Cam questions
05-29-2009, 10:01 PM
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Cam questions 99 z28 camaro 4.10,s pacesetter LTs and catless y what kinda cam will make good power and sound good as well but not be to loud someone said 228/228 i have no clue what those numbers mean so if anyone could explain what those numbers mean and mabey suggest me a different cam i would apprcieate it thanks
05-29-2009, 11:14 PM
#2
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Alright man there are a lot of cams out there for LS1's, not many guys would help you out on this one, most would say research. However, I'm one to try and help everyone. You seem not to know much about cams so...here's a basic cam overview. We will call it CRASH COURSE 101. lol Yes, a 228/228 cam would be a good choice for a DD (Daily Driver). However, you also have to take into consideration what LSA (Lobe Separation Angle) you want on a cam. For instance, a cam with a 114 LSA has a very smooth idle, whereas, a LSA of 112 sounds pretty choppy. This could be the answer to keeping your car sounding relatively quiet with a cam, going with either a 113 or 114 LSA.
Take into consideration, having a cam with a higher LSA also changes the powerband of your cam, and where power/torque is predominately developed. A higher LSA (114) will give you less down-low torque and a higher top-end hp, whereas, a lower LSA (112 or 110) will develop more torque down-low and less top-end. This is where the term "Overlap" comes from.
Overlap is- the period at the end of the exhaust stroke and the beginning of the intake stroke when both intake and exhaust valves are open at the same time. Tightening the LSA increases overlap, and widening it vice versa.
Next question, "What does 228/228 stands for?" These numbers represent the intake and exhaust durations of the cam. In simple terms, how long a valve stays open. The higher the number '228,229,230...', the longer the vale stays open.
Now, when looking for cams, lift is also a factor. Too much lift on a cam can cause PTV (Piston To Valve) clearance issues. There are many theories and hypothesis on what lift and duration is too much to run on a DD cam. However, I feel if you want to stick with a quiet sound that's not too noticeable...stay under .600 lift, if using stock heads. However, this is just my own personal opinion, others would contradict.
Now, lest look at a TSP Torquer V.2 cam. It has a duration of 232/234 and a lift of .595/.598. The first of the two numbers represent the intake side of a cam (air entering the engine), and the second represents the exhaust side (the burned air/fuel mixture aka exhaust leaving your engine). This is to give you a brief understanding what to look for when picking out a cam. Another issue is the rpm range of a cam. This is similar to the LSA and where power is developed. A higher lift cam, with more duration, will function better at higher rpms and vice versa.
Now, I only gave you the CRASH COURSE 101 because you have to know a little bit about cams to start looking for what you want out of a cam. A cam is the brain of the engine, it tells it how to breath and how to react at different rpms.
My suggestions, take what I have told you and use it as a foundation and check out what TSP, Thunder Racing, Patrick G and other people have to offer. In fact, many sponsors are willing to sit you down and talk about your application and what your aspirations are for your vehicle and help you pick a cam that is right for you.
However, I can offer a few TSP cams that may suit your profile; (228r with 228/228 .588"/.588", Torquer V.2 with 232/234 ".595/.598 or 224r with 224/224 duration and a .581"/.581" lift.) I am not a cam guru, but like I said, use what I have provided you with and try to go from there. Hope this helps.
Take into consideration, having a cam with a higher LSA also changes the powerband of your cam, and where power/torque is predominately developed. A higher LSA (114) will give you less down-low torque and a higher top-end hp, whereas, a lower LSA (112 or 110) will develop more torque down-low and less top-end. This is where the term "Overlap" comes from.
Overlap is- the period at the end of the exhaust stroke and the beginning of the intake stroke when both intake and exhaust valves are open at the same time. Tightening the LSA increases overlap, and widening it vice versa.
Next question, "What does 228/228 stands for?" These numbers represent the intake and exhaust durations of the cam. In simple terms, how long a valve stays open. The higher the number '228,229,230...', the longer the vale stays open.
Now, when looking for cams, lift is also a factor. Too much lift on a cam can cause PTV (Piston To Valve) clearance issues. There are many theories and hypothesis on what lift and duration is too much to run on a DD cam. However, I feel if you want to stick with a quiet sound that's not too noticeable...stay under .600 lift, if using stock heads. However, this is just my own personal opinion, others would contradict.
Now, lest look at a TSP Torquer V.2 cam. It has a duration of 232/234 and a lift of .595/.598. The first of the two numbers represent the intake side of a cam (air entering the engine), and the second represents the exhaust side (the burned air/fuel mixture aka exhaust leaving your engine). This is to give you a brief understanding what to look for when picking out a cam. Another issue is the rpm range of a cam. This is similar to the LSA and where power is developed. A higher lift cam, with more duration, will function better at higher rpms and vice versa.
