92slowmaro

iTrader: (22)

what does it mean if you have a cam with a certain lsa and then you have advanced ground into it? what is the purpose of this and how does it help? ive been doing some googling and what not but havent come up with much...

SOMbitch

iTrader: (8)

Advance ground in will bring torque in sooner. It also affects the intake centerline (ICL). For instance my cam is on a 111LSA +2* advance ground in so the ICL is 109. Advance also affects PTV. The more advance the closer PTV on the intake side but adds more room on the exhaust side.

TooLateVTEC

iTrader: (2)

Basically from how I understand it, is that if you have a cam thats a 114+4 LSA than since its already advanced 4*, than it makes it act like its on a 110 LSA (114-4=110).

Im more old school, im used to running cams that dont have any advance ground into them, when you buy it its on a 108 LSA and thats F'n it. If you wanna advance or retard it then you better buy an adjustable timing set lol.

00pooterSS

iTrader: (40)

LSA is Lobe seperation angle, that is the amount that the lobes are split apart from one another, advance or retard moves the whole cam as you already stated you do that with the adjustable set so you've got that part, but when you advance or retard it it does nothing to the LSA becuase you are not changing the lobe location in relation to each other on the camshaft you are just changing the position of the camshaft in relation to the crankshaft.

The rest of it gets really complicated. Lower/Narrower LSA's cause more overlap that causes a choppy idle and increases scavenging, but it can cause a shorter "power band" or RPM range of increased power than a wide LSA ( higher number LSA ). But increased duration also effects overlap along with LSA so you get a combined effect between the two

I think there is a sticky at the top of this forum that describes the in's and out's of cam specs.

00pooterSS

iTrader: (40)

This is at the top of this forum the link is called "cam guide" get some coffee and a comfortable spot its a lot to read.

https://ls1tech.com/forums/generatio...cam-guide.html

Sales2@Texas-speed

iTrader: (5)

That's basically it, but keep in mind it's the ICL not the advance that determines that valve event. A 115LSA+4 and a 110LSA+4 (same advance) have quite different valve events and therein piston to valve clearance.

It's more in the lime-light now....but cam companies have been grinding in advance to their camshafts for lots 'o' years! Even the "old school" SBC camshafts have been ground with advance/retard in them for decades!

92slowmaro

iTrader: (22)

ok i understand alittle better. im getting a 113+3 so it should act like a 110?

crainholio

iTrader: (2)

No. It should act like a 113, but the torque curve should be shifted slightly earlier in the RPM range.

92slowmaro

iTrader: (22)

oh ok cool.

00pooterSS

iTrader: (40)

No not at all whatsoever. If that were the case it would just be 110 LSA cam and the +3 would be a non factor and would not be listed. What you are describing is a cam that has 113 degrees of seperation between the intake and exhaust lobes, the +3 means that both of those lobes have been ground to where they lift and close the valves 3 degrees in rotation earlier than they would if there were no advance ground in.

A 110 will act like a 110 and a 113 will act like a 113 it does not depend on the +3 which is the advance in this case since it is a +, + signifies advance where 0 would indicate no advance or retard in cam timing and a -would indicate retard in cam timing. Advance makes the valve events happen earlier than if there were none, and retard makes the valve events happen later than if there were none. Valve events meaning at which point the valve opens and then closes during the rotation of the cam. So with advance the intake will open earlier than with no advance and it will close earlier, same with the exhaust. The lobes do not move in relation to each other/do not change angles in relation to each other (LSA) based on advance or retard. Which is what you are thinking based on your statement that it would act like a 110.


The 113 is the Lobe Seperation Angle, the +3 is the ground in advance.

You can advance or retard the cam timing with an adjustable timing gear set or by having a cam cut with either advance, retard, or niether in which it would be labeled as a - for retard, +0 for neither and + for advance, and it does NOT have ANY effect whatsoever on the LSA... They are not related in a way that you are relating them, really they are not related at all. LSA describes the amount of degrees of seperation between the lobe centers of the intake and exhaust lobes, the +3 is 3 degrees advance. The advance or retard will effect mostly the RPM range in which the power curve is most noticeable, the LSA will affect pretty much everything but its not as simple as just taking those two numbers and making a simple calculation and seeing a specific result.

Please read the link I posted and you will have a much greater understanding. I hope that whole novel I wrote didn't come off as being harsh, I have had plenty of beer so I hope it all makes sense and I didn't repeat anything but in all seriousness the link I posted will really help you. Cams are very very complicated.

$750 L98

iTrader: (7)

I have a 113+3 cam, in plain terms I can tell you what this will mean for your basic engine characteristics, just from experience, I'm not a cam whiz lol

A cam like that depending on size isn't going to have a very choppy idle, mine is a 232/234 .595/.598 on a 113+3 (torquer v2/XER281HR). In my LQ4 it idled fairly smooth at 950rpm with just a hint of that "cammed" sound.

Off idle torque is incredible, it's hard to keep the tires from spinning unless you are very careful, and if you have more compression than me (greater than 8.7:1-9:1) you will notice a very responsive and torque rich low end. However it doesn't really "pull" hard until about 3k rpm.

The cam isn't my favorite, and it doesn't have a "lopey" sound, but it is pretty different, I haven't heard another motor that sounds the same.

What cam are you going with exactly?