Walter Noah is a process engineer who has a knack for resolving even the toughest technical issue. Good cam for a lower rpm street engine. Ultimately, it makes the 110 LSA an oil-consuming LSA. For a better experience, please enable JavaScript in your browser before proceeding. Maybe even 114. dur. I wouldn't assume 4 links fuel requirements will mirror yours at all. The reduced rate of the EGR effect lowers oxygen circulation in the engines combustion chamber. Boom, you get the lobe separation angle of that engine. Usually, an old gas tank is responsible for a vehicle bogging down during acceleration. 110 LSA: But, contrarily, at 110 LSA, you dont have to face the problem of engine knocking. you cannot just take a random change in a lobe separation angle and say 1 is better than the other. The article was called "Separation of Power" and they tested 5 cams ranged from 106 to 114 LSA. 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. 4-Link72, do you run racing gas or pump with 10.5:1 CR? Check out the Comp Cams catalog, even the biggest hydraulic rollers use 110. 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. The only reason the advance or retard a camshaft profile is to get the timing events where they need to be. These favorable mechanical features depict the powerful acceleration capacity of the engine with higher oil and energy consumption rate, overheating problems, and other mechanical problems. However it is at the expense of a small amount of bottom end power and idle quality, due to the increased overlap. 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 A wider lobe separation angle can often provide more power, but it can also lead to more wear on the engine. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! 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. It may not display this or other websites correctly. 108 Lobe Separation These are my motors specs 1979 - 347 Stroker 10:1 Compression Holley 670 Street Avenger or a Holley 650 (I have both) Roush 200 Cylinder Heads (minor head work) 1.6 Roller Rockers Shorty BBK Headers 373 Rear End 5 Speed Transmission Cross Gap Intake (Power Band 1500-6500) FlowMaster Dual Exhaust (of course no Cats) MSD 6Al If you changed the lobe separation of a street engine from 112 degrees to 106 and didnt do anything else, adds Kaase. How To Properly Replace Ignition CoilsContinue. So, without wasting any moment, lets find out the answer. I think the compression ratio has something to do with LSA too. http://www.mustangworks.com/cgi-bin/moi-display.cgi?220, http://www.popularhotrodding.com/en6em_camshaft_specs/lobe_seperation_angle.html. LSA is a result of valve timing events. Camshaft: Hydraulic Roller, Comp Cam custom grind (ADV Duration 281-287,@ .050 230-236, lift 622I & 625E w/1.6 rockers.) 12 In terms of power production, the stroker LS3 performed best with the tightest lobe separation angle. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. The lobe separation angle in a natural car engine conveys a considerable impact, especially regarding the maximum torque. 106 LSA: The scale of efficient compression rises at 106 LSA. 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. In my opinion, the rougher the idle the better! The intake lobe centerline is measured in crankshaft degrees. 110 LSA: On the other hand, 110 LSA is comparatively a wider LSA; it can generate a massive amount of RPM for the engine. The 110 is probably a better choice for a performance street engine. 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. Another related thought to consider when selecting a cam is inches of vacuum for your engine application when deciding upon a Lobe Center. 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. The only reason I . The Fora platform includes forum software by XenForo. I'm sorry to disagree with that incredibly well written article, but lobe separation by itself is absolutely freaking meaningless. in some cases,, the average torque can equal out. Idle quality was rough and the vacuum gauge showed only 9.8 in-Hg (inches of mercury). 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. 08 Additional components used to build the stroker included a set of Comp hydraulic roller lifters, ARP head studs, and a new oil pump. The higher the compression and the higher you try and rev it, the more it will like a wider lobe center. Hopefully It will do fine in my 2276 mostly drag bug. But nothing comes without a cost, and idle vacuum suffers as LSA shrinks. Cam swaps are all the rage and for good reason. 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. You must log in or register to reply here. The 114 cam will give more low end torque, good midrange, less power up high. 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. The power and torque curve lay directly in between the last two cams, as did the peak horsepower and torque, 488.7 at 6,200 rpm and 487.1 at 4,600 rpm, respectively. If you're an OEM automaker looking for a steady idle, good fuel economy, and passing tailpipe emissions, this is the cam of choice. Whatever you do, stay under 270 advertised duration and shoot for a 110 lobe separation. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. I have 108 for LSA and my headlights take awhile to go up when the car is idling. For your convenience, I am providing a comparison table to give you an overall idea about the comparison. If all the specs remained the same what will going from a 110 to a 112 lsa do to driving characteristics? by Mr. P. Fri Dec 12, 2008 6:36 pm, Powered by phpBB Forum Software phpBB Limited, General engine tech -- Drag Racing to Circle Track. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. Everyone has a different idea of gentle.While its true that the duntov cam may seem rough in a 283 it is still a factory offering and they never go to radical on there profiles for street cars.If you want a rough idle, try a 283 with a .550'lift roller and 13.5 to 1 compression,THATS ROUGH. 