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! Post Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. Leave the 108 for solid rollers turning big rpms. The Crane has a smoother idle, broader power band, and . Another important measurement was the torque production at 4,000 rpm and this cam checked in with 484 lb-ft of torque. My duration will be about 230 degrees. Re: Lobe separations on 383-406 cids.104-106-108-110. I just bought a 86b Webcam with 112 lobe centers for my 2276. by Paul H Tue May 13, 2003 1:24 pm, Post 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. 07 Though the CNC-ported heads offered plenty of flow, it was necessary to upgrade the supplied valvesprings. Lobe separation angle does. So, without wasting any moment, lets find out the answer. Ultimately, it comes down to how you want the engine to run, the car's intended purpose, and what you are willing to tolerate. Camshaft: Hydraulic Roller, Comp Cam custom grind (ADV Duration 281-287,@ .050 230-236, lift 622I & 625E w/1.6 rockers.) 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. (2002) et rappel sur une carte hors texte. 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. 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. We even treated them to some chamber work before installation. 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. Seeking 1/2" ID x 5/8" OD Black Exit Tubing for Radiator Overflow Reservoir. To establish the position of each lobe, the traditional reference point is where the lobes reach max lift. 110 LSA: But here, quite surprisingly, you have to face the reduction of the EGR effect due to the 110 LSA. Now lets move to the exhaust. 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. Aluminum flywheel & pullies. 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. 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. 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). so it is a solid flat tappet, torker intake, 1" 4-hole tapered spacer and 750 carb (QFT) transmission is a wide ratio toploader, rear is a 9" 3.89 geared 26"rear tires. It will have slightly higher vacuum at idle, feel smoother through the power curve but have a bit less midrange. More than any other component, the cam profile determines things like idle quality, mileage, and overall driveability. But to choose the perfect cam, all of that information needs understanding. 02 The 402-inch stroker short-block combined an aluminum LS2 block with a 4.000-inch crank and 6.125-inch rods. 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. This is ground into the cam and can't be changed without changing cams. The intake lobe centerline is measured in crankshaft degrees. That notion is completely false. O onovakind67 Registered Joined Dec 14, 2001 6,242 Posts LSA is a result of valve timing events. 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. 106 LSA: On the contrary, if we look at the 106 LSA, we will find it more advantageous and energy efficient than the 110 LSA engine. The only reason the advance or retard a camshaft profile is to get the timing events where they need to be. 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. 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. 106 LSA: The overlapping is higher as 106 LSA is comparatively tighter LSA than 110 LSA. Lobe separations on 383-406 cids.104-106-108-110? 1966 Toyota Landcruiserunder construction. Bad idea in my view. It produces peak torque earliercoming on quicker and strongerbut also it falls off quicker too. 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. After spending 8 years in plant production engineering, Noah wanted to join Engine Addiction as a key member of all cars specific guides, reviews, repairs, suggestions, and more. It provides a spark plug with the high voltage needed for combustion. 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. 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. by Hoxviii Mon May 12, 2003 7:50 pm, Post The lobe separation angle is the angle in camshaft degrees between the maximum lift points, or centerlines, of the intake and exhaust lobes. dur. If the overlap phase occurs too early, it will create an overly rich condition in the exhaust port, severely decreasing the gas mileage. Tests 2 and 3 meant dissecting the motor on the dyno to get the old cam out. Do you like to go fast? 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. 110 LSA: On the contrary, it is pretty unpleasant to inform you that the efficient compression rate decreases at 110 LSA. The center of those 2 events is the LOBE CENTERLINE (ECL). The extra cubic inches will smooth out a rough idle in a 327. After swimming through the entire article, I hope you are now well aware of the 102 vs 110 lobe separation angle. in some cases,, the average torque can equal out. It will sound lovely I'm sure. 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. Given that nitrous works best in the mid- to upper-rpm range, nitrous-powered engines need a wider lobe separation, like 112 . 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. On the cranking. JavaScript is disabled. Nothing makes mouths drop like a car that sounds and looks like it can't keep it self still! its got a 3.73 posi and the Stock 4 speed with a very low 3.42 1st gear. 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? But i would nt go any wider than 110. . 110 LSA: On the other hand, 110 LSA is comparatively a wider LSA; it can generate a massive amount of RPM for the engine. Realize what the engine is going in, however, as you may not be able to use the wildest cam out there. Thanks again. 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 testing was performed with an Aeromotive fuel pump feeding a set of 42-lb/hr injectors. Wide LSA cams are also applicable in forced-induction applications where less exhaust overlap is required. Save my name, email, and website in this browser for the next time I comment. GRIND #: CRB3 3194 /3196 HR111. Compression willl be 9.75:1. On engines equipped with independent intake and exhaust cams, the LSA is adjustable. The engine has AFR heads, Crane rockers, a TCI balancer, a Scat Rotating assembly with Mahle pistons, an Edelbrock RPM Air-Gap intake, an MSD ignition, and an Aeromotive fuel system. 11 Doing LS cam swaps on the engine dyno is a breeze, each taking less than 1 hour. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. We borrowed Westech Performance's shop mule, a 370ci small-block Chevy and its SuperFlow 902 engine dyno and spent a day running each cam back-to-back to gauge its effect on peak horsepower, peak torque, cranking compression, idle vacuum, and the powerband as a wholeall the variables that define an engine's character on the street and track. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. Increased overlap improves upper RPM power. by SStrokerAce Sat Dec 06, 2008 7:36 pm, Post A cam with a tighter LSA will require a looser torque converter, may not be able to run vacuum-assisted brakes, and doesn't play nice with fuel injection. Around 70 percent of muscle-car performance cams fall into this range. Usually, this separation angle ranges from 95-degree to 120-degree. by randy331 Sat Dec 06, 2008 10:00 pm, Post The engine will have weak performance in the low-end range.A low vacuum can also cause the brake pedal to be quite difficult to press. I am trying to pick out a hydraulic roller cam for my 351W with AFR 185s. He also enjoys reading books a lot and his favorite author is Paula Coelho. FWIW. However, it is fixable. The second cam would have a rougher idle, produce more torque and would rev quicker. The Wastegate works by releasing the pressure built inside, Read More What Are The Wastegate Stuck Open Symptoms?Continue, Oops! A lower efficient compression rate leads to a higher fuel consumption rate by your engine to produce higher power. 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. Split duration/lift only helps when your intake/exhaust ratio is low on the exhaust side. Turbochargers are not as simple as they may sound; you may think of them only as power-boosting components. As usual, Marc (aka Master) is correct. Again, these are general bits of conventional wisdom. If you shift at 7500-7800 add 4-6 degrees to both intake and exhaust and spread the lobe separation to 108-110. For a better experience, please enable JavaScript in your browser before proceeding. Lucky for us, Brian Tooley Racing stepped up with a dual spring package that allowed us to safely run our 0.624-lift cam. Read More Chevy 350 Ignition Coil Location And Everything About ThemContinue, What causes a car to bog down when accelerating? In general, a stock replacement camshaft with duration of less than 200 degrees will have a lobe separation angle of more than 114 degrees.