CARB & EFI 4.8L INTAKE TEST

you're going to the junkyard to pick up an ls and you're going to run it carbureted here's the question what intake should you use [Music] if you're looking for an ls there are obviously lots to choose from but if you go to the wrecking yard the two most common are the 4.8 liter and the 5.3 liter this video is about an intake test run on the smaller 4.8 now intake choice for the little 48 is even more critical in this video we're going to take a look at an intake comparison between a single plane intake and a dual plane intake on the little 4.8 liter and just to spice the test up a little bit we're also going to include the factory truck intake that came on the motor when you got it from the wrecking yard okay before we get going i want you to take a look at the reflection in my glasses from my light if you take a look at that i think that i might have a superpower i might have developed x-ray vision it's kind of cool this is our 4.8 liter and they're easy to find in the wrecking yard whenever we go there this is one of the most common engines that we find we find either a 4.8 or a 5.3 very rarely do we ever see a six liter if we do we snatch it up right away but they're really hard to find i can almost never get there and find a six liter it's either it's either already gone by the time i get there there aren't any there but there are usually a lot of four eights and five threes this test was actually run on a 4.8 liter and i did originally get this thing from the wrecking yard we used it a lot but we ended up hurting it i heard a piston on it we cracked a ring land because you know probably because i didn't do the ring gap like i'm supposed to when i was running boost or nitrous or something a lot of times we're not really nice to these motors but we ended up replacing it with a je forged piss and it was 10 over it has a small dome on it so it's got a little bit higher than stock compression but otherwise it is a stock rod stock crank stock block in the 10 over block as we've machined it it had a set of 706 heads with 26 918 valve springs on it and it had a very small extreme energy comp cam in it it was a i'm going to give you the specs on it here it's a 265 cam that we've run a lot we did a bunch of testing with but it has a 522 529 lift split 212 to 18 degree duration split and 114 degree low separation angle now we got this thing and we also equipped it with an edelbrock victor junior intake manifold for the ls and then the 650 holley xp carburetor although the other carburetor i like to run on this and if you take a look at the other videos where i did the the cheap car versus the expensive carb that brawler carburetor obviously works just as well especially on a mild combination like this so if you're looking for a carbureted ls application i i think and you're trying to do it on the cheap i definitely would go with the brawler carb this thing was run actually both ways we tried it with an msd ignition controller which works just fine and we also ran it with a holley hp management system because we were eventually going to run and we did run fuel injection on this so we ran this combination as i said with that small cam stock heads and a carbureted combination with the victor jr and the small 650 holley long tube headers you know kind of the way that you do it if you're setting up for a mild kind of performance application but run in this manner with the single plane intake manifold this combination produced 376 horsepower peak torque checked in at 336 foot-pounds and i want you to notice that peak torque occurred on this combination on what is admittedly supposed to be a fairly mild combination occurred all the way out at 5200 rpm and even though we had a pretty small cabinet peak power occurred at 6 300 rpm and while this is a lot of guys choose the single plane intake i don't think it's ideal for an ideal choice for a carbureted application on this small displacement 4.8 liter so now let's take a look and see what happened when we started doing some intake changes after running our 4.8 liter with the edelbrock single plane victor junior intake and 650 holley carburetor it was time to perform an intake swap and the nice thing about an ls is intake swaps are very easy on that you don't have to unhook the water or anything so it takes no time at all they all have o-rings for like sealing and stuff so an intake swap is kind of a joy on an ls application so we removed the single plane victor junior intake and then we installed this l brock dual plane rpm air gap air gap style intake or rpm intake manifold and the dual plane is kind of the go-to intake manifold for any kind of street application whether it's a small block chevy or small block four or even even some big blocks we like the dual plane intake because it's designed to run in this kind of rpm range something up to 6000 or even 6500 you'll get a little bit of a trade-off usually between a typical single plane and dual plane test where the single plane might make a little more peak power and the dual plane makes more power down low but in this case as you'll see on the ls application there really is no there really is no choice there's no consideration here so let's take a look and see what happened when we ran the dual plane intake on here so this is the rpm the rpm is in red and you can see it made almost identical peak power 375 horsepower but take a look at the torque production the peak torque was up to 341 foot pounds but it occurred down here at 800 rpm in fact it carried basically the same torque number the peak tarik was 341 it was still making 341.5 actually the peak torque is a little bit higher out but it made dual torque peaks let's say down here 3800 and then again here at 4 800 and this thing was just almost perfectly flat from for about a thousand rpm and take a look at the torque here uh i'll go ahead and move my recording up a little bit you can see take a look at the torque difference here below 3500 rpm i mean we're talking about 340 foot-pounds versus 282 foot-pounds for the single plane the single plane just does not help the carb meter very well down there there's just no signal to it but on a dual plane there's a ton of signal and that's it all helps it make a ton of torque so basically what the dual plane did was make every bit of power that the single plane did at the top end all the way out past 6 500 rpm it basically mirrored the single plane from 5800 out to 6700 rpm but everywhere below that it just made a ton more torque which is where you're going to spend 90 percent of the time driving on a street and even on a street strip car for a strip application the dual plane would just kick the heck out of this single plane manifold