Merc 280 and Drag with Optimax or high pressure direct efi injection ? Why not?

[espen]

Thats what we want isnt it ? Bolt on some 2.5L optimax parts and heads, bump up the air and fuelpressure to max ?
Sliding on and off exhaust valves in the back plate and we have 150hp low rpm fuel economy....and some extra top HP from a even bigger exhaust port. Would be a great xcat engine compared to the 15" 400hp Verado.
Please Merc :-)

[BoomerMuskoka]

Thats what we want isnt it ? Bolt on some 2.5L optimax parts and heads, bump up the air and fuelpressure to max ?
Sliding on and off exhaust valves in the back plate and we have 150hp low rpm fuel economy....and some extra top HP from a even bigger exhaust port. Would be a great xcat engine compared to the 15" 400hp Verado.
Please Merc :-)

im not firmiliar with direct injection , i dont think they can spin the high pressure pump high enough.... something like that, i hope someone chimes in to shed some light.

[espen]

Maybe a drag opti would need 2 air and fuel injectors for each cylinder ...
From this web page :http://www.webpages.uidaho.edu/niatt...751_N09-02.pdf

Two-stroke DI engines exist in the marine outboard industry where they have been shown to
have UHC+NOx emissions similar to four-stroke engines while having less CO emissions [20].
Although DI has been successful in the marine industry, many obstacles needed to be overcome
for a DI system to be successful in a snowmobile application. The main reason why DI systems
had not appeared on snowmobile engines until recently was their high-performance nature.
Snowmobile two-stroke engines operate at significantly higher engine speeds with greater fuel
demands. They operate at speeds in excess of 8000 rpm with specific power outputs of nearly
150 kW/liter, compared to marine engines with rated engine speeds around 6000 rpm and
specific power outputs of just 70 kW/liter. At peak loads, a short period of time (< 4 ms) exists
where a large amount of fuel must be injected and fully atomized without being short-circuited.
Large peak-load fuel requirements pose a challenge for low load and idle fuel requirements. This
challenge is only increased with the added fuel requirements of E85. This means that an injector
nozzle designed to deliver high quantities of fuel quickly usually has poor light-load and idle
fuel-spray qualities [20]. A two-stroke DI running on E85, at full power can use in excess of 55
kg/hr of fuel while at idle only needs 0.5 kg/hr, leading to the difficult task of designing a
precision nozzle capable delivering high flow rates and precise fuel metering.

[powerabout]

Brp etec injectors can do 10k ( later versions)
several model skidoos run to 8500
Im sure orbital engines in OZ can tell you what the air blown injectors are capable of

[BoomerMuskoka]

Maybe a drag opti would need 2 air and fuel injectors for each cylinder ...
From this web page :http://www.webpages.uidaho.edu/niatt...751_N09-02.pdf

Two-stroke DI engines exist in the marine outboard industry where they have been shown to
have UHC+NOx emissions similar to four-stroke engines while having less CO emissions [20].
Although DI has been successful in the marine industry, many obstacles needed to be overcome
for a DI system to be successful in a snowmobile application. The main reason why DI systems
had not appeared on snowmobile engines until recently was their high-performance nature.
Snowmobile two-stroke engines operate at significantly higher engine speeds with greater fuel
demands. They operate at speeds in excess of 8000 rpm with specific power outputs of nearly
150 kW/liter, compared to marine engines with rated engine speeds around 6000 rpm and
specific power outputs of just 70 kW/liter. At peak loads, a short period of time (< 4 ms) exists
where a large amount of fuel must be injected and fully atomized without being short-circuited.
Large peak-load fuel requirements pose a challenge for low load and idle fuel requirements. This
challenge is only increased with the added fuel requirements of E85. This means that an injector
nozzle designed to deliver high quantities of fuel quickly usually has poor light-load and idle
fuel-spray qualities [20]. A two-stroke DI running on E85, at full power can use in excess of 55
kg/hr of fuel while at idle only needs 0.5 kg/hr, leading to the difficult task of designing a
precision nozzle capable delivering high flow rates and precise fuel metering.

thank you for posting, i am very interested in this sort of thing.

[espen]

The easy route looks like the BRP ETEC injectors with a head made like in the link text above. But Merc is never going to use a BRP solution ? The Yamaha HPDI is not used anymore but some in the sled community is begging for it to appear.
A new developed air injector for our purpose is probably to costly for the small series, even if BRP has shown how much more reliable the injector got when it was made to perform wider outside the used envelope.
In the text above they clams snow mobile engines has 150kw pr liter thats 201hp each litre and that is times 2,5L = 502hp
That could be something to really get the blood running in the scream and fly community :-).
We would get the same reliability increase in the 280-320-"502" hp as the other models going to DI , no gasoline diluted lubricant. I guess the reliability increase will be even more in the high rpm engine. And the engines ability to run stratified charge says is less prone to detonations if there of any reason gets less fuel. This added reliability can be used to make more hp !
I want you all to be with me and reason on this ides and I will send the link of the discussion if we find some good solutions to Mercury High performance.
Its time to get out of the everything was better before hiperf depression and benefit from the new developments. We all love our light weight 2 strokes and the 2.5l powerhead is so compact and light and slowly modifyed for so many years its stupid to trow it away.