Now, I only gave you the CRASH COURSE 101 because you have to know a little bit about cams to start looking for what you want out of a cam. A cam is the brain of the engine, it tells it how to breath and how to react at different rpms.
My suggestions, take what I have told you and use it as a foundation and check out what TSP, Thunder Racing, Patrick G and other people have to offer. In fact, many sponsors are willing to sit you down and talk about your application and what your aspirations are for your vehicle and help you pick a cam that is right for you.
However, I can offer a few TSP cams that may suit your profile; (228r with 228/228 .588"/.588", Torquer V.2 with 232/234 ".595/.598 or 224r with 224/224 duration and a .581"/.581" lift.) I am not a cam guru, but like I said, use what I have provided you with and try to go from there. Hope this helps.
05-30-2009, 12:40 AM
#4
Tightening the split (lowering the LSA number) will move the powerband down.
Here's a good, though a bit outdated, "quickie" guide: http://www.ls1howto.com/index.php?article=23
Originally Posted by LS1HowTo.com
Cam Basics:
When deciding which camshaft is right for you, the best you can do is try to make an educated guess based on previous experiences or other's experiences. There are countless books about camshaft design and theory, so trying to explain what all to choose is pointless and this is why vendors are out there to see what works well in the LS1 for us. They do the research, and thus, they get our money.
When buying a cam, you'll see specs like "220/224 0.550/0.558 114lsa". The first two numbers are intake duration (in degrees) followed by exhaust duration (in degrees). The next two numbers are valve lift for the intake (in inches) and valve lift for the exhaust (in inches).Finally, the last number is the Lobe Separation Angle.
Duration:
Duration really plays a big factor in how the cam will drive and idle. The bigger the duration, the longer the valves stay open, and generally the 'lopier' and worse driving the cam will be. The numbers you'll usually see are the duration in degrees that the valve is open MORE than 0.050" of an inch. Cam cdumdumdums will also list duration at 0 lift, and that will be a number like 270-290'ish. Cams that have the same duration for intake and exhaust are symmetrical, cams with more intake than exhaust are called "reverse split", and cams with more exhaust than intake are sometimes referred to as "traditional split".
LSA (Lobe Separation Angle):
Lobe Separation Angle, usually referred to as "LSA", is the angle of separation between the exhaust peak and intake peak. The lower the angle, the more the lobes will overlap, and that means more lope, gas smell, and drivability issues...however, the lower LSA can also mean more power and you get it sooner in the RPM range to boot. Duration and LSA are 2 very important items in clueing you into how a cam will idle and drive, although there is a LOT more to a cam than this.
Lift:
Cam lift, in my opinion, is less of a complicated matter on these motors. There's not much of a reason to run less than 0.550" of valve lift, so anything between 0.550 and 0.600" is probably going to be fine. If you have ported heads, it may be best to lean towdumdumdums cams with 0.570" lift and up as most ported heads will just keep flowing more and more as that valve lift increases. Note that a cam cdumdumdum will show lobe lift, which is the actual lift of the cam lobe. Once you take lobe lift and multiply it by the ratio of the rocker arm (stock is 1.7), you get valve lift.
Lobe Profile
The Lobe profile of a cam basically is the curve at which a valve is opened and closed. Some lobes are very EXTREME and will snap a valve open very quickly and then slam it shut, while others are "softer" and slowly open and close valves. The more extreme the lobe, the noisier your valvetrain will be and the hdumdumdumer it is on your valve springs...however, a more extreme lobe will generally idle better than a less extreme lobe with the same duration at 50 thousandths. If your cam has very aggressive lobes and your cam lift is up there, I'd suggest you try to lighten your valvetrain by getting titanium retainers if possible.
Choosing the cam for you
For cars that need to stay stock sounding and driving, but still want a kick in the pants for horsepower, something between a 214 and 220'ish duration would probably be best. For the majority of the cars out there, anything in the 221-227 range is probably a better selection, and for the guys that want all they can get 228+ duration cam shafts are generally the minimum. As a novice all you can do is ask around, listen to cars, look at track/dyno results, and make your best guess. As long as you pick a cam close to what might fit you (i.e. mild, average, or extreme given the criteria above) you really can't go wrong. It's not a life or death decision here. A few degrees here and there isn't something you should sweat about until you've gotten a few cams under your belt and know more about what you want.
Sharpe's note: The image below is OLD. 230's cams on tight splits are far from "extreme" nowadays!
When deciding which camshaft is right for you, the best you can do is try to make an educated guess based on previous experiences or other's experiences. There are countless books about camshaft design and theory, so trying to explain what all to choose is pointless and this is why vendors are out there to see what works well in the LS1 for us. They do the research, and thus, they get our money.
