WOW! new 4 stroke 50 merc

[jim dozier]

Re: WOW! new 4 stroke 50 merc

The difference in emissions with direct injection engines such as the Etec is that the fuel isn't injected into the combustion chamber until after the ports close. As a result there is a lot less unburned fuel going out the exhaust port. Remember that in a normally aspirated 2 stroke the only thing keeping the fresh fuel charge from going directly out the exhaust port (and as a result contributing to high emissions) is the direction of the charge in loop charged ports and the piston deflector in cross scavenged ports. Neither of these are 100% effective. With direct injection, if applied efficiently, you may lose some air out the exhaust port but the fuel isn't added until the ports are closed and you get a cleaner burn. Also I would expect that you can regulate the mixture a litte tighter because you don't have to account for fuel dropping out of the mixture during contact with the crankcase and ports in the initial mixture. Remember there are lots of variable in what determines emissions. <br />Fuel/air mixture. <br />Degree of mixing.<br />Charge stratification.<br />Combustion chamber shape.<br />Port timing and efficiency.<br />Combustion temperature.<br />Ignition timing.<br />I'm sure there are other issues.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

Thanks JimD,<br /><br />that was informative, but I was asking about the difference between 4 stroke and Etec 2 stroke emissions.

 

[winoandino]

Re: WOW! new 4 stroke 50 merc

Ask an you shall receive:<br /> http://www.epa.gov/air/caaac/2004awar.html <br /><br />Right off the EPA's website. "Compared to a similar 2004 four-stroke engine, carbon monoxide emissions with Evinrude E-TEC are typically 30 to 50 percent lower; and at idle are lower by a factor of 50 to 100 times."

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

thats very intereesting, I do not understand how they accomplish that, Ill have to do some reading when I have time.<br /><br />How does the no oil change work?<br /><br />I guess the crank bearing oil could be reused for ever ( in theory) as long as it is not contaminated by teh combustion process.<br /><br />I would like to see one with a few years of use on it.<br /><br />I think its neat technology, maybe it will allow some form of 2 strokes to live a bit longer.

 

[jim dozier]

Re: WOW! new 4 stroke 50 merc

Ozarkeep, no doubt if you applied the same direct injection technology to a four stroke engine you would see improvement in emissions for similar reasons- less unburned fuel going out the exhaust valves. Stratified charge fuel injected 4-stroke engines have been experimented with before. Remember that current versions of electronic fuel injection as in your car and the current 4-stroke OBs are multi-port fuel injection. That is, the fuel is injected into the intake manifold just in front of the cylinder head intake port - not directly into the combustion chamber. In a general sense 4-stroke engines using the same aspiration technology will be cleaner than 2-strokes using the same aspiration technology (carb to carb, EFI to EFI, etc.) If you change aspiration technology on one you can clean it up relative to the other. You really would not want to compare a carbureted 4-stroke with a direct injection 2 stroke if you were trying to analyze which engine technology was inherently cleaner.<br /><br />As to the no oil change. I believe the ETec is just a refined version of other 2-stroke oil injection systems. You keep putting clean oil in the tank and the engine keeps burning it up. The difference with previous oil injection systems is in how quickly you are burning it up. I am assuming that they have made an effort to maximize the recycling of puddled oil in the crankcase to reduce the consumption rate.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

ahh, I see now.<br /><br />so they are basically "oil injected" but likely at a really lean oil/fuel mix as well, like the oly yamaha engines that specd 100:1.<br /><br />most of the oil injection 2 stroke stuff I have dealt with are variable ratio from 200:1- 40:1<br /><br />I dont see how that consumes less oil than an engine that only "consumes" oil from blowby, unless they are figuring the used oil as "consumed"<br /><br />Id like to see emissiontest data on the engiens side by side, there is alot of "sales pitching" going on the evinrude website, careful wording to make it appear golden.<br /><br />IM sure its a great engine though. I still wonder about the cylinder ports and piston ring life though, thats always been my problem with 2 strokes.

 

[Paul Moir]

Re: WOW! new 4 stroke 50 merc

This isn't much use since they don't test for CO emmisions (yet) and they don't seperate HC from NOx emissions, but it is good to give you an overall picture:<br /> CARB's Off Road certification database.<br /><br />But please don't sit around all summer reading emmissions test data. Go out and enjoy that 50hp.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

Hey thanks for that link Paul!<br /><br />Its hard to know which is which there, but the 995CC is the merc 4 stroke 50, and 4 stroke efi 60 ( both 995CC) ( 2 differetn HC + NOx levels.) ( dont know which is which?<br /><br />Does any one know which engine in the bombadier group is a E-Tec 50 Hp?<br /><br />I guess at the closest one ( displacement size) and one number is smaller, and the other is higher, BUT the engine has fewer cubic centimeters ( by over 100), so it actually pollutes More per Cubic centimeterthan the merc<br /><br />but again, I am not sure which engine I am looking at on the chart.

 

[Paul Moir]

Re: WOW! new 4 stroke 50 merc

They group the engines together if they're similar enough designs. That way they don't have to test each one, as long as the manufacturer can prove that changes to one will have similar emissions change results in the others. If you look at page 2 on that, they use a 50hp engine (37KW) as the worst case scenarios. So there is no separate 60hp test.<br />Why Mercury 'updated' it's FEL (Family Emission Limit) in the -1 one, I don't know. Perhaps they tightened up manufacturing tolerances? I think the Certification Level is more important.<br /><br />EDIT: I forgot about the E-Tec 50hp - it's the very first one on the BRP list. And don't forget the fundamental difference that the E-Tec is a two stroke, so it has 'effectively' double the CCs of a four stroke since it has two combusions for every one of the four-stroke. (Practically speaking, it's not nearly double since the CCs don't include port height, etc, plus there's always a lot of exhaust gasses still left in the cylinder) So, of course a CC vs emissions is always going to favour the four stroke.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

so according to that chart:<br /><br />E Tec 50 13.44/17.11<br /><br />there are 2 listings for the 995CC merc ( I dont understand why)<br /><br />Merc 50 EFI 14.3/14.8<br />Merc 50 EFI 14.3/17.3

 

[butlp]

Re: WOW! new 4 stroke 50 merc

Wino,<br />1. You may have good dealer support in your area but I don't! All the old dealers were let go and the new ones seem to be dropping the line because its just too expensive compared with the other manufactures.<br />2. Don't know how you can say the e-tec 115 is proven as they are not even on the market yet and are different from the 90hp and the big motors.<br /><br />"If there is any Di 2-stroke engine having problems now it's the opti-pop."<br /><br />So what problems has the new 115 hp 3 cylinder Optimax had?<br /><br />I'm sure you're very happy with your new e-tec and feel that its the best thing since "sliced bread" but its not for everyone. Only time will tell if 3 years between servicing is acceptable and which of us made the right purchase.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

Yeppers Lost Canadian.<br /><br />There is another post here where the poor guy is still waiting on his E-Tec.<br /><br />They had to order my 50 merc, and it was installed within a week from the day I paid.<br /><br />Time will tell for sure, there are no dealers around here for anything but merc, and I think Tohatsu now ( recently)<br /><br />How much is a 50 E-TEC engine?

 

[pwiseman]

Re: WOW! new 4 stroke 50 merc

Originally posted by ozarkjeep:<br /> got the boat back from the rigger/sales shop.<br /><br />I am VERY impressed by this little engine.<br /><br />got the first 3 hours of breakin done yesterday ( fighting rain and cold wind).<br /><br />the engine starts instantly, with just the turn of a key, nothign else required.<br /><br />and it is so quiet at idle, that the cooling bypass water ( pisser) is LOUDER than the engine.<br /><br />now the big question, there are 12 more hours of more normal driving break in before getting all of the fluids changed. is there anything else I need to do or watch out for?<br /><br />Im loving it so far, I want to keep it that way!

I bought one in 2002. First year they had EFI. Just sold it yesterday, and believe me it was hard to do. This motor is strong, smooth, and dependable. Merc got this one right. I also found it to troll down very very well. about 1 mph. Had it on a Lund Explorer 1650. Wide Open with this motor is impressive. Like butter.

 

[ozarkjeep]

Re: WOW! new 4 stroke 50 merc

Originally posted by Paul Wiseman:<br />

I bought one in 2002. First year they had EFI. Just sold it yesterday, and believe me it was hard to do. This motor is strong, smooth, and dependable. Merc got this one right. I also found it to troll down very very well. about 1 mph. Had it on a Lund Explorer 1650. Wide Open with this motor is impressive. Like butter. [/QB][/quote]<br /><br /><br />Why did you sell it?, what were your annual service costs, and did you ever have ANY type of problems with it?<br /><br />How tough is the impeller install? the valve adjustment? the oil changes?<br /><br />thanks for your input!