Chevyman85 said:
joe_padavano said:
I'll be the heretic here - my kid is going to have to breathe this air in 50 years. If Chevy can get 500 smog-legal horsepower out of a pushrod small block, what's the problem?
Well I'm not out trying to screw the environment I just feel that a vehicles emissions have nothing to do with how efficent it is.
My tired 350 I had before would sail through emissions with tons of blow by, it only got about 10 MPG. Now I have double the horsepower and I get better mileage. I'm just not a big fan of emissions, especially with all the other exemptions such as Diesels.
At the risk of getting off topic here, there are two different measurements of emissions, parts per million and total pounds of pollutant. Most tailpipe tests simply measure PPM at one, or sometimes two engine speeds. As you've found, it's not real hard to tweak an engine to pass. Unfortunately, this is just a spot check and not a measurement of all operating conditions. More importantly, a tailpipe spot check doesn't measure the total pounds of pollution emitted per year - which I'd argue is the more important measurement. Unfortunately, it's also the one that can't be measured practically.
Obviously, lower BSFC almost always means lower emissions (except for NOX, but that's a different case anyway). On the other hand, if you're moving more air and making more horsepower, you're possibly putting more total pounds of pollutants in the air for the same number of miles. Of course, taking this argument the other way, a modified car that is only driven 1-2,000 miles a year puts out far less total pollutants than the newest economy car driven normally. Unfortunately that's a concept the lawmakers can't and won't understand. By the way, we're in violent agreement on the exemptions. Unfortunately, hot rodders don't have a lobby with the same clout as the trucking companies.
Oh, and Chevy is getting 500 HP out of a pushrod BBC 427 in the Vette, I apologize if I misunderstood that, but your right it is possible to make serious power with emissions, its just easier w/ out :wink:
Last time I checked, the LS-series motors were considered small blocks, despite the 7.0 liter displacement in the Z06.