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. Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. In reality, a cam with 220 at 0.050" and a lobe center angle of 112 will have the exact same mechanical overlap as a cam with 217 at 0.050" and a lobe center angle of 109. I think the compression ratio has something to do with LSA too. The custom cams we selected all featured 0.624-inch lift (both intake and exhaust) and a 232/242-degree duration split. Turbochargers are not as simple as they may sound; you may think of them only as power-boosting components. The tighter the lobe separation angle, the peakier the power curve will be, confirms Bolander. Consequently, decreased torque rate often leads to more energy consumption. Lunati's New Bootlegger Camshaft Series Has Strong Race - Dragzine Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. 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! 108 vs. 110 lobe separation angle?? | Vintage Mustang Forums Hopefully It will do fine in my 2276 mostly drag bug. Engine builders Chuck Lawrence, left, and Doug Patton. 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. what does 112+2 lsa mean?? - LS1GTO Forums Noah knows a lot about whats happening in the car industry with the latest piloting productions thanks to his professional experience. This comparison highlights that the 106 LSA is a good performer in a few mechanical aspects than the 110 LSA. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. But remember, although a broader powerband has a couple of acceleration advantages, it also comes with a few drawbacks. The #1 intake lobe centerline is usually between 100 If you take any of the . 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. Vintage/Classic/Historical Engine Tech, 3V Performance Engine & Valve train Development, Race Cars & Parts - For Sale or Wanted. No, it is not even close to the ultimate performance grind most would have picked. However, the plentiful exhaust overlap (31 degrees) meant there was lots of exhaust dilution at low engine speed and high vacuum. Contributions la connaissance de la flore du Maroc et de l'Afrique du 554"/577" lift. 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. You cannot look at just the LCA without looking at other specs too. A cam with a 112 lobe center will idle smoother than a cam with a 110 lobe center. Many later model engines use wide lobe separation angles to reduce overlap for idle quality and fuel economy. 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. Camshaft: Hydraulic Roller, Comp Cam custom grind (ADV Duration 281-287,@ .050 230-236, lift 622I & 625E w/1.6 rockers.) 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. . Full text of "Pediatric Books" However, finding them might be challenging if you dont have any prior knowledge. 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. LSA is a way of summing up the relative timing of the intake-valve events (intake opening, intake closing) to the exhaust-valve events (exhaust opening, exhaust closing) in relation to each other, and it's a great approximation of how the engine will operate. The first cam featured a wide 120-degree LSA, while cam number two narrowed the angle to 112 degrees. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. i've heard of this being done something about the massive amounts of duration allowes gasses to disipate? 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. Thanks for the replies, particularly that link Marc, very informative. This table will create a map in your head, and I bet it will make your understanding crystal clear. 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. Usually, an old gas tank is responsible for a vehicle bogging down during acceleration. Yearh, I have been reading a lot about this issue. The Crane has a smoother idle, broader power band, and . 110 LSA: But here, quite surprisingly, you have to face the reduction of the EGR effect due to the 110 LSA. To further minimize any dyno variations, the engine's oil and water temperatures were kept the same for each pull. 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. Its the shifting problem again with your Chevy! It made 472.4 lb-ft at peak, a 21.5lb-ft disparity from the 101 cam. In this segment, I am going to compare those two lobe separation angles based on a couple of mechanical factors. by jim martin Mon May 12, 2003 7:10 pm, Post how well would a 108 lsa cam do on the street over a 110? 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. by Marc Mon May 12, 2003 11:38 am, Post Armed with more information on camshaft theory, what will you build? Known as "The Gladiator" around Westech Performance, this Dart SHP blockbased, 370ci, small-block Chevy has made thousands of dyno pulls testing all manner of heads, intakes, cams, and every other crazy thing us magazine folk have coerced Westech's Steve Brul to bolt to it. But, the narrow or broad powerband choice varies from person to person. Do you like to go fast? And better gas mileage. Chevy Transmission Wont Shift Into 3rd: Finding the Main Culprit, Yamaha Lower Unit Drain Plug Size [Explained Everything], Does It Matter Which Ignition Coil Goes Where? by Paul H Tue May 13, 2003 1:24 pm, Post Ultimately, it makes the 110 LSA an oil-consuming LSA. Well get out of that stocker and build a hipo motor for your VW. Comp cam hydraulic roller lifters. probably just enough to get me in trouble.. The absence of engine knocking ensures that your car engine is reasonably combusting the fuel. 