jay260z Posted March 2, 2011 Share Posted March 2, 2011 I have a set of Vortec heads that im putting onto my 355 sbc with a new Hydraulic roller camshaft and wanted to konw what kind of power it should make. The Engine 4 bolt block bored .030 Manley 5.7 I beam rods SRP flat tops with valve reliefs ARP bolts Lunati VOODOO 60111 installed on a 106 ILC as speced by lunati (219/227@.050 .515 .530) New Lifters OEM type(Vortec Block) The Vortec Heads have 2.02/1.60 Screw in studs with guide plates Machined valve guide Machined spring seats to fit required springs Mild port job (i dont have any flow numbers) Should i degree the cam other than what the cam card specs to help out any? I dont have a set hp number that I am reaching for just a healthy morotr for the ol Z to cruise around in and play with at the strip on the weekends Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 2, 2011 Share Posted March 2, 2011 (edited) Ive generally had the best results with installing a cam STRAIT UP or in most cases 4 degrees retarded from the dot-to dot install location most manufacturers suggest. a hydraulic cam will limit valve train control to about 6200rpm you failed to mention several variables, like the compression ratio, header config, intake,carb,transmission and rear gearing, converter stall or manual trans?,etc. but Im going to assume youll take the time to maximize most of those to gain a reasonable combo, it should be obvious that while I can give you some good idea as to potential, the other parts you select and the care during assembly, and any mods to those parts will effect the results vortec heads have a minimum cross sectional area near the push-rod of approximately 1.7 sq inches most vortec heads max on flow at about 240cfm, which in theory means they could be expected to feed up to about 480hp with the correct cam,compression etc. but with a cam like your selecting thats limited your peak potential in favor of more low and mid rpm torque. peak torque will occur at about 3800rpm-4000rpm, youll be lucky to exceed 1.25 ft lbs per cubic inch or about 430ft lbs even with good headers a rough guess says it torque peaks or noses over by about 5500rpm, and that would limit that combo to about 420hp max with that cam and stock heads because the formula for hp=torque x rpm/5252 so if we give you the max torque and assume it carrys effectively up to 5500rpm 350 cubic inches x 1.25=437ft lbs x 5500rpm/ 5252=458hp x .9 max volumetric efficiency =412hp http://www.rbracing-rsr.com/runnertorquecalc.html obviously you can use a software program like desk top dyno to get a good guess, but Id be surprised if you exceed those approximate numbers (412-to-420hp (flywheel)) running pump octane fuel and that cam with un-ported heads once its tuned and installed use this calculators to see if results are close http://www.dragtimes.com/horsepower-et-trap-speed-calculator.php http://robrobinette.com/et.htm Edited March 3, 2011 by grumpyvette Quote Link to comment Share on other sites More sharing options...
jay260z Posted March 3, 2011 Author Share Posted March 3, 2011 I have a performer RPM air gap, 650 holley streep HP, 1 5/8 long tube headers dual 2 1/2 exhaust, Mallory digital ign, 3:90 differential ratio, all of the fuel system needs to support it all, and the list just goes on. I have plans on posting results of how it performs both on the steet and the track. If the power output isnt enough I may go to a larger cam or a 750 carb ive got laying around but I dont want to go to large and only have a small gain at the track but loose street mannors. Whats a Hydraulic Roller cam you may suggest in the future to get the most out of the setup I have now? Thanks for the info you have posted. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted March 3, 2011 Share Posted March 3, 2011 (edited) I have a performer RPM air gap, 650 holley streep HP, 1 5/8 long tube headers dual 2 1/2 exhaust, Mallory digital ign, 3:90 differential ratio, all of the fuel system needs to support it all, and the list just goes on. I have plans on posting results of how it performs both on the steet and the track. If the power output isnt enough I may go to a larger cam or a 750 carb ive got laying around but I dont want to go to large and only have a small gain at the track but loose street mannors. Whats a Hydraulic Roller cam you may suggest in the future to get the most out of the setup I have now? Thanks for the info you have posted. one factor thats always a P.I.T.A. is theres always ways to improve a combo and it always allows you to spend more money on a project than the results may be worth, sure you can build a 500 plus hp engine, but at some point the cost vs value makes it rather foolish to constantly upgrade components as the cost starts to increase faster than the resulting power even if it is impressive! you still didn,t post the transmission or stall speed youll use,or if its an automatic trans, and since you asked about maximizing the combos potential ,one of the 350sbc strong points is its ability to rev if the correct cam, valve train and compression are used, a max piston speed of about 4000fpm with basically stock type components should be a reasonable limitation and thats about 6700rpm, obviously the hydraulic valve-train is not ideal, and a solid roller and roller rockers with a stud girdle should be used, and youll need to swap to much better springs and clearance the valve train for about a .600 minimum lift if your intention is to maximize the power curve, and if that is your goal Id have selected a manual trans, got the compression up in the 10.5-11:1 range and installed a solid roller valve train with a cam similar to a 501B1lun http://static.summitracing.com/global/images/instructions/lun-501b1lun.pdf which will allow you to drag every last bit of flow from mildly ported stock vortec heads with the required better valve springs, and that rpm air gap intake and 750cfm carb. obviously that won,t be an ideal combo for a daily driver but it should be good for a weekend track and street toy, ID also point out that there are 206cc vortec heads that would significantly boost the combos potential you should read these threads http://forum.grumpysperformance.com/viewtopic.php?f=69&t=1040&p=3686&hilit=large+vortec#p3686 http://forum.grumpysperformance.com/viewtopic.php?f=52&t=181&hilit=large+vortec http://forum.grumpysperformance.com/viewtopic.php?f=52&t=401&p=6078&hilit=large+vortec#p6078 Edited March 3, 2011 by grumpyvette Quote Link to comment Share on other sites More sharing options...
