Hey guys, can anyone tell me how rough of a idle a cam would be with a 108 lobe separation? 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 I'm sorry to disagree with that incredibly well written article, but lobe separation by itself is absolutely freaking meaningless. 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. 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. Every spec is a road map to what the valves are doing, the most common of which are lift, duration, and lobe-separation angle (LSA)the latter needing the most explanation. The world of fuel injection is where wide LSA cams like the 113 really shine. Engine builders Chuck Lawrence, left, and Doug Patton. These issues can often be worked through by an advanced tuner, but always present a challenge and compromise in tuning strategy. Well, it is quite a natural event that you may not find the lope separation angle mentioned at the engine body. This comparison highlights that the 106 LSA is a good performer in a few mechanical aspects than the 110 LSA. The SAME can be said. Noah knows a lot about whats happening in the car industry with the latest piloting productions thanks to his professional experience. by mike thompson Tue May 13, 2003 4:03 am, Post OK, what is hydraboost, and how do you like how the cam performs??? 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. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. Aluminum flywheel & pullies. by Paul H Tue May 13, 2003 1:24 pm, Post Powerband serves a massive contribution to the acceleration car. I just installed a Comp Cams XE262 in a 9:1 350 with stock iron heads. Its also critical that valve overlap is kept to a minimum as the induction system can create a suction that pulls water into the motor, adds Bolander. The only reason I . I wouldn't assume 4 links fuel requirements will mirror yours at all. 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. Ultimately, it makes the 110 LSA an oil-consuming LSA. This table will create a map in your head, and I bet it will make your understanding crystal clear. thanks. Also present during testing was a set of 1 7/8-inch Kooks headers, Comp hydraulic roller lifters, and F-body oil pan. Lobe Separation Angle "LSA "Jump to Latest Follow 1 - 17 of 17 Posts . If you look at any given cam catalog, you will find that the majority of street-oriented cams fall in this range. It provides a spark plug with the high voltage needed for combustion. As a result, you can enjoy a pleasing engine outcome. 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. 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. Ed JTO learn to park Joined May 31, 2009 180 Posts Yeah but do the experiment on the dyno and tell me your intuition is correct. More over-simplifications: A cam's lobe separation determines where and for how long peak torque occurs in an engine's rpm range. 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. 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. Simply put, both 106 and 110 lobe separation angles have many advantages and disadvantages. 108: 110: 112: 114 . 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. 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. 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. Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. But, you may wonder knowing that a higher valve clearance rate reduces the chance of damaging the valve by the piston. its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. Test 1 was easy. It really comes down to the application. 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 introduction of Lunati'snew Bootleggerhydraulic series - with its wicked 108-degree lobe-separation angle, fast opening profile and plenty of area under the lift curve - will serve only to fuel the flames on this heated bench-racing topic. For a better experience, please enable JavaScript in your browser before proceeding. Idle vacuum showed a considerable spike to 14.7 in-Hg, likely the difference between being able to run power brakes and a mandatory leg workout. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. NOTE: Classic Inlines stocks the above profiles in 108, 110, and 112 lobe centers. The 290 advertised duration and 114 lobe separation would contribute to a lazy power curve. Hopefully It will do fine in my 2276 mostly drag bug. Thanks for the replies so far. However it is at the expense of a small amount of bottom end power and idle quality, due to the increased overlap. Bolander says those cams help promote torque in a controlled and predictable manner, especially in no-wake zones and around the docks. 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). The 114 LSA is good for a blower or nitros motor. After swimming through the entire article, I hope you are now well aware of the 102 vs 110 lobe separation angle. 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. A tighter LSA is always going to have more overlap, which allows the exhaust and intake systemif they're tuned wellto work together.". 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. But nothing comes without a cost, and idle vacuum suffers as LSA shrinks. whats the difference in how the car will run. I personally prefer to sacrifice the small amount more power for better idle quality. When you don't have any overlap, you can't have any wave tuning. The only reason the advance or retard a camshaft profile is to get the timing events where they need to be. by 3V Performance Sat Dec 06, 2008 4:38 pm, Post Given that nitrous works best in the mid- to upper-rpm range, nitrous-powered engines need a wider lobe separation, like 112 . If you want a lumper idle go with a cam with 108 LSA, the tigher the LSA the idle will be rougher. so the power will come on a litter sooner with the 114, and fall off a little sooner? 06 The ported heads featured a 2.165/1.590-inch valve combo. 110 LSA: On the contrary, at 110 LSA, the engine fails to reach the maximum torque, resulting in a decrease in torque rate. No, it is not even close to the ultimate performance grind most would have picked. 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. What happens when you change ONLY. A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. Turbochargers are not as simple as they may sound; you may think of them only as power-boosting components. Torsion Beam Vs Multi Link: Who Wins the Battle? 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. Walter Noah is a process engineer who has a knack for resolving even the toughest technical issue. by lazaris Fri Dec 12, 2008 2:18 pm, Post Higher lift and longer duration profiles add power, but do so at higher engine speeds (especially true of duration). Save my name, email, and website in this browser for the next time I comment. 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. - Sheryl Crow. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. So, sit tight back and explore. The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. I just bought a 86b Webcam and Im using 1.5's. 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. probably just enough to get me in trouble.. http://www.mustangworks.com/cgi-bin/moi-display.cgi?220, http://www.popularhotrodding.com/en6em_camshaft_specs/lobe_seperation_angle.html. Cylinder-head flow and LSA are directly related: as a rule of thumb, the better the head flows, the wider the LSA can be. 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. 110 LSA: Oppositely, the cylinder pressure is comparatively lower at 110 LSA than at 106 LSA. I forgot to add that poor vacuum is not much of a concern to me because I have no power accessories. 110 LSA: On the contrary, it is pretty unpleasant to inform you that the efficient compression rate decreases at 110 LSA. 106 LSA: At this LSA, the car machine has to confront the reduction of idle vacuum rate quite often. If the overlap phase occurs too early, it will create an overly rich condition in the exhaust port, severely decreasing the gas mileage. Post Similarly, 110 LSA is also found to be a more fabulous performer in several mechanical aspects. Now its not shifting into 3rd and you are here. A mobile functional near-infrared spectroscopy (fNIRS) was used to record cerebral oxygenation signals in the left prefrontal cortex (LPFC), right prefrontal cortex (RPFC), left parietal lobe (LPL), and right parietal lobe (RPL) and analyze the EC of the cerebral cortex. But, you may find a lobe wider than a 120-degree angle in any car engine.But, I must let you know that those are customized car engines prepared for any special purpose, such as racing, drag racing, off-road riding, or performing stunts. Let's just talk lobe sep angle. Widening their separation angle helps increase upper rpm power output. If you shift at 7500-7800 add 4-6 degrees to both intake and exhaust and spread the lobe separation to 108-110. A narrower lobe separation angle can provide less power but can also lead to less wear. The second cam would have a rougher idle, produce more torque and would rev quicker. In general, a stock replacement camshaft with duration of less than 200 degrees will have a lobe separation angle of more than 114 degrees. For a better experience, please enable JavaScript in your browser before proceeding. The custom cams we selected all featured 0.624-inch lift (both intake and exhaust) and a 232/242-degree duration split. A cam card with its myriad numbers, acronyms, and abbreviations is one red-pen stroke away from a failed math test. But, at 106 LSA, the cranking compression may increase above the standard PSI level. ditto with the above. Engine builders Chuck Lawrence, left, and Doug Patton. 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. The valve covers, valvetrain, intake manifold, harmonic balancer, front cover, timing set, and cam were yanked. After consulting with many experts, you are still in confusion between 106 and 110- lobe separation angles. Most street cams are ground 4 degrees advanced which boosts bottom end, throttle response, vacume, mpg driveability etc. 106 LSA: There is an increasing chance of engine knock at the 106 lobe separation angle. The 234o duration kind of eliminates the RV usage. Moreover, a user from the Chevelle forum said. Lobe separation angle does. 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. in some cases,, the average torque can equal out. LSA CAM TEST-108 vs 112 vs 120 Richard Holdener 239K subscribers 168K views 2 years ago WESTECH PERFORMANCE GROUP FULL RESULTS-CHANGE ONLY LSA-LS CAM TEST. The other thing is that you need to tune your ignition advance to maximize your performance. True enough, the tight LSA improved power through the entire rev range, from 3,600 to 6,500 rpm, but the extra power came with a penalty in idle quality. As lobe seperation spreads does the powerband. such as 290 @.050? i think a little more torque will be good for my car.With the XE274 it was a little slugish until around 3000 rpms. = Moderately Tight 106-104 Deg. The center of those 2 events is the LOBE CENTERLINE (ECL). And better gas mileage. You must log in or register to reply here. = Extremely Tight . It a 355. thanks in advance.
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