Simply put, both 106 and 110 lobe separation angles have many advantages and disadvantages. Camshafts with a substantial overlapping tendency should not be used in vehicles driven on public streets. What Are The Wastegate Stuck Open Symptoms? = Moderately Tight 106-104 Deg. It should still make close to 600hp and 600tq in my 512" stealth headed big block. "When you've properly tuned a performance motor, you create high- and low-pressure waves in the intake and exhaust that help cylinder filling," said Comp Cams' Billy Godbold. 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. 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). The Fora platform includes forum software by XenForo. Similarly, 110 LSA is also found to be a more fabulous performer in several mechanical aspects. I'm surprized at these questions as well as some of the replies. " I just bought a 86b Webcam with 112 lobe centers for my 2276. That is why 106 LSA consumes less oil. 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. 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. 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 . The 114o lobe will add a lot more vacuum at idle. We even treated them to some chamber work before installation. 106 LSA: 106LSA results in a decrease in piston-to-valve clearance. = Moderate 108-106 Deg. The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. = Moderately Wide 110-108 Deg. See all 14 photos 13 The three power curves indicate that the wide (120-degree). 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. Let's just talk lobe sep angle. The taller lobe seperation will have a longer powerband but will have to rev higher to make the power than the lower lobe seperation! I know a little about cams. 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. Your best bet would be to talk to one of the experts at a cam company to get a custom grind if you're that into the specs. Maybe even 114. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. For a better experience, please enable JavaScript in your browser before proceeding. What brand and what are the specs on your cam, 4-linked72? or just enough to keep the neighbors pissed? 06 The ported heads featured a 2.165/1.590-inch valve combo. 106 LSA: There is an increasing chance of engine knock at the 106 lobe separation angle. 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. Required fields are marked *. Check out the Comp Cams catalog, even the biggest hydraulic rollers use 110. Realize what the engine is going in, however, as you may not be able to use the wildest cam out there. 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. whats the difference in how the car will run. But, the internal processings are much more complicated. Unfortunately, good street manners are often at odds with performance, as wilder cam timing usually decreases idle and (low-speed) driveability. For a better experience, please enable JavaScript in your browser before proceeding. It will have slightly higher vacuum at idle, feel smoother through the power curve but have a bit less midrange. 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. 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. A narrower LCA will increase valve overlap and close the (intake) valve earlier, which explains the typical rougher idler and more midrange behaviour. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. Tight LSA cams make excellent low-end torque and have a beautiful power curve. ALL bolts are ARP. A narrower lobe separation angle can provide less power but can also lead to less wear. Re: Lobe separations on 383-406 cids.104-106-108-110. The 114 cam will give more low end torque, good midrange, less power up high. I'd run it, just be sure to check valve to piston clearance, coil bind and retainer to guide boss/seal clearance. Fixing the ignition coils is essential when you experience issues like engine misfire and the Check Engine light that wont go off. O onovakind67 Registered Joined Dec 14, 2001 6,242 Posts But remember, although a broader powerband has a couple of acceleration advantages, it also comes with a few drawbacks. i think a little more torque will be good for my car.With the XE274 it was a little slugish until around 3000 rpms. 13 The three power curves indicate that the wide (120-degree) LSA (green lines) lost considerable torque to the other two cams. Well, I saw that Erson makes some nice hydraulic rollers with 108 LSAs, and I know that tighter LSAs have more midrange, so I thought they might be worth a try. Simply put, both 106 and 110 lobe separation angles have many advantages and disadvantages. I forgot to add that poor vacuum is not much of a concern to me because I have no power accessories. This recommendation is only if you shift at no more than 7000. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. ditto with the above. Ultimately, it makes the 110 LSA an oil-consuming LSA. = Tight Below 104 Deg. In my opinion, the rougher the idle the better! A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. To overcome this inherent problem in wide LSA camshafts, you simply need a higher-flowing intake port. Yearh, I have been reading a lot about this issue. Hopefully it turns out great. Despite no changes in lift or duration, this cam sounded much more aggressive than the other two with wider LSAs. Build your own custom newsletter with the content you love from EngineLabs, directly to your inbox, absolutely FREE! Higher lift and longer duration profiles add power, but do so at higher engine speeds (especially true of duration). 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. 4 Impaired episodic memory and semantic knowledge are common in TLE, although dysexecutive traits . 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. Okay, have a sigh because you have opened the right door. 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. I probably would have gone with 3.55 gears had I knows better.. A tighter LSA is always going to have more overlap, which allows the exhaust and intake systemif they're tuned wellto work together.". "Ninety-nine percent of cranking compression is dictated by static compression ratio and intake-valve closing point," said Comp Cams' Billy Godbold. A cams Lobe center angle equals intake centerline plus exhaust . It made 472.4 lb-ft at peak, a 21.5lb-ft disparity from the 101 cam. Again this is dependent on your shift rpm and assuming you truly have 14-1 compression. I have Crane hydraulic link bar style roller lifters, so I dont have to use the spider style. Its the shifting problem again with your Chevy! But there is a drawback of higher cylinder pressure: higher cylinder pressure may sometimes lead to piston or piston ring problems. Overlap is the amount of time that both valves are open in the same cylinder. I personally prefer to sacrifice the small amount more power for better idle quality. Also know as Lobe Separation; Lobe Center is simply the distance between the peak opening points on the Intake and Exhaust lobes. On larger displacement units 116 to 118 degrees of separation are common. As a result, a wider valve opening system with no overlapping allows more oil to fall through the oil inlet. The 110 is probably a better choice for a performance street engine. 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. JavaScript is disabled. Nitrous engines, which make plenty of power and torque, often run wide lobe separation angles to moderate cylinder pressures and temperatures. The tighter the lobe separation angle, the peakier the power curve will be, confirms Bolander. 108* or narrower lobe separation angle (LSA) is "Narrow" and 114* or wider (up to 117* or 120* for stock cams) is "Wide" , with 110 to 112* being the "normal" hot-rod cam. How To Properly Replace Ignition Coils, Chevy 350 Ignition Coil Location And Everything About Them, Heres What Causes Your Car to Bog Down When Accelerating. A cam with a 112lobe center will idle smoother than a cam with a 110lobe center. 106 LSA: You can see an increasing EGR effect at 106 LSA. As you can see in the graph, the 101 LSA cam actually had the highest cranking compression of the batch: 185 psi. It is possible to advance and retard the timing events, but the distance between the centerline of the lobes will remain constant. 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. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. dur. I though my car would have a nice rough idle with the solid cam with a tight LSA I put in my car, its go a slight lope to it, but it pulls hard. 108 versus 110 will drive the power band down. A forum community dedicated to Ford performance owners and enthusiasts. 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 If two cams are identical with the exception of lobe separation angle (we'll say 108 and 114) the cam with 114LSA will make more low end power than the 108LSA cam? Your email address will not be published. lobe centers and lobe separation are 2 different things . pump gas, no additive's as well, runs good, i will put the highest octane in, which is 93.. LS Exhaust Manifold Bolt Torque (Everything You Need To Know), Holley Power Valve Sizes: Everything There is to Know. 106 LSA: The overlapping is higher as 106 LSA is comparatively tighter LSA than 110 LSA. Generally, naturally aspirated engines run narrower lobe separation angles of around 106 to 108 whereas supercharged, turbo or nitrous engines operate with 112 to 114 and higher. If identical and for a given displacement the 110 will give more power. in some cases,, the average torque can equal out. Whatever you do, stay under 270 advertised duration and shoot for a 110 lobe separation. A Pro Stock engine builder may prefer a wide LSA to help keep the power from breaking traction tOo early. 