Here are the basics: higher lift values open the valves to increase airflow and longer duration keeps the valves open longer. In my opinion, the rougher the idle the better! If identical and for a given displacement the 110 will give more power. Well, I saw that Erson makes some nice hydraulic rollers with 108 LSAs, and I know that tighter LSAs have more midrange, so I thought they might be worth a try. " - Voltaire. But this is not the only reason. 108 is very tight producing lower vacuum and more of a 2 stroke "punch" powerband. The 108-degree cam (blue lines) outperformed the other two, but idle quality suffered. 110 LSA: On the other hand, 110 LSA is comparatively a wider LSA; it can generate a massive amount of RPM for the engine. Supercharged and nitrous race engines typically benefit from a wider LSA because they dont require as much overlap for exhaust scavenging as does the naturally aspirated engine, continues Bolander. A forum community dedicated to hot rod owners and enthusiasts. This has been my long time understanding! OK, what is hydraboost, and how do you like how the cam performs??? A tighter LSA is always going to have more overlap, which allows the exhaust and intake systemif they're tuned wellto work together.". dur. It a 355. thanks in advance. I am pretty sure, right now, you find yourself in the middle of the rising debate of 106 vs 110 lobe separation angle. by jim martin Mon May 12, 2003 7:10 pm, Post And better gas mileage. Realize what the engine is going in, however, as you may not be able to use the wildest cam out there. 238/248 duration, 300/310 adv. Check out the Comp Cams catalog, even the biggest hydraulic rollers use 110. such as 290 @.050? Adding an aftermarket cam to an otherwise stock engine can boost output by 40-60 hp (or more) with no other changes (except possibly a valvespring upgrade). I normally run a 106 to a 108 because I like the "hit" a tighter LC cam has when it come up on the came. 108* or narrower lobe separation angle (LSA) is "Narrow" and 114* or wider (up to 117* or 120* for stock cams) is "Wide" , with 110 to 112* being the "normal" hot-rod cam. However, a cam with 108 will only pull 12-16", which is not enough for power assisted accessories. This causes the engine's street manners and tuning to become fickle. 110 LSA) and Crane's #341191 (238/248, .563"/.587", 114 LSA), display considerably different characteristics. Pretty much standard for an RV type cam. While most of our customers know what lift and duration are, most are unfamiliar with the term Lobe Center and how it affects the engines performance. . The second cam would have a rougher idle, produce more torque and would rev quicker. I'd run it, just be sure to check valve to piston clearance, coil bind and retainer to guide boss/seal clearance. 110 LSA: The 110 LSA shows up mechanically advantageous in mechanical aspects like higher RPM, lower engine knock, moderate cylinder pressure, improved idle vacuum, and higher piston-to-valve clearance. However, finding them might be challenging if you dont have any prior knowledge. So, which is better? Lucky for us, Brian Tooley Racing stepped up with a dual spring package that allowed us to safely run our 0.624-lift cam. L'auteur prsente une nouvelle contribution de floristique nord-africaine consacre la flore du massif du Rif et des rgions du nord du Maroc, dans le cadre gographique prdfini par le Catalogue des Plantes vasculaires du Nord du Maroc de Valds et al. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. Your email address will not be published. One segment that truly benefits from a wider LSA is the marine marine market. . Also, the wider LSA contributes to chassis stability in drag racing by avoiding the delivery of a ferocious blast of power that would break tire traction. The only reason the advance or retard a camshaft profile is to get the timing events where they need to be. Split duration/lift only helps when your intake/exhaust ratio is low on the exhaust side. The world of fuel injection is where wide LSA cams like the 113 really shine. to use this representational knowledge to guide current and future action. 110 will be a bit punchier in the midrange and probalby make a little more peak horsepower as long as a good exhaust is used. And better gas mileage. Ultimately, it comes down to how you want the engine to run, the car's intended purpose, and what you are willing to tolerate. Copyright 2022, S&S Motorsports LLC, All Rights Reserved - Powered by,, haft/3.htm, Webcam 86A 108LC w/1.5 vs 86B 112LC w/1.3s. I just bought a 86b Webcam and Im using 1.5's. Tests 2 and 3 meant dissecting the motor on the dyno to get the old cam out. The article was called "Separation of Power" and they tested 5 cams ranged from 106 to 114 LSA. The 120-degree cam minimized torque production through most of the curve, while the 112-degree cam offered more torque but slightly less peak power. 