MC experiment continued

[eleeski]

When I last entertained you with this thread, I had just drilled a massive hole in the wrong spot on my new 11 MC. The blue 04 MC slalom wake benefitted from a bubbler hole further aft but the startup had an unsettling little catch that I could never get rid of. Lisa didn't like the new 11 MC slalom wake so I drilled a bubbler. I went further forward in an attempt to cure the startup issues. Prop slippage, a funky feel and no softening of the wake ended that effort. Plus I had to take the boat to a tournament. So break out the glass and epoxy and the hole is history.

 

But Lisa is still struggling with the slalom wake. So before I launched the boat back from Imperial tournament I had to try something. I had an old prop that was a couple pitches taller (17 vs 13 I think) so I threw that on. Scratch a taller prop off the list! Sluggish startup, the advantages from C3 erased, poor balance (for tricks also!) and a harder rooster tail made this is a failed experiment.

 

As far as useful experiments, I did get some good data. The boat came back from Imperial with a full tank of gas. The full tank made the wake bigger and harder (the stock prop went right back on). I normally run 1/4 tank of fuel and the wake is reasonable. The 40 gallons in there when full generates a bigger harder wake. MC could improve the slalom wake easily by offering a 10 gallon gas tank option.

 

Note that for me the 11 MC is the best wake I've ever felt. Tricks are so much better than ANY other current offering. At my slalom level (running 32 on a good day @34mph), this boat is the best feel. My scores are up in practice and tournament after training behind this boat. Personally, I love it!

I want to preserve this aspect while making it more friendly for Lisa (that 15 off wake is tough). My experimental quest is to maintain the trick wake, maintain the slalom feel I like and to soften the wakes for Lisa.

 

Trim tabs next?

 

Eric

[Horton]

Wow do I hate to encourage you but, when you drill holes, why don’t you install a threaded plug like the one in the engine box?

 

I imagine some blood vessels explode in Aarne's head every time you talk about this.

[DW]

The fuel experiment gives you a hint of what to do (more weight rearward or making the boat pitch a bit transom down is obviously bad). Trim tabs should work and would be pretty easy to do, but anything that will "lift" the transom should help: more hook, lighter platform, no rear seat, fuel tank forward. I would think maybe the CC adjustable tab might be an interesting test (use a slotted piece of aluminum to test it out so you can adjust up/down (tap a few holes to attach to transom).

[Dirt]

Add a cavitation plate with the giant foot pedal like my old flat bottom, v-drive k boat. You can change the wake while driving her. I also recommend naming the boat and painting that name across the back. Ex. "Ball of Hair Hater"

Joking aside, I think that boat already has a bunch of hook in the back of the hull to lift it. I have a 2000 MC with the rudder with a wing on it. I was told that it can be fixed by grinding off the wing and adding hook to the back of the hull.

[Horton]

Eric,

Again I hate to encourage you but.... you know that there is close to 500 pounds of upholstery in most boats. Strip the sucker down and then see how Lisa likes it.

[ForrestGump]

The later MC's I've seen have relateively little hook in the hull. Some have more than others, though. We had some sweet skiing 10s last year that all had a good bit of hook. the 11s we got around here this year had less. It would be interesting to put a hydrogate on a 197 to add artificial hook. Now THAT would make Aarne have an aneurysm! LOL. For what it's worth, CC has some boats out there in testing with deeper hydrogates than the production ones.

[eleeski]

Who has an old hydrogate for me to try?

Eric

[sunperch]

Does it seem weird to anyone else that such drastic measures are being taken to improve the wake of a brand new boat? For that kind of $$$ I would expect a boat that skiied great at all speeds/line lengths.

[ForrestGump]

The problem, sunperch, is that a hull design for longer line slalom is not conducive to good trick wakes and vice versa. Which is one reason for Nautique's hydrogate.

[Roger]

@eleeski - "The 40 gallons in there when full generates a bigger harder wake."

 

40 Gallons? Really? The Mastercraft site says fuel capacity is 28 gallons... (for the 197). Do you have a wakeboard boat?

 

Edited to add: I see a PS214 has a 40 gallon tank; is that what you have?

[Jordan]

I would experiment with weight distribution and different props. Going bigger made the wake worse...maybe smaller will make it better.

 

Maybe 4 blade or a 5 blade.

