Post A cam 112LSA with 4 degrees advance puts the intake centerline at 108 degrees. Realize what the engine is going in, however, as you may not be able to use the wildest cam out there. I forgot to add that poor vacuum is not much of a concern to me because I have no power accessories. I do believe that stock VW seperation is 108 and 112 is used alot in turbo and midrange cams for VW's while 106 is used for the top end cams. also,, wider will produce a wider and more flat torque curve that doesn't fall off as abruptly up top rpms. 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. 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. 15,215. ohio. The takeaway from this test is camshaft LSA is a double-edged sword. how much boost on a 110 lob sep cam vs 112 vs 114 106 LSA: The scale of efficient compression rises at 106 LSA. Lobe separation angle does. As a result, you can enjoy a pleasing engine outcome. If you look at the cam card, you will find a maximum lift column on the card.Now, all you have to do is, add up the two mentioned maximum angles and divide the summation by 2. I have Crane hydraulic link bar style roller lifters, so I dont have to use the spider style. Average power was also down, but the engine pulled ahead of the 101 cam at 5,400 rpm, picking up 6.5 hp at peak. Really wide lobe separation angles are used in boosted applications. 110 vs. 112 lobe seperarion on a cam - Chevy Message Forum So, without wasting any moment, lets find out the answer. The 114o lobe will add a lot more vacuum at idle. If a street car has smaller lift and duration numbers, they might run 112 or 114. Is a 108 Lobe Separation 2 Much? | Hot Rod Forum Re: Lobe separations on 383-406 cids.104-106-108-110. So, you can enjoy a mighty acceleration power at 110 LSA. If the overlap phase occurs too early, it will create an overly rich condition in the exhaust port, severely decreasing the gas mileage. So, this LSA is suitable for your engine and its components. This may be of concern if you have vacuum assisted accessories, such as power brakes or steering. This comparison highlights that the 106 LSA is a good performer in a few mechanical aspects than the 110 LSA. O onovakind67 Registered Joined Dec 14, 2001 6,242 Posts Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. The lobe separation angle is a comprise of what the engine needs depending on the compression, combustion chamber, rpm, engine size, head volume, and many, many other variables. On the surface, the camshaft's job is simpleopen and close the valvesbut beyond that topical description, it's one of the most mysterious and misunderstood engine components. A narrower lobe separation angle can provide less power but can also lead to less wear. To further minimize any dyno variations, the engine's oil and water temperatures were kept the same for each pull. This cam also offered the highest torque output at 4,000 rpm with 522 lb-ft. Based on the peak numbers alone you might be tempted to grab the one with the tightest (108-degree) LSA, but there is more to a cam test than power. This cam split the difference between the 101 and 113 down the middle, and in theory should have walked the line between the results of the last two tests in every waywhich it did. But for small-block Chevys (like the LS applications in this story), the LSA is ground into the cam. its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. The Crane has a smoother idle, broader power band, and . I'm sorry to disagree with that incredibly well written article, but lobe separation by itself is absolutely freaking meaningless. I don't think your duration figures are too outlandish and with the tight LCA and high lift, it should make some big torque. As boost increases, the air will be forced through the cylinder, vs. being trapped in the cylinder. (ICL + ECL) / 2 = LOBE SEPARATION ANGLE (LSA) LSA is a RESULT of the PROPER events. Copyright 2022, S&S Motorsports LLC, All Rights Reserved - Powered by, http://www.webcamshafts.com/cam_glossary.html, http://www.newcovenant.com/speedcrafter haft/3.htm, Webcam 86A 108LC w/1.5 vs 86B 112LC w/1.3s. LSA helps determine the cam's behavior; you can take a given set of lift and duration figures, change the LSA, and get cams with vastly different characteristics. Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. . Leave the 108 for solid rollers turning big rpms. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. A cam with a 112 lobe center will idle smoother than a cam with a 110 lobe center. Pick the cam with the valve timing events that fit the engine best, forget about LSA, it is only a result of the events. Let's just talk lobe sep angle. Another related thought to consider when selecting a cam is inches of vacuum for your engine application when deciding upon a Lobe Center. Despite no changes in lift or duration, this cam sounded much more aggressive than the other two with wider LSAs. It creates an unsteady manifold vacuum condition that, on a fuel-injected engine, confuses manifold air pressure (MAP) sensors, making it hard for them to regulate fueling. Well get out of that stocker and build a hipo motor for your VW. by xstfudonniex Sat Dec 06, 2008 4:21 pm, Post On a naturally aspirated engine, the lobe separation angle has an effect on whether the engine reaches peak torque a little earlier or later in the rpm range. Camshaft: Hydraulic Roller, Comp Cam custom grind (ADV Duration 281-287,@ .050 230-236, lift 622I & 625E w/1.6 rockers.) My lift will be about .580" intake and exhaust, with about 230/236 duration with a 1.7 rocker ratio, utilizing a Jesel shaft rocker system. Ultimately, it makes the 110 LSA an oil-consuming LSA. Valve lift will bear weight in any decision regarding LSA. Icao Annex 10 Aeronauticaltelecommunicationsvolumeiv-Surveillanc The 108-degree cam (blue lines) outperformed the other two, but idle quality suffered. i've heard of this being done something about the massive amounts of duration allowes gasses to disipate? As a result of this fall, the idle of the engine has to face suffering quite often. Engine knocking generally occurs when the burning of the fuel by the engine is uneven. I've seen a few comments in threads on here that have said things like "going to the 112LC from the 108LC gives 4lbft more torque at the bottom and 2bhp more at the top" yet this would seem to go against what webcam say on. that is why people running 112 or 114 lobe centres retard the cam ,that way the exhaust event is back were it was before .this helps in exhaust valve tempatures--anyway today i talked too barry who is the owner of shadbolt cams and we talked about cam lobe centres -he considers 108 centre quite narrow and for a very narrow power band operation ,with a 112 he figures with the carbs with straight & even runs at the valves there should be no noticable loss of low end power, a 112 lobe would be a great choice for a great street strip motor -better lower torque followed with a flatter rising torque curve as well as rpm range extended 500-700 rpm -. 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. If it occurs too late, it will lean out the cylinder and greatly hinder the performance of the engine. In terms of horsepower, the disparity between all three cams was only 6.5 hp, with a scant 100 rpm separating the peaks. The 402 was run with a FAST LSXR LS3 intake and matching 102mm throttle body along with stock LS3 rockers, a Holley HP management system and 7.4-inch hardened pushrods (from Comp Cams). 106 LSA: 106LSA results in a decrease in piston-to-valve clearance. Need some Cam Advice! | Chevy Tri Five Forum Contributions la connaissance de la flore du Maroc et de l'Afrique du If you compared these two cams side by side in identical engines, the first cam would actually have a slightly better idle and would produce slightly more peak power at upper RPM's. 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. Its the shifting problem again with your Chevy! Like one cam is 112 degree and the next is 108 the 108 cam will allow less "leakage"? The center of those 2 events is the LOBE CENTERLINE (ECL). Maybe even 114. The tighter the lobe separation angle, the peakier the power curve will be, confirms Bolander. It made 472.4 lb-ft at peak, a 21.5lb-ft disparity from the 101 cam. Frontal lobe epilepsy (FLE), the second most common focal epilepsy syndrome after temporal lobe epilepsy (TLE), is frequently drug-resistant and MRI-negative. Is There a Sequence? Epilepsy is a chronic noncommunicable brain (neurological) disorder associated with excessive neuronal activity and unprovoked seizures referred to as 'epileptic seizures' and sensory-motor deficits that cause neurobiological, cognitive, psychological, and social consequences to the patient. I don't know about 13 to one but I have seen 12 to one on a 350 chev in hot rod article, BUT the guy soft petals around on the street with no full throttle use and puts racing gas in at the track. It depends on the combination of engine size, head flow and head flow balance, as well as a big one, exhaust flow capabilities. Builds More High-RPM Power Increase Piston-Intake Valve Clearance Decrease Piston-Exhaust Valve Clearance EFFECTS OF CHANGING LOBE SEPERATION ANGLE (LSA) Tighten (smaller LSA number) Moves Torque to Lower RPM Increases Maximum Torque Narrow Power band Builds Higher Cylinder Pressure Increase Chance of Engine Knock Increase Cranking Compression dur. 108 vs 112 LSA | Team Camaro Tech Lower cylinder pressure is advantageous for your engine. 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. Aeromotive; 913.647.7300; AeromotiveInc.com, AFR Heads; 661.257.8124; AirFlowResearch.com, Federal Mogul/Felpro; 248.354.7700; FederalMogul.com, Mahle; 248.347.9700; Mahle-Aftermarket.com, Scat Enterprises; 310.370.5501 ScatEnterprises.com, SuperFlow Dynamometers and Flow Benches; 515.254.1654; SuperFlow.com. Lobe Separation Angle "LSA "Jump to Latest Follow 1 - 17 of 17 Posts . Anybody here run a 108 LSA? 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.
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