Is a .623 intake .623 exhaust 112 lsa cam to much cam for....
08-06-2012, 05:35 PM
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Is a .623 intake .623 exhaust 112 lsa cam to much cam for.... I found a new 6.23 /.623 cam for pretty cheap. I was wondering if it will be too big to run in my 4.8L with a 76 or 88mm turbo?? I currently currently have a .212/.218 114 lsa low lift cam. I dont know if the cam I have will be good enough. I also have .650 and .675 dual springs that I will use with them.. Not sure which set yet tho...
Any comments on this huge cam??
Any comments on this huge cam??
08-07-2012, 06:40 AM
#4
Others might argue but I don't see a prob with it. 212@.050''/.561'' is enough to run solid 9's in my 76mm 4850 LB 6.0L truck. 212/218 .530'' ish isn't that bad for a 76mm 4.8L. One thing to consider these turbo cars, and trucks almost always mph, but the problem often is getting them off the line. Also valve control is just as important as the valve events. At .62x'' is going to be pretty aggressive lobe unless duration is 240* +, and you will be pushing your luck with the ptv clearance as well. JMO
08-07-2012, 07:56 AM
#5
The peak lift # isn't what makes a cam "big". It is the larger duration.
A 218° .550"ish 115° would work wonders on a small turbo motor. If you want a little more aggressive idle the 112° LSA will do it.....but turbo motors generally like a wider lobe seperation angle.
A 218° .550"ish 115° would work wonders on a small turbo motor. If you want a little more aggressive idle the 112° LSA will do it.....but turbo motors generally like a wider lobe seperation angle.
08-07-2012, 08:28 AM
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ok I see... The LSA is what makes a big cam... Thanks for that info... seems like I already have a decent cam for a turbo in the low lift I already have.
08-07-2012, 01:33 PM
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Depends on how high you want to rev.
There's a guy on TTF w/4.8, 230/236, PT88, and 4.11 or more, and he shifts at 7500 or so.
But he describes it as like two different trucks. It doesn't really spool till 5k.
LSA = Big - not really.
I called Duttweiler once, well, several times until they answered.
But for a gen 1 350 and a 215 or so hyd flat cam, he said 112 LSA.
HR's are a little bigger at .006 than a flat tappet but you still only add a degree or so for that maybe.
I called an old timer cam designer once for a 6.0 and 6200 shift. He came back with a 219/219 113 iirc.
It really depends on what parts you are using in the whole combo. Heads, CR, turbine size, fuel, and desired shift point.
For a stock 4.8 street build, I say a 212 if you already have it or an LS9 cam with a 67-76 turbo and the more strip use the bigger in that range. Note - a 76HPSH or BW475 will do at least 1k fhp on a 4.8.
There's a guy on TTF w/4.8, 230/236, PT88, and 4.11 or more, and he shifts at 7500 or so.
But he describes it as like two different trucks. It doesn't really spool till 5k.
LSA = Big - not really.
I called Duttweiler once, well, several times until they answered.
But for a gen 1 350 and a 215 or so hyd flat cam, he said 112 LSA.
HR's are a little bigger at .006 than a flat tappet but you still only add a degree or so for that maybe.
I called an old timer cam designer once for a 6.0 and 6200 shift. He came back with a 219/219 113 iirc.
It really depends on what parts you are using in the whole combo. Heads, CR, turbine size, fuel, and desired shift point.
For a stock 4.8 street build, I say a 212 if you already have it or an LS9 cam with a 67-76 turbo and the more strip use the bigger in that range. Note - a 76HPSH or BW475 will do at least 1k fhp on a 4.8.
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08-08-2012, 08:08 AM
#8
What makes a cam "act big" are really the duration of the lobe and the LSA. A longer intake duration will make more power, but USUALLY higher in the rpm range. And you USUALLY need a longer exhaust duration to evacuate all of that which the intake took in. That combined with LSA or lobe seperation angle creates an area of overlap-----where both intake and exhaust valves are open.
It is a small triangle at the bottom of a lobe diagram. If this triangle of overlap is large---the cam will probably chop harder at idle....sounding "big". It will also have a "hit". Meaning if in 4th gear at 20mph you smash the throttle to the floor, at a certain rpm you will feel the valve events come in line with the intake manifold and exhaust system in harmony and the car will lunge forward and really start to move.
If on the other hand the overlap is fairly small, and the LSA is larger the cam will have a broader power range, and less of a hit and more of just a constant push. A turbo likes a larger LSA because it minimized the time that both valves are open. When both valves are open some of the boost will leak right out the open exhaust valve.
Combination, coimbination, combination. Pick a cam based on what heads, intake, exhaust, driving style, REAL USE OF THE CAR (that one is important). Lift is not going to be that critical on a boosted car. Talk to PatG and be serious about answering the questions and he will get you a cam that is worth the money. Or just put in a Z06 cam and enjoy!
If any of that information above is off base the experts can just pick it apart.
It is a small triangle at the bottom of a lobe diagram. If this triangle of overlap is large---the cam will probably chop harder at idle....sounding "big". It will also have a "hit". Meaning if in 4th gear at 20mph you smash the throttle to the floor, at a certain rpm you will feel the valve events come in line with the intake manifold and exhaust system in harmony and the car will lunge forward and really start to move.
