4 Strokes

[Scream And Fly]

Will you ever accept them?

[BLACKBIRD]

makes it hard to figure why the continued r&d in 4 strokes?
Yes their quiet but the new DFI's the quietest that a 2 stroke has ever been. I can't fathom paying the repair bill on some of honda's new hy-tech auto motors much less an OB v-6 with multivalve,twin overheadcam, variableduration valve magnesim(for weight)motor with a supercharger!:confused: :eek:
makes an opti-max seem like a simple motor all over again:p

[Mark75H]

Magnesium is so far down on the dielectric scale its really hard to use on a boat at all much less on the motor. Aluminum boats use magnesium sacrificial anodes instead of zinc anodes. Thats why we don't see it already.

Maybe an integrated turbo, some of its housings cast into the block for compactness and weight reduction. Still, I agree, the Opti is starting to look simple

[BLACKBIRD]

Just don't know what would be lighter than alum.

[JW]

They are already superior kicker/pontoon/small fishing rig motors. They may never match a green two-stroke in the high performance area, but do we have a choice?

[Flat Out]

Saw it on Snowmobiler TV. It actually was impressive. Spun up to 10,000 RPMs in a blink. Looks like a motorcycle from the back with it's twin pipes.Be interesting to see how well it works once its had a season or two on it. I guess will have to get some snow first.

[Flat Out]

Saw it on Snowmobiler TV. It actually was impressive. Spun up to 10,000 RPMs in a blink. Looks like a motorcycle from the back with it's twin pipes.Be interesting to see how well it works once its had a season or two on it. I guess will have to get some snow first.It was interesting to see because this is one of the first performance applications of a 4s in place of a 2s. The sled suppose to weigh the same as a 2s. We'll see.

[Techno]

Titanium is better than aluminum but its price still has to come down. This isn't an arguement for or against since you can use it in a 2-stroke too.
You can use electrical breaks also and use anything you want, no flow no need for sacrifical anodes.

I think that the OB itself needs to be re-engineered. we're still using a heavy modular system that most of us don't need.
There is no reason the mid-section can't be the engine block. By sealing the engine and using sealed compartments the engine could be dropped down and the weight could be reduced.
This would eliminate the high located weight mass and the need to have shortened shafts, this could be done with the LU.
The norstar system, I think was developed for inaccessablility, do the same thing.

If the 4-cycle can make the power at the required weight I would use it. I will use anything that gets the job of the powerplant done.

[JR IN JAX]

As I look at the "crotch rocket" type motorcycles, I see 1000cc turning out 160 hp with a 250# integrated transmission powerplant. I think these also turn some high r.p.m. [around 10k]. I realize the power band is tight on these, but some type of tranmission might be practical.

The biggest problem that I can see is with this type of powerplant is that marine applications require high percentages of continious h.p.. This is what our aircraft engines are designed for [100% for 1 minute and 75% continious] @ 2,250 rpm. I regularly cruise my pmax at 80% [75 m.p.h] @ 5500, but would never consider holding any my cars' engines at 80% power more than 30 seconds.

thanks,
JR

[tlwjkw]

Has any body heard about the twin turbo inline six Merc has at THAT PLACE? TW

[Booger]

Honda just released a Turbo 4-Stroke PWC. The article I read said it was fairly light. Comparable or less than even some of the 2-Strokes.

Someday maybe they will develop a Transmission such as an ECVT that will be light. Something that would allow the high revving 4-Stroke (motorcycle style) to work as an outboard.

Sadly, once again the ugly issue of complexity rises.

Its also unlikely I will ever buy one anyway. I'm usually limited to buying old used crap and fixing it to fit my needs. The new stuff is Waaaaaaaaaaaaaaaay to spendy.


On another note-----Greg, since you started this post. Maybe I can catch you here. You haven't answered my e-mails.

My original login - laser - won't let me post. I'm changing my isp, therefore I had to change my e-mail. Now it won't let me post. :confused:

[laser]

Thanks for the quick action. Much appreciated. I was having major withdrawls. :D

Don't worry, I only voted once!

[fastbass9]

my main hangup is running it at the high rpms for an extended peroid. Sure it is one thing to say we wont, just like we dont run our cars flat out all of the time, but with no cops out on the water to slow us down, you better bet the throttle is going to be burried on a long run durring a bass tournament trying to keep up with someone running a 2-stroke. Me i might run a 18hp 4-stroke tohatsu on my small boat, only b/c they dont make the 2-stroke anymore. As for the big boat unless they do something drastic it will always be a 2-stroke. I know we should move forward with technology, like when everyone switched from casesetts to cd's. We did this because they were way better and therfore no longer used casesetts, b/c they are impratical. everything was much better with a cd no wating to rewind no fast forwarding past the song you wanted to hear, etc.... Back to outboards i just dont think the 4-stroke is the cd to the 2-stroke casette. Not there is anything bad with 2-strokes, i just think the epa is a bunch of whiners who are against all fun.

[sosmerc]

How many of us would prefer to have a 2 stroke in our cars and trucks?

[LaveyT]

I recieved a print from a foundry that we do machining for.
Its from Gil/Corsa,The part is an aluminum casting that is fabricated (welded) to other parts to make a twin engine bracket.
The title of the print is "F-225 fourstroke outboard twin engine bracket".I needed to call the engineer from Gil because of the poor quality of a faxed drawing to clarify some dimensions.While I had him on the phone I asked "what makes it a four stroke bracket?" "Oh nothing really,you could put two strokes on it."
You can read into this what you want,but that is where the industry thinks its going.I guess I will ask next time if maybe they
had to redesign the bracket to hold the weight of four strokes?
:rolleyes: