any input is appreciated guys, thanks. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. This table will create a map in your head, and I bet it will make your understanding crystal clear. 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. That is why 106 LSA consumes less oil. Howards Cam Vs Comp Cam: Which Is The Best Option For You? The lobe separation angle in a natural car engine conveys a considerable impact, especially regarding the maximum torque. I will be running an Edelbrock Performer RPM, with a Quick Fuel 750cfm with a screw adjustable vacuum secondary; it's called the Pro-vac. I just bought a 86b Webcam and Im using 1.5's. The 110 is probably a better choice for a performance street engine. 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. BUT, 114 will have more vacuum at idle, which will work better with some fuelinjection. Come join the discussion about popular models such as the Mustang, Galaxie, Falcon, Fairlane, Torino, Shelby and many more! Around 70 percent of muscle-car performance cams fall into this range. Bolander says those cams help promote torque in a controlled and predictable manner, especially in no-wake zones and around the docks. 106 LSA: There is an increasing chance of engine knock at the 106 lobe separation angle. 114LSA +4 puts the intake centerline at 110 degrees before top dead center. by bigjoe1 Sat Dec 06, 2008 10:48 pm, Post Aug 20, 2006. However, it is fixable. 112 will have a smoother idle, a wider power band, and will work better with fuel injection. Your email address will not be published. "When the low-pressure wave in the exhaust reflects into the intake, the pressure delta actually helps pull air and fuel into the cylinder. On the cranking. 12 In terms of power production, the stroker LS3 performed best with the tightest lobe separation angle. If you take any of the . The center of those 2 events is the LOBE CENTERLINE (ECL). Some of the programs like engine analyzer pro and dynomation seem to like some of the wider lsa's.Thanks again JOE. 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. also,, wider will produce a wider and more flat torque curve that doesn't fall off as abruptly up top rpms. Either learn to fix it, or learn to write checks. 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 commonly held misconception is that intake/exhaust overlap contributes to lower cranking compression. Frontal lobe epilepsy (FLE), the second most common focal epilepsy syndrome after temporal lobe epilepsy (TLE), is frequently drug-resistant and MRI-negative. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Disclaimer: Remember to always consult with an expert first before trying anything at home. It had a robust powerband with tons of usable torque. But, at 106 LSA, the cranking compression may increase above the standard PSI level. After the next three pulls, it was clear the 113 cam was way down on low-end torque. More than any other component, the cam profile determines things like idle quality, mileage, and overall driveability. you cannot just take a random change in a lobe separation angle and say 1 is better than the other. If that were the only consideration, the 101 cam is the clear winner. Call for details with your specific combination. 1-3 Cognitive impairment is common in both FLE and TLE and adversely impacts quality of life and psychosocial functioning. Pretty much standard for an RV type cam. But an interestingly shocking fact is that this event escalates the air-fuel mixtures reaction rates, causing temperatures to rise and causing the problem of overheating the engine. 3.75" stroke= 108 LSA 4.00" stroke= 110 LSA 4.25" stroke= 112 LSA 4.50" stroke= 114 LSA I can see exactly where his theory is coming from. by Kdub Sat Dec 06, 2008 11:05 pm, Post To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. dont sound like a verry street friendly motor butany thoughts? Valve lift will bear weight in any decision regarding LSA. The ported heads were capable of supporting over 700 hp, so we knew they would not be restrictive on our stroker. 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. [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]. Tight lobe separations, such as 108 or shorter, will cause the peak torque to build earlier in the RPM range and peak-out in a short amount of . While lift and duration are most often discussed when talk turns to cam timing, there is a third variable that has a decided effect on both power and personality. All three terms are similar, as they all relate to the relationship between the centerline of the Intake lobe and the centerline of the Exhaust lobe. So, without wasting any moment, lets find out the answer. 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. Ed JTO learn to park Joined May 31, 2009 180 Posts As usual, Marc (aka Master) is correct. But i would nt go any wider than 110. Powerband serves a massive contribution to the acceleration car. 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. I'd run it, just be sure to check valve to piston clearance, coil bind and retainer to guide boss/seal clearance. 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. 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. Whatever you do, stay under 270 advertised duration and shoot for a 110 lobe separation. Higher overlapping lets less oil fall through the oil inlet. 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. 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. 