300r vs 300xs on same boat

[Noah Burns]

This may be the case in the Auto world but I don`t see many if any LS motors in offshore race boats or cruisers for that matter. Big blocks still have their place. If they ever develop a big block LS type motor then all bets are off.

The new GM big block is cathedral ported and coil per plug. It went the way of LS technology many years ago. Difference is, big blocks are/were already making such efficient power at every rpm range that the changes weren't as huge of a thing as they were in the LS small block element.

[Chaz]

BRP has a turbocharged 2 stroke sled designed to retain power at high elevations.

850cc @ 4lbs boost makes 165 HPs.
Thats 53 cu in’s fellars.

Or .85 of a liter, or .185 of a 4.6 liter V-8 4 stroke Merc.

So if we left boost at 4 lbs �� and multiplied that puny .85 of a liter X the 5.41 to equal the 4.6 liters of the Merc we’d be at 892.65 HP’s.

So while the new Merc is a way cool motor, it still ain’t a 2 stroke ��

Give a smart O/B guy (Dave Bush, Al Stoker etc) a yr @ BRP, unchained.

And yes, Chrysler and GM both were working on 2 strokes not long ago.
The down side, that I read, was w/the needed EPA crap made it big enough they couldn’t get the hood line as low as they wanted.

Hey G-man, stop using a lil math and common sense to make the 450R look like it's asleep ...
With size comes parasitic, thermal and efficiency, loses ... so the "super-sized" 850 might only make 860-870 ..
And yes the EPA thought they were going to go from Bobambi to Hildabeast, so they had their foot on everyone's throat, right up until POTUS Trump came in and said ... YOUR FIRED ! But by then, those who wanted to stay in buiz had already bowed to the Leftard bureaucrats and started building eco-friendly cream puff's. I gotta give Merc credit, they took the lemons and made lemonade. It's not cheap to drink it, they, like everyone else, had to spend a fortune just to keep the doors open, let alone come up with a better mouse trap. They might revisit the two-stroke, but as a pet project maybe. Too much at stake. Down the road, the tards will get back in and devise yet more ways and means to ruin our manufacturing capability. I can't think of anyone at that point, that would invest in anything other than wind-mills and cell-phone batteries ...

Bull seyz :

This may be the case in the Auto world but I don`t see many if any LS motors in offshore race boats or cruisers for that matter. Big blocks still have their place. If they ever develop a big block LS type motor then all bets are off.

Noah follows up :

The new GM big block is cathedral ported and coil per plug. It went the way of LS technology many years ago. Difference is, big blocks are/were already making such efficient power at every rpm range that the changes weren't as huge of a thing as they were in the LS small block element.

The LS guys I still do a little work here and there, for, actually prefer the iron block 6.0 or 6.2L based models. The GM aluminum is a bit .. ahh .. weak for any real power.
The real LS claim to fame is that they are throwaways. I reckon that's why most guys buy them out of a junkyard, gap the rings and put a chink-nees $99.95 hair dryer on it and go. 40 runs later, they do another one ..
Just like anything else .... guys with money will have one built from aftermarket parts.

Big blocks .. all iron ones with 4-bolt mains and square port heads, were missing from the junkyards about the time I graduated high school.
Between then and today, I bought a tall Bow-Tie iron block from a dealership to build a 598 inch motor. It went 7.30's / 180 for ...... years. Other than that, I didn't even know they build rat motors @ GM anymore ..
I would think that if you actually wanted a real one .. the aftermarket is the only place you'll find one that's "up to date".

Watch what this 959" motor does to "King Kong" when Lizzy plugs it in second and high ... LMAO

[engineermike]

BRP has a turbocharged 2 stroke sled designed to retain power at high elevations.

850cc @ 4lbs boost makes 165 HPs.
Thats 53 cu in’s fellars.

Or .85 of a liter, or .185 of a 4.6 liter V-8 4 stroke Merc.

So if we left boost at 4 lbs �� and multiplied that puny .85 of a liter X the 5.41 to equal the 4.6 liters of the Merc we’d be at 892.65 HP’s.

So while the new Merc is a way cool motor, it still ain’t a 2 stroke.

gsxr750 has no turbos and makes 148 hp. That’s 46 cu in’s and it’s a 4-stroke. Is it relevant? About as relevant as that snowmobile I would say.

[Z06man]

If there is a better outboard outboard out there I want to see it for sale . I have some cash left. Not quite CRT money though.

[Instigator]

I give Merc a ton of credit for doing what they did.

Not like the others turning their already engineered/paid for car moter on its head.
IMO, currently available, they are in a league if their own.

But better than a 2 stroke?? Come on.

Apply current, available technology to one and see what you have.

Of course the 4 strokes did dominate motocross.
250cc 4 strokes beat 125cc 2 strokes.
450cc 4 strokes beat 250cc 2 strokes.

But wait, how bout F-1 road racing motorcycles you say??

Correct.
They took leading edge technology 900 cc 4 strokes and beat 30 yr old designed 500cc 2 strokes.

Who would brag about that?

Sorry but I think I’ll sit back and watch.
Not like I’ve got $30K for a new motor anyhow ; )

[Instigator]

Point being that BRP figured out how to make a turbo work and live on a 2 stroke, w/a warranty when no one else has.

As a 2 stroke guy, I find that impressive and like what that may mean to the future.

gsxr750 has no turbos and makes 148 hp. That’s 46 cu in’s and it’s a 4-stroke. Is it relevant? About as relevant as that snowmobile I would say.

