I think it's fair to say that direct inject engines do not enter into the discussion. Following up on what Family Afair said; that's what probably kept 2-strokes in the market this long. But I'm still willing to bet the 225 OX66 makes more power than the F225. Are Grady performance curves available that test the same boat with these engines?
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Yami 4 stroke question
- Thread starter Surely Bassey
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family affair
Well-Known Member
Tucker, you are right. Di has kept 2 strokes alive primarily because of the significant reduction in emissions, but I wonder how much further they can go.
Were ox66's and F225's made at the same time? If so, Grady probably does have fuel and speed tests. Peak HP numbers on a 225 FI 2-stroke would be similar to a F225, but I would bet the 2-stroke makes better, broader torque. That said, both engines are great, it just depends on what your needs are.
Were ox66's and F225's made at the same time? If so, Grady probably does have fuel and speed tests. Peak HP numbers on a 225 FI 2-stroke would be similar to a F225, but I would bet the 2-stroke makes better, broader torque. That said, both engines are great, it just depends on what your needs are.
family affair said:How much more power does a fuel injected motor make than one with a carburator? ZERO!
For what the industry calls fuel injection, you are correct.
Direct injection however, you are 100% wrong. :sorry
FI systems usually run at about 90 psi. Gas DI systems on the otherhand run at several thousand PSI (diesels run over 25,000 psi!). Just like presurrized liquid refrigerant causes a significant temp drop when the liquid changes state and the pressure drops, the same happens with gasoline. This temp drop results in a dramatic drop in fuel/air charge temp allowing the engines to run much higher compression ratios resulting in significantly more power with the same displacement engine... not to mention usually lower emissons.
As for head to head comparisons, the method of comparing engines based solely on HP is a bit of a joke. HP and torque curves can vary dramaticlly from one engine to another, but the manufacturers only advertise a peak number. The average person has never experienced this unless they have driven or ridden a race engine. They typically make impressive peak numbers, but the low RPM performance is so poor that some won't even idle!
Are you talking two stroke DI or four stroke DI?
Tucker
GreatGrady Captain
Agreed, some rate at the powerhead, some at the prop, some with max HP when all conditions right (stars aligned?); only way to tell is real test on the water. Haven't seen that test yet...
family affair
Well-Known Member
jethro,
The comment was made that a 4-stroke will never have power similar to a 2-stroke. My point was that a DI 4-stroke could get close to or exceed the horsepower and torque of current DI 2 stroke outboards while having similar weight.
For example, Ford is already building a production DI 305hp 3.5 liter with ~270 ftlbs of torque that runs on regular unleaded for the Mustang... and that's just the initial offering. 350 hp and 300+ ftlbs of torque running midgrade gas is attainable with a 3.5 liter. Yamaha's 300 HDPI was around 3.5 liters if I'm not mistaken.
The comment was made that a 4-stroke will never have power similar to a 2-stroke. My point was that a DI 4-stroke could get close to or exceed the horsepower and torque of current DI 2 stroke outboards while having similar weight.
For example, Ford is already building a production DI 305hp 3.5 liter with ~270 ftlbs of torque that runs on regular unleaded for the Mustang... and that's just the initial offering. 350 hp and 300+ ftlbs of torque running midgrade gas is attainable with a 3.5 liter. Yamaha's 300 HDPI was around 3.5 liters if I'm not mistaken.
BobP
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Family Affair, refer to the lastest Yamaha catalog for the correct product line info.
http://www.yamaha-motor.com/outboard/pr ... /home.aspx
Modern 2 strokes can't be beat pound for pound, dollar for dollar, that's why Yamaha sells them. Traditional 2 strokes went by the wayside many years ago.
ETECS are same 3 star carb rating as any 4 stroke, and the venerable 200 HPDI as well as the VMAX lives on in spite of the usual 4 stroke marketing BS - some 12 years after introduction. How many more decades will it take ?
Turbos and superchargers are nothing new. Merc has been using very compact superchargers in their 4 strokes for many years now. How one is going to find room for a turbo in an outboard only heaven knows
http://www.yamaha-motor.com/outboard/pr ... /home.aspx
Modern 2 strokes can't be beat pound for pound, dollar for dollar, that's why Yamaha sells them. Traditional 2 strokes went by the wayside many years ago.
ETECS are same 3 star carb rating as any 4 stroke, and the venerable 200 HPDI as well as the VMAX lives on in spite of the usual 4 stroke marketing BS - some 12 years after introduction. How many more decades will it take ?
Turbos and superchargers are nothing new. Merc has been using very compact superchargers in their 4 strokes for many years now. How one is going to find room for a turbo in an outboard only heaven knows
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Tucker
GreatGrady Captain
family affair
Well-Known Member
How one is going to find room for a turbo in an outboard only heaven knows
Simple, the housings just get bigger!