 

At least it's easier to reverse than another hole in the bottom. : )

[Nick Sullivan]

Its a 28 gallon tank. The boat needs more hook. Get some bondo and put some hook in it yourself.

[Mateo_Vargas]

It's traditionally been published as 28 gallons but I've never been able to get close to that. It's closer to 23 gallons and I think they forgot to subtract for the rudder access hole.

 

How about adding inflatable bladder to the fuel tank so you can limit the amount of fuel without changing the tank.

[Nick Sullivan]

Bladder adds extra weight, I just use the guage and usually only put 10 maybe 15 gallons in at a time.

 

I agree, the tank seems alot smaller than 28.

[6balls]

How about only putting in 5-10 gal at a time even it it's got 80 gal capacity?

[eleeski]

My 04 MC only seemed to hold 15 gallons. The new boat is a world team not a tournament team - maybe that makes it different. But I put in 30 gallons with a quarter tank in the bottom (visually estimated) to take it full to the tournament. It has a big tank. The wake with full tanks is harder than my normal 1/4 tank and below fuel operating range.

 

Sunperch, two factors are at work here. One, I enjoy playing with things (is drilling an easily repairable hole really "drastic"?). Second, for me the wakes are optimal, Lisa is the one who doesn't like the slalom wake. Keeping the performance the same for me and softening the rooster tail for Lisa is way cheaper than getting a Centurion for only Lisa to only slalom behind (note that I don't like the feel of the Centurion slalom feel as much as my MC - and the trick wake isn't).

 

I'ved played with ballast in the bow. For me it didn't help. And the 15 off rooster tail is still tough regardless of the weighting.

 

Lisa was OK with the 04 MC, I tolerated it. Essentially the same hull so I know it should be possible to tune things. I'm looking for the best of both worlds.

 

Hey Aarne, where's my bulb strut?

 

I'll keep playing and enjoying the process.

 

Eric

[danbirch]

Just put a triangular gas tank in the bow, and run a line back to the engine. Be sure you don't hit anything head on...or BOOM!

[DW]

Eric, you will need to make your own version of the hydrogate, the hull profile will be different, thus the comment on simply cutting a piece of aluminum and attaching to the transom. Slots would allow pretty quick change (loosen a few screws, slide up or down to adjust amount of exposed tab) so you can adjust for different skiers.

[Chef23]

Start throwing some carbon fiber in there to lighten the boat up.

[Horton]

Chef is right. Splash the hull and make the carbon LeeCraft

[jipster43]

My favorite thread continues! I have a mint '93 Stars & Stripes if you ever want to experiment on one of those Eric!

 

By the by:

 

[eleeski]

Carbon is so last decade. It will be a Boron fiber boat! Whether I save enough gas to pay for the Boron fibers - I can't ski that many hours.

 

Seriously, weight loss in a boat is the best way to improve the wakes. Ballast can be added (in the best places) to enhance the trick and wakeboard wakes. More power is available for jump and the slalom wake disappears. All good!

 

There are building techniques that could substantially reduce the weight of a boat (vacuum bagging, compression molding and probably several others) as well as judicious selection of materials. Marine engine development has completely ignored weight - or at least weight loss (heavier the better for wakeboarding?).

 

But these are out of what I can do for my boat. So I'm stuck playing with patches for the fun of it.

 

Eric

 

[Dusty]

Sort of off topic but in line with Eric's remark about powerplant weight- I noticed that Ford is moving or has moved to no longer building (gas) V-8's... When/if the other manufacturors do the same? Will the engines weigh less and have enough torque? The Ford eco-boost V-6 appears to have beaucoup torque and decent fuel economy. Just asking...

[Wish]

The V6 in the Fords have turbo chargers among other things to achieve V8 power and better fuel economy. Not sure all those things can be marinized. But what do I know. Half the time I can't start my leaf blower.

[MCskiFreak]

The problem with running a turbo motor like an eco-boost is a) getting a company to design the needed marine components and b) routing the associated plumbing for cooling the turbos in what is a very confined space.

 

If the money is spent to develop that engine into a marine package I think it would be great for the industry.

[DW]

Actually, the LS small block series from GM is all aluminum (block/heads/manifolds) and reduces the weight, but at a price so the marinizers aren't jumping 100% on them yet. You could certainly special order one if you wanted, they are available. The series goes from 5.7 liter (LS2) to 7.0 liter (LS7). Transmissions could certainly use an aluminum case. One step farther on the trans case, use magnesium just like VW/Porsche do for their gearboxes. Correct, reduding weight makes a huge difference, I have pulled 250 out of mine and it shows.

