The case for tuned 4 cylinder 4 strokes

[WavetoWave]

Is there a market for 450 pound 200+ HP outboards? Four strokes would have to be based on the popular 4 cylinder platforms. They are inexpensive, reliable and capable of making the power.

Take a look at the article. What do you think?

https://www.wavetowave.com/home/2018/9/13/are-four-stroke-outboards-good-for-tuning-the-case-for-the-4-cylinder


http://i64.tinypic.com/2me761c.jpg

[home made tunnel]

I'll slap a turbo on my 115 pro xs and let you know . . . But I'm all for it! Upgraded cam shafts, more power, only 360lbs..

[David]

Based on the market for the 200XS, I'd say no. Used 200XS engines don't fly off the shelves, or the SnF buy and sell forum. Admittedly the 200XS was stupid expensive new - more than a 300XS

Sub 20' performance boats are getting pretty rare. Too rare for the OEMs don't support and I'm not optimistic about the aftermarket. That's why I wound up with 2 new engines this year. Bass boats keep getting bigger. I used to joke with my wife that the fish got faster every year as bass boats got faster. Now the fish get bigger every year.

I hope I'm wrong.

[Radiant]

Mercury could’ve slapped on a new DOHC Head on that 3.0 and probably gotten to 200hp. Yamaha makes 200 from 4 cylinders and it is known as one of the weakest 200s on the market. Mercury was smart to move to a lightweight V6 platform.

But i do know on a lot of these light boats, Weight is key. Personally I would love to see the V6 merc in a 250r version. High revving, lighter than an old 250 optimax, but you’d probably sacrifice a little torque.

The problem is theres just not a huge market for this. Now, if a company came out with some parts for the 4 cylinder or v6 to make some serious power, I would be interested

[powerabout]

brp 60 degree 2.7 needs to be a 200hp, stops at 175 for some reason?

[WavetoWave]

brp 60 degree 2.7 needs to be a 200hp, stops at 175 for some reason?

The G2 2.7 comes as a 200, and without the Integrated steering is about 495 Lbs. Not a bad engine.

[WavetoWave]

Based on the market for the 200XS, I'd say no. Used 200XS engines don't fly off the shelves, or the SnF buy and sell forum. Admittedly the 200XS was stupid expensive new - more than a 300XS

Sub 20' performance boats are getting pretty rare. Too rare for the OEMs don't support and I'm not optimistic about the aftermarket. That's why I wound up with 2 new engines this year. Bass boats keep getting bigger. I used to joke with my wife that the fish got faster every year as bass boats got faster. Now the fish get bigger every year.

I hope I'm wrong.

I definitely see your point Dave. I think the affordability of the 4 cylinders is appealing, and although they will never be monsters, 200 or 225 on most light boats is adequate. There seems to be demand, but nothing available.

[powerabout]

The G2 2.7 comes as a 200, and without the Integrated steering is about 495 Lbs. Not a bad engine.

I mean the eagle based engines now at 150hp 2.6 ltr 419lbs

[WavetoWave]

Mercury could’ve slapped on a new DOHC Head on that 3.0 and probably gotten to 200hp. Yamaha makes 200 from 4 cylinders and it is known as one of the weakest 200s on the market. Mercury was smart to move to a lightweight V6 platform.

But i do know on a lot of these light boats, Weight is key. Personally I would love to see the V6 merc in a 250r version. High revving, lighter than an old 250 optimax, but you’d probably sacrifice a little torque.

The problem is theres just not a huge market for this. Now, if a company came out with some parts for the 4 cylinder or v6 to make some serious power, I would be interested

Totally agree with you on the 225, that was a missed opportunity, appeals to a wide range of boats. The V8 is just too heavy for most.

Stay tuned, we have a couple projects looking at this!

[WavetoWave]

I mean the eagle based engines now at 150hp 2.6 ltr 419lbs

Oh right, ya they used to make a 200 version. Phasing those 2.6s out. If that G2 was just 30 Lbs lighter, it would be no contest in that HP range.

[nitro_rat]

The problem for us poor folks is that it just costs too much money for a boat manufacturer to build a small/affordable boat. It doesn't cost much more in material and labor to build a 24' (+) monster than it does to build a 17' rig. The big one sells for a whole lot more so the profit margins are better. As long as there are guys standing in line to buy the big boats (and banks willing to finance them) we don't stand a chance!

[powerabout]

The problem for us poor folks is that it just costs too much money for a boat manufacturer to build a small/affordable boat. It doesn't cost much more in material and labor to build a 24' (+) monster than it does to build a 17' rig. The big one sells for a whole lot more so the profit margins are better. As long as there are guys standing in line to buy the big boats (and banks willing to finance them) we don't stand a chance!

All the small boats should be built in china and shipped ovrr

[WavetoWave]

The problem for us poor folks is that it just costs too much money for a boat manufacturer to build a small/affordable boat. It doesn't cost much more in material and labor to build a 24' (+) monster than it does to build a 17' rig. The big one sells for a whole lot more so the profit margins are better. As long as there are guys standing in line to buy the big boats (and banks willing to finance them) we don't stand a chance!

In general it is true, but the repower market is huge, and these 4 cyl 4 strokes are relatively affordable new, plus there are tons on the used market. You're right about the really small boats, but 18-22 is a really nice size range, that can be reasonably priced.

[XstreamVking]

All the small boats should be built in china and shipped ovrr

Bad idea! If you thought the Hydrostreams were built shoddy, wait until you see what the chimeese would ship over. PURE JUNK.....

[WavetoWave]

Bad idea! If you thought the Hydrostreams were built shoddy, wait until you see what the chimeese would ship over. PURE JUNK.....

I think he was joking. Or I hope he was!

[home made tunnel]

All the small boats should be built in china and shipped ovrr

Then we might have guys like "Tunnels", who was banned, building the boats.

In other news, the Honda 150hp outboard is built on the K24 Honda motor in the accords, civics, etc. The tuner guys were getting 300 naturally aspirated horsepower out of those K24 engines... That could be moved over to the outboard world.

[WavetoWave]

Then we might have guys like "Tunnels", who was banned, building the boats.

In other news, the Honda 150hp outboard is built on the K24 Honda motor in the accords, civics, etc. The tuner guys were getting 300 naturally aspirated horsepower out of those K24 engines... That could be moved over to the outboard world.

I talk about that in the article. It's happening as we speak.

http://i63.tinypic.com/nb9mop.png

[Radiant]

Keep us updated on that. I saw that on your Instagram page I think

[nitro_rat]

There are snall chinese built boats available by the container load listed online. Probably pure junk like the scooters and atv's that are for sale at sketchy roadside shops everywhere!

[XstreamVking]

300 hp out of a 150 hp designed gear case is gonna blow up at the worst time.

[90VIPER]

Will a 3.0 sporty bolt up to a 150 merc fourstroke? The gear cases look very similar.

[Radiant]

Will a 3.0 sporty bolt up to a 150 merc fourstroke? The gear cases look very similar.

Probably not without an adapter plate. I’m sure it’s an easier swap than let’s say a sporty on any other manufacturer

[powerabout]

I talk about that in the article. It's happening as we speak.

http://i63.tinypic.com/nb9mop.png
Is it a v-tec?
Just wondered will it have enough torque left to get on the plane?

[WavetoWave]

300 hp out of a 150 hp designed gear case is gonna blow up at the worst time.

Gearcase won't be stock.

[WavetoWave]

Will a 3.0 sporty bolt up to a 150 merc fourstroke? The gear cases look very similar.

The 150 Pro uses the 4.88" from the Verado. So the taller gear Verado cases are probably compatible, not sure how adaptable the SM is.

[powerabout]

Honda enters the performance boat market???

[rude tim]

418276418277

This bad boy makes almost 900hp to the rear wheels on gas! It is the worlds fastest Honda. It made a one way pass at Bonneville with an exit speed of 311.472mph in the Ferguson streamliner.

[powerabout]

BMW a long way in front of that years ago..
https://en.wikipedia.org/wiki/BMW_M12

[DangerNewb]

Mercury was smart to move to a lightweight V6 platform.

But i do know on a lot of these light boats, Weight is key. Personally I would love to see the V6 merc in a 250r version. High revving, lighter than an old 250 optimax, but you’d probably sacrifice a little torque.

I'd be surprised if Merc doesn't offer the V-6 in a high performance package with 250 or more HP in the next couple of years. Crazy expensive but for those who can afford one it would probably be a great motor.

[wtsjr66]

Hope no one actually wants a 150 hp ProXS, I have had one on order through a local dealer since late February. Has anyone actually taken delivery of one of these engines?

[loop]

probably a dumb question but are any of the 4 strokes pushrod motors and if not,why?

[blacktruck]

probably a dumb question but are any of the 4 strokes pushrod motors and if not,why?

All the 4 cylinder ones mentioned are double overhead cam, except the merc is single overhead.

[blacktruck]

Hope no one actually wants a 150 hp ProXS, I have had one on order through a local dealer since late February. Has anyone actually taken delivery of one of these engines?

So it's backlogged as well? I thought since it was just a tuned 150, it would be available right away?? Unless it's just sold out. But I haven't seen any real reports on it yet so maybe it's delayed for some reason.

[loop]

All the 4 cylinder ones mentioned are double overhead cam, except the merc is single overhead.

Thats what I thought andl to the best of my knowledge all the 6cy motors are too. Just wondering why they wouldnt try a simpler, lighter weight, lower maintenance and more compact push rod motor.

[David]

Is the 150XS a 4 valve engine?

its easier to do a crossflow canted valve head with overhead cams then pushrods, and easier to do a 4 valve head. I suspect the cam ramps can be steeper. But GM is still working magic with pushrods.

[powerabout]

Thats what I thought andl to the best of my knowledge all the 6cy motors are too. Just wondering why they wouldnt try a simpler, lighter weight, lower maintenance and more compact push rod motor.
ls3 standing on its end....

[blacktruck]

Thats what I thought andl to the best of my knowledge all the 6cy motors are too. Just wondering why they wouldnt try a simpler, lighter weight, lower maintenance and more compact push rod motor.

I think the advantage of the OHC is the efficiency and longevity, plus they aren't necessarily heavier. The SOHC design from Merc is smart for simplicity, SOHC can provide plenty of torque. The DOHC, can are really efficient and rev really high.

[loop]

ls3 standing on its end....

exactly
even half of one would make a strong light durable motor

[blacktruck]

Is the 150XS a 4 valve engine?

its easier to do a crossflow canted valve head with overhead cams then pushrods, and easier to do a 4 valve head. I suspect the cam ramps can be steeper. But GM is still working magic with pushrods.

No, it's a 2 valve. It won't ever rev like the Yamaha, or Honda, but can make decent power. The 3.0 150 4S Merc is pretty bulletproof.

[FMP]

Had a 115proxs out for a spin, Lund 18. I just kept waiting for something to happen. Smooth yes but not anywhere near what I expected for performance. Stupid four blade prop, set up by dealer, wouldn't turn 5201. Maybe 29hrs on it, needs to back for diagnostic check, no snot in it at all. Etec 115ho would eat it.

[powerabout]

Had a 115proxs out for a spin, Lund 18. I just kept waiting for something to happen. Smooth yes but not anywhere near what I expected for performance. Stupid four blade prop, set up by dealer, wouldn't turn 5201. Maybe 29hrs on it, needs to back for diagnostic check, no snot in it at all. Etec 115ho would eat it.
thats why we buy 2 strokes

[FMP]

Was looking for a comparison video etc for the 115proxs vs 115ho Etec , can't find anything?

[wtsjr66]

Don't know what the problem is, but like I said been waiting over six months with no firm delivery date in sight!!

[blacktruck]

Don't know what the problem is, but like I said been waiting over six months with no firm delivery date in sight!!

That's crazy. You'd think there would be an update. I haven't even seen OE pics of one in the wild yet, or performance tests.

[powerabout]

I wonder if half a ls3 would have a better torque curve than a Merc 150 4?
How about a 3.0ltr 140MCM engine in aluminum with a better head??

[home made tunnel]

A full LS3 is called a seven marine lol

[blacktruck]

A full LS3 is called a seven marine lol

Haha, true. And the Seven 527 is about 1100 Lbs. They look amazing, I love the design.

Lightweight 4 cyl 4 strokes that are tuned to rev and make more power, makes sense to me.

[powerabout]

Haha, true. And the Seven 527 is about 1100 Lbs. They look amazing, I love the design.

Lightweight 4 cyl 4 strokes that are tuned to rev and make more power, makes sense to me.
but they dont do they, 150 Merc outboard not much better than 40 yr old iron duke 3.0 4 cyl in the HP race?
Makes less power per ci than a Mercrusier 6.2 if you want something a bit more modern
They might be a great engine but not because they are 150 hp for 3.0ltr

[blacktruck]

but they dont do they, 150 Merc outboard not much better than 40 yr old iron duke 3.0 4 cyl in the HP race?
Makes less power per ci than a Mercrusier 6.2 if you want something a bit more modern
They might be a great engine but not because they are 150 hp for 3.0ltr

Agreed. But The Pro version is a start, makes 163 HP. The gears are awful. But I think for tuning, the idea that 4 cyl 4 strokes are affordable, reliable, lighter than the big V6s, and can make decent power is a plus. Not perfect, but for repowering, they are good if there were some bolt on goodies.

[Rynobull]

A 400r is 2.6L. It is what 667 pounds as a 20 inch motor.
The tech is there to make a reliable 3 cylinder 200hp or 4 cylinder 275hp lightweight, high revving motor. I bet they could be low to mid 400 pounds with a short mid.

The problem is there just isn't enough market for them. They sell the 400r's by the 2,3,or 4 at a time for the big boats. It just doesn't add up when selling them 1 at a time to a smaller market unfortunately.

However it would be sweet to have a 430 pound, 200hp, 3 cylinder that spun 7grand or better stock, with a warranty!

[blacktruck]

A 400r is 2.6L. It is what 667 pounds as a 20 inch motor.
The tech is there to make a reliable 3 cylinder 200hp or 4 cylinder 275hp lightweight, high revving motor. I bet they could be low to mid 400 pounds with a short mid.

The problem is there just isn't enough market for them. They sell the 400r's by the 2,3,or 4 at a time for the big boats. It just doesn't add up when selling them 1 at a time to a smaller market unfortunately.

However it would be sweet to have a 430 pound, 200hp, 3 cylinder that spun 7grand or better stock, with a warranty!

The market is huge actually, because it encompasses bass, flats and performance. Basically, the current 150/175 engines like the ProXS and SHO are basically just decals on basic engines. They are slightly tuned, usually just the ECU. But if you had solid mounts, and an optional gearcase, the higher performance bass, flats, and repower boats would be first in line for that engine. I understand Merc Racing is focused on the Big sterndrives, and the 250 to 400 outboards, but the 150 to 200 market is huge.

[Rynobull]

I won't deny that it is a large portion of the market, BUT in mother Merc's eyes.... it's a tiny part of overall sales and I don't think they will out the r and d into it without seeing more $$$$

I would love a 200R for a hydrostream resto project!!

[blacktruck]

Would love to see the new V6 on a weight scale. Has anyone weighed it? I have a funny feeling it weighs more than advertised.

[Rynobull]

Would love to see the new V6 on a weight scale. Has anyone weighed it? I have a funny feeling it weighs more than advertised.


I haven't kept up with the v6s, but the v8 300r is 515 pounds dry correct?

[gotboostedvr6]

Add a lower and fluids and it's more like 575 to 600

[WavetoWave]

The Honda BF150 K24 I am doing with 4Piston will be about 250 HP at the prop. We will try to get it to 460 to 470 Lbs.

[wettek]

Add a lower and fluids and it's more like 575 to 600

The dry weight doesn't include lower unit? Seems crazy.

[blacktruck]

The dry weight doesn't include lower unit? Seems crazy.

It technically does, but there seems to be some discrepancy between advertised weight and real world weight, by about 35 lbs.

Being in the 450 range over 200 HP is getting decent power to weight.

A Rotax 1630 in the Sea Doo is a 3 cyl 4 stroke makes 300 HP.super light.

[Rynobull]

It technically does, but there seems to be some discrepancy between advertised weight and real world weight, by about 35 lbs.

Being in the 450 range over 200 HP is getting decent power to weight.

A Rotax 1630 in the Sea Doo is a 3 cyl 4 stroke makes 300 HP.super light.



Now that rotax 1630 would be badass in outboard form. Dare I say sub 450 pounds??

[gotboostedvr6]

The Honda BF150 K24 I am doing with 4Piston will be about 250 HP at the prop. We will try to get it to 460 to 470 Lbs.

I had a built K24 in my 1999 Civic hatch. 260 whp

It had very little torque under 4000 rpm.

[powerabout]

A whipper snipper sounds better than a 4cyl 4s

[gotboostedvr6]

There were precious few cars that could take my little weed wacker hatchback from a roll.

[WavetoWave]

I had a built K24 in my 1999 Civic hatch. 260 whp

It had very little torque under 4000 rpm.


This one is being built with that in mind, plus quite a bit more power overall than that. Should have plenty.

[Markus]

probably a dumb question but are any of the 4 strokes pushrod motors and if not,why?

Because we are in 2018.

[loop]

Because we are in 2018.
Is that really your best answer? Educate me on why it wouldnt work.
dont get me wrong i am a huge fan of OHC motors. Especially a pneumatic valve 19,000 RPM F1 motor. I know a pushrod motor wouldnt be suitable for that but why wouldnt it work for a 6000rpm, 200hp 4 cylinder? Thats a 4 stroke i would consider buying. lightweight,simple,compact,durable

[home made tunnel]

GM is the master of pushrod motors with their 4.8L, 5.3L, 6.0L, 6.2L, .... well we can just say all their V8's. Even the ZR1 is still a pushrod motor.

I'd love to see some home-tuning software come out for the 4-strokes, as the auto market has EFI Live, and other programs like that.


BY THE WAY - Anyone know of another lower unit that bolts to the 115 Pro XS?

[FMP]

Is the housing not different between the 2.07 and the other?

[FORBESAUTO]

If I had to guess why no push rod motors, it would be for emissions. You have so much more ability to control emissions and still yet make gobs of power with a wider power curve with variable dual overhead cam timing where you can control exhaust and intake cam timing independently of each other allowing you to control valve overlap. Another bonus is this time of system allows you to totally eliminate the EGR system for controling NOX emissions

[home made tunnel]

If I had to guess why no push rod motors, it would be for emissions. You have so much more ability to control emissions and still yet make gobs of power with a wider power curve with variable dual overhead cam timing where you can control exhaust and intake cam timing independently of each other allowing you to control valve overlap. Another bonus is this time of system allows you to totally eliminate the EGR system for controling NOX emissions

You know pushrod motors have variable valve timing also? My 2011 chevy Colorado with the 5.3L V8 has the variable valve timing. Some motors had the option of DOD (Displacement on Demand) which would shut 4 cylinders off and sip fuel. Unfortunately, they gave that option to the full-size trucks, and not my little Colorado (where it could have gotten 30mpg).

[FORBESAUTO]

You are correct, but with one cam you’re only advancing and retarding valve timing and not able to change overlap. Being able to change the overlap is where the advantage is.

[nitro_rat]

Is that really your best answer? Educate me on why it wouldnt work.
dont get me wrong i am a huge fan of OHC motors. Especially a pneumatic valve 19,000 RPM F1 motor. I know a pushrod motor wouldnt be suitable for that but why wouldnt it work for a 6000rpm, 200hp 4 cylinder? Thats a 4 stroke i would consider buying. lightweight,simple,compact,durable

A pushrod motor would work, but why? Pushrods are just an extra level of complexity. In a 8v 4 cylinder there are at least 16 moving parts eliminated by going OHC (pushrods and lifters). Once you go OHC, an 8v and 16v engine can share a common block. VVT is simpler, cam timing adjustments are simpler, everything is simpler when you don't have to worry about pushrods! It's all about being able to share common parts across a wide HP range of engines, lowering production costs, etc.

As Bunky Knudson (or some GM exec) said, "parts left out cause no problems and cost no money!"

[loop]

If I had to guess why no push rod motors, it would be for emissions. You have so much more ability to control emissions and still yet make gobs of power with a wider power curve with variable dual overhead cam timing where you can control exhaust and intake cam timing independently of each other allowing you to control valve overlap. Another bonus is this time of system allows you to totally eliminate the EGR system for controling NOX emissions
I dont doubt the advantages of variable valve timing and how its easier to do with OHC but its a system that adds complexity,weight,and costs. EGR valves have been on motors since the 1970's. Simple,inexpensive and effective.
Chevrolet and Dodge both are proving pushrod motors to be just as efficient and powerful as their OHC competitors. I guess they havent heard its 2018...

