Thread: Shelby Aluminum
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Old 07-12-2004, 10:33 PM
steelcomp steelcomp is offline
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KC
What have you done about combustion chamber design? You don't mention a word about that. What have you done to focus on low lift/mid lift flow numbers? We have found that more low lift flow (and even over all flow) can be found in chamber design and valve job than in port design, and that flow numbers really mean nothing. How many valve head shapes have you tried? Have you ever wet flowed your heads? What were the results? At how many in. of mercury do you flow your heads? When talking about port volume vs flow, how do you account for the fact that an FE head is missing half the intake port as compared to other heads? (It's part of the manifold) Do you think your flow numbers are relative to the industry? (BBF, BBC, other competition heads)
Do you think the saying "open flow numbers aren't as important as low/mid lift, since the valve only sees full lift once in the cycle"? is true?
Do you back cut your exhausts? If so, why? What were the results? What guide clearances do you run and how do you check them? Are the face of your valves the same angle as your seats?
Who actually decides what changes to make to your port designs, based on what kind of info? How do you determain what spring pressures to run? (Do you, from scratch, determain a proper spring pressure by using the valve train info, ie: valve train weight, lobe acceleration, deceleration, cyl. pressure, etc?) Do you know the recip mass of your piston/rod assy so as to determin the proper rod bolt? And rod? Are your engines built with stroke/rod length ratio considered as a factor? Ring material, widths and tensions? Piston material and clearances? Bearing clearances? Journal dia's and finishes? Oil pressure and type? How much oil do you run in your motors on the dyno? Is the oil pressure the same on the dyno as when a customer gets his engine? Same oil? Bore finish? Head gasket material and sealing?
Have you ever used a spin-tron? What kind of valve bounce do you experience with your best set-up? How do you minimize valve bounce? Why do some cams have so much lash?

These are the kind of questions I'd like to hear answered. And a lot more.
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