[Bill Gladding]

Transmissions at least on new stuff are already aluminum. Give me an aluminum block and heads then give me closed loop cooling and heat exchanger. Aluminum manifolds don't last unless used only in freshwater but they don't cost as much as an engine if they do. I drove a Maristar 230 with a VW diesel in it. It pushed the Maristar pretty well but wasn't a racehorse up to max speed. It had closed loop cooling and was a V6 advertised at 325kg bobtail. No cheap or simple substitute for cubic inches and iron but something will come along eventually along with changes in the hull construction and design also.

[kona]

"Does it seem weird to anyone else that such drastic measures are being taken to improve the wake of a brand new boat? For that kind of $$$ I would expect a boat that skiied great at all speeds/line lengths."

 

That makes me laugh.

[6balls]

I find it odd that if a little weight in the nose or a little hook in the hull clearly makes a boat better that the manufacturer(s) don't set their boats up this way. Or when the majority of skiers prefer a prop that is not standard...why isn't it the standard prop? Given something as simple as prop choice, one would expect the best prop for the job when spending $50K.

Having said all of this...I have not skied a MC 197, CC 196/200 or 'BU LX/LXI I don't like unless too many people/too much gas in it. Even then I only notice more bump at 28 off but shorter is fine.

[MCskiFreak]

@kona, a boat with a good shortline 36mph wake as well as good slow speed long line wakes, and good trick table are very nearly diametrically opposed. In other words you end up with a severely compromised boat that everyone would have some gripe about.

[DW]

Also, don't forget that the boat has to appeal to a fairly wide audience, so things like trunks, big tanks, plush upholstry are needed to sell to the "masses". Many of these things hurt the wake but are needed to sell them.

[boarditup]

One potential hitch - GM fuel pumps are fuel cooled. When you have less than 1/4 tank (or so) the pump may not be cooled efficiently - reducing its life. Replacements are expensive.

 

In my opinion, MC and CC boats are so overbuilt that they could easily loose some hull weight. They could even have a "tournament lake special edition" that would be more expensive, but use less materials.

 

The modern V-6 motors could easily propel a ski boat. The hp versus wetted hull surface area (with some air drag) is the primary driver of performance. Wetted hull surface area is mainly a function of weight and physical dimensions. Loosing both hull and motor weight would really help slalom wake, but may sacrifice trick and tracking.

[MCskiFreak]

They are over built imo and could benefit a huge amount from using infusion or other techniques to lighten the boat. Unfortunately the demands of production outweigh the cost of doing that to a very few models.

[MattP]

There is actually a demand for production?

[boarditup]

Maybe, but likely not. The typical response to hull integrity has been to increase thickness and increase stringer thickness. If you go to a dealer, most will have plugs of various hulls and will discuss the layup thickness as desirable. The USCG mandates hull thickness for commercial fiberglass vessels. The thickness of the layup has a history of hull durability.

 

If you go thinner for a tournament lake only slalom boat - it would perform well. If you put that boat, second or third hand, on a large lake with heavy seas, shoals, and poor trailering practices, you will have an underperforming boat and reputation will suffer. So, you are sorta stuck.

 

Everyone wants a great performing slalom boat. Everyone wants a tour team boat with very high resale value. The secondary market is friendlier to family boats with good size fuel cells, plush seats, generous size, storage compartments, and cup holders. Purists are typically lonely people - not a great place for a sales driven organization.

[Bulldog]

That is very true look at how many closed bow boats are sold vs open bow...

[eleeski]

Unfortunately, Matt has a point. I doubt that creative new molds are imminent. Some weight savings may go along with processes that may save material costs, barebonesing the finish or exotic material substitutions but we are likely to be stuck with the boat choices very close to what we currently face.

 

That is why I am experimenting to get exactly what I want.

 

Karl, I hope the fuel pumps are more robust than you say. It gets up to 50c (~125f and over the design temps for lots of electronic equipment) at my lake in the summer. I have not had problems with the motors in the fuel pumps. My 04 did have the hose in the fuel pump fail but that is not a temp related issue and the repair was cheap. And 1/4 typically is my full.

