On the cranking. so it is a solid flat tappet, torker intake, 1" 4-hole tapered spacer and 750 carb (QFT) transmission is a wide ratio toploader, rear is a 9" 3.89 geared 26"rear tires. . Due to the tightness and frequent overlapping of the intake and exhaust valves, the engine cant generate the high RPM as it is supposed to. 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. I just installed a Comp Cams XE262 in a 9:1 350 with stock iron heads. However it is at the expense of a small amount of bottom end power and idle quality, due to the increased overlap. 110 LSA: On the contrary, if you look at the powerband at 110 LSA, the powerband is comparatively broader. Nothing makes mouths drop like a car that sounds and looks like it can't keep it self still! I would have to say that your cam choice sounds like a winner to me. We even treated them to some chamber work before installation. 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. A wider lobe center will give you more overall torque (comes in earlier and stays later). 110 LSA: On the contrary, 110LSA has a higher piston-to-valve clearance rate. But, after comparing these two LSA based on a few mechanical aspects, such as maximum Torque, RPM, powerband, oil consumption, and many more, you will find the 106 LSA with better performance output. Howards Cams Retro-Fit Hydraulic Roller Camshaft and Lifter Kits CL120325-08. by Paul H Tue May 13, 2003 1:24 pm, Post document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Disclaimer: Remember to always consult with an expert first before trying anything at home. 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. or just enough to keep the neighbors pissed? A cam in the 110112 LSA range provides the necessary idle lobe to appease gearhead ears with acceptable manifold vacuum to run vacuum-operated accessories. 110 LSA: On the other hand, 110 LSA is comparatively a wider LSA; it can generate a massive amount of RPM for the engine. But, at 106 LSA, the cranking compression may increase above the standard PSI level. 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. But, the narrow or broad powerband choice varies from person to person. Simply put, the lobe separation angle (LSA) is a measurement of how the intake and exhaust lobes are phased with each other. Known as "The Gladiator" around Westech Performance, this Dart SHP blockbased, 370ci, small-block Chevy has made thousands of dyno pulls testing all manner of heads, intakes, cams, and every other crazy thing us magazine folk have coerced Westech's Steve Brul to bolt to it. The stock valvesprings supplied with the CNC LS3 heads were swapped out in favor of a set of dual springs from Brian Tooley Racing. [img]http://i67.photobucket.com/albums/h291/downsideup09/DSCF2616-1.jpg[/img], [img]http://photos-g.ak.fbcdn.net/hphotos-ak-snc1/hs139.snc1/5928_111214857139_110806152139_2127222_6826389_n.jpg[/img]. A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. I'd run it, just be sure to check valve to piston clearance, coil bind and retainer to guide boss/seal clearance. "Ninety-nine percent of cranking compression is dictated by static compression ratio and intake-valve closing point," said Comp Cams' Billy Godbold. 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 its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. ~These are just some of the drawbacks weas guys who like to go mach 10 with our hair on fire and these little motors screaming at rpms that make other guys cryhave to deal with.~. The 110 is probably a better choice for a performance street engine. Valve lift will bear weight in any decision regarding LSA. It also depends on what the vehicle will be used for and if economy and vacuum are important. The graph above compares intake valve closing points of the three cams used in the test. Defining Lobe Center and It's Importance to Engine Performance: A Blog. As a result, a wider valve opening system with no overlapping allows more oil to fall through the oil inlet. " - Voltaire. Save my name, email, and website in this browser for the next time I comment. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. Full text of "Pediatric Books" Test 1 was easy. It a 355. thanks in advance. Save Share. LSA is a result of valve timing events. 108: 110: 112: 114 . 15,215. ohio. A 112-114 degree lobe center will have a better idle and produce more vacuum with less overlap. A lower efficient compression rate leads to a higher fuel consumption rate by your engine to produce higher power. However, it is fixable. This form of short-term memory is supported by the prefrontal cortex (PFC) and is believed to rely on the ability of selectively tuned pyramidal neuron networks to persist in firing even after a to-be-remembered stimulus is removed from the environment. 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? somthing to that aspect. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. When degreeing in the camshaft, you are making sure the intake centerline is precisely where the cam is intended to be. Because during the lower units oil change, you can go through the issue that the lower plug, Read More Yamaha Lower Unit Drain Plug Size [Explained Everything]Continue, Among the crucial parts of a vehicle ignition system is the ignition coil, also called a spark coil. 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). 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. turbo camshafts lobe centers and lobe separation 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. . Depending on the engine combination, the opposite results can occur. Lobe Separation Angle "LSA "Jump to Latest Follow 1 - 17 of 17 Posts . 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. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. In this segment, I am going to compare those two lobe separation angles based on a couple of mechanical factors. Also know as Lobe Separation; Lobe Center is simply the distance between the peak opening points on the Intake and Exhaust lobes. Some prefer a narrow powerband, and some prefer the broader one. It is dangerous to be right in matters on which the established authorities are wrong. It is the DESIGNED events that yield CENTERLINE. A 112 LSA would be better if I had an automatic, but the engine builder (who has built many, many drag racing engines)told me I would have much faster acceleration with the 108, at the expense of a broader power band of course, but that 108 would not unduly penalize me for the street. Camshaft Kits - 108 Lobe Separation (degrees) - Summit Racing These numbers can vary a few inches one way or the other, depending on several other aftermarket factors and your individual engine specifications, so you may want to check your vacuum once the cam is installed. One segment that truly benefits from a wider LSA is the marine marine market. Lobe separation angle does. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. by mike thompson Tue May 13, 2003 4:03 am, Post Increasing the EGR effect has a good side in that it reduces the amount of oxygen in the combustion chamber. What Are The Wastegate Stuck Open Symptoms? This process slows down the reaction rates of the air-fuel mixture, causing temperatures to drop and preventing the engine from overheating. Lobe separation angles, he continues, are influenced by the camshaft grind. Comp cam hydraulic roller lifters. The Wastegate works by releasing the pressure built inside, Read More What Are The Wastegate Stuck Open Symptoms?Continue, Oops! However, the plentiful exhaust overlap (31 degrees) meant there was lots of exhaust dilution at low engine speed and high vacuum. Well, If I am not mistaken, you must be looking for which angle has what impact on your engine or which would be the best. We will safeguard your e-mail and only send content you request. This comparison highlights that the 106 LSA is a good performer in a few mechanical aspects than the 110 LSA. Come here to talk with others who like to drive fast. by SStrokerAce Sat Dec 06, 2008 7:38 pm, Post Only once the intake valve has closed can compression begin to build. The tighter the lobe separation angle, the peakier the power curve will be, confirms Bolander. The exhaust has an opening even and a closing event. The right camshaft choice | Hemmings 2023 Power Automedia. BUT, 114 will have more vacuum at idle, which will work better with some fuelinjection. To reiterate another point, I realize that wider LSAs tend to broaden the power band, but for a car I would like to bracket race a bit, as well as enjoy on the street, I was told that a narrower LSA will help the car accelerate at a faster rate. 106 LSA: The overlapping is higher as 106 LSA is comparatively tighter LSA than 110 LSA. 110 for sure. The valve covers, valvetrain, intake manifold, harmonic balancer, front cover, timing set, and cam were yanked. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Do you like to go fast? Now its not shifting into 3rd and you are here. As boost increases, the air will be forced through the cylinder, vs. being trapped in the cylinder. It may not display this or other websites correctly. But that doesnt mean high-strung racing engines cant see gains, as well. That was all, and we have already reached the concluding point. 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. If the intake valve opens too early, it will push the new charge into the intake manifold. Really wide lobe separation angles are used in boosted applications. Re: Lobe separations on 383-406 cids.104-106-108-110. When choosing a cam, power gains shouldn't be the only consideration. JavaScript is disabled. 10 Tuning the timing curve and fuel from the 42-lb/hr FAST injectors was handled by this Holley HP management system. The #1 intake lobe centerline is usually between 100 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. 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. 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. 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. Has anybody experienced it/ tried it? Kevko baffled oil pan & Milidon windage tray. The 114 cam will give more low end torque, good midrange, less power up high. by mrsmythe Tue May 13, 2003 5:45 am, Post Well, it is quite a natural event that you may not find the lope separation angle mentioned at the engine body. 06 The ported heads featured a 2.165/1.590-inch valve combo. 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. I have used some cut on a 110 that worked well too, but they never sounded as good as the tight ones. I also like the 106 lobe separation with the intake on 103. Is a 108 Lobe Separation 2 Much? | Hot Rod Forum 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. It is the average centerline between both lobes and expressed in degrees ranging from 95 on the extremely narrow/tight side to upward of 120 on the wide end. The 110 is probably a better choice for a performance street engine. Myoinositol reduction in medial prefrontal cortex of obsessive 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. That is no accident. 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 Fora platform includes forum software by XenForo. Once more the engine came apart to install the third test cam, a 107 LSA. Simply put, the lobe center of the camshaft controls where the power curve is applied. How do the lobe separations change when you factor in turbocharging? The 290 advertised duration and 114 lobe separation would contribute to a lazy power curve. 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 -. I believe you have got the idea of what you were seeking. 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. 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. #2---Choosing a Cam - Hughes Engines The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. Overlap is the amount of time that both valves are open in the same cylinder. Camshafts Demystified - CarTechBooks Its the shifting problem again with your Chevy! Need some Cam Advice! | Chevy Tri Five Forum Okay, have a sigh because you have opened the right door. If all the specs remained the same what will going from a 110 to a 112 lsa do to driving characteristics? hydraboost is the same as a vacuum brakebooster, only the booster is replaced by a unit that does the same but under hydraulic pressure. = Moderately Wide 110-108 Deg. Camshaft Lobe Separation Angle | Classic Car Restoration Club My duration will be about 230 degrees. 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. The other thing is that you can make more power with a smaller aftermarket cam. Around 70 percent of muscle-car performance cams fall into this range. 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. 110 LSA: But, contrarily, at 110 LSA, you dont have to face the problem of engine knocking. Ultimately, it comes down to how you want the engine to run, the car's intended purpose, and what you are willing to tolerate. 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. 238/248 duration, 300/310 adv. JavaScript is disabled. I would say 114-117* would be a normal 1960's stock cam range and 117* to 120* is more what we see on modern engines. 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). More than any other component, the cam profile determines things like idle quality, mileage, and overall driveability. Thanks again. 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.
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