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. i have a 4 bolt 351C, stock bore, 10.5 cr with 351C Boss heads ,boss crank and rods. Like choosing a cam in general, the key to eliminating separation anxiety is to find the proper balance of driveability and performance. That was just a glimpse of the information you were looking for. A narrower lobe separation angle can provide less power but can also lead to less wear. So, you can enjoy a mighty acceleration power at 110 LSA. 4 Impaired episodic memory and semantic knowledge are common in TLE, although dysexecutive traits . But, the narrow or broad powerband choice varies from person to person. For Example: A 110-degree lobe separation means that the peak opening points of the Intake and Exhaust lobes is 110 degrees apart. The Crane has a smoother idle, broader power band, and . I've heard similar cams (only about 5*'s off) and they have a nice rumble to them. to use this representational knowledge to guide current and future action. I had an XE 274 in it. The same is true for intake valve closing. O onovakind67 Registered Joined Dec 14, 2001 6,242 Posts *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. 110 degrees on the lobe separation angles. 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. An RV or towing camshaft, which is considered a mild performance or an economy cam, will often have a narrower LSA, between 112 and 114 degrees. Say you have a cam ground on a 115 and the other on a 110. The 108-degree cam (blue lines) outperformed the other two, but idle quality suffered. 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. So, sit tight back and explore. The second cam would have a rougher idle, produce more torque and would rev quicker. 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. A 112-114 degree lobe center will have a better idle and produce more vacuum with less overlap. 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. In terms of horsepower, the disparity between all three cams was only 6.5 hp, with a scant 100 rpm separating the peaks. FWIW. Engine builders Chuck Lawrence, left, and Doug Patton. You can modify the lobe center a little bit but not enough to change the actual overlap of the grind. Getting back to the sound of an engine, its no secret that a raucous, lumpy idle is often preferred by street cruisers, regardless of the ill manners and inefficiency of such an engine setup. Really wide lobe separation angles are used in boosted applications. by Paul H Tue May 13, 2003 1:24 pm, Post For a better experience, please enable JavaScript in your browser before proceeding. 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. 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. For a better experience, please enable JavaScript in your browser before proceeding. If it occurs too late, it will lean out the cylinder and greatly hinder the performance of the engine. . Noah knows a lot about whats happening in the car industry with the latest piloting productions thanks to his professional experience. Thanks again. The LSA, or lobe separation angle, is ground into the cam and cannot be changed. A forum community dedicated to hot rod owners and enthusiasts. Now here is where it gets tricky. Vintage/Classic/Historical Engine Tech, 3V Performance Engine & Valve train Development, Race Cars & Parts - For Sale or Wanted. 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. 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. My duration will be about 230 degrees. But there is a drawback of higher cylinder pressure: higher cylinder pressure may sometimes lead to piston or piston ring problems. 110 LSA: On the other hand, 110 LSA is comparatively a wider LSA; it can generate a massive amount of RPM for the engine. 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. Camshafts with a substantial overlapping tendency should not be used in vehicles driven on public streets. i think a little more torque will be good for my car.With the XE274 it was a little slugish until around 3000 rpms. If the exhaust valve closes too early it will trap some of the spent gases in the combustion chamber, and if it closes too late it will over-scavenge the chamber and take out too much of the charge, again creating an artificially lean condition. Before getting to the cam profiles, we had to make sure we had a reasonable test engine. For example, an oval-track small-block that needs to motivate the car off the turns quickly might have a narrow LSA of around 106 degrees, resulting in more overlap. According to the Comp Cams catalog, "The lobe separation angle (LSA) is equal to 1/2 the angle in crankshaft degrees of rotation between the maximum exhaust valve lift and maximum intake lift.". A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. by Hoxviii Mon May 12, 2003 7:50 pm, Post The tighter the lobe separation angle, the peakier the power curve will be, confirms Bolander. 108 is very tight producing lower vacuum and more of a 2 stroke "punch" powerband. If you look at any given cam catalog, you will find that the majority of street-oriented cams fall in this range. In the 106 LSA, the engine can reach the maximum torque, making the driving more efficient and saving energy. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. Although both wide (112-116) and narrow (102-110) lobe separation angles do have an effect on overlap, it's still possible to get a lot of overlap with very wide lobe separation angle cams. so the power will come on a litter sooner with the 114, and fall off a little sooner? Wide LSA cams are also applicable in forced-induction applications where less exhaust overlap is required. 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. 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. The 110 is probably a better choice for a performance street engine. So, this LSA is suitable for your engine and its components. As boost increases, the air will be forced through the cylinder, vs. being trapped in the cylinder. Depending on the engine combination, the opposite results can occur. 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. Test 1 was easy. Because the lobes are closer together on the 101 LSA cam, the intake closing point is advanced (closes earlier) and the piston has more time to build compressionexactly what the gauge showed.