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pintoracer1
11-29-2010, 01:09 PM
running 2300 on pavement 2100lb car turning 7800 to 8200 rpm. 1/4 mile track no port work allowed stock valve dia. 350 holey carb. what would be the best cam to run and also the best rod lenghth to run also the best header

84Dave
11-29-2010, 03:52 PM
It's now off-season & time to take advantage of the greater time on your hands. Go to MotionSoftware.com . Think about spending close to $50 for their DeskTop Dyno 5 engine simulator software program with its Pro-Iterator. Input your engine parameters and play with cam duration, lifts, & lobe separation angles (LSA). And if you want the software to get terribly close to what you'd experience in the real world, take your completed, ready-to-race head to a flow bench & get intake/exhaust flow numbers every .050" of valve lift. Then you can take those flow-chart numbers and enter them into the Dyno 5 software. Example of the Pro-Iterator portion of the software: Pick a lobe separation of 110-degrees and tell the software you'd like 'dyno runs' +/- 5-degrees either side of the 110. Pick a lift of .400" and +/- .100" each side. Pick a duration of 245-degrees & +/- 5-degrees. Let 'Pro-Iterator' figure it out. I've input a representative number of the above, and it took the software nearly 1-hour and 8,000+ 'dyno runs' to get all the answers. Then the Iterator process would select the 'Top Ten' dyno runs and present the 'numbered' results. And yes..... the software also allows selection of various rod lengths & compression-ratios. For cams, you can select solid, roller, or hydraulic. I've used Engine Sim software from the time it first appeared on the market. Some of the early software was junk. But one could work around the faults by using already gained experience in engine building. Today's software, relative to the early versions, is a slam-bang product to help with engine building. There's no need, at our 4-cylinder level, to spend $500 on Dynomation software, which also helps with ground-floor engine 'design'. DeskTop Dyno 5 will more than get you where you need to be to assemble a race-winning engine...... under your required Rules. Some of the best $$$ you'll ever spend on a race engine @ our 'hobby' level. -Dave-