 

Also, excess horsepower is critical for high level jumpers. A V6 could easily power a boat designed for a V6 but just repowering my boat might make it a really crappy jump boat. And the Nautique 200 seems to need every cylinder just to slalom. Modern fuel injection keeps the excess displacement from drinking more fuel. Dropping in an aluminum V8 engine - now that might be cool! But drilling a couple holes in the bottom of the boat is a lot less money and work.

 

While hull thickness is one measure of strength, it is not the only way to make a hull strong. Perhaps marketing likes a thick hull but engineering does not require it. Perhaps a core sandwich could keep everybody happy and light.

 

Eric

[boarditup]

Fuel pumps are commonly replaced after they get hot. The bearings seize. The pumps are the in-tank pumps with a half-foot metal top for GM motors. Older designs - pre- fuel injection do not use the high-pressure pumps. The reason for the pumps is to avoid vapor lock in high temps. The downside is you need to have plenty of fuel to keep them cool.

 

Sandwich materials cannot be used below the water line. Fiberglass is porous - weigh a hull after a month in the water and you can prove it. When sandwich materials are used, the hull absorbs water and begins to separate at the coring materials. The only vessels where sandwich materials are used are off-shore racing vessels where they are not in the water for very long and are custom-built for that application. The USCG bans that layup for commercial vessels below the water line. The layup is commonly used for decking materials and sometimes sides and gunnels. It is also common to use foam for stringers. Although they do not rot, they can also absorb water over time.

[boarditup]

Fuel pumps are commonly replaced after they get hot. The bearings seize. The pumps are the in-tank pumps with a half-foot metal top for GM motors. Older designs - pre- fuel injection do not use the high-pressure pumps. The reason for the pumps is to avoid vapor lock in high temps. The downside is you need to have plenty of fuel to keep them cool.

 

Sandwich materials cannot be used below the water line. Fiberglass is porous - weigh a hull after a month in the water and you can prove it. When sandwich materials are used, the hull absorbs water and begins to separate at the coring materials. The only vessels where sandwich materials are used are off-shore racing vessels where they are not in the water for very long and are custom-built for that application. The USCG bans that layup for commercial vessels below the water line. The layup is commonly used for decking materials and sometimes sides and gunnels. It is also common to use foam for stringers. Although they do not rot, they can also absorb water over time.

[wlrottge]

Her is an easy to install hull modification that you could try.

 

http://rocamarine.com/index.php?v=KgEFCQwCbhQwKBcRBBhMNARGDgQBAhIkFQEXEQgYWj9HGw8WWSlfSVQ=

 

If the link doesn't work, just google Roca Speed Rails.

 

We've used them on what was already a REALLY good hull (not a "ski" boat, 23' power boat designed by Jim Wynn w/24 degrees of dead rise) and it made it even better. We installed the large set as suggested by the manual. It wasn't a totally different hull, but it did lessen port/stb sensetivity to weight distribution and generally improved stability.

 

Boat picked up ~500 RPM on the top end (~400hp 454) and put it into the mid 80 mph range (+ ~5mph).

[wlrottge]

Her is an easy to install hull modification that you could try.

 

http://rocamarine.com/index.php?v=KgEFCQwCbhQwKBcRBBhMNARGDgQBAhIkFQEXEQgYWj9HGw8WWSlfSVQ=

 

If the link doesn't work, just google Roca Speed Rails.

 

We've used them on what was already a REALLY good hull (not a "ski" boat, 23' power boat designed by Jim Wynn w/24 degrees of dead rise) and it made it even better. We installed the large set as suggested by the manual. It wasn't a totally different hull, but it did lessen port/stb sensetivity to weight distribution and generally improved stability.

 

Boat picked up ~500 RPM on the top end (~400hp 454) and put it into the mid 80 mph range (+ ~5mph).

[MCskiFreak]

Really no boats use coring that is below the waterline?!! There are a number of very large builders both production and custom that use cored hull bottoms. Not many of them are still using balsa, but they are using foam and honeycomb cores. Which USCG reg states there was ever a ban?

[MCskiFreak]

Really no boats use coring that is below the waterline?!! There are a number of very large builders both production and custom that use cored hull bottoms. Not many of them are still using balsa, but they are using foam and honeycomb cores. Which USCG reg states there was ever a ban?