Turbo diesel outboard. How much does this princess weigh!?! :shock:
http://www.megoutboard.com/index.php
Tucker
GreatGrady Captain
Yami S200 2-strokes carbed getting 1.4 MPG, 24GPH at 30-knots. Still looking for real life fuel burn specs for 200HP 4-strokes at same speed. I Still think the industry is beating the fuel economy thing to death to get the consumer to shell out the big bucks. Yea, they're a little more fuel efficent but not enough to justify what they cost. You can buy a lot of fuel and oil for what those big thumpers cost. I still don't see the sense in repowing if the old 2-smokes are still running good. I think some of us get caught up in the "latest is the greatest", just like cell phones. But that's just me...
Have to say I agree with Tucker. I was all set on new 150 4 strokes but after some research I kept 100lbs off the bracket saved $8500 of hard earned money by going with leftover 150 Carb models. They may not be cutting edge but if the last pair did 16 years on the boat and as I'm not running 50 miles offshore every time I go fishing they are actually better for my needs. $8500 is alot of gas.
Tucker
GreatGrady Captain
Adam, where are you finding left over 2-stroke carb motors? I've been looking and all I find is used, hours unknown.
Tucker
GreatGrady Captain
Didn't see anything on either web site. What do they have HPDI's? I've read posts on several forums by Yam techs that say the 200 HPDI is the best motor Yamaha ever made. That's obviously subjective.
I think they only have the 150 Carb models not the injection. Its still sold everywhere else in the world just not in the US now all the emission laws have been tightened up, Yamaha had some emission credits left so there were some imported last year. They are not really left overs just an old model. 150 HPDIs seem to be long gone but I think you can still buy 200HPDIs as a current motor. My mechanic always says if emissions werent a problem we would all still have 2 strokes. Wait till you see what a catalytic converter on an outboard does to hole shot and thats coming next.
BobP
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At the NY Boat Show a few weeks ago, the factory yamaha rep updated me on the saltwater product line changes.
The F200 & F225 are discontinued and ceased production.
The F250 I refer to now as F250 mechanical controls - lives on.
The V8 F300 is discontinued.
The new V6s are 225, 250, and 300 HP, that now I call electronic control.
I would say the mechanical F250 lives on since it has a cost advantage due to mechanical controls, over the electronic control new model. As well, the F250 is different in a few other design aspects that make it desirable and mechanical controls may to some be ultra reliable, the F200 discontinued for lack of popularity and overweight, and the F225 gone because of the way less than 225 tested HP and exhaust manifold related catastrophic powerhead failures blogged to death over at THT.
When I asked what Yamaha has to replace the F200 for 200 HP 4 stroke customers, the answer was 200 HPDI.
That last statment speaks it all, the 200 HPDI still can't be beat, outlasted an entire 4 stroke product line life.
The 200 HPDI remains in production. If not, Yamaha looses more business to ETEC.
4 stroke customers were abandoned by Yamaha several years ago in the 175HP range by failing to crank up the F150 introduction HP (as Suzie did), and now have done the same thing to those who desire 200HP 4 strokes or 200 x 2 on twins, i.e. the Gulfstream is limited to 400 HP max twin 4 strokes.
The F200 & F225 are discontinued and ceased production.
The F250 I refer to now as F250 mechanical controls - lives on.
The V8 F300 is discontinued.
The new V6s are 225, 250, and 300 HP, that now I call electronic control.
I would say the mechanical F250 lives on since it has a cost advantage due to mechanical controls, over the electronic control new model. As well, the F250 is different in a few other design aspects that make it desirable and mechanical controls may to some be ultra reliable, the F200 discontinued for lack of popularity and overweight, and the F225 gone because of the way less than 225 tested HP and exhaust manifold related catastrophic powerhead failures blogged to death over at THT.
When I asked what Yamaha has to replace the F200 for 200 HP 4 stroke customers, the answer was 200 HPDI.
That last statment speaks it all, the 200 HPDI still can't be beat, outlasted an entire 4 stroke product line life.
The 200 HPDI remains in production. If not, Yamaha looses more business to ETEC.
4 stroke customers were abandoned by Yamaha several years ago in the 175HP range by failing to crank up the F150 introduction HP (as Suzie did), and now have done the same thing to those who desire 200HP 4 strokes or 200 x 2 on twins, i.e. the Gulfstream is limited to 400 HP max twin 4 strokes.
DB
Well-Known Member
I think you are talking about Yamahas New V-Max Super High Output Four strokes...check them out at http://www.yamaha-motors.com :mrgreen: