Am I wrong. All the 3.0litre Mercury OPTIMAX, Have more torque & acceleration than any of the newer 4strk's in the same size HP rating. Anyone have comparisons of the same boat with new 4strk. power. THANKS.
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Am I wrong. All the 3.0litre Mercury OPTIMAX, Have more torque & acceleration than any of the newer 4strk's in the same size HP rating. Anyone have comparisons of the same boat with new 4strk. power. THANKS.
Good question. Hope somebody can answer it. I've never heard anything negative about the "new" four-strokes. Can that be possible?
I think the 300R is faster and has better acceleration. That’s been discussed a bunch on the main board here.
From what I have heard, it's not a one size fits all answer. The four strokes have the torque advantage. But on the small lightweight boats the 2 strokes are faster. But on the bigger heavier boats the fourstrokes are faster. Setup is also a huge factor. Setups that work great on a 2 stroke works like **** on a fout stroke. And vice versa.
A 300R is 4.6L versus 3.2L for the 300XS Opti. Liter per liter (or dollar for dollar, or pound to pound) the 4-jokes aren't even close... a 4.6L Opti would easily be up 100hp on the 300R. (Plus cheaper, lighter, probably cleaner, etc.)Quote:
Originally Posted by David
I have not seen an instance where a (properly set up) 300R gets out run by any other 300 two stroke or 4 stroke unless they were modified or in a short drag spurt. We are discovering that you can really make a 300R run with some added compression and head work.
Joe
Still, a "modern" two-stroke of the same displacement built using state-of-the-art design and manufacturing would humiliate them.
Example: all the modern 2-stroke kart & motorcycle engines use a different style bearing cage with a dramtically better lifespan. Modern = increased durability.
Example: CNC porting noticeably improves tuneabily and output; along with durability.
Example: modern engine management systems adjust fuel & timing on individual cylinders... increasing output and reliability.
I just keep taking my vitamins and hoping I live long enough to see the next two-stroke Renaissance! :cheers:
Quote:
Originally Posted by David - WI
There aren't enough vitamins; who is going to jump into the marine performance market against Mercury and then try to incorporate 2 emission requirements into their product line? 2 stroke performance outboards have sailed into the sunset unless you are at the drag races, Champ boat races, or vintage races. We ran over 80 miles today at a cruise of 90 to 115. These things just roll along at 5700 providing 111 mph on the dash. Fuel is a non-issue with low consumption and 87 octane available everywhere along our path on the St. Johns river between DeLand and Jacksonville.
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Joe
I'm guessing it will be Mercury... the tide will turn back at some point; it has (to a limited extent) in snowmobiles, dirt bikes, and ATVs. Once you get past the "hype" people realize that four-strokes are not inherently cleaner, cheaper, lighter, more powerful, or more reliable than two-strokes built with equivalent technology.
Maybe not until the next economic downturn... but the worm will probably turn again.
how to put a 4stroke in a drag class?
Also, 1970's era RAVE-style variable exhaust ports would add another 100hp to the top end and 50 lb-ft to the bottom end.
All it would take to shift the product line back toward 2-strokes is a couple retirements and the right replacements... maybe a former Polaris or Bombardier exec gets hired to a key position?
Maybe a couple board members at Brunswick age out and are replaced by a snowmobiler and a dirt bike rider who see through the 4-stroke hype? :cheers:
The RAVE system was proposed on the initial launch of the 3.4L 300 motor but never made it to production. To my knowledge, the only motor that had the RAVE system was the 3 cylinder 115-150 just before BRP pulled the plug on Evinrude. It would be nice to know why this system never made it to production, on-paper seemed a good option.
Quote:
Originally Posted by JPEROG
They might work great for big boats like yours, but for us small (16'-21' ft) guys that don't want a huge, heavy apartment block hanging off the back, bring back the 2-strokes. Just as clean, just as fuel efficient, but most importantly, smaller and lighter.
There is some great data on Wildmans threads he has rigged them all new on same boats
That would be great to see efficient 2-strokes, but I hope without adding too many parts and complications for things to go wrong.
The four strokes don’t accelerate as quick as the two strokes in my experience but up top they work well. Plenty of 100mph plus boats but in the friendly drag races the two strokes are cleaning up. Even modded and tuned four strokes don’t accelerate like a stock 260 or 300 promax etc. at least not that I’ve seen
I had a 25 Liberator with twin 300XS opti and another with twin 300R 4 strokes. The 4 stroke boat was stronger in acceleration and top end. About 7mph on top. Acceleration was seat of the pants. No hard measurement.
