When choosing a cam, power gains shouldn't be the only consideration. Thanks. Now its not shifting into 3rd and you are here. For a better experience, please enable JavaScript in your browser before proceeding. by mrsmythe Mon May 12, 2003 11:15 am, Post 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. Most cars use more than, Read More Does It Matter Which Ignition Coil Goes Where? not exactly true, Ive seen custom grinds that are on 108 lca, smooth idle, high vacuum an even able to run efi, usually on an off the shelf cam it is true. A wide LSA reduces valve overlap, softens the idle and improves overall drivabilityespecially on the street where performance engines benefit from 112 to 114 LSA. Really wide lobe separation angles are used in boosted applications. But, you may find it quite shocking that the piston-to-valve clearances decreasing rate raises the chance of damaging the valve by the piston. Whatever you do, stay under 270 advertised duration and shoot for a 110 lobe separation. 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. Well, it is quite a natural event that you may not find the lope separation angle mentioned at the engine body. 106 LSA: So, if I talk about the powerband at 106 LSA, the powerband is narrow. The lumpy-idling 101 LSA cam churned out an average of 484.0 hp at 6,100 rpm with 493.9 lb-ft of torque at 4,400 rpm. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. Lobe separations gives lots of overlap and lobe centers just happens when the grinder decides how the peak of the lobe will arrive on a specific grind by their tooling. The world of fuel injection is where wide LSA cams like the 113 really shine. GRIND #: CRB3 3194 /3196 HR111. A cam with a 112lobe center will idle smoother than a cam with a 110lobe center. A wider lobe center will give you more overall torque (comes in earlier and stays later). 12 In terms of power production, the stroker LS3 performed best with the tightest lobe separation angle. You are using an out of date browser. It should still make close to 600hp and 600tq in my 512" stealth headed big block. 2023 Power Automedia. = Extremely Tight . lobe centers and lobe separation are 2 different things . As you can see in the graph, the 101 LSA cam actually had the highest cranking compression of the batch: 185 psi. 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. How do the lobe separations change when you factor in turbocharging? I am pretty sure, right now, you find yourself in the middle of the rising debate of 106 vs 110 lobe separation angle. For large port heads like the CNC 044's which can use the extra lift 1.4's make a noticable difference. More over-simplifications: I've seen that Webcam cams can be ordered with either of the above. The LSA, or lobe separation angle, is ground into the cam and cannot be changed. It produces peak torque earliercoming on quicker and strongerbut also it falls off quicker too. 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. Like one cam is 112 degree and the next is 108 the 108 cam will allow less "leakage"? He also enjoys reading books a lot and his favorite author is Paula Coelho. 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. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! 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. That lopey idle that is universally loved, and part of the allure of a tight LSA cam, is actually misfire caused from a combination of exhaust dilution in the intake manifold and poor cylinder filling at idle. Say you have a cam ground on a 115 and the other on a 110. I personally prefer to sacrifice the small amount more power for better idle quality. THis is a real generalization, but the weaker your heads, the more you will like the smaller centers ( 106-108) the better the heads, and the higher the compression, the more it will like the wider centers ( 112-114)everything else falls somewhere in the middle( 108-110) Once you get close with the cam centerlines, it wont make much differance if you change it up or down by 2 degrees. 106 LSA: You can see an increasing EGR effect at 106 LSA. by xstfudonniex Fri Dec 12, 2008 5:24 pm, Post If you shift at 7500-7800 add 4-6 degrees to both intake and exhaust and spread the lobe separation to 108-110. Frankly cams with a 108-114 lca unless in the perfect combo you won't usually see more than 15hp and you won't really feel the difference except for either a peaky or broad power band. If you're an OEM automaker looking for a steady idle, good fuel economy, and passing tailpipe emissions, this is the cam of choice. 4-Link72, do you run racing gas or pump with 10.5:1 CR? Lobe Separation or Lobe Centers is another way of expressing the Valve Overlap, which was the term formerly used by cam manufacturers before industry standard verbiage changed. Hey guys, can anyone tell me how rough of a idle a cam would be with a 108 lobe separation? So, this LSA is suitable for your engine and its components. What brand and what are the specs on your cam, 4-linked72? After spending 8 years in plant production engineering, Noah wanted to join Engine Addiction as a key member of all cars specific guides, reviews, repairs, suggestions, and more. 554"/577" lift. Required fields are marked *. Re: Lobe separations on 383-406 cids.104-106-108-110. Lobe separation angles, he continues, are influenced by the camshaft grind. For any additional clarification or questions please contact our Tech Line at 714 523-0530. https://www.youtube.com/watch?v=57gfBu8uc6k&t=1s. A cam with a 112 lobe center will idle smoother than a cam with a 110 lobe center. After swimming through the entire article, I hope you are now well aware of the 102 vs 110 lobe separation angle. Increasing the EGR effect has a good side in that it reduces the amount of oxygen in the combustion chamber. its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. It is dangerous to be right in matters on which the established authorities are wrong. The extra cubic inches will smooth out a rough idle in a 327. 