[WILDMAN]

I have checked fuel mileage the old fashioned way on 300R and 300XS and 300X by dividing miles by gallons after a fill up. On a 21 Liberator at 4000 RPM, 300xs got 6mpg, 300R got 5 mpg.
Running hard all day, the 300XS got 4mpg and the 300R got 3.3.
The 300X got 3mpg at 4000 and 2mpg running hard

On a twin 25 Liberator, the pair of 300XS at 3500 rpm got 3.7mpg and the 300R got 3.2mpg
Running hard, the 300XS motors got 2.4 and the 300R got 2mpg
300X's got 2.25 at 4000 and 1.5 running hard

Basically, the 300R uses about 15% more fuel than the 300XS.

[engineermike]

..Apply current, available technology to one and see what you have.

You're right about that. Imagine what a 4.6 v8 could do with GDI, 12/1 compression (still 87 octane enabled by the GDI), variable cam timing, variable intake manifold runners, and some knock sensors!

[HydroSkreamin]

Point being that BRP figured out how to make a turbo work and live on a 2 stroke, w/a warranty when no one else has.

As a 2 stroke guy, I find that impressive and like what that may mean to the future.

I’m impressed with the technology and results of the BRP sled too. It also has a $18,500 price tag, MORE than what the turbo’d 4-stroke sleds are. They also only released them to the mountain customers because they don’t want us flatlanders torture testing them and giving them a bad name.

IF BRP would ever cross-breed their technology between sleds/PWC’s/OB they’d have something for Merc performance-wise on the large OB market, but for now the 250 HO and the 300 ETEC are basically the same engine and struggle keeping up with most competitor engines (never ran a Suzuki, can’t speak for that). Maybe 2020 Miami International Boat Show will show us something...

If we want to have fun with math, Merc’s 2.6L 400R (current production/technology) is 158.5 CID (2.524 HP/cube) or 153 HP/L. If they’d apply that technology that they obviously already know how to produce, that would put the 4.6L at 707 HP. Contrary to belief, warranties must mean something to the core customers, otherwise you’d think Merc would be squeezing that new engine like a teenager squeezing a zit. Now think of how many hours a 300R can potentially run on 87 octane!

I’m guessing in the near future we’ll be looking for who has pistons, cams, Stroker kits, CNC programs for heads, and maybe even aftermarket heads. When the “next big thing” comes out you’ll see the prices come down. Until then, I’m going to enjoy watching guys like Wildman, JPerog, Z06Man and now Warren play with these things.

[AZMIDLYF]

Another 24 Skater, XS to R conversion that is getting dialed in.

[AZMIDLYF]

[Trimmed Out15]

Is anyone playing with the cowl on the 300R like they are on the 450R? If so does it make a difference like on the 450?

[powerabout]

Perhaps the lightweight 2 stroke will be the new 150 3 cyl brp and boosted to 200hp?

[Instigator]

Yep.

Reminds me of when the F-1 bikes went to 4 stroke.

The speed of advancement in technology was stunning.
Once rules changed, the tech in the 30 yr old 2 strokes stopped.
More importantly, they went from a race only motor to a modified consumer unit that they could win with Sunday and sell Monday.

W/the new Merc 8, they are doing similar.

Their not building 260’s, 280’s, 300X’s, 300XS’s that mainly only sell to go fast guys.
Look what these things are ending up on!

40’ Formulas!

Makes way more business sense.

Being the group OMC flag waver, I do have to point out OMC had a 3.6 liter V-8 on carburetors making 300 HP’s in 1985 ��

Perhaps the lightweight 2 stroke will be the new 150 3 cyl brp and boosted to 200hp?

[Chaz]

If technology from all sizes, shapes, forms or fashion don't interest you, then .. you're satisfied with where you're at. Not into improving your own game unless someone else does the hard part, and you follow. Or ( I don't understand it ) Ya have better things to do with you're time and energy. Any of which is OK, I reckon.

Wild .. thanks for the honest, accurate fuel numbers ...

X = ( or replica ) old school 2 stroke, easy to build, easy to fix, not much money for what you get. Horrendous gas mileage, socially unacceptable to the Smythe's, but the Smith and Jones still love em .. For those that worry about fuel mileage, buy a VW jetta or KIA ..

XS = an old gal with some make-up and a new dress. A little harder to work on. And so far, no real way to make any more power unless you throw away the "claim to fame" fuel system ..

R = Just what the Smythe's have been waitin for. Big loaffy NA four stroke. Miss the prop size or set-up. Load a half a dozen of your football player friends and go for a ride, plenty of cubic inches ( 100" more than a 3.0L * ) tends to hide all sins.
I was surprised to hear that it's behind the "eight ball" by 15% on the gas sipper.
But then, it takes fuel to feed sheer size and make power, no matter how efficiently it uses it.

* = 97.63 ci For my OCD friends ..

1000 ci big blocks = See R

850 cc turbo 2 pokes = Cool tech, lightweight, expensive, prob a little impractical in real life ...

GSXR = My kid loves em, fast on the road course. A good run on the showroom to the masses despite the uncomfortable riding position. When they thought they would make a few passes .. (to show the drag racers how it's done) .. Most found out unless they let Mike Brusso or Pee Wee Gleason ride it, they had no idea on how to hold the front end down, or keep it from falling off the 10,000 to 14,000 RPM powerband. None that I remember showed back up twice to finesse it down the incremental's .... That scoreboard makes it where even the man on the moon can see for himself, how good you are .. or aren't. Another, good, hi-tech, small inch, canyon carver for a targeted market.
However, a RGV500 or old school GS-1100 - 1150 it aint.

9.5 OMC flat top = Capt. Insane-O hate's to work on em. On a Jon boat, you can go in some skinny-azz water. Catch a lot of Snook, and thinkin back .. I can't think of another boat that I banged more ***** on, than that lil POS ...