Another difference between the two involves the power curve. 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 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. 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. We'll send you raw engine tech articles, news, features, and videos every week from EngineLabs. 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 possible to advance and retard the timing events, but the distance between the centerline of the lobes will remain constant. from the intake to the exhaust and vise-versa.Thats why a performance cam will usually have a rougher idle than a stock one. When boost or nitrous are introduced, and engine builders contemplate choices between single-, dual- or reverse-pattern camshafts then the discussion gets muchmore technical. The idle quality was better with the 112-degree LSA but not as good as the wider 120-degree cam.The ultra-wide 120-degree LSA lost low-speed power and never recovered, but know that this wide LSA is often beneficial on positive displacement, supercharged applications. One segment that truly benefits from a wider LSA is the marine marine market. The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. The Fora platform includes forum software by XenForo. its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. 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. Here are the basics: higher lift values open the valves to increase airflow and longer duration keeps the valves open longer. 106 LSA: The scale of efficient compression rises at 106 LSA. lobe centers and lobe separation are 2 different things . It should still make close to 600hp and 600tq in my 512" stealth headed big block. 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. I'd also go to a 110-112 lobe separation angle. A 232 deg duration cam with a 108 deg LCA will have the same valve overlap as a 236 deg cam with a 110 deg LCA and idle will probably be very similar. *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. Not a HUGE, but a significant difference between 110 and 112, but those are the trends. by ANT Tue May 13, 2003 1:08 pm, Post by Kdub Sun Dec 07, 2008 1:20 am, Post you cannot just take a random change in a lobe separation angle and say 1 is better than the other. The custom cams we selected all featured 0.624-inch lift (both intake and exhaust) and a 232/242-degree duration split. 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. Post You can research your heads to find out where yours are, but honestly I don't think it will be worth the effort on a tow vehicle. The 234o duration kind of eliminates the RV usage. 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. We even treated them to some chamber work before installation. Anybody do any real testing on LSA in a 3.75 stroke small block chevy?I have always used 104-106 and was thinking about trying a 108 or 110 design.I know there is a lot of variables but just a general opinion from any experts.This is for motor only no nitrous.600-640 HP engine combos.Much appreciated! The intake air control valve (IAC), which regulates idle speed, also has to work overtime and often attempts to "catch" the idle, but usually shoots high or low. 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. 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.". document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Disclaimer: Remember to always consult with an expert first before trying anything at home. On engines equipped with independent intake and exhaust cams, the LSA is adjustable. Making this the biggest obstacle to overcome when selecting a cam profile with one of our tech advisors, explaining the definition and importance of the Lobe Center. = Tight Below 104 Deg. But, at 106 LSA, the cranking compression may increase above the standard PSI level. Similarly, 110 LSA is also found to be a more fabulous performer in several mechanical aspects. In the 106 LSA, the engine can reach the maximum torque, making the driving more efficient and saving energy. by farmer Mon May 12, 2003 3:14 pm, Post 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. We do not stock profiles with 109 or 114 lobe centers. 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. The only reason I . The engine would idle a lot rougher and generate worse exhaust emissions largely because of unburned fuel.. After swimming through the entire article, I hope you are now well aware of the 102 vs 110 lobe separation angle. The takeaway is simple on the surface: A tighter LSA makes more low-end and peak torque at the expense of just a few top-end ponies. 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. Turbochargers are not as simple as they may sound; you may think of them only as power-boosting components. Tuning this cam would be slightly more difficult due to the reduced idle vacuum, but it is hard to argue with all the extra power. 106 LSA: So, if I talk about the powerband at 106 LSA, the powerband is narrow. by jim martin Mon May 12, 2003 7:10 pm, Post 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. by mrsmythe Mon May 12, 2003 11:15 am, Post As lobe seperation spreads does the powerband. JavaScript is disabled. No, it is not even close to the ultimate performance grind most would have picked. Do you like to go fast? 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 popular models such as the Mustang, Galaxie, Falcon, Fairlane, Torino, Shelby and many more! The takeaway from this test is camshaft LSA is a double-edged sword. The lobe separation angle is the angle between the two camshaft lobes that act on the valves. 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. Like one cam is 112 degree and the next is 108 the 108 cam will allow less "leakage"? [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]. The 108 LSA offered the lowest idle vacuum of the three (down 4 inches). to use this representational knowledge to guide current and future action. by bigjoe1 Sat Dec 06, 2008 10:48 pm, Post I am pretty sure, right now, you find yourself in the middle of the rising debate of 106 vs 110 lobe separation angle. Enter lobe separation angle. 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. 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. 112 will have a smoother idle, a wider power band, and will work better with fuel injection. Its the shifting problem again with your Chevy! " - Voltaire. I would have to say that your cam choice sounds like a winner to me. Things like idle vacuum, fuel economy, and tuning all factor into picking the right cam. The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes, says Eric Bolander of Erson Cams. 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. But that doesnt mean high-strung racing engines cant see gains, as well. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. . I've heard similar cams (only about 5*'s off) and they have a nice rumble to them. The 110 is probably a better choice for a performance street engine. Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. Re: Lobe separations on 383-406 cids.104-106-108-110. pump gas, no additive's as well, runs good, i will put the highest octane in, which is 93.. Generally speaking, decreasing the lobe centerline angle increases overlap. 