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 -. on average with a N/A motor if you stick the two cams in at the track the tighter lsa will be faster at the expense of idle quality. Your best bet would be to talk to one of the experts at a cam company to get a custom grind if you're that into the specs. A tighter LSA is always going to have more overlap, which allows the exhaust and intake systemif they're tuned wellto work together.". Thanks for the replies, particularly that link Marc, very informative. by ANT Mon May 12, 2003 1:47 pm, Post So, without wasting any moment, lets find out the answer. dur. However, in application, there is a lot more to consider. Engine builders Chuck Lawrence, left, and Doug Patton. Good luck. And better gas mileage. Lobe separations on 383-406 cids.104-106-108-110? The taller lobe seperation will have a longer powerband but will have to rev higher to make the power than the lower lobe seperation! But there is a drawback of higher cylinder pressure: higher cylinder pressure may sometimes lead to piston or piston ring problems. Some prefer a narrow powerband, and some prefer the broader one. This is one of the many reasons why Clay Smith Cams always recommends degreeing your camshaft in using the Lobe Center Method. 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. Save Share. With the first cam loaded in the engine (the 101 LSA) Westech's Steve Brul made three dyno pulls, the average of which was saved to compare to the next cam. 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 The tighter the lobe center, the lower the RPM range; the wider the lobe center, the higher the RPM range. Engine builders Chuck Lawrence, left, and Doug Patton. by SStrokerAce Sat Dec 06, 2008 7:38 pm, Post Similarly, 110 LSA is also found to be a more fabulous performer in several mechanical aspects. I'd also go to a 110-112 lobe separation angle. 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. When degreeing in the camshaft, you are making sure the intake centerline is precisely where the cam is intended to be. 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. Usually, an old gas tank is responsible for a vehicle bogging down during acceleration. With minimal overlap and a steady manifold vacuum signal, they work great with fuel-injection systems and are the norm on modern pushrod engines, such as the LS and Gen III hemi. This recommendation is only if you shift at no more than 7000. If two cams are identical with the exception of lobe separation angle (we'll say 108 and 114) the cam with 114LSA will make more low end power than the 108LSA cam? 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. Chevy Transmission Wont Shift Into 3rd: Finding the Main Culprit, Yamaha Lower Unit Drain Plug Size [Explained Everything], Does It Matter Which Ignition Coil Goes Where? 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. Moreover, a user from the Chevelle forum said. Lobe seperation cant be seperated from duration,the 2 are connected.the old duntov cam had a lot less duration than many new cams so the valve overlap was not extreme and the engine ran with a gentle lope.Increase the duration by 20* and this cam would shake a 283 out of the car at idle,but then increase the lobe seperation by 4* and the motor will have a gentle lope again. The 290 advertised duration and 114 lobe separation would contribute to a lazy power curve. Bad idea in my view. After consulting with many experts, you are still in confusion between 106 and 110- lobe separation angles. Thanks for the replies so far. = Moderately Wide 110-108 Deg. It will also give you a smoother idle and probably even better gas mileage. We even treated them to some chamber work before installation. 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 And better gas mileage. But nothing comes without a cost, and idle vacuum suffers as LSA shrinks. 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. It affects the powerband and temperament of a motor more than any other single part, and a slight change can turn a car from a mild-tempered grocery-getter to a downright nasty machine. Powerband serves a massive contribution to the acceleration car. 108 versus 110 will drive the power band down. A few other major and, Read More Heres What Causes Your Car to Bog Down When AcceleratingContinue, Your email address will not be published. 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. (LOBE SEPARATION ANGLE)cam CRANES 110921 has the intake close at 45 degrees ABDC while the wider lsa CRANES 114681 closes the valves at 50.0 ABDC . Part Number: HRS-CL120325-08. The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes. 110 LSA: However, if you look at the rate of cranking compression at 110 LSA, you will find a reduced compression rate from the standard cranking compression PSI level. My engine shop builds all kinds of hot rod motors, and they told me that because I am running a 4 speed manual, I will better be able to take advantage of the 108 LSA. When you don't have any overlap, you can't have any wave tuning. If you take any of the . Realize what the engine is going in, however, as you may not be able to use the wildest cam out there. The takeaway from this test is camshaft LSA is a double-edged sword. A commonly held misconception is that intake/exhaust overlap contributes to lower cranking compression. Retarding the camshaft (a higher intake lobe centerline number 108 vs. 104) will generally start the power band later in the RPM range and decrease the cylinder pressure. To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. Exhaust reversion is another undesirable side effect that can be caused by overlap. by flat4racer17 Mon May 12, 2003 1:40 pm, Post Our content is merely suggestive, not intended to use without proper safety precautions and advice. This is very critical for manifold vacuum, throttle response, emissions, and gas mileage. 