110 LSA: Oppositely, the cylinder pressure is comparatively lower at 110 LSA than at 106 LSA. It is an important note you must keep; due to the lobe separation angle, there creates an overlapping of intake valve opening time and exhaust valve closing time and vice versa. A cams Lobe center angle equals intake centerline plus exhaust . If it occurs too late, it will lean out the cylinder and greatly hinder the performance of the engine. Tight LSA cams make excellent low-end torque and have a beautiful power curve. A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. Brul slid the 113-LSA cam, the widest of the test, into the engine's heart and set about putting all the pieces back in place. Simply put, both 106 and 110 lobe separation angles have many advantages and disadvantages. kinda off topic.. but while we're on the topic of cams, duration,lift,ect has anybody heard of using high compreshion (13:1) on pump gas, by useing alot of duration? Okay, have a sigh because you have opened the right door. The first cam featured a wide 120-degree LSA, while cam number two narrowed the angle to 112 degrees. Generally, naturally aspirated engines run narrower lobe separation angles of around 106 to 108 whereas supercharged, turbo or nitrous engines operate with 112 to 114 and higher. The 114 cam will give more low end torque, good midrange, less power up high. also,, wider will produce a wider and more flat torque curve that doesn't fall off as abruptly up top rpms. So, now you, Read More Chevy Transmission Wont Shift Into 3rd: Finding the Main CulpritContinue, While changing the oil on your boats lower unit, you may need to change the drain plug, too. Changing the lobe separation angle changes the amount of overlap that exists during the time the intake and exhaust valves are both open, echoes Doug Patton of Pro Line Race Engines. A cam with a 112 lobe center will idle smoother than a cam with a 110 lobe center. Despite no changes in lift or duration, this cam sounded much more aggressive than the other two with wider LSAs. 110 LSA: On the contrary, it is pretty unpleasant to inform you that the efficient compression rate decreases at 110 LSA. its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. The power and torque curve lay directly in between the last two cams, as did the peak horsepower and torque, 488.7 at 6,200 rpm and 487.1 at 4,600 rpm, respectively. . But it is a piece of good news for your engine. Save my name, email, and website in this browser for the next time I comment. changing just the LSA on my cam wouldnt make a bit of difference on vacuum operated items E ericnova72 More for Less Racer Joined Jan 13, 2007 22,026 Posts It also depends on displacement, some guys will run a bigger cam and widen the LCA to give a better idle but in my opinion it kills power. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. It made 472.4 lb-ft at peak, a 21.5lb-ft disparity from the 101 cam. On a torque graph it tends to resemble a triangular shape.. This overlapping has a direct influence on the oil consumption rate of the engine. A good amount of idle vacuum or increased idle vacuum found at 110 LSA advances the engines efficiency. If you shift at 7500-7800 add 4-6 degrees to both intake and exhaust and spread the lobe separation to 108-110. The engine will have weak performance in the low-end range.A low vacuum can also cause the brake pedal to be quite difficult to press. (ICL + ECL) / 2 = LOBE SEPARATION ANGLE (LSA) LSA is a RESULT of the PROPER events. Chuck Lawrence of Jon Kaase Racing Engines was asked to give a 520ci BBF a Pro Stock sound, so he went with a 108 LSA in place of a more conventional 112 LSA. It's the scavenging effect of the high velocity exhaust gases rushing out that pulls the fresh fuel/air charge into the chamber. Another important measurement was the torque production at 4,000 rpm and this cam checked in with 484 lb-ft of torque. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. Kevko baffled oil pan & Milidon windage tray. from the intake to the exhaust and vise-versa.Thats why a performance cam will usually have a rougher idle than a stock one. The lobe separation angle or LSA is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes. Selecting a camshaft for a given engines purpose usually involves a compromise between low- or high-end power options, and the lobe separation angle (LSA) is one of those factors where engine builders have to make a choice between those priorities. music to your ears? Hopefully It will do fine in my 2276 mostly drag bug. A cam with a 112lobe center will idle smoother than a cam with a 110lobe center. A cam's lobe separation determines where and for how long peak torque occurs in an engine's rpm range. In reality, a cam with 220 at 0.050" and a lobe center angle of 112 will have the exact same mechanical overlap as a cam with 217 at 0.050" and a lobe center angle of 109. Simply put, the lobe separation angle (LSA) is a measurement of how the intake and exhaust lobes are phased with each other. As the RPM's go up this is not as critical as the higher velocity of the air/fuel moving thru keeps it from getting contaminated. Hopefully it turns out great. Elle concerne 264 taxons des degrs divers. The custom cams we selected all featured 0.624-inch lift (both intake and exhaust) and a 232/242-degree duration split. As a result, you can enjoy a pleasing engine outcome. by mrsmythe Mon May 12, 2003 11:15 am, Post Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! ditto with the above. The 112-degree cam offered nearly all the low-speed and mid-range torque of the 108 cam but the peak power suffered above 5,200 rpm. by Kdub Sat Dec 06, 2008 11:05 pm, Post You can research your heads to find out