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Old 04-21-2021, 09:34 AM
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eschaider eschaider is offline
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Join Date: Feb 2006
Location: Gilroy, CA
Cobra Make, Engine: SPF 2291, Whipple Blown & Injected 4V ModMotor
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Jim, if you don't go to a builder/designer (like Brent) who already has experience with your basic engine package, then you need to start with some more sophisticated than the average bear engine modeling software that allows you to build engine models with detailed cam profiles and then use the modeling software's optimization tools to narrow down the universe of cam profile possibilities for the power and torque curves you are looking for and then optimize them for the engine.

When you get done with that, you need to use a software tool (for the older software probably not with newer software) to optimize the opening and closing profiles for smooth operation. This is a graph of the velocity, acceleration, and jerk curves for the closing side of my passenger side exhaust cam. It is not easy to get them to look that smooth, especially the acceleration and jerk curves.



This is different than the opening side ramp for the cam and in my case because of the different rotation side to side for my cams, it is also different than the closing ramp for the driverside exhaust cam. Your lobe profiles will be a bit easier because of the OHV vs OHC design nuances.

All that said, you will still need access to some modestly pricey equipment and software tools to get your first profile onto a camshaft. The stuff I was fortunate enough to be able to have access to was a generation or more behind the tools that are available today, so some of what I had to do by hand can be done by software tools today.

When you are all done describing your new paper tiger you will need to reduce all he whizzy stuff to a camshaft you can put into the engine and test on the dyno. This step like so many is an iterative process that will be repeated a number of times (read grind more than one camshaft) until you get the power curve you intuitively were looking for way back when as you began this process.

There is considerable value that Brent and guys like Brent bring to the table in this process. As a consumer of his products and services you are buying the literally years of testing, rethinking and retesting he has done to get to the cam recommendations he is providing you as the consumer of the advice and products from him, today.

To duplicate this end result takes lots of time (think years), lots of effort and yes lots of money spent on the process. A good even handed (think realistic) approach to what you are looking for packaged into a dialog with him is an absolute win on your side of the table. You skip literally all of the hard work and sometimes painful discovery process and head to the finished solution without any of the abuse you would have otherwise subjected yourself to.

My best recommendation would be to call Brent, use a cam he recommends and enjoy the engine and driving experience it affords you.


Ed
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Last edited by eschaider; 04-21-2021 at 10:34 AM.. Reason: Spelling & Grammar
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