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. How do the lobe separations change when you factor in turbocharging? Good luck. I've heard similar cams (only about 5*'s off) and they have a nice rumble to them. Generally speaking, decreasing the lobe centerline angle increases overlap. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. We do not stock profiles with 109 or 114 lobe centers. 110* LSA - lobe separation angle (lobe displacement angle) The +2* means your intake lobe centerline is advanced to obtain a 108* ICL - intake centerline and a 112* ECL - exhaust centerline. You can modify the lobe center a little bit but not enough to change the actual overlap of the grind. 110 LSA: On the contrary, at 110 LSA, the engine fails to reach the maximum torque, resulting in a decrease in torque rate. Walter Noah is a process engineer who has a knack for resolving even the toughest technical issue. I believe you have got the idea of what you were seeking. Lobe Separation Angle "LSA "Jump to Latest Follow 1 - 17 of 17 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. Now lets move to the exhaust. A good amount of idle vacuum or increased idle vacuum found at 110 LSA advances the engines efficiency. Engine builders Chuck Lawrence, left, and Doug Patton. It really comes down to the application. Mike Magda is a veteran automotive writer with credits in publications such as Racecar Engineering, Hot Rod, Engine Technology International, Motor Trend, Automobile, Automotive Testing Technology and Professional Motorsport World. OK, what is hydraboost, and how do you like how the cam performs??? You get a better idle, vacuum, and response from a 112o-114o lobe. 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. by Kdub Sat Dec 06, 2008 11:05 pm, Post How To Properly Replace Ignition CoilsContinue. 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. 110 LSA: But, contrarily, at 110 LSA, you dont have to face the problem of engine knocking. 110 LSA: Oppositely, the cylinder pressure is comparatively lower at 110 LSA than at 106 LSA. So, the 110 LSA engine is a suitable choice for people prone to be the fan of a powerful engine with mighty acceleration power. 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. . Our content is merely suggestive, not intended to use without proper safety precautions and advice. 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. Post When degreeing in the camshaft, you are making sure the intake centerline is precisely where the cam is intended to be. To further minimize any dyno variations, the engine's oil and water temperatures were kept the same for each pull. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. That notion is completely false. Save Share. An icon used to represent a menu that can be toggled by interacting with this icon. Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. The world of fuel injection is where wide LSA cams like the 113 really shine. Usually, this separation angle ranges from 95-degree to 120-degree. 01 Choosing the right lobe separation angle for your LS cam shouldn't cause anxiety. Many later model engines use wide lobe separation angles to reduce overlap for idle quality and fuel economy. I also like the 106 lobe separation with the intake on 103. Simply put, the lobe center of the camshaft controls where the power curve is applied. For large port heads like the CNC 044's which can use the extra lift 1.4's make a noticable difference. by mrsmythe Tue May 13, 2003 5:45 am, Post In general, a stock replacement camshaft with duration of less than 200 degrees will have a lobe separation angle of more than 114 degrees. If it occurs too late, it will lean out the cylinder and greatly hinder the performance of the engine. Aug 20, 2006. It had a robust powerband with tons of usable torque. I don't think your duration figures are too outlandish and with the tight LCA and high lift, it should make some big torque. LSA is a result of valve timing events. Call for details with your specific combination. I wouldn't assume 4 links fuel requirements will mirror yours at all. Only once the intake valve has closed can compression begin to build. i've heard of this being done something about the massive amounts of duration allowes gasses to disipate? However, these rules are not absolute. Looking at 108vs. 15,215. ohio. The second cam would have a rougher idle, produce more torque and would rev quicker. It is the angle that separates the intake and exhaust lobe for a particular cylinder, and is measured in camshaft degrees. 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. You must log in or register to reply here. If that were the only consideration, the 101 cam is the clear winner. 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. Nothing makes mouths drop like a car that sounds and looks like it can't keep it self still! In the 106 LSA, the engine can reach the maximum torque, making the driving more efficient and saving energy. 292S-112: 292/292 - 240/240 - .495/.495 - 112* - 3400-7200. "When the low-pressure wave in the exhaust reflects into the intake, the pressure delta actually helps pull air and fuel into the cylinder. A commonly held misconception is that intake/exhaust overlap contributes to lower cranking compression. by jobes Sat Dec 06, 2008 3:51 pm, Post He also enjoys reading books a lot and his favorite author is Paula Coelho. 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. Boom, you get the lobe separation angle of that engine. So, without wasting any moment, lets find out the answer. Lobe seperation cant be seperated from duration,the 2 are connected.the old duntov cam had a lot less duration than many new cams so the valve overlap was not extreme and the engine ran with a gentle lope.Increase the duration by 20* and this cam would shake a 283 out of the car at idle,but then increase the lobe seperation by 4* and the motor will have a gentle lope again. Tests 2 and 3 meant dissecting the motor on the dyno to get the old cam out. I've seen that Webcam cams can be ordered with either of the above. 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. A 112-114 degree lobe center will have a better idle and produce more vacuum with less overlap. 68 Mustang, 306, AFR 185\'s, CI cam, FPA\'s, Bigs 650 DP, T5Z, 9" w/4.33's. 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. 110 LSA: The 110 LSA shows up mechanically advantageous in mechanical aspects like higher RPM, lower engine knock, moderate cylinder pressure, improved idle vacuum, and higher piston-to-valve clearance. 02 The 402-inch stroker short-block combined an aluminum LS2 block with a 4.000-inch crank and 6.125-inch rods. . by flat4racer17 Tue May 13, 2003 9:12 pm, Post its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. Widening their separation angle helps increase upper rpm power output. dont sound like a verry street friendly motor butany thoughts? 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. The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. The higher the compression and the higher you try and rev it, the more it will like a wider lobe center. I've seen that Webcam cams can be ordered with either of the above. Bolander says those cams help promote torque in a controlled and predictable manner, especially in no-wake zones and around the docks. The Wastegate works by releasing the pressure built inside, Read More What Are The Wastegate Stuck Open Symptoms?Continue, Oops! 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 Now its not shifting into 3rd and you are here. Alternatively, if you are running a bigger camshaft to gain maximum top-end power, cam makers often suggest reducing the lobe separation angle to recover power lost in the lower rev range.. A wide lobe seperation is not always better than a narrow one, or vise versa. A lower efficient compression rate leads to a higher fuel consumption rate by your engine to produce higher power. 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. The graph above compares intake valve closing points of the three cams used in the test. by farmer Mon May 12, 2003 3:14 pm, Post 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. For Example: A 110-degree lobe separation means that the peak opening points of the Intake and Exhaust lobes is 110 degrees apart. Moreover, a user from the Chevelle forum said. by Paul H Tue May 13, 2003 1:24 pm, Post 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. Save my name, email, and website in this browser for the next time I comment. If the cylinder heads are the lungs of an engine, the camshaft is the brain. camshaft is a Cranecams F238. However, it is fixable. This causes the engine's street manners and tuning to become fickle. If you look at the cam card, you will find a maximum lift column on the card.Now, all you have to do is, add up the two mentioned maximum angles and divide the summation by 2. Exhaust reversion is another undesirable side effect that can be caused by overlap. (2002) et rappel sur une carte hors texte. The takeaway from this test is camshaft LSA is a double-edged sword. Wide LSA cams are also applicable in forced-induction applications where less exhaust overlap is required. It's the scavenging effect of the high velocity exhaust gases rushing out that pulls the fresh fuel/air charge into the chamber. 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. by xstfudonniex Fri Dec 12, 2008 5:24 pm, Post A wider lobe center will give you more overall torque (comes in earlier and stays later). 2023 Power Automedia. Defining Lobe Center and It's Importance to Engine Performance: A Blog. Part Number: HRS-CL120325-08. That way you can discuss what you want from the engine and how changes in LSA or any of the other specs will affect how the engine performs.

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