Sherman Bird
Senior Member
- Joined
- Jun 28, 2019
- Posts
- 1,551
- Reaction score
- 2,349
- Location
- Houston, Texas
- Ram Year
- 1998
- Engine
- 5.2
Inasmuch as the hydrocarbon, gasoline, is a liquid, it has to be broken down as much as possible into very fine mist in the fuel delivery system at the injector or at the carburetor venturi. The more turbulent the air/fuel mixture is, the more completely it will burn. This is why a vehicle run on natural gas does far better in lower emissions and complete fuel combustion that those on gasoline.I remember CVCC, Vortec, and fast-burn cylinder heads. It didn't cost much more in materials or machining, either. Just the development non-recurring costs. All this other techno-glitz gizmos (VVT, ECM, GDI, MDS, whatevs) is absurd.
Soichiro Honda was a brilliant engineer. His collaboration with other automotive engineering teams was legendary.
GM kept the patent rights for the swirl combustion chamber, but licensed it out to Honda, as I read it.
In 1996, GM pulled the Vortec configuration off the shelf and dusted it off and employed it in 4,6, & 8 cylinder engines in order to meet OBD2 emissions mandates. The design also enhanced the fuel mileage, so that was a good thing. The only problem with the SBC (small block chevy) engine was the siamesed exhaust ports on the cylinder heads... thus the introduction of the LS engine family. The very first LS showed up in the 1997 Corvettes, the truck lines got them in late 1999. The "R" engine, the Vortec design SBC was phased out after the 2001 MY. The Vans and a few larger trucks used them.
Chrysler brought back the Hemi for similar reasons, I'd extrapolate.
As we enter this new phase of CAFE/emissions mandates, a new design of powertrains are headed this way.
The future will routinely see engines tuned to run over 15:1 AFR (air fuel ratio) up to 16:1 as I've read in research.
To address your comment concerning VVT, It's the best of both worlds when they function. Being able to adjust cam timing events to exploit the most efficiency out of an engine throughout it's RPM range is a huge part of WHY these newer 4 cylinder cars today are so friggin fast!
For me, seeing 4 cylinder cars of the 70's, 80's, and 90's go from 55 HP then to 200 routinely today, along with so many other advances in technology, one wonders how close to the limits of physics we really are!