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. This is very critical for manifold vacuum, throttle response, emissions, and gas mileage. I know a little about cams. 114LSA +4 puts the intake centerline at 110 degrees before top dead center. A tighter LSA is always going to have more overlap, which allows the exhaust and intake systemif they're tuned wellto work together.". 108 vs 112 lobe seperation. With a 108 degree lobe center, a cam will have a rougher idle and produce less vacuum due to more overlap. 4-linked72, what cam are you using that has a 108 LSA? The taller lobe seperation will have a longer powerband but will have to rev higher to make the power than the lower lobe seperation! Exhaust reversion is another undesirable side effect that can be caused by overlap. The 108-degree cam offered both the most power and torque, but idle quality suffered compared to the wider LSAs. Increasing the EGR effect has a good side in that it reduces the amount of oxygen in the combustion chamber. by bigjoe1 Sat Dec 06, 2008 10:48 pm, Post TH400 Vs Powerglide: Which One is Ideal for You? VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Unfortunately, good street manners are often at odds with performance, as wilder cam timing usually decreases idle and (low-speed) driveability. 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. by 3V Performance Sat Dec 06, 2008 4:38 pm, Post 108 vs 112 lobe seperation - Shoptalkforums.com 13 The three power curves indicate that the wide (120-degree) LSA (green lines) lost considerable torque to the other two cams. A forum community dedicated to Ford performance owners and enthusiasts. I just installed a Comp Cams XE262 in a 9:1 350 with stock iron heads. (LOBE SEPARATION ANGLE)cam CRANES 110921 has the intake close at 45 degrees ABDC while the wider lsa CRANES 114681 closes the valves at 50.0 ABDC . 1966 Toyota Landcruiserunder construction. What Are The Wastegate Stuck Open Symptoms? thanks. Lower cylinder pressure is advantageous for your engine. Come here to talk with others who like to drive fast. If you shift at 7500-7800 add 4-6 degrees to both intake and exhaust and spread the lobe separation to 108-110. Methods: We evaluated 30 individuals with PD (62.47.2 years) and 22 age-matched healthy controls (61.06.4 years). This causes the engine's street manners and tuning to become fickle. #2---Choosing a Cam - Hughes Engines The intake lobe centerline is measured in crankshaft degrees. My duration will be about 230 degrees. But it is a piece of good news for your engine. Also If you go with 112 lobe centers, you create less valve overlap which will increase your compretion. Say you have a cam ground on a 115 and the other on a 110. Valve lift will bear weight in any decision regarding LSA. That is no accident. 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. As a result of this fall, the idle of the engine has to face suffering quite often. 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. Good luck. 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. 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. Seeking 1/2" ID x 5/8" OD Black Exit Tubing for Radiator Overflow Reservoir. In my opinion, the rougher the idle the better! I forgot to add that poor vacuum is not much of a concern to me because I have no power accessories. 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. Engine knocking generally occurs when the burning of the fuel by the engine is uneven. It will have slightly higher vacuum at idle, feel smoother through the power curve but have a bit less midrange. 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. It is the average centerline between both lobes and expressed in degrees ranging from 95 on the extremely narrow/tight side to upward of 120 on the wide end. If all the specs remained the same what will going from a 110 to a 112 lsa do to driving characteristics? "Ninety-nine percent of cranking compression is dictated by static compression ratio and intake-valve closing point," said Comp Cams' Billy Godbold. Tests have shown that, for a given cam profile, a tighter (smaller) lobe center will produce more average horsepower and a quicker revving engine. The only reason the advance or retard a camshaft profile is to get the timing events where they need to be. However, in application, there is a lot more to consider. A cam with a 112lobe center will idle smoother than a cam with a 110lobe center. The 110o will make more power overall. Mailbag: Camshaft Lobe Separation, Nitrous Oxide & How They Relate I had a 110 cam in my beetle and I didn't like it-the bottom end was doggy. I think you are asking a lot of a cam . lobe separation angle | For A Bodies Only Mopar Forum The 402-inch LS2/LS3 hybrid stroker started out with an LS2 aluminum block. CAMSHAFT guys, explain lobe centers to me | The H.A.M.B. If that accessory still does not assist the cam in producing enough vacuum, then as a last resort you can use a vacuum pump. 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. I wouldn't assume 4 links fuel requirements will mirror yours at all. 106 LSA: As you know, the intake and exhaust lobes centerline distance is known as lobe separation angle. Increased Effective Connectivity of the Left Parietal Lobe During The Fora platform includes forum software by XenForo. A cam card with its myriad numbers, acronyms, and abbreviations is one red-pen stroke away from a failed math test. It affects the amount of valve overlap; that is the brief period of time when both the intake and exhaust valves are open. That means your engine can produce more power with a minimum amount of fuel combustion. 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.