RFP for the Engine Build for the Missile

Lots of good information here from guys that have first hand experience.

One thing I'd like to re-iterate that MadDart replied about with accuracy is the minconception that you have to constantly adjust a solid lifter cam. Those days are pretty much behind us. I'm sure if you use junk rocker arms and soft pushrods that may be the case but I've found that even with a moderate performance cam and spring pressures as long as you use good parts you will rarely have to adjust the lash. I built a 418 for a buddy a couple yrs. back and used a Cam Motion solid flat tappet cam (264 at .050 @ .610 lift measure at the valve) and he has ran the crap out of it and only adjusted the valves twice and the last time they barely needed any adjustment at all. Unless it's a grocery getter or real low budget build I rarely even consider a hyd. flat tappet anymore. Your just leaving too much on the table with them IMO.

As for the sims programs: If you input everything perfectly there is still room for error because all those programs assume some things you can't adjust. Things like 100% ring seal, cam lobe intensity (I know there is an adjustment on some of those programs but rarely does it really follow your cams lobe profile perfectly and that is an issue with small blocks with their less than perfect lifter to pushrod angle), a perfect tune up and perfect port match with all cylinders flowing the same amount of air just to name a few. Don't get me wrong, I'm not saying their not any good, just saying their not near perfect and your results can and probably will vary. I have 2 dyno sim programs that I play with and compare the results and take into consideration things I have learned building engines then make my decision.