[HydroSkreamin]

You guys are on the right track here, but remember, in the good ol' US of A, engines have to meet emissions requirements, and that is becoming increasingly hard to do with ANY 2-stroke.

What do you think the 2.5XS was? What do you think the 200XS ROS and 200XS Drag are? Have you checked the price of these? What are you willing to pay for an Opti with 2 fuel systems on it? What do you think Merc would charge? How many 200XS's do you think they make a year? Why are they race only? If you answer all of these questions, the business picture for Merc to do a hi specific output engine with or without a warranty gets pretty blurry. I don't like it either.

Sounds like as long as the long arm of the law can't reach you, the door is open for entrepreneurs to do one-off stuff. Don't expect any manufacturer to pay attention to our <1%'ers needs, they are too busy trying to figure out how to lighten 4-strokes!

[espen]

Powerabout :-) good suggestions ! Maybe you can send an email to Orbital and ask them , even suggest they contribute to our discussion.
Mercury should go the "Verado" route...grab a retired Rotax engineer morph the rotax cylinders and exhaust valves onto the same 2.5 block.
Make Orbital make a better air injector that copes with the rpm, a thick magnetic shaft on the titanium air valve and stronger magnet and thats it , or maybe it works already with some peak and hold boost up to 24v in the opening and ramp down to hold it open.
Merc need Xcat UAE support to make this happen and the F1 croud to.
OHMG I can already see the 2.5L 500hp sticker on the cowling on a STV River rocket :-) LOL A 4 cyl version of the 500hp would be 333hp a 3 cylinder version would give 250hp...the 3 cyl engine could share the same fronthalf and same crank as the 2.5, just with a strange looking connection rod using 2 bearings.Or 2 full lightweight connection rods and a piston with centre bearing support , this way the piston can be made lighter and dome of piston stronger and cooled better.

2016 .Santa, I also want carbonfiber midsection and the stainless steel lowerunit with carbon cavitation plate.
:-) Please dream a little with me , let the gurus come up with some cool idees !

[espen]

HydroSkreamin, good chain of toughts. I had no idee a 200xs Drag exists is it same as 2.5xs 240ish hp? Maybe it has to be a powerhead only project for the race community, then the emission problem is solved, compared to the existing, 280. It would be a new era in less pollution. Even if it will be in the borderline of emission.
I would guess the oil consumption is the problem , but if the oil could be changed into acceptable food for plankton ?
Why bother try make a light weight 4 stroke when the 2 stroke is already here? :-) I have seen they are testing a verado 400hp 15" substitute for the 280 hp in the xcat series. I just dont belive in a long straight 6cyl crankshaft for compact light weight and headgasket problems in this long head. Its a impressive engine but I guess it will never weight like a 280 ros like most boats in this community needs , and the boats are so fine tuned to the weight and therefore sensitive and can get dangerous.
Its like the development from straight 6 two stroke to the V6 two stroke.
3 cylinder 4 stroke compressor engines for jet skis are putting out impressive numbers maybe thats the 280HP substitute future ? The 280 is still high priced, here in Norway with 10,32 USD a gallon running 2x260s or 2x280s pluss all the oil is just to expensive .
Who wants to pay top dollar for a 240HP when you used to have 280HP ? I think the enthusiasm needs to be kept alive for Mercury to keep its position.

[PanRonnie]

http://www.f1h2o.com/news/articles.php?idnews=612

DTA

[powerabout]

4 valve engine that does 10500rpm?
I cant imagine it can pull the skin off a rice puddin without 10 gears

[1BadAction]

You guys should start engineering for merc, since you seem to know way more about DFI engines than they do. lmao.

[TEXAS20225]

Its cold over there in Icicle land Jim lots of free time

[espen]

Amazing videos PanRonnie :-) maybe 4 stroke can be some fun ...1BadAction cant you play the "we are the Mercury high performance engineers" game with us ? Its allowed to dream a little is it ? I know you have some good ides how a low fuel consumption light weight 280-300hp could be made. If it was to the Merc engineers we would probably have everything fun we could imagine, just to bad the money guys do the decisions ?

[Umassot50]

nice pipe dream. the only reason snowmobile engines can achieve that high specific power output is that they have a CVT clutch. they only need to operate in a 3000 rpm band or so. they dont have to pull a load from idle to peak rpm. a boat engine does. snowmobile engines also have tuned expansion pipe exhausts which increase power 50-100% or so. your power figures will not scale up to your v6. its complete nonsense. specific power does not grow linearly with displacement. displacement grows with the square of the bore (exponentially). port wall area is linear. not to mention the architecture of an outboard block only lends its self to really ****ty port ducts. you will be lucky to get a PR rep to reply to you from orbital. neither firm is going to have their engineers wasting their time reading this. sorry thats the truth.