110 LSA: On the contrary, 110LSA has a higher piston-to-valve clearance rate. How do the lobe separations change when you factor in turbocharging? These issues can often be worked through by an advanced tuner, but always present a challenge and compromise in tuning strategy. AquaTraction Vs SeaDek: Which One Is Better For you? Exhaust reversion is another undesirable side effect that can be caused by overlap. 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. If identical and for a given displacement the 110 will give more power. While a cam with a 108 lobe center will idle rougher. A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. As you can see in the graph, the 101 LSA cam actually had the highest cranking compression of the batch: 185 psi. We even treated them to some chamber work before installation. Despite no changes in lift or duration, this cam sounded much more aggressive than the other two with wider LSAs. 110 LSA: On the contrary, it is pretty unpleasant to inform you that the efficient compression rate decreases at 110 LSA. whats the difference in how the car will run. Also, the wider LSA contributes to chassis stability in drag racing by avoiding the delivery of a ferocious blast of power that would break tire traction. 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 seen a dyno test where an engine using identical duration and lift made more peak power with a 112 LSA than a 110 LSA. For a better experience, please enable JavaScript in your browser before proceeding. 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. Not a HUGE, but a significant difference between 110 and 112, but those are the trends. 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 -. 108 versus 110 will drive the power band down. The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. That notion is completely false. Cylinder-head flow and LSA are directly related: as a rule of thumb, the better the head flows, the wider the LSA can be. Unfortunately, good street manners are often at odds with performance, as wilder cam timing usually decreases idle and (low-speed) driveability. 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. This table will create a map in your head, and I bet it will make your understanding crystal clear. Our content is merely suggestive, not intended to use without proper safety precautions and advice. When boost or nitrous are introduced, and engine builders contemplate choices between single-, dual- or reverse-pattern camshafts then the discussion gets muchmore technical. I just bought a 86b Webcam and Im using 1.5's. - Sheryl Crow. That is why 106 LSA consumes less oil. Fixing the ignition coils is essential when you experience issues like engine misfire and the Check Engine light that wont go off. Usually, this separation angle ranges from 95-degree to 120-degree. Again, these are general bits of conventional wisdom. 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. For a better experience, please enable JavaScript in your browser before proceeding. 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. This is why the LS series, and many other modern engines, can make great power on top and bottom with wide LSA camshafts and why a plethora of factory cylinder heads are flowing near (or above) 300 cfm. = Extremely Tight . Cam timing plays an important role not only in the power generated but also the overall character of the powerplant. Lower cylinder pressure is advantageous for your engine. Required fields are marked *. 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. 4 Impaired episodic memory and semantic knowledge are common in TLE, although dysexecutive traits . I know a little about cams. Engine knocking generally occurs when the burning of the fuel by the engine is uneven. To illustrate the differences offered by changes in the LSA, we had Crane cams grind us three cam profiles that shared the same lift and duration figures, but differed only in the LSA. by flat4racer17 Tue May 13, 2003 9:12 pm, Post Enter lobe separation angle. 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. Thanks for the replies, particularly that link Marc, very informative. Methods: We evaluated 30 individuals with PD (62.47.2 years) and 22 age-matched healthy controls (61.06.4 years). 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. ALL bolts are ARP. All rights reserved. But, the internal processings are much more complicated. It is dangerous to be right in matters on which the established authorities are wrong. 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. Meaning the lower lobe seperation will have a very quick and fast powerband (Snappy!) by SStrokerAce Sat Dec 06, 2008 7:38 pm, Post This process slows down the reaction rates of the air-fuel mixture, causing temperatures to drop and preventing the engine from overheating. (ICL + ECL) / 2 = LOBE SEPARATION ANGLE (LSA) LSA is a RESULT of the PROPER events. 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 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. but less of it at the same time. The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes. If the cylinder heads are the lungs of an engine, the camshaft is the brain. 110 LSA: On the other hand, 110 LSA is a wider LSA with almost no overlap. The taller lobe seperation will have a longer powerband but will have to rev higher to make the power than the lower lobe seperation! (2002) et rappel sur une carte hors texte. Introduction. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. As you tighten the centers ( 108 ) the same engine will make MORE power through the mide range and top end. i've heard of this being done something about the massive amounts of duration allowes gasses to disipate?
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