guitarjunkie28

that's true for the closing edge--not for the runner.

R.P.M.

Ya man, you want turbulence in the runners to swirl up the air to mix properly with the fuel.

guitarjunkie28

he won't listen because i said it. he's pissed off about soem mis-information i called him on about apex seals.

R.P.M.

Ok, but would that sound right to you guitarjunkie28? It makes a whole lot of sense to me!!

guitarjunkie28

sorta.. it's not exactly to swirl the mix--rather keep some turbulence along the port wall so the fuel doesn't stick to it.



but even so, i think it's less of a concern on the secondaries. by the time they're utilised, the air should be moving faster (and more of it), so there's less chance of that happening. also, the heated air from the turbo (if applicable) helps keep the fuel in mixture.

GTUs

[quote name='guitarjunkie28' date='Apr 13 2005, 09:16 AM']you want the primaries rough to add turbulence.


[/quote]



just a hint, you know the pri runners got only air inside untill the last inch or so before get into the chamber. can you remember where your pri injectors are?



you got the right idea about a/f mixing, but.......

guitarjunkie28

i've never seen anyone polish half the runner, but i know what you're talking about.

GMON

[quote name='guitarjunkie28' date='Apr 14 2005, 05:51 AM']i've never seen anyone polish half the runner, but i know what you're talking about.


[/quote]



Lets think about this for a sec. Before the injector should be nice and smooth. After the injector is about an inch of travel and its also the port outlet. Your saying you want turbulance here. Yeah, didnt think so. Also, on efi cars you dont need to worry about the fuel atomizing good enough in areas like this becuse you use whats called a FUEL INJECTOR they are amazing little things that atomize fuel.



The only reason you dont want a shine on the surface here would be becuse when you get on and then off throttle quickly the fuel can come out of atomization becuse of the quick pressure change and a shiny surface can make that happen easier. However, this area is also hot enough where that is really not much of a problem.



So there ya go, I have just dispelled every one of your rough surface points. What say you?



Ive ported to a shine on both pistion and rotary aplications in areas just like the primarys and had absolutely no problems. Gives that added low end grunt. Carbs are a different story however but who the hell still uses those??

guitarjunkie28

exactly how well do you think a fuel injector atomises? yea, it's better than pissing fuel in with a carburetor, but it's definately not a perfect world--especially when you use bigger injectors.



if you really wanna mix it up, talk to richard paul about injecting fuel into an axial-flow supercharger....it reaches the point of homoginisation.

guitarjunkie28

btw, i think we have a different definition of rough.