When buying a cam, you'll see specs like "220/224 0.550/0.558 114lsa". The first two numbers are intake duration (in degrees) followed by exhaust duration (in degrees). The next two numbers are valve lift for the intake (in inches) and valve lift for the exhaust (in inches).Finally, the last number is the Lobe Separation Angle.
Duration:
Duration really plays a big factor in how the cam will drive and idle. The bigger the duration, the longer the valves stay open, and generally the 'lopier' and worse driving the cam will be. The numbers you'll usually see are the duration in degrees that the valve is open MORE than 0.050" of an inch. Cam cdumdumdums will also list duration at 0 lift, and that will be a number like 270-290'ish. Cams that have the same duration for intake and exhaust are symmetrical, cams with more intake than exhaust are called "reverse split", and cams with more exhaust than intake are sometimes referred to as "traditional split".
LSA (Lobe Separation Angle):
Lobe Separation Angle, usually referred to as "LSA", is the angle of separation between the exhaust peak and intake peak. The lower the angle, the more the lobes will overlap, and that means more lope, gas smell, and drivability issues...however, the lower LSA can also mean more power and you get it sooner in the RPM range to boot. Duration and LSA are 2 very important items in clueing you into how a cam will idle and drive, although there is a LOT more to a cam than this.
Lift:
Cam lift, in my opinion, is less of a complicated matter on these motors. There's not much of a reason to run less than 0.550" of valve lift, so anything between 0.550 and 0.600" is probably going to be fine. If you have ported heads, it may be best to lean towdumdumdums cams with 0.570" lift and up as most ported heads will just keep flowing more and more as that valve lift increases. Note that a cam cdumdumdum will show lobe lift, which is the actual lift of the cam lobe. Once you take lobe lift and multiply it by the ratio of the rocker arm (stock is 1.7), you get valve lift.
Lobe Profile
The Lobe profile of a cam basically is the curve at which a valve is opened and closed. Some lobes are very EXTREME and will snap a valve open very quickly and then slam it shut, while others are "softer" and slowly open and close valves. The more extreme the lobe, the noisier your valvetrain will be and the hdumdumdumer it is on your valve springs...however, a more extreme lobe will generally idle better than a less extreme lobe with the same duration at 50 thousandths. If your cam has very aggressive lobes and your cam lift is up there, I'd suggest you try to lighten your valvetrain by getting titanium retainers if possible.
Choosing the cam for you
For cars that need to stay stock sounding and driving, but still want a kick in the pants for horsepower, something between a 214 and 220'ish duration would probably be best. For the majority of the cars out there, anything in the 221-227 range is probably a better selection, and for the guys that want all they can get 228+ duration cam shafts are generally the minimum. As a novice all you can do is ask around, listen to cars, look at track/dyno results, and make your best guess. As long as you pick a cam close to what might fit you (i.e. mild, average, or extreme given the criteria above) you really can't go wrong. It's not a life or death decision here. A few degrees here and there isn't something you should sweat about until you've gotten a few cams under your belt and know more about what you want.
Sharpe's note: The image below is OLD. 230's cams on tight splits are far from "extreme" nowadays!
05-30-2009, 07:47 PM
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I mean I'm no genius, you could very well be right. It does seem that the dropping the angle of seperation, "tightening" will result in a more choppy idle and will make more power up in the higher RPMs. This is why folks that get the big and ridiculous cams tend to need more gearing. I'm not saying I'm right, I'm just curious at this point...
05-31-2009, 12:40 PM
#6
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oh my goodness this thread makes me queezy. way too many generalizations. The LSA is all relative to what is going on with the valve events. You can't just lower or raise the separation angle and change where the the cam makes it's power. Typically, cams grinds that use a tight LSA also have long intake and exhaust durations which requires low gears to bridge the idle to engaged tranny status. if you have a 238/242 cam run with a 109 lsa...I promise you, you won't be making power below 4k rpm.
06-01-2009, 01:19 AM
#7
I mean I'm no genius, you could very well be right. It does seem that the dropping the angle of seperation, "tightening" will result in a more choppy idle and will make more power up in the higher RPMs. This is why folks that get the big and ridiculous cams tend to need more gearing. I'm not saying I'm right, I'm just curious at this point...
No there are not. "The fastest way to teach someone nothing is to try to teach them everything at once." Your post meant very little if anything to the OP.
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06-01-2009, 06:10 AM
#8
We have had good results with the 228R camshaft. If you'd like I can send you over some engine dyno data from installing that camshaft on both stock heads, PRC LS6 heads, PRC 2.5 5.3l heads, and afr 205 heads. Let me know if I can help!
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Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
06-02-2009, 04:21 PM
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Ha, I'm not going to get offended if I'm just wrong... It just sparked my curiosity.