Sounds like some of these guys should have supported Caldwells efforts to make a new two stroke. I never thought that I would be a four stroke fan after watching the results of boats rigged with a single 2.6 Inline 6. My old 300X motors modified and stock would outrun all of them on a performance level but they were definitely more user friendly (dock manners) then my set ups. Since the release of the 4.6, there is no looking back. We also have an STV with a 3.4 that runs very well (not going to compete with an X), but the advantages of efficiency, smoothness, warranty, noise level, smokeless, and reliability outweigh the upside of just pure performance. We are not typical lake boaters that run a mile or two at a time-we have 40 miles between stops and used to have to carry fuel cans in the boat (maybe I am just getting old).
Joe
That all makes sense, except that a "modern" two-stroke designed using state-of-the-art engine simulations, CNC machining, and advanced engine controls would be at least as efficient, smooth, reliable, quiet... and "clean" as any of the current four-strokes. Plus lighter, cheaper, and more powerful.
I think it will take a major disruption... recession, pandemic, terror attack, or maybe a war to force Mercury (or someone else) to lose enough revenue that they have to look at engines they can build and sell for less money without less performance.
I'm with you.. Trust me I am. I'm an Allison guy.. But the efficient and clean emissions DFI outboards are very close in weight to the 4 strokes and the reliability is not on par.. Sadly, for the DFI 2 strokes to meet those fuel efficiency and emission standards they have to be run extra lean, like on the edge of death.. Any tiny particle of dust that makes it into the fuel system ends in a melted piston.. The 4 strokes don't have that problem, if they have an injector problem they just present with a misfire, replace or clean the injector and your good instead of rebuilding a powerhead.Quote:
Originally Posted by David - WI
If I'm going to pay new outboard money for a 2 stroke it better be significantly lighter than its 4 stroke competition and just as reliable.. Otherwise what's the advantage? You can rebuild an old lightweight Carb or EFI 2 stroke for less than 1/4 the cost of a new 4 stroke and it'll be bad on gas but it'll be light, powerful and reliable. The new stuff is just Crazy expensive. I'm a peasant, it would be really hard for me to justify that.
We run far too. Usually 80 mile runs. I can go about 85-90 miles on 25 gallons at 80mph+. My rig is slow compared to most guys I run with everyone else is in the 100+ club. One guy runs a Daytona with a 400r that is now off for a 450R next year. I believe his hull is 23’ long. Anyways he uses more than double the fuel I do but it is a giant boat and lord knows what it weighs.
The only real metric I can measure any of this too is the sleds where a 300mile day is not uncommon and the two strokes and four strokes are almost identical in range and the two strokes outdo the four strokes in most areas of performance. Again those etec motors rule the day. Rarely blow up and sleds go through far more extreme conditions than boats do. I’ve left on a run early am at -22F and come home at dinner time at +55F. Less than twelve hours to see that temp change. The carb motors would be very doggy without a rejet at those temps changes and no one out ripping stops mid day to rejet so it was what it was. Etec performance barely changes and runs safe low octane fuel hardly uses oil and so on. Plus iirc brp said their etec outboards were cleaner than the four strokes on market did they not? So the emission nonsense is a non starter.
Where BRP blew it imo with boats is where they win with sleds. You would think they would know this but a 300lb 300hp two stroke outboard ready to race that would embarrass any 2.5 production motor would have been a hard pill for any of us Merc guys to swallow or argue against. Hopefully this in turn would have nudged Merc to counter. Merc blew it with the mechanical pressure system imo. Too much gack when a stout electric system would have been superior. The irony too being that Kiekhaefer was Mr lightning electric man originally. It would have been great to see Meecury engineer the finest two stroke electric hpf tech and dominate the performance world with over achieving underweight two stroke outboards.
I agree, the 850s are good on fuel, use hardly any oil, and don't smoke like 2 strokes of the recent past. We have both and I still find myself taking the XRS or Mach over the 850s. We have a couple 850 Turbo Rs and they have less then 500 miles on them (feel like riding a 125 motocross bike Vs. my 480 Beta). I just love the lengthy torque band the 4 stroke turbos offer.
Joe
The tuned sidewinders and t-cats are insane. The tuned 900ace turbos are pretty wild too. But a hot muscle triple two smoke from back in the day is still a beast. Fastest factory sled I’ve ever seen was a Mach z 1000. The ones with the electric problems but those things fly
We ran Hooper 1050s, and 1108s on the trail until 17' when everyone made the jump to the turbo 998s with Turbo Dynamics or Speedwerks. The two stroke triples from 89 to 94 Polaris, (mostly modified by Doug Flannery and Rob Shooping), then the cats up until 2017 gave us ton of thrills and I we are so blessed to have those memories and friendships made with them. They were very raw in comparison to what we play with today and the Gen 5 ski doo chassis is hard to beat. Hope to have a good year for snow as indications are predicting.
Joe
I just found out today that the inline Verado was only 2-star CARB rated... Opti & ETEC were 3-star. Crazy how Merc slipped that past all the boating magazines without having to pay anybody off. :icon_bs: