by raceman14 » Fri Mar 02, 2012 4:33 pm
Madbill,
Sounds like you were at the Engine Builders Challenge. All of the things you reference are correct. GM 604 crate springs are not much of a spring checking about 100# on the seat, my treated springs are less than that statically and dynamically as the treatment process sacrifices some seat pressure for harmonic frequency tuning. Oil is a significant consideration as is the oil filter in stock GM crate engines. About 50% of my spring customers have started to use my oil and filter to gain some additional rpm. Springs net 250-300rpm, oil and filter contribute 300-500rpm depending on the lineage of the engine and how the pump and other engine parameters were set-up from the factory.
Laser inferometry on the lifters is how you can determine how much actual lift and duration occur at the camshaft/lifter interface and also at the valve. To accomplish this you need upwards of 40 channels at the cost of about $100K per channel. To make more power not much else of all that scientific $hit matters, when the indicator says more lift and duration at the valve, and the dyno says more air and fuel sucking in the engine and the dyno wheel or drum says more HP that is what counts !!! If it is repeatable that is what really counts.
First time I met this guy was at Daytona in about 1998 and he walked up to me and said, if you give me $500 cash right now, in 5 minutes I will make that car you have been messing around with all week long faster than it has ever been. Conditions were roll the car into a private stall and give him 5 minutes without being watched. What the hell, I just paid $2800ea for manifold updates from Wilson and that was for 4 cars over $10K, whats $500 in the scheme of things. It didn't take him 2 minutes and looking at the car you could not even tell what he did. We went out next session and shot from 21st place on the time sheet to the top of the stob...freakin P1 in a couple minutes. We immediately got called into Joe Wells office and had to take the carb, plate and manifold off the car for inspection.
Well after that me and Waddell Wilson become best friends and he came to almost every practice and race we went to for the next couple years. Oh yea, it was 6 pieces of legally place tape to make air do what he wanted it to.
That is the kind of education no amount of money can buy, and he was a pretty good engine builder in the day too.
911 and CamGuru,
The ports and intake don't need any work, have you ever flowed a set of 604 heads and intake???
Mike I am not a cam grinder so I would not tell you how to grind a cam, although I have ground them before in another life. 911 don't know what you do but I wouldn't tell you how to do your job.
Where you are missing the boat is knowledge about what you are working with...there are 4 different intake generations and now 5 generations of cylinder heads. Heads vary in port volume from 187cc to 214cc, is bigger better, check them on the flow bench and see for yourself. Seat height in the intake and exhaust port is also a critical measurement for air flow and that number can vary +/- .100" in stock heads and +/- .250" when you install new seats in a head. Talk to a cylinder head guy and see what he says about that. Valves make a huge difference and not all stock valves are the same. Go thru about 100 of them and you'll see. I have a flow fixture made just to slap valves in and out of so I can see what number they make. Change the margin .020" and see what happens to the flow numbers.
With swapping intakes and heads around I have seen +/- 47cfm@25". Run that thru your Horsepower calculator and see what that nets.
I know there has to be more folks out there like Jed that has built spec engines. I ain't just making the stuff up for fun over here, I spent 7 hours on the flow bench last night flowing a new pile of heads and intake manifolds. It is no different than building a super stock engine using Canadian heads and intake with hollow truck valves and certain 2g's that flow better...Why do you think people give their left nut for 'X' heads these days, if you have some of the old 2101 stuff you'll see it is 15-20 HP better than the new ones, wonder why?
Not everything works out quite the way you plan and sometimes you have to look at How along with Why ???
Bill Jones taught me to look closely at everything I touch, Alan Lockheed taught me that "you can build engines on a computer if you have the right input" & that was in the 80''s when we published along with Myron Cottrell of Chaska MN. Mike Chapman taught me that "all that glitters is not gold", Smokey taught me "not to take anything with a grain of salt", Jim Feuling taught me that "air has different phases at different speeds and it really changes super-sonic" ( he had a 600HP Flow bench at his shop and that thing would suck your eardrums out if you weren't careful ), and there is a hundred other folks way smarter than we that have helped me thru the years.
Bottom line = take from it what you can use and throw the rest away...
More is always better!!! Most of the time.
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