psfred,

We have an ozone action day here in Corpus Christi today. They mentioned on TV last night that one hour of mowing your lawn produces the same amount of pollutants as driving the average car 350 miles.

Lawn mowers are terrible -- low compression, usually have leaky valves (so you can pull start them), truely ancient design. The only thing worse is tractors -- some of them still have ancient Zenith updraft carbs, neatly marked Pat. 1907!

Keep the blade sharp (a Dremel tool with a medium stone works great, no need to remove the blade except to balance it), mow as infrequently as you can manage, and if you have a small yard (1/2 acre or less) consider an electric mower.

LA banned them recently, and air quality improved immediately. Only major improvement since the advent of the catalytic coverter.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I’ve often wondered why the don’t put catalytic converters on Lawn mowers
As I see it they could replace the mufflers with the converters.
I know a catalytic converter needs additional air to burn the stuff up, but that
Wouldn’t be that hard to do.
The noise wouldn’t be that much more considering what little there is to the
Mufflers to begin with

PEH: my experience is that management holds back the engineers. Even worse is an engineer becoming a manager without any training. I think the oil companies fear of losing half of their sales volume is more historically correct, at least in the context of this thread.

No problem playing with somebody's patent. That's why the patent is available for you to look at and possibly improve. You're a bad guy if you profit or help somebody else profit. If you really want to CYA then document your time and assign a value to it. The use of the patent has to stop when you go past the break even point. And you can't sell or give away the equipment (the buyer will profit, not the patent holder).

The off-road stuff is behind in emissions control because nobody made them do it. I deal with the big stuff now (power plants). New testing for emissions is expensive - roughly $50,000 per data point is the argument I make with the utilities to make sure they have their ducks in a row before our crew shows up. $1,000 per data point would not be unreasonable for a new lawn mower design, and less over time as more engines get tested. If the results are bad then you've only learned what doesn't work. Would you spend that kind of money if you didn't have to, and remembering that you do have to make a profit for the owner/shareholder?

You could buy a minature Jersey cow for those one-acre yards. Not much bigger than a Great Dane/St. Bernard, and you get milk and fertilizer in addition to a pet and lawn mower.

__________________
daBenz - 1970 220D

A catalytic converter on a lawn mower will melt in short order -- you have to have fairly clean combustion with reasonable unburned hydrocarbons before a catatlys will stay cool enough to survive long! This is one reason why diesels didn't have them -- too much air all the time, they overheat (and plug with carbon, etc). They've been perfected for diesels now, but aren't the same as gasser catalysts.

Exempting heavy equipment from emissions regulations was foolish, but I'm sure there was plenty of "grease" applied to prevent it (ditto for trucks, especially pickup trucks).

A low emissions lawn mower engine is easy to design -- just apply any of the solutions common in automotive engines. Problem is that lawn mower engine manufacturers simply don't have much engineering capacity -- they've been building the exact same engines for fourty years!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Outdoor power equipment has come a long way in the past 10 years. While some manufacturers are still making side valve flathead type motors these are being phased out with new overhead valve and even overhead cam designs widely available. Honda (they don't have engineering capacity???) has taken the lead on this with Briggs and even Tecumseh not too far behind. There are emissions standards now in place for this type of machinery and the "new" technology is the only way to meet them. There are even tiny 4-cycle weedwackers now that are much more fuel efficient and low pollution compared to the 2-cycles of old. RT

__________________
When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

Carbs designed later than 1910 help a lot too -- the B&S Quantum on my "new" 7 year old mower used considerably less fuel than the same hp "old" B&S on the thrity year old Snapper.

Took government action to get the improvements, though, something for the "no goverment is the best government" crowd to consider.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!