[FORBESAUTO]

Emissions get more and more strict each year. A push rod design can only do so much and requires more pollution devices to be added to it to try and clean it up. The DOHC with variable valve timing is able to run so much cleaner without the added pollution devices. If a manufacturer is gonna spend all this time and money in R&D, why invest it in something that’s gonna get faded out because unable to meet emission requirements 5 years down the road?

[Markus]

Is that really your best answer? Educate me on why it wouldnt work.
dont get me wrong i am a huge fan of OHC motors. Especially a pneumatic valve 19,000 RPM F1 motor. I know a pushrod motor wouldnt be suitable for that but why wouldnt it work for a 6000rpm, 200hp 4 cylinder? Thats a 4 stroke i would consider buying. lightweight,simple,compact,durable

That was a serious answer. It is not that it wouldn't work, but it would not be worth the trouble to make it work.

You don't see any clean sheet designs of pushrod engine/car combos, and very few clean sheet designs of pushrod engines. Where do you see new push rod engine designs is where they are needed for legacy packaging reasons, i.e. they are supposed to fit where another pushrod engine used to sit, i.e. at GM. There are no such packaging restrictions inside the cowling of an outboard engine.

The 7 Marine has a max rpm of 6000, which is on the low side for an outboard application. If you want to run an engine at a sustained 6000-7000 rpm, you won't go with push rods if you have a choice. Now, you can make a pushrod engine rev high, but then it gets expensive to lighten the valve train.

[WavetoWave]

Block is sleeved, large bore piston from Wiseco, Saenz connecting rods. Custom ECU by Motec. Custom 4Piston cylinder head for this application.

http://i65.tinypic.com/amcy9f.png

[WavetoWave]

Latest article talks about how this project came to be.

https://www.wavetowave.com/home/2018/9/25/project-honda-bf-150-the-k24-outboard-revs-up

[Whaaaaat]

How much of the weight is in the mid? I'm guessing a lot. 25 to 30% ? I keep dreaming about lightweight skeleton mids that would accept these modern engines and sport master lowers. I think a real significant weight savings could be had as well as lowering the center of gravity on those top heavy four strokes.

[home made tunnel]

How much of the weight is in the mid? I'm guessing a lot. 25 to 30% ? I keep dreaming about lightweight skeleton mids that would accept these modern engines and sport master lowers. I think a real significant weight savings could be had as well as lowering the center of gravity on those top heavy four strokes.

You wouldn't be lowering the CG if you take all the weight out of the middle with a skeleton Mid

[gotboostedvr6]

Mmmm Skeleton midsection

https://www.screamandfly.com/attachment.php?attachmentid=419166&d=1537922325

[gotboostedvr6]

It would sound like 5hit with a 4 cyl 4 stroke tho.

[Whaaaaat]

You wouldn't be lowering the CG if you take all the weight out of the middle with a skeleton Mid

I should have specified making them shorter as I don't think any of the OEM are making anything shorter than 20 inch motors.

[Whaaaaat]

It would sound like 5hit with a 4 cyl 4 stroke tho.

True. Though you might be able to get a street bike sound out of it.

[Whaaaaat]

Latest article talks about how this project came to be.

https://www.wavetowave.com/home/2018/9/25/project-honda-bf-150-the-k24-outboard-revs-up

Is that the same base engine they put in the jet ski with the turbo?

[home made tunnel]

I should have specified making them shorter as I don't think any of the OEM are making anything shorter than 20 inch motors.

That's true - 20" is the shortest out there available. They don't even make many 15" motors for the kickers either.

[FMP]

Could ad a fart can exhaust and make it sound like civic

[gotboostedvr6]

Etec come in 15" up to 30hp.

[blacktruck]

Now that rotax 1630 would be badass in outboard form. Dare I say sub 450 pounds??

Sub 400 probably.

[powerabout]

800 etec sled motor is 180 hp, make it a v4, now your talking, even with compromised exhaust you would end up with 300HP and still pick it up