Michael Posted March 6, 2011 Share Posted March 6, 2011 I don’t have intelligent advice to offer about component replacement for gaining another 20-30 hidden horsepower, but after working on one “high-performance†engine for many years, it’s worth noting the importance of reliability and simplicity over maximum performance. Maybe the present combo has insufficient duration to move the torque-peak to the rpm that you prefer, or the hydraulic roller cam will float the valves before the hp peak noses over. Maybe the headers aren’t scavenging optimally and you get a midrange dip in torque. Or the intake is poorly designed and some cylinders are running richer than others. If this isn’t a sophisticated competition engine, are any of these drawbacks genuinely profound losses? I would opine that a reasonably workable combo – where bearings aren’t getting spun, where valve guides are not puking oil, where the spark plugs are not fouling every 100 miles, where the rings are holding compression and the engine doesn’t stutter when you mash the throttle because the carb’s power-valve blew out insidiously – well, that combo is already a pretty good combo. And the route to improvement is through incremental massaging of an already proven combination. Even the most expensive and most exotic engine only makes about 1/3 hp sitting on the engine stand – and that’s if you’re in good shape and can run swiftly while pushing the stand. Quote Link to comment Share on other sites More sharing options...
jay260z Posted March 8, 2011 Author Share Posted March 8, 2011 I have thought these things out before actually picking out the parts to make up any of the engines combo's that have went thrugh my mind. This engine I chose to keep it more along the lines of a nice performance steet motor over a tame race engine. Once the fun wears off or get a wild hair to want more power or try somethign unique this motor will perform well enough. Quote Link to comment Share on other sites More sharing options...
rsicard Posted March 10, 2011 Share Posted March 10, 2011 I have thought these things out before actually picking out the parts to make up any of the engines combo's that have went thrugh my mind. This engine I chose to keep it more along the lines of a nice performance steet motor over a tame race engine. Once the fun wears off or get a wild hair to want more power or try somethign unique this motor will perform well enough. Purchase David Vizard's latest book for ideas. It's too late now, yet when building the bottom end go to 383 cu in by spending another $200.00 for a cast stroker crank. Rods and (Professional SRP very lightweight) Pistons are nearly the same cost as already spent. Then invest in good cylinder heads AKA AFR 195 SBC heads. Spend the extra $500.00 and get the competition heads and you have the best bar none! Forget the Hyd cam and go to solid roller of about 240 - 250 duration at .050, 1.6 ratio rockers (honest good valve lift all the time) and a good intake and fuel system. Then 500+ streetable HP/TQ is well within reach. Quote Link to comment Share on other sites More sharing options...
jay260z Posted March 12, 2011 Author Share Posted March 12, 2011 I have been looking into books to buy and learn from but just havent bought any yet. That engine you just described is basicly the exact setup I want to build but money says otherwise and thats why I have this simple build going on. Thanks for the info Quote Link to comment Share on other sites More sharing options...
jay260z Posted March 27, 2011 Author Share Posted March 27, 2011 Well the motor runs but the weather aroud here isnt working for my favor in getting this put into the car. Ive been able to fire it up on an engine stand, idles nicely around 850-900 rpm with about 14 in. of vacuum and hase nice crisp throttle responce. Quote Link to comment Share on other sites More sharing options...
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