LSA CAM TEST-108 vs 112 vs 120

you know I get a lot of questions on LS camp ships one of the most popular questions what happens if I just changed the LSA on the camp without changing the lift or duration let's find out in this video I'm going to illustrate the change in lobe separation angle by running three different camshafts now all three of the cams share the same lift and the same duration the only change in the three camshafts is lobe separation angle dam chef number one has a 1:08 camp chef number two a 112 in a final cam camp chef number three has a 120 degree lobe separation angle now originally there's also supposed to be a 116 but we never got that camp tested so let's find out what a change in just lobe separation angle does to the power curve the first test in our discussion on lobe separation angle is a comparison I did back when I did the original stock cam test where we tested all the factory LS cams when I did that and we ran all of the LM 7 L LS one two three four five six seven eight nine ten you name it we ran all of them but this is a comparison actually between the factory ls9 cam which has a very wide lobe separation angle and a an aftermarket crank and when I picked this because this is the closest combination I had that had basically the same kind of intake duration and this this crane cam will overlay this first then we can take a look at this and as you can see the crane cam give you some cam specs here the crane cam was a 210 218 duration the 116 LS a so it's still fairly why affair lis wide and 551 lifts so it kind of matched the lift of the ls9 cam and the ls9 cam for reference is a 562 lift to 11 and but 230 degrees of exhaust eration and a 122 and a half it's designed obviously for the positive displacement supercharged accommodations and that's why they do that they extend the make the LS a fairly wide and they in doing that they kind of soften the bottom end up as we can see here big difference in bottom end powers matter of fact I whipped 6,000 almost between these two cams but that's because the positive displacement supercharger adds a bunch of immediate boost even though the short runners which I don't like would be nice to they can combine the immediate boost with longer runners and then actually I would pick a different cam that without losing all that bottom in but that's just me but this is our comparison between a 210 crane cam and the 211 degree duration ls9 cam as you can see the ls9 cam is a lot softer down low as a matter of fact through most of the curve it's a it loses a substantial amount of torque below let's 5,000 rpm and a lot down low I mean down here in the 2500 to 3000 range we're talking about 333 foot-pounds vs. 368 so this is like 35 foot-pounds it's quite a bit so this is kind of what you can expect from a really wide lobe separation angle cam it tends to shift the power curve up top although again the comparison between these two cams it's not ideal because we've changed more than the lobe separation angle so I know you're thinking well we want to see a test of only the lobe separation angle change so let's take a look and see what happens on the cam test where I changed only the lobe separation [Music] [Music] after taking a looking at our comparison on the 5/3 with the factory ls9 cam compared to that crane aftermarket cam a lot of people are asking can you guys do a test where you just changed the LSA so I had done this test quite a while ago and what I wanted to do is I asked the guys from crane to grind me specific cams what I wanted them to do is grind something that had the same lift and duration and I wanted to just to change the lobe separation angle so I asked them to do something on a 108 and a 112 and a 116 in a 120 unfortunately I didn't get the 116 and I can only test the 108 the 112 and 120 cam but you know this should give us a really good idea on what's going on when we just changed lobe separation angle so what I did was we had a test motor I want to make sure we had enough test motor to take advantage of the cams so what I did was put together a stroker we had a 402 basically for our 2 inch stroker ls2 version so it had a 4 inch crank in 6 125 rods JD Pistons which were flat tops and we top that off with a set of GM performance parts cnc ported ls3 heads and had a valve spring upgrade from BTR to work with the camshaft to make sure that we had in the valve spring and we had a fast LSX our intake manifold 102 millimeter throttle body and this is all controlled by the Holley HP we also have a set of inch and 7/8 cooks you know stainless long tube headers on it here we ran all this on obviously on the dyno westtech performance so first up was our hundred and twenty LSA camshaft so the specs on the cam to give you an idea for our 402 or 624 lifts both the intake and the exhaust to 32 to 42 duration at 50 and in this particular cam on the graph here 120 LSA so equipped with that camshaft our for our two combination produce peak power of 570 hor power and five hundred and thirty four point five foot-pounds of torque and I wanted to show you a lot of the curve we were able to run this through a 3000 rpm spread on the dyno from 3500 to 6500 and yes I know everybody's gonna want me to run it down all the way down 1500 and fortunately the dyno the engine dyno won't do that the engine dyno won't run a sweep from 1500 RPM to 6,500 RPM it doesn't have the ability to do that it can't run that long the spread sometimes we can get maybe 4,000 RPM sweep out of it but usually not any more than that because if you do then the the numbers that you generate at the beginning at the end of those of that span become inaccurate the dyno is just is just not able to do that it's easy to do on a like a inertial chassis dyno and stuff but on an engine dyno it's it becomes more and more difficult but this was our 120 LSA cam here's what happened when we change the camshaft to 112 you can see it did kind of what we would expect judging by what the cam swap happened in the 5.3 the results that we got on that the tighter LSA improved the power output especially down low by quite a bit now we picked up as much as if we look at the torque curve here down that 37 or 38 hundred in from 474 to 502 so we picked up a lot of torque and we started to see just a little bit of a change in peak power although not dramatic it's not something that I would consider to be you know you're talking about four horsepower there so it's almost nothing so going to the 112 degree LSA without changing the lift or changing the duration had a dramatic change in what the camshaft does so this is still holding true just like with the ls9 cam a wider LSA definitely was losing power down low so here's what happen when we went from the 112 to the 108 tightened it up quite a bit again no change in lift and duration 108 LSA we got another improvement in low-speed torque which we kind of would expect we picked up you know another [Music] eleven foot pounds of torque there but the interesting thing is that we picked up power through most of the curve I mean here in the 5500 rpm range we picked up you know 552 557 so seven or eight foot pounds and even a little bit out at the very top which I found was interesting based on the change from one 120 to 108 I kind of expected there to be a loss at the top but this is why we this is why we test the theory says one thing but sometimes the dyno tells us something else now maybe if well you know I was gonna say maybe if we run it all the way out to 7,000 or 7,500 or something on this stroker which is we'd be way past where it's making wanting to make power with this particular camp chef you might see a change and you also might see a change if we ran this on a smaller displacement if it was only a 6.0 or a 5.3 so let me know what you guys think would this change if we ran these specific camshafts on a smaller displacement would we see a difference I mean I know it's going to make people a different rpm but would the relative differences change would with the smaller displacement all of a sudden like the 120 LSA cam or like the 112 or the 108 let me know what you guys think but this is kind of typically what we see when we change the LSA a wide LSA tends to not make as much power down low usually it makes a little more power on the top like we see with the LS 9 cam test and the tighter LSA tends to improve power and mid-range and sometimes through most of the curve like I did here but what it does do is also hurts idle quality so if you want something that has the chop definitely get the tight LSA and obviously it also makes power let's get to our conclusion ok guys what did you think about our tests on lobe separation angle now I know we like to isolate the individual components of the camp chef so if we change the lift it always does this if we change the duration it always does this and like this test if we change the lobe separation angle it always does this the problem is although generalities do exist so do exceptions but you know what that's why I keep testing armature holds there guys thanks for watching make sure to like share subscribe ring the bell and I'll keep testing

Channel: Richard Holdener

Views: 90,079

Rating: 4.9547071 out of 5

Keywords: lsa, ls, cam change, swap, dyno, test, torque, hp, wide, narrow, 108, 112, 120

Id: JUHwVCDjonU

Length: 11min 1sec (661 seconds)

Published: Mon Mar 23 2020