Jarmo, hur mycket effekt får du ut med 42mm:s ventil och 36,5mm under ventilen?Jarmo Y skrev:Darin Morgan: "Make no mistake, velocity is the primary variable in the design of the entire induction system. I often say that my job title should be Velocity Manager instead of Cylinder Head Designer. Air speed is 10 times more important than raw flow numbers. If you kill the velocity by 10 percent, you will kill almost 40 percent of the wave and ram energy that dynamically fills the cylinder! Raw airflow cfm is an important variable as well; it's just not as important. If you buy a cylinder head that is properly sized for a flow of 400 cfm and your engine is only asking for 350 cfm, you will not only fail to achieve the power potential that the 400 cfm would have given you, you will also fail to reach the power that the 350 cfm would have given you. That's because you killed all the air speed in the induction system. If your engine is asking for 350 cfm and you give it a properly sized cylinder head flowing 350 cfm, your airflow demand is matched and your air speed is matched. You then have a chance of achieving the power potential that 350 cfm can give you.
En exempel, VW Bubbla boxer motor och en förgasade i mitten, det blir långa insugsrör. En liten ventil funkar bättre en större, original 35.5mm insugventil räcker långt, jag har haft 44mm och det gör ingen skillnad, tvärtom. En 37mm är suverän, 44mm flöder mycket mer men vad hjälper det om insug är så lång. Motor 1600 cc.
42mm insugventil hade varit bra i 2150 volvomotor, tycker jag. Om man har tex. 36.5mm under ventilen, fps blir ganska bra. Måste komma ihåg att denhär 2150 cc RC motor har inte byggt från F1 delar, inte ens på folkracedelar..kan inte vänta stora effektsiffror på höga rpm.
En hyfsad 2150 motor lämnar 210 hästar, en riktigt bra mer.
Erland