If on the other hand the overlap is fairly small, and the LSA is larger the cam will have a broader power range, and less of a hit and more of just a constant push. A turbo likes a larger LSA because it minimized the time that both valves are open. When both valves are open some of the boost will leak right out the open exhaust valve.
Combination, coimbination, combination. Pick a cam based on what heads, intake, exhaust, driving style, REAL USE OF THE CAR (that one is important). Lift is not going to be that critical on a boosted car. Talk to PatG and be serious about answering the questions and he will get you a cam that is worth the money. Or just put in a Z06 cam and enjoy!
If any of that information above is off base the experts can just pick it apart.
08-10-2012, 10:44 AM
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What makes a cam "act big" are really the duration of the lobe and the LSA. A longer intake duration will make more power, but USUALLY higher in the rpm range. And you USUALLY need a longer exhaust duration to evacuate all of that which the intake took in. That combined with LSA or lobe seperation angle creates an area of overlap-----where both intake and exhaust valves are open.
It is a small triangle at the bottom of a lobe diagram. If this triangle of overlap is large---the cam will probably chop harder at idle....sounding "big". It will also have a "hit". Meaning if in 4th gear at 20mph you smash the throttle to the floor, at a certain rpm you will feel the valve events come in line with the intake manifold and exhaust system in harmony and the car will lunge forward and really start to move.
If on the other hand the overlap is fairly small, and the LSA is larger the cam will have a broader power range, and less of a hit and more of just a constant push. A turbo likes a larger LSA because it minimized the time that both valves are open. When both valves are open some of the boost will leak right out the open exhaust valve.
Combination, coimbination, combination. Pick a cam based on what heads, intake, exhaust, driving style, REAL USE OF THE CAR (that one is important). Lift is not going to be that critical on a boosted car. Talk to PatG and be serious about answering the questions and he will get you a cam that is worth the money. Or just put in a Z06 cam and enjoy!
If any of that information above is off base the experts can just pick it apart.
It is a small triangle at the bottom of a lobe diagram. If this triangle of overlap is large---the cam will probably chop harder at idle....sounding "big". It will also have a "hit". Meaning if in 4th gear at 20mph you smash the throttle to the floor, at a certain rpm you will feel the valve events come in line with the intake manifold and exhaust system in harmony and the car will lunge forward and really start to move.
If on the other hand the overlap is fairly small, and the LSA is larger the cam will have a broader power range, and less of a hit and more of just a constant push. A turbo likes a larger LSA because it minimized the time that both valves are open. When both valves are open some of the boost will leak right out the open exhaust valve.
Combination, coimbination, combination. Pick a cam based on what heads, intake, exhaust, driving style, REAL USE OF THE CAR (that one is important). Lift is not going to be that critical on a boosted car. Talk to PatG and be serious about answering the questions and he will get you a cam that is worth the money. Or just put in a Z06 cam and enjoy!
If any of that information above is off base the experts can just pick it apart.
08-10-2012, 07:37 PM
#10
I was informed by Brian Tooley today that he had a 2010 camaro that was in a N/A motor with the EHT .675 springs and because of the 457lbs of open pressure or anything over 400lbs on stock rockers that those springs chewed the valve tips up on the stems of the valves over time.
I would use the .650 springs.
Use the smaller cam, install on 112 or 111icl.
I would use the .650 springs.
Use the smaller cam, install on 112 or 111icl.
08-11-2012, 11:50 AM
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I was informed by Brian Tooley today that he had a 2010 camaro that was in a N/A motor with the EHT .675 springs and because of the 457lbs of open pressure or anything over 400lbs on stock rockers that those springs chewed the valve tips up on the stems of the valves over time.
I would use the .650 springs.
Use the smaller cam, install on 112 or 111icl.
I would use the .650 springs.
Use the smaller cam, install on 112 or 111icl.
08-16-2012, 05:34 AM
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1camwndr, I got a question.. with everything you said, do you think this cam will perform good with a turbo?? Its supposed to be a "turbo/blower" cam... I guess I will just have to get the extra stuff at the bottom of that description to make it work with my 4.8..... What are your thoughts on this????
Lingenfelter GT-7
http://www.lingenfelter.com/mm5/merc...egory_Code=C31
Lingenfelter GT-7
http://www.lingenfelter.com/mm5/merc...egory_Code=C31
08-16-2012, 02:42 PM
#14
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08-16-2012, 02:52 PM
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thats just what I was thinking... It says it right in the description that this cam is perfect for superchargers or turbochargers.... I was wondering what this guy got this info from... he clearly has no clue...
08-16-2012, 03:07 PM
#16
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When the reality is, unless they do back to back testing with dozens of profiles on their specific setup, any custom cam is as much a guess as an off the shelf cam. And given there are literally hundreds of off the shelf cams, you can bet there are plenty that will work great.
But getting back to basics, mild cams will work well on any setup with boost. There really arent any downsides. Unless of course you want a choppy idle, then obviously they wont be for everyone, as mild cams are usually nice and smooth.
