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hmm, I see. I suspect that a catalytic could bring the UHC down to ~1g/kwh but much beyond that is pushing it. Possibly going to a stratified charge as well as after treatment could get us there. But the target is a moving on, by the time that could be sorted the regulations will have shifted...

I'm not terribly up to date on modern automotive emission specs but maybe we can start to quantify this. The DI snowmobile engines I'm used to dealing with have no catalytic aftertreatment and emission numbers are approximately as follows on a production engine. This is also not a variable...

There are examples of 2-stroke DI motors with very very clean emissions, cleaner than the 4-strokes they compete against in those particular classes. Particularly outboard boat engines and snowmobiles.

If you're getting into it for personal satisfaction, there's no such thing as too late. However if you're getting into it for financial reasons, a future worth calculation can provide a much more qualitative answer than any number of opinions we can provide.

They may not need it. But they want it, and they're willing to pay for it.

...also care about how it feels to drive, whether it gets good fuel mileage (which is generally in good proportion to the mass.) 10-14 bar BMEP is the rule of thumb I use. The 70ft*lbs gets tricky, I've dealt with 2-stroke motocross engines that when set-up properly make nearly 4 times that.

I've seen some of those engines ya. And yes society seems so caught up in the cylinder swept volume that they neglect the more basic metrics. There seems to be an assumption that an engine with a larger swept volume will be massier. Altho you take that little 4 cylinder box 4 turbo, and start...

I'd like to point out that the displaced volume is a rather arbitrary means of comparing engines. Personally I thought outright mass or geometric size is a much more relevant comparison. Doesn't sell as well on the paper perhaps, but I for one am extremely impressed with the LS7's mass specific...

The real question is will management stop using the buzzword of the minute and applying it on Engineers? Lean, Siz Sigma, Paradigm Shift, 7 Habits, Green, etc.

vote #3 for "Miss Shilling's Orifice" it IS a shame that it all went down that way, she saved a lot of lives with that little contraption.

lmao rb1957, my first thought was also immediately somewhat dirty. "it's the tip of the <insert biological reference here>"

Ya Fort Mac was hit hard, my understanding is that it's starting to pick up again with the price of crude back in the $80 range, it really needs to be over $100 for the Athabascan sands to be in high gear, but there's plenty of build projects underway. That said, I wouldn't recommend Fort Mac...

if you've got experience in oil&gas head for Fort McMurray in Northern Alberta, big money in that area, altho not a whole lot in the way of vacation material, and the winters are generally harsh. Newfoundland also has a fairly large oil/subsea industry and is probably better for a vacation spot...

given the push for clean coal that is at the moment the most pallatable option politically that's capable of filling the grids needs. I'd say it's a big ask to take carbon sequestration off the table.

388hp on an 86mm squared 4 cylinder at 6250 rpm comes out to be right around 28 bar of BMEP. More than reasonable for an absolute pressure of 2.6 bar in my opinion. To put it in perspective that'd be just over 10bar at atmospheric pressure, which is actually relativly mild tune. Ofcourse you...

it'll depend heavily on ignition timing, valve/port timing and the distance the EGT is from the port/valve.

gotta concur with imcjoek. however you can easily enough calculate the differences in power loss to spin up 2 wheel/tire sets of known inertias and decide for yourself if the inertia gain is worth the added traction.

No experience with that particular engine but looking at the bore/stroke I'd be inclined to go with a shorter duration, tighter lobe centers and more lift. your 25m/s limit comes at 7800rpm, at 13bar BMEP and expecting peak torque at ~6500 so that it can have a nice fat torque curve and continue...

I'd expect: reduced compression less peak torque a broader torqueband peak torque will occur at higher RPM reduced maximum cylinder pressure and therefor increased piston life. better idle quality and vacuum. increased NOx emissions All that said, this isn't that big a shift so these changes...

The legality becomes even trickier when liability comes into play. If you get in a car accident driving from a jobsite to your house rather than from the jobsite to your office, how will the insurance company look on that? Or if you fall off a ladder before your scheduled end time.