Half a croissant, on a plate, with a sign in front of it saying '50c'

h a l f b a k e r y
Tempus fudge-it.

idea: add, search, annotate, link, view, overview, recent, by name, best, random

meta: news, help, about, links, report a problem

account: Browse anonymously, or get an account and write.

User:
Pass:
Login
Create account.


       

coaxial dual-poppet valves
Earlier opening allows longer valve duration
  (-2)
(-2)
  [vote for,
against]


Take a standard intake valve, cut four holes through the sealing end, and put a smaller valve inside the big one. Now you have the smaller valve opening first, allowing some air in through the four holes, and then the bigger valve opening later allowing the rest of the air in. This solves the problem of interfering valve design, where you can't open a valve too early or it will hit the piston. A way to get more air into the chamber at high RPM.

bagpipey1234, Dec 21 2004

[link]






       Yes, it's all about the valves. I weld them tight in my engine design at Horible Terrible Ice-Bots, recent submission.

mensmaximus, Dec 21 2004
  

       Unless you have a blower or pressure from a tuned intake no air is trying to get past the valve before or near top dead center. Opening before top dead center is done to give the valve a "head start" so it will be more open when air must pass through it. It's less wear and tear on the machinery to give the valve a little head start instead of forcing the valves open and shut faster with more aggressive cam profiles.

hangingchad, Dec 23 2004
  
      
[annotate]
  


 
back: main index
 business 
 computer 
 culture 
 fashion 
 food 
 halfbakery 
 home 
 other 
 product 
 public 
 science 
 sport 
 vehicle