A forum community dedicated to Ford performance owners and enthusiasts. As you tighten the centers ( 108 ) the same engine will make MORE power through the mide range and top end. 03 The 4.000-inch crank and 6.125-inch rods were combined with a set of forged asymmetrical pistons from JE. It also depends on what the vehicle will be used for and if economy and vacuum are important. Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! The 110 is probably a better choice for a performance street engine. Knife edged & profiled 4MA Cleveland crank weighing 50lbs. Ultimately, it comes down to how you want the engine to run, the car's intended purpose, and what you are willing to tolerate. I've seen that Webcam cams can be ordered with either of the above. All testing was performed with an Aeromotive fuel pump feeding a set of 42-lb/hr injectors. It really comes down to the application. by Kdub Sat Dec 06, 2008 11:05 pm, Post Brul spun the engine over with the dyno's starters and recorded 185 psi of cranking compression. For a better experience, please enable JavaScript in your browser before proceeding. Hey guys, can anyone tell me how rough of a idle a cam would be with a 108 lobe separation? 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 only reason I . However it is at the expense of a small amount of bottom end power and idle quality, due to the increased overlap. Lobe separation angles, he continues, are influenced by the camshaft grind. 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 Howards Cam Vs Comp Cam: Which Is The Best Option For You? Camshaft: Hydraulic Roller, Comp Cam custom grind (ADV Duration 281-287,@ .050 230-236, lift 622I & 625E w/1.6 rockers.) 110 will be a bit punchier in the midrange and probalby make a little more peak horsepower as long as a good exhaust is used. Say you have a cam ground on a 115 and the other on a 110. hydraboost is the same as a vacuum brakebooster, only the booster is replaced by a unit that does the same but under hydraulic pressure. 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? Has anybody experienced it/ tried it? Despite no changes in lift or duration, this cam sounded much more aggressive than the other two with wider LSAs. Exhaust reversion is another undesirable side effect that can be caused by overlap. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. by SStrokerAce Sun Dec 07, 2008 12:22 am, 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. 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. A lower efficient compression rate leads to a higher fuel consumption rate by your engine to produce higher power. It affects the powerband and temperament of a motor more than any other single part, and a slight change can turn a car from a mild-tempered grocery-getter to a downright nasty machine. If you take any of the . Kevko baffled oil pan & Milidon windage tray. Aluminum flywheel & pullies. 110 LSA: On the contrary, it is pretty unpleasant to inform you that the efficient compression rate decreases at 110 LSA. 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. 05 To ensure our stroker combo had sufficient airflow, we installed a set of Chevrolet Performance CNC-ported LS3 heads from Gandrud Chevrolet. They also reduce stress on the outdrive. If you're an OEM automaker looking for a steady idle, good fuel economy, and passing tailpipe emissions, this is the cam of choice. 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. The first cam featured a wide 120-degree LSA, while cam number two narrowed the angle to 112 degrees. Armed with more information on camshaft theory, what will you build? If a street car has smaller lift and duration numbers, they might run 112 or 114. JavaScript is disabled. Generally speaking, decreasing the lobe centerline angle increases overlap. by bug1914 Tue May 13, 2003 2:56 am, Post So, this LSA is suitable for your engine and its components. [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]. A commonly held misconception is that intake/exhaust overlap contributes to lower cranking compression. 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. The 110o will make more power overall. A cam 112LSA with 4 degrees advance puts the intake centerline at 108 degrees. 