where yours are, but honestly I don't think it will be worth the effort on a tow vehicle. While a cam with a 108 lobe center will idle rougher. I am trying to pick out a hydraulic roller cam for my 351W with AFR 185s. Walter Noah is a process engineer who has a knack for resolving even the toughest technical issue. Before getting to the cam profiles, we had to make sure we had a reasonable test engine. by SStrokerAce Sat Dec 06, 2008 7:36 pm, Post by mrsmythe Tue May 13, 2003 5:45 am, Post However, the plentiful exhaust overlap (31 degrees) meant there was lots of exhaust dilution at low engine speed and high vacuum. This is very critical for manifold vacuum, throttle response, emissions, and gas mileage. It also depends on what the vehicle will be used for and if economy and vacuum are important. As a result, a wider valve opening system with no overlapping allows more oil to fall through the oil inlet. I bet you won't see a bit of difference. AquaTraction Vs SeaDek: Which One Is Better For you? Required fields are marked *. In a blower motor when the valve timing events are where they need to be the lobe sep will usually wind up in the 114-115 range on most Combos. That means your engine can produce more power with a minimum amount of fuel combustion. We use 86b webcams with 1.25 rockers frequently in stroker motors.It's a nice way of getting close to .500" for hot street motors with average heads. 108 Lobe Separation These are my motors specs 1979 - 347 Stroker 10:1 Compression Holley 670 Street Avenger or a Holley 650 (I have both) Roush 200 Cylinder Heads (minor head work) 1.6 Roller Rockers Shorty BBK Headers 373 Rear End 5 Speed Transmission Cross Gap Intake (Power Band 1500-6500) FlowMaster Dual Exhaust (of course no Cats) MSD 6Al The 112-degree cam (red lines) picked up much of the torque, but the big winner was the cam with the tightest lobe separation angle. 110 LSA: On the contrary, at 110 LSA, the engine fails to reach the maximum torque, resulting in a decrease in torque rate. It may not display this or other websites correctly. You must log in or register to reply here. I probably would have gone with 3.55 gears had I knows better.. According to the Motortrend, LSA (Lobe Separation Angle) is a wonderful approximation of the operation of the engine because it takes into account the relative time of the intake-valve events (intake opening, intake closing) and the exhaust-valve events (exhaust opening, exhaust closing) concerning each other.Above mentioned sequential activities allow LSA to be an accurate representation of the operation of the engine. Professionally ported & polished iron 4V head with titanium intake valves, stainless exhaust, titanium retainers & keepers & dual springs. Thanks. That was just a glimpse of the information you were looking for. The intake air control valve (IAC), which regulates idle speed, also has to work overtime and often attempts to "catch" the idle, but usually shoots high or low. 11 Doing LS cam swaps on the engine dyno is a breeze, each taking less than 1 hour. It is dangerous to be right in matters on which the established authorities are wrong. Lobe sepsration is an advanced description for overlap.If you take a cam on a 112,and grind it on a 108,you add more overlap,the time the valves are both open.Narrower lobe centers mean more low end and midrange torque,along with a peakier powerband,and a slightly rougher idle.Tradeoffs are sensitivity to octane ratings,total timing, and air fuel ratio.A lot to swallow I know,hope this helps you. Nothing makes mouths drop like a car that sounds and looks like it can't keep it self still! = Extremely Tight . Making this the biggest obstacle to overcome when selecting a cam profile with one of our tech advisors, explaining the definition and importance of the Lobe Center. It has been tried in the VW business earlier, but then they gave it up because of problems with too high temperatures around the exhaust valve, causing them them to break. Introduction. More over-simplifications: Engine builders Chuck Lawrence, left, and Doug Patton. This table will create a map in your head, and I bet it will make your understanding crystal clear. Pretty much standard for an RV type cam. 106 LSA: At 106 LSA, the cylinder pressure is a bit higher. Everyone has a different idea of gentle.While its true that the duntov cam may seem rough in a 283 it is still a factory offering and they never go to radical on there profiles for street cars.If you want a rough idle, try a 283 with a .550'lift roller and 13.5 to 1 compression,THATS ROUGH. by ANT Thu May 15, 2003 6:44 pm, Copyright 2022, S&S Motorsports LLC, All Rights Reserved - Powered by phpBB Forum Software phpBB Limited. Again this is dependent on your shift rpm and assuming you truly have 14-1 compression. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. I think that cam had 110 lobe sep. Im loking at a summit cam with close to the same lift and duration #s but 114 lobe sep. The higher the compression and the higher you try and rev it, the more it will like a wider lobe center. Pontiac 326 Vs Chevy 327 Differences & Similarities. As lobe seperation spreads does the powerband. 