the numbers on cams

So I just took my 2010 camaro to a shop and they are going to a pro charger, injectors, fuel pump, dod delete, torque converter, and a cam. They said the cam specs are
Int. exh
Adv dur. 227 297
Dur @ .050 227 244 lope sep 115.0
Valve lift. .613 .596


Can anyone explain these numbers to me, and this is a pretty big cam right? Thanks
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Old 08-13-2018, 11:05 AM   #2
metrogdor22
 
Drives: 2013 2SS M6
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Int. and Exh. are Intake and Exhaust, so the numbers below them correspond to the Intake and Exhaust lobes respectively.

Adv. Dur. is Advertised Duration, or the angle in degrees of crankshaft rotation that the valve is open for. For example, your intake valve opens, then 227 degrees of crankshaft (113.5 degrees of camshaft) rotation later, the intake valve closes. Advertised Duration varies from one manufacturer to the other because they define "open" and "close" differently.

Dur @ .050 is a standardized version of Advertised Duration. .050-lift duration is measured from the point where the cam moves the lifter up .050 inch until .050 inch before the lifter is all the way back down.

Lobe Sep. is Lobe Separation, which is the angle in degrees between the peak of the intake lobe and the peak of the exhaust lobe. You might see a number behind this such as +4. That's advance ground into the cam. So if it were 115.0+4, the valves would open 4 degrees sooner than stock.

Valve Lift is how much the valve opens or closes at its peak.

For reference, stock LS3 cam specs are

Intake Exhaust
Duration @ .050 in.: 204/211
Valve Lift: 0.551 in./.525 in.
Lobe Sep: 117

So you have a good bit more duration (the valves are open for longer), some more lift (the valves open more), and a bit tighter separation (your idle will be a little choppy). It's a bigger cam than stock, but nothing crazy. It's close to a BTR Stage 3 N/A cam with more exhaust duration and not as tight separation.
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Old 08-13-2018, 11:24 AM   #3
Firehawk321
 
Drives: 2010 SS Camaro
Join Date: May 2017
Location: Oklahoma
Posts: 34
Quote:
Originally Posted by metrogdor22 View Post
Int. and Exh. are Intake and Exhaust, so the numbers below them correspond to the Intake and Exhaust lobes respectively.

Adv. Dur. is Advertised Duration, or the angle in degrees of crankshaft rotation that the valve is open for. For example, your intake valve opens, then 227 degrees of crankshaft (113.5 degrees of camshaft) rotation later, the intake valve closes. Advertised Duration varies from one manufacturer to the other because they define "open" and "close" differently.

Dur @ .050 is a standardized version of Advertised Duration. .050-lift duration is measured from the point where the cam moves the lifter up .050 inch until .050 inch before the lifter is all the way back down.

Lobe Sep. is Lobe Separation, which is the angle in degrees between the peak of the intake lobe and the peak of the exhaust lobe. You might see a number behind this such as +4. That's advance ground into the cam. So if it were 115.0+4, the valves would open 4 degrees sooner than stock.

Valve Lift is how much the valve opens or closes at its peak.

For reference, stock LS3 cam specs are

Intake Exhaust
Duration @ .050 in.: 204/211
Valve Lift: 0.551 in./.525 in.
Lobe Sep: 117

So you have a good bit more duration (the valves are open for longer), some more lift (the valves open more), and a bit tighter separation (your idle will be a little choppy). It's a bigger cam than stock, but nothing crazy. It's close to a BTR Stage 3 N/A cam with more exhaust duration and not as tight separation.
Thank you so much that made it really easy to understand.
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Old 08-13-2018, 12:07 PM   #4
acammer
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That cam has 5.5* of overlap. That's a good deal more than stock, but not really wild. You'll hear it, but it's not going to be like an aggressive NA cam. A cam specific for positive displacement boost (in a fairly mild street application) tends not to have a large amount of overlap as it bleeds boost right out the exhaust.

By comparison, the biggest NA "shelf" (can be run with stock heads without cutting valve reliefs) cam's for these cars like the BTR Stg4, TSP F-35, GPI SS3 all have 15-19* of overlap and are significant more choppy (and less friendly).

It looks like a good cam for your setup, it should make for a very nice combo that makes STRONG power everywhere on the street. It's not going to run out to 7500rpm - but with all that torque who needs to!?
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