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. It should still make close to 600hp and 600tq in my 512" stealth headed big block. For your convenience, I am providing a comparison table to give you an overall idea about the comparison. "It's not having what you want, it's wanting what you've got!" 110 LSA: But here, quite surprisingly, you have to face the reduction of the EGR effect due to the 110 LSA. I've heard similar cams (only about 5*'s off) and they have a nice rumble to them. Seeking 1/2" ID x 5/8" OD Black Exit Tubing for Radiator Overflow Reservoir. Cam swaps are all the rage and for good reason. A wider lobe center will give you more overall torque (comes in earlier and stays later). Its the shifting problem again with your Chevy! The 112-degree cam produced peak numbers of 567 hp at 6,200 rpm and 540 lb-ft of torque while pumping out 511 lb-ft of torque at 4,000 rpm. by mrsmythe Mon May 12, 2003 11:15 am, Post But there is a drawback of higher cylinder pressure: higher cylinder pressure may sometimes lead to piston or piston ring problems. We will also custom grind any of the above profiles with a custom lobe center, for an additional $20 dollars. Chuck Lawrence of Jon Kaase Racing Engines was asked to give a 520ci BBF a Pro Stock sound, so he went with a 108 LSA in place of a more conventional 112 LSA. whats the difference in how the car will run. The result sounded wonderful, but it didnt rev as enthusiastically and it made 30 less horsepower than normal, says Lawrence. ~These are just some of the drawbacks weas guys who like to go mach 10 with our hair on fire and these little motors screaming at rpms that make other guys cryhave to deal with.~. 106 LSA: As the 106 LSA is a tighter LSA, it fails to generate maximum power. 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. There are General guidelines about the effects of LSA but it should not be the deciding factor in choosing a cam. So, sit tight back and explore. 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. Post A cam card with its myriad numbers, acronyms, and abbreviations is one red-pen stroke away from a failed math test. Overlap is the amount of time that both valves are open in the same cylinder. 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. Engine knocking generally occurs when the burning of the fuel by the engine is uneven. As boost increases, the air will be forced through the cylinder, vs. being trapped in the cylinder. A cam with a 112 lobe center will pull approximately 16-20" of vacuum, which is good for power brakes. This is ground into the cam and can't be changed without changing cams. But for small-block Chevys (like the LS applications in this story), the LSA is ground into the cam. This process slows down the reaction rates of the air-fuel mixture, causing temperatures to drop and preventing the engine from overheating. The 108-degree cam (blue lines) outperformed the other two, but idle quality suffered. Comparison Table Between 106 Vs 110 Lobe Separation Angle. This may be of concern if you have vacuum assisted accessories, such as power brakes or steering. It will have slightly higher vacuum at idle, feel smoother through the power curve but have a bit less midrange. A Pro Stock engine builder may prefer a wide LSA to help keep the power from breaking traction tOo early. by ANT Thu May 15, 2003 6:44 pm, Copyright 2022, S&S Motorsports LLC, All Rights Reserved - Powered by phpBB Forum Software phpBB Limited. . The second cam would have a rougher idle, produce more torque and would rev quicker. . Lucky for us, Brian Tooley Racing stepped up with a dual spring package that allowed us to safely run our 0.624-lift cam. 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. In terms of horsepower, the disparity between all three cams was only 6.5 hp, with a scant 100 rpm separating the peaks. Coupled that with the low first gear of the five speed, it ought to create some real traction problems. The 402-inch LS2/LS3 hybrid stroker started out with an LS2 aluminum block. It may not display this or other websites correctly. 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. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. 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. A 110-degree lobe separation angle means that the peak opening points of the intake and exhaust lobes are 110 degrees apart. The other thing is that you can make more power with a smaller aftermarket cam. (ICL + ECL) / 2 = LOBE SEPARATION ANGLE (LSA) LSA is a RESULT of the PROPER events. http://www.mustangworks.com/cgi-bin/moi-display.cgi?220, http://www.popularhotrodding.com/en6em_camshaft_specs/lobe_seperation_angle.html. Now here is where it gets tricky. Topping the short-block was a set of Chevrolet Performance CNC LS3 heads from Gandrud Chevrolet. It made 472.4 lb-ft at peak, a 21.5lb-ft disparity from the 101 cam. Thats just the way the customer wants to roll, and engine builders find its easy to deliver such a powerplant. This has been my long time understanding! Simply put, the lobe separation angle (LSA) is a measurement of how the intake and exhaust lobes are phased with each other. How do the lobe separations change when you factor in turbocharging? Also know as Lobe Separation; Lobe Center is simply the distance between the peak opening points on the Intake and Exhaust lobes. Typically, narrower lobe separation develops peak torque at lower rpm and widening the separation tends to build peak torque higher in the rpm range. If identical and for a given displacement the 110 will give more power. 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. 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.