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. The center of those 2 events is the LOBE CENTERLINE (ECL). As boost increases, the air will be forced through the cylinder, vs. being trapped in the cylinder. Another important measurement was the torque production at 4,000 rpm and this cam checked in with 484 lb-ft of torque. A cam with a 112lobe center will idle smoother than a cam with a 110lobe center. 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. Elle concerne 264 taxons des degrs divers. 108: 110: 112: 114 . FWIW. 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. 110 LSA: On the contrary, if you look at the powerband at 110 LSA, the powerband is comparatively broader. 4-linked72, what cam are you using that has a 108 LSA? On the cranking. 03 The 4.000-inch crank and 6.125-inch rods were combined with a set of forged asymmetrical pistons from JE. any input is appreciated guys, thanks. 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). "When the low-pressure wave in the exhaust reflects into the intake, the pressure delta actually helps pull air and fuel into the cylinder. The ported heads were capable of supporting over 700 hp, so we knew they would not be restrictive on our stroker. But you always have a cam card with the engine. Aug 20, 2006. 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. Camshafts with a substantial overlapping tendency should not be used in vehicles driven on public streets. Many later model engines use wide lobe separation angles to reduce overlap for idle quality and fuel economy. Test 1 was easy. Widening their separation angle helps increase upper rpm power output. JavaScript is disabled. The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. A forum community dedicated to Ford performance owners and enthusiasts. It is dangerous to be right in matters on which the established authorities are wrong. If a street car has smaller lift and duration numbers, they might run 112 or 114. Also know as Lobe Separation; Lobe Center is simply the distance between the peak opening points on the Intake and Exhaust lobes. Your email address will not be published. Tests 2 and 3 meant dissecting the motor on the dyno to get the old cam out. The LSA, or lobe separation angle, is ground into the cam and cannot be changed. I just installed a Comp Cams XE262 in a 9:1 350 with stock iron heads. 110 for sure. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. The 114 cam will give more low end torque, good midrange, less power up high. The 114 cam will give more low end torque, good midrange, less power up high. 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. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. I know a little about cams. The graph above compares intake valve closing points of the three cams used in the test. You are using an out of date browser. 110 LSA: But here, quite surprisingly, you have to face the reduction of the EGR effect due to the 110 LSA. We will safeguard your e-mail and only send content you request. Introduction. The 290 advertised duration and 114 lobe separation would contribute to a lazy power curve. 1-3 Cognitive impairment is common in both FLE and TLE and adversely impacts quality of life and psychosocial functioning. 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. At a lower LSA, the engine reaches the peak of the torque earlier than the standard time but generates a lower RPM.On the contrary, at a higher LSA, the engine reaches the peak torque at a higher resistance level and generates a bulk number of RPM. 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. A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. 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. I'm surprized at these questions as well as some of the replies. " While most of our customers know what lift and duration are, most are unfamiliar with the term Lobe Center and how it affects the engines performance. music to your ears? 106 LSA: There is an increasing chance of engine knock at the 106 lobe separation angle. ( 2 ) Estimated Ship Date: Feb 23, 2023 (if ordered today) Drop Ship. Coupled that with the low first gear of the five speed, it ought to create some real traction problems. The final cam was tighter still, with a 108-degree LSA. 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. However, the plentiful exhaust overlap (31 degrees) meant there was lots of exhaust dilution at low engine speed and high vacuum. 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'm sorry to disagree with that incredibly well written article, but lobe separation by itself is absolutely freaking meaningless. by jobes Sat Dec 06, 2008 3:51 pm, Post A cam with a 112 lobe center will idle smoother than a cam with a 110 lobe center. 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. A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. ALL bolts are ARP. 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. It will sound lovely I'm sure. 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. Also present during testing was a set of 1 7/8-inch Kooks headers, Comp hydraulic roller lifters, and F-body oil pan. I wouldn't assume 4 links fuel requirements will mirror yours at all. Cam swaps are all the rage and for good reason. The 114 LSA is good for a blower or nitros motor. 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. For your convenience, I am providing a comparison table to give you an overall idea about the comparison. Walter Noah is a process engineer who has a knack for resolving even the toughest technical issue. LSA is the distance from the centerline of the intake lobe to the centerline of exhaust lobe. A wider LSA moves intake- and exhaust-valve events farther apart and creates less overlap, which hurts intake-wave tuning. A wide lobe seperation is not always better than a narrow one, or vise versa. Either learn to fix it, or learn to write checks. 2.1.3 Transponder reply modes (air-to-ground) 2.1.3.1 Transponders shall respond to Mode A interrogations in accordance with the provisions of 3.1.1.7.12.1 and to Mode C interrogations in accordance . 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. After consulting with many experts, you are still in confusion between 106 and 110- lobe separation angles. 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. Hey guys, can anyone tell me how rough of a idle a cam would be with a 108 lobe separation? We promise not to use your email address for anything but exclusive updates from the Power Automedia Network. = Extremely Tight . 108 vs 112 lobe seperation. 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. 554"/577" lift. Frontal lobe epilepsy (FLE), the second most common focal epilepsy syndrome after temporal lobe epilepsy (TLE), is frequently drug-resistant and MRI-negative. 110 LSA: On the contrary, at 110 LSA, the engine fails to reach the maximum torque, resulting in a decrease in torque rate. by Paul H Tue May 13, 2003 1:24 pm, Post 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. i think a little more torque will be good for my car.With the XE274 it was a little slugish until around 3000 rpms.
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