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. That is why 106 LSA consumes less oil. JavaScript is disabled. This may be of concern if you have vacuum assisted accessories, such as power brakes or steering. I had a 110 cam in my beetle and I didn't like it-the bottom end was doggy. but less of it at the same time. 06 The ported heads featured a 2.165/1.590-inch valve combo. 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. Wide LSA cams are also applicable in forced-induction applications where less exhaust overlap is required. Next up was the 112-degree cam, which actually lost out in peak power slightly to the 120-degree cam, but offered considerably more torque. The 114 cam will give more low end torque, good midrange, less power up high. 2.1.2.4.2 Side-lobe suppression shall be provided in accordance with the provisions of 3.1.2.1.5.2.1 on all Mode S-only all-call interrogations. The 110 is probably a better choice for a performance street engine. 1-3 Cognitive impairment is common in both FLE and TLE and adversely impacts quality of life and psychosocial functioning. See all 14 photos 13 The three power curves indicate that the wide (120-degree). I'd run it, just be sure to check valve to piston clearance, coil bind and retainer to guide boss/seal clearance. An icon used to represent a menu that can be toggled by interacting with this icon. 15,215. ohio. 02 The 402-inch stroker short-block combined an aluminum LS2 block with a 4.000-inch crank and 6.125-inch rods. Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. Mike Magda is a veteran automotive writer with credits in publications such as Racecar Engineering, Hot Rod, Engine Technology International, Motor Trend, Automobile, Automotive Testing Technology and Professional Motorsport World. 110 LSA: On the contrary, if you look at the powerband at 110 LSA, the powerband is comparatively broader. "It's not having what you want, it's wanting what you've got!" 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. So, you can enjoy a mighty acceleration power at 110 LSA. Your email address will not be published. Before we all start suffering from separation anxiety, we need to understand what lobe separation angle actually is and then how it affects your engine. The Fora platform includes forum software by XenForo. Read More Chevy 350 Ignition Coil Location And Everything About ThemContinue, What causes a car to bog down when accelerating? In my opinion, the rougher the idle the better! Yearh, I have been reading a lot about this issue. However, the plentiful exhaust overlap (31 degrees) meant there was lots of exhaust dilution at low engine speed and high vacuum. Knife edged & profiled 4MA Cleveland crank weighing 50lbs. Frontal lobe epilepsy (FLE), the second most common focal epilepsy syndrome after temporal lobe epilepsy (TLE), is frequently drug-resistant and MRI-negative. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. If you drew a line that divided the intake lobe in half right at the point of maximum lift, then did the same to the exhaust lobe, then measured the distance in cam degrees between the two, that would be the lobe separation angle. So the wider LSA introduces a broader and therefore longer torque band.. Come join the discussion about restoration, modifications, NOS parts, troubleshooting, VIN codes, and more! The 112-degree cam produced peak numbers of 567 hp at 6,200 rpm and 540 lb-ft of torque while pumping out 511 lb-ft of torque at 4,000 rpm. For your convenience, I am providing a comparison table to give you an overall idea about the comparison. For a better experience, please enable JavaScript in your browser before proceeding. The final, 108-degree cam stepped power up even further, with peaks of 572 hp at 6,300 rpm and 544 lb-ft at 5,200 rpm. I've seen that Webcam cams can be ordered with either of the above. by ANT Tue May 13, 2003 1:08 pm, Post 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. If you changed the lobe separation of a street engine from 112 degrees to 106 and didnt do anything else, adds Kaase. I have seen a dyno test where an engine using identical duration and lift made more peak power with a 112 LSA than a 110 LSA. JavaScript is disabled. Now lets move to the exhaust. such as 290 @.050? As a result, a wider valve opening system with no overlapping allows more oil to fall through the oil inlet. Some of the confusion on this subject comes from what the meaning of "bottom" and "top" is to the speaker, I suppose. However it is at the expense of a small amount of bottom end power and idle quality, due to the increased overlap. As you tighten the centers ( 108 ) the same engine will make MORE power through the mide range and top end. The 402-inch LS2/LS3 hybrid stroker started out with an LS2 aluminum block. The first cam featured a wide 120-degree LSA, while cam number two narrowed the angle to 112 degrees. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Disclaimer: Remember to always consult with an expert first before trying anything at home. I would have to say that your cam choice sounds like a winner to me. Big strokers like tighter LCA but it really depends on your combo and usage, theres great OTS cams but for a custom engine a custom cam is the way to go With identical cam lobes you won't see a bit of difference.
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