108: 110: 112: 114 . Read More Chevy 350 Ignition Coil Location And Everything About ThemContinue, What causes a car to bog down when accelerating? The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. Torsion Beam Vs Multi Link: Who Wins the Battle? The balance of midrange torque and top-end horsepower lends this LSA range to the majority of street/strip engines. LSA is the distance from the centerline of the intake lobe to the centerline of exhaust lobe. by mike thompson Tue May 13, 2003 4:03 am, Post For any additional clarification or questions please contact our Tech Line at 714 523-0530. It will have slightly higher vacuum at idle, feel smoother through the power curve but have a bit less midrange. Again, these are general bits of conventional wisdom. Now that we have a basic understanding of lobe separation angle, we can put together a test to illustrate just what happens when you make changes to it. We promise not to use your email address for anything but exclusive updates from the Power Automedia Network. 112 will have a smoother idle, a wider power band, and will work better with fuel injection. Howards Cam Vs Comp Cam: Which Is The Best Option For You? What Are The Wastegate Stuck Open Symptoms? In the 106 LSA, the engine can reach the maximum torque, making the driving more efficient and saving energy. The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes, says Eric Bolander of Erson Cams. 110 LSA: But here, quite surprisingly, you have to face the reduction of the EGR effect due to the 110 LSA. But it also has a lot of lobe separation. A 112-114 degree lobe center will have a better idle and produce more vacuum with less overlap. 114LSA +4 puts the intake centerline at 110 degrees before top dead center. Really wide lobe separation angles are used in boosted applications. The tightest LSA (101) was worth 21.5 lb-ft of torque and a much broader powerbandat the cost of much lower idle vacuum, which would make it more temperamental in a street car. 2.1.3 Transponder reply modes (air-to-ground) Transponders shall respond to Mode A interrogations in accordance with the provisions of and to Mode C interrogations in accordance . Compression willl be 9.75:1. Seeking 1/2" ID x 5/8" OD Black Exit Tubing for Radiator Overflow Reservoir. The piston and cylinder damage possibility is pretty low at 110 LSA. 4-linked72, what cam are you using that has a 108 LSA? I believe you have got the idea of what you were seeking. or just enough to keep the neighbors pissed? A cam with a tighter LSA will require a looser torque converter, may not be able to run vacuum-assisted brakes, and doesn't play nice with fuel injection. This is one of the many reasons why Clay Smith Cams always recommends degreeing your camshaft in using the Lobe Center Method. 106 LSA: The overlapping is higher as 106 LSA is comparatively tighter LSA than 110 LSA. Since we were only changing the lobe separation angle, we had to make sure every variable (air/fuel, timing, water, air, and oil temps) was identical during testing. The idle quality was better with the 112-degree LSA but not as good as the wider 120-degree cam.The ultra-wide 120-degree LSA lost low-speed power and never recovered, but know that this wide LSA is often beneficial on positive displacement, supercharged applications. by ANT Tue May 13, 2003 1:08 pm, Post by trmnatr Sat Dec 06, 2008 10:45 pm, Post Side-lobe suppression shall be provided in accordance with the provisions of on all Mode S-only all-call interrogations. *If you do not have enough vacuum, you can in some cases install a vacuum canister or reservoir, which works by storing the peak vacuum in the reservoir. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Post That is why 106 LSA consumes less oil. The 110 is probably a better choice for a performance street engine. 110 LSA: On the contrary, 110LSA has a higher piston-to-valve clearance rate. Comparison Table Between 106 Vs 110 Lobe Separation Angle. Thanks again. For a better experience, please enable JavaScript in your browser before proceeding. To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. Anybody do any real testing on LSA in a 3.75 stroke small block chevy?I have always used 104-106 and was thinking about trying a 108 or 110 design.I know there is a lot of variables but just a general opinion from any experts.This is for motor only no nitrous.600-640 HP engine combos.Much appreciated! A narrower lobe separation angle can provide less power but can also lead to less wear. For a better experience, please enable JavaScript in your browser before proceeding. 110 degrees on the lobe separation angles. You cannot look at just the LCA without looking at other specs too. Come join the discussion about restoration, modifications, NOS parts, troubleshooting, VIN codes, and more! by jobes Sat Dec 06, 2008 3:51 pm, Post Build your own custom newsletter with the content you love from EngineLabs, directly to your inbox, absolutely FREE! Re: Lobe separations on 383-406 cids.104-106-108-110. JavaScript is disabled. But remember, although a broader powerband has a couple of acceleration advantages, it also comes with a few drawbacks. The Fora platform includes forum software by XenForo. pump gas, no additive's as well, runs good, i will put the highest octane in, which is 93.. . An icon used to represent a menu that can be toggled by interacting with this icon. See all 14 photos 13 The three power curves indicate that the wide (120-degree).