| Re: Interesring article on fluid dynamics and airflow |
Subject: Re: Interesring article on fluid dynamics and airflow by BeachBum on 2008/11/24 2:27:35 # 26 is talking about wetflow, which I know is what Dart has hung their marketing hat on..... My only problem with wetflow is that its an unproven science at this point for street/strip cylinder heads.(actually unproven on any cylinder head.... they just don't know enough about it yet.... its not easy to see the results and then when you have figured out how to look at the results, what does what were looking at even mean and how do we improve it?) Many years ago, some of the pro-stock teams utilized a make-shift wetflow machine and did some testing, I've heard with mixed results, but all gains were fairly modest. Thats not to say that isn't good.... it is, with those pro-stockers, every single hp they can find might be the difference between qualifying or going home on Saturday..... but it really hasn't been in-corporated in your typical off the shelf cylinder head yet, except, as advertised by Dart..... I know they had an advertorial going around the publications that showed I think some dart pro 1s and then some platinum 1's that increased the hp by I think around 20 hp, and had around 5 cfm more flow on the intake and 10 more cfm on the exhaust. This test really wasn't all that impressive considering the test engine results..... thats not to say they didn't find some power with it, but the end result wasn't really anything to write home about. I can give a comparison of the exact same engine & cam with 1/2 point less compression and a different cylinder head that didn't utilize wetflow making 20+ more HP .... but it doesn't matter, and I don't want to go there anyway. On cylinder head flow.... so many I don't think understand it. Its treated as an element of a cylinder head by many, but its really not, its a culmination of all the good stuff you did.... in otherwords, its the result of a well designed port, not another element..... cylinder head porters raise or lower the roof, tighten up the throat, clean up the pinch..... all of these things typically increase the flow of the cylinder head, and thats a good thing ! Wetflow and Airflow go hand in hand.... not against each other.... if you introduce a liquid in the same density and weight of the gasoline in the stream, you're hoping to see good things with that well designed, good flowing airflow.... in fact, you want to tie them together, you want lots of airflow and you want the fuel to stay suspended and enjoy the ride that the airflow gave you. As most know, fuel is heavier than air, thus it'll spatter on the walls if the air flow is too slow or in-sufficient to carry it... which is what this is all about. Of course there are other things that make a good cylinder head.... for the serious racers, having a good thick casting that can easily be heavily modified by the serious porting guys. (Dart is one of the best with this).... also having the proper spark plug location, seat, etc..... its all important, but to be honest, all of the aftermarket cylinder head manufacterers figured out the basics a long time ago.... I don't worry about it. Actually, at the end of the day, none of this matters..... there are around 5-10 aftermarket cylinder head manufacturers that all make good products that "will" give you a nice performance increase, and Dart is certainly one of those companies. My advise, pick your poison and go have fun with it !! Disclaimer: All of the above is just my opinion, if I'm right, I want a trophy, a trophy girl and a good cigar, if I'm wrong, my name is Pedro, and I don't speak english. |
