Posted by eg2 frank (email@example.com)
on June 20, 1998 at 19:59:08:
In Reply to: T.O.O. your thoughts on swirling air... posted by body on June 20, 1998 at 19:44:47:
the Q is who/what "the place that makes the spiral swirling thing" is/are... this isn't an aftermarket device is it?
If it's the funky silly thing like "Tornado", forget about it, it doesn't
do jack xxxx. Swirling air into the cumbustion chamber helps alot... Honda
VTEC-E engine uses it... on DOHC VTEC's in the low rpm lobes there's primary
and secondary profile. One opens a bit later... that's to help the swirl
too. Although I'm not sure if the GDI (direct injection into the chamber)
engines need swirling air anymore...
Posted by Eric Knops (firstname.lastname@example.org)
on June 20, 1998 at 20:11:41:
In Reply to: swirling air into the cylinder is good, but not before it... posted by body on June 20, 1998 at 19:59:08:
What I've always heard is that "high swirl" is good for low RPM burning of the fuel - it gives you the benefits described earlier. At high RPM, however, you go to "tumble" flow. I'm not sure if this is because you have to, due to aerodynamic properties, or if it actually burns better at high RPM this way. This is one of the reasons for VTEC, particularly VTEC-E. I think the new 3-stage VTEC in Japan uses all three modes (swirl, normal, and aggressive) to get the best of everything.
Posted by T.O.O. on June 20, 1998 at 20:25:06:
In Reply to: Re: swirling good at low RPM, not at high RPM? posted by body on June 20, 1998 at 20:11:41:
I don't open one intake valve before the other, and bias the port floors
to make power at low rpm, but with the exception of a few programs where
we built some 3.0 and 3.5 ltr. engines which were port induced high swirl,
and high swirl combustion, and the rev range was 15,000rpm, the fact that
we made well over 4 hp/ci, it couldn't possibly work.
Sorry to be an Asshole, but I thought that all that low rpm crap disappeared in 1987 when I went away.