so it's just a better combination especially on this little 4.8 liter so if you're looking at a carbureted combination you definitely want to put a carburetor on some sort of early muscle car you're swapping this thing in or you want to do it on the cheap and you use the the msd ignition controller and a simple carburetor remember go with a brawler carburetor on this application go with the dual plane put together a 480 and this combination will actually work pretty well a 375 horsepower small block would be would be a healthy combination especially one that has a torque curve like this or a torque plateau as we like to call it when we're when we're talking about ls stuff so this is what happened when we ran the dual plane versus a single plane as you can see it's really no competition go with the dual plane especially on the 4.8 liter now let's take a look at one other intake test that we also ran while we had this thing up on that and here's basically the completion of our intake comparison on the 4.8 liter and this i'm sure should get all the efi guys like up in arms and and get them chanting and telling the carbureted guys how terrible carburation is when the reality is between any kind of comparison between carburetion fuel injection if you run it on the same intake manifold the carburation usually makes more power only because it offers charge cooling that the efi does not do now the cool thing about efi we've been through this 100 times is that you can dial in the air fill curve at every combination of rpm and load point which is something you cannot do with a carburetor it would be nice if you could um and then the other thing is a lot of guys say well okay what happens if i put the fuel injections like the throttle body fuel injection on a carbureted intake you can do that and and that helps with charge cooling and it adds power you can do some tuning with it but you can do individual cylinder tuning the way that you can with port injection so there's always going to be a trade-off in no matter what kind of combination you pick so if it's but in this case this is just basically we're going to compare the truck intake to this dual plane intake because to the single plane it's just not even a comparison but to the dual plane intake it makes makes an interesting comparison but it's not carburation versus fuel injection because this is a completely different intake design so here's what happened anyway this is our this is our 4.8 liter with the dual plane rpm intake and that 650 holley here's what happened when we ran it efi with the factory truck intake manifold the one that comes with the motor when you get it from the wrecking yard so go ahead and move myself up here back i'm going to put myself down here in the corner so the blue is the factory truck intake and as you can see as we would kind of expect all the runners are the same length you know they're all long runners it's designed to enhance power production it was designed for the motor that it was on so it has a lot of things going for it you know it's it's just a good combination so equipped with a truck intake this thing made 382 horsepower and torque peak torque was up to 359 foot-pounds of torque so the truck intake obviously a good choice for a 4.8 liter the interesting thing is not so much that the truck did truck intake did better we kind of expected that the only thing is you know in the carburetor's defense you still have to have fuel injection to run the truck intake so you have to have a complete motor with all the fuel injection be able to tune it and all that so there's something to be said for guys that want a carburetor and i and i'm not going to go into the which one's better if you think one is better more you know than the other one that's okay you guys can argue you guys can all argue about that but the interesting thing that i want to point out is take a look even though the truck intake has very long runners and you'd think that it would be really really good at torque production take a look at what happened below 4 300 rpm on the dual plane intake and i s and i've run this kind of test a lot and this this always happens with the dual plane the dual plane carbureted intake actually makes more low speed torque than the long runner truck manifold does and that's kind of surprising but i mean if you look at dual plane intakes on factory factory carbureted combinations back through the through the many decades they always perform really well they always have good drivability they always have really good torque production so if you were to look at an old 350 or 327 with a dual plane intake i mean this is what you see it makes really good low speed power all the way down below 3500 rpm even better than that long runner truck intake does only from 4 500 out to you know like 6 500 does the truck intake you know show its superiority so it's just an interesting combination between you know an or an interesting comparison between the dual plane intake and the truck intake so all ufc efi guys now can jump up and talk about how cool how much better fuel injection is than carburation but i just wanted to show the carbureted guys hey this is what you're giving up and it might be something to consider if you can run the factory fuel injection and have somebody tune it you can get some extra power you know maybe some extra drivability but also know down below 4 000 rpm or even below 4200 rpm it's gonna have less torque let's get to our conclusion okay guys what do you think about our comparison between the single plane intake and the dual plane intake on the little 4.8 liter here's the takeaway if you're going to get the little motor the little 4.8 liter which i love but i love all of them but if you're going to get the little 4.8 liter definitely pick the dual plane intake it is a much better choice for any kind of street operation if you're going to rev this thing out to 9000 rpm then yeah maybe look at a single plane otherwise for any stock or mildly cam 4.8 liter definitely pick the dual plate but if you're going to go to the wrecking you're going to get a motor pick the bigger 5.3 liter you'll be much happier it makes more torque it'll make more power it'll make the intake choice easier but even on the three i'd still pick a dual plane for almost any combination except the 9000 rpm stuff armature holder guys thanks for watching make sure to like share subscribe ring the bell do all that stuff what about that truck intake i'll keep testing

Channel: Richard Holdener

Views: 24,846

Rating: 4.9573069 out of 5

Keywords: LS, 4.8L, INTAKE, TEST, DYNO, SINGLE PLANE, DUAL PLANE, CARB, EFI, JUNKYARD

Id: tfQRR6QSJWY

Length: 13min 5sec (785 seconds)

Published: Tue Aug 18 2020