[boarditup]

Check out NVIC 8-87 for the use of cores in some applications. For passenger vessels carrying 13 or more in international waters - not used. Over 200 GT - not used.

 

For custom applications for an individual (recreational), you can get virtually anything. USCG inspected vessels - that is another story. I have seen several vessels proposed for passenger use fail inspection due to coring issues. Anything that has a void space under the waterline has the potential of being filled by water in fiberglass.

 

The quality of the resin, the ratio of resin to glass, and the directional layup of the glass can be used to create a high-strength hull with minimal weight. The NVIC has a testing method to demonstrate the strength of the layup. Materials other than glass can also increase strength without weight. It is a matter of cost, workability, and customer acceptance. People like a dead hull - it sounds and feels solid.

[boarditup]

Check out NVIC 8-87 for the use of cores in some applications. For passenger vessels carrying 13 or more in international waters - not used. Over 200 GT - not used.

 

For custom applications for an individual (recreational), you can get virtually anything. USCG inspected vessels - that is another story. I have seen several vessels proposed for passenger use fail inspection due to coring issues. Anything that has a void space under the waterline has the potential of being filled by water in fiberglass.

 

The quality of the resin, the ratio of resin to glass, and the directional layup of the glass can be used to create a high-strength hull with minimal weight. The NVIC has a testing method to demonstrate the strength of the layup. Materials other than glass can also increase strength without weight. It is a matter of cost, workability, and customer acceptance. People like a dead hull - it sounds and feels solid.

[MCskiFreak]

A 200 GT passenger vessel is a considerably different scenario than a recreational powerboat which was the scope of the discussion.

 

Thanks for the info though, seems to be at odds with what ABS rules say in there 2006 guidelines. I'll have to look into it some more.

[MCskiFreak]

A 200 GT passenger vessel is a considerably different scenario than a recreational powerboat which was the scope of the discussion.

 

Thanks for the info though, seems to be at odds with what ABS rules say in there 2006 guidelines. I'll have to look into it some more.

[boarditup]

The NVIC references ABS rules. I got out of the USCG inspections arena in 1996, so my background is dated. There is a 5-year rule for new technologies and materials. To the best of my knowledge, the USCG has never approved coring below the waterline on a commercial vessel above a 6-pak.

 

My point is the boat buying public is conservative regarding new hull materials technology. You just don't see the materials innovation in ski and wakeboard boats. Off-shore and racing boats, yes. Not so much in the 20-foot range product. Boat builder reputations are built on 10-year old boats and how well they hold up. I don't know of many that want to put a cored hull on a trailer.

 

Reggie Fountain had a factory in my AOR (NC). I remember him on his back with an angle grinder working on the keel pad of one of his boats. He has an incredible attention to detail and personally ensured that every boat coming out of his factory was "just so." He was one of the pioneers in cored hulls. He spent a lot of time on layups, where the trailer bunks would contact the hull, and myriad other details to make sure the hulls would last under extremely stressful conditions. He sweat the details and has a lot of knowledge that I am sure is under wraps. Coring is not easy below the waterline.

[boarditup]

The NVIC references ABS rules. I got out of the USCG inspections arena in 1996, so my background is dated. There is a 5-year rule for new technologies and materials. To the best of my knowledge, the USCG has never approved coring below the waterline on a commercial vessel above a 6-pak.

 

My point is the boat buying public is conservative regarding new hull materials technology. You just don't see the materials innovation in ski and wakeboard boats. Off-shore and racing boats, yes. Not so much in the 20-foot range product. Boat builder reputations are built on 10-year old boats and how well they hold up. I don't know of many that want to put a cored hull on a trailer.

 

Reggie Fountain had a factory in my AOR (NC). I remember him on his back with an angle grinder working on the keel pad of one of his boats. He has an incredible attention to detail and personally ensured that every boat coming out of his factory was "just so." He was one of the pioneers in cored hulls. He spent a lot of time on layups, where the trailer bunks would contact the hull, and myriad other details to make sure the hulls would last under extremely stressful conditions. He sweat the details and has a lot of knowledge that I am sure is under wraps. Coring is not easy below the waterline.

[kona]

"a boat with a good shortline 36mph wake as well as good slow speed long line wakes, and good trick table are very nearly diametrically opposed. In other words you end up with a severely compromised boat that everyone would have some gripe about."

 

My point exactly it doesn't exists.