Mastercraft Problems
Cyberjerk
isnt as good as the 94 or prior. If you have skied it at shortline you
know that there is virtually no spray down through 38, and the trick
wakes are much improved. 94 and prior wakes were much softer and rounded
at trick/wakeboard/kneeboard speeds.
As far as the malibu rep guy who writes: We all know what your gonna say
so why not jsut post your name. As far as stock in inverntorie goes,
Dealer in my town sold 23 at winter boat show, doesnt sound to me like
people are moving away from mastercraft. I will admit that the malibu is
a fine boat, better? I dont feel so, but thats my opinion. Plus Malibu
what a stupid name. For the same money I'm with the craft.
Iskidaily
boat, I'm wondering if anyone has found a boat that skis or drives as well
or better?
Barefootr
say so why not jsut post your name.>>>
Okay Ted.
I'll present the facts and let you present the opinions.
Peter. :)
_____________________________________________
Upper Valley Watersports Malibu Boats Promo Rep
In the business because I love the sport
HO Sports/Hyperlite * Straightline * Masterline * Eagle
^_____________________________________________^
CRMUSE
(Cyberjerk) writes:
> For the same money I'm with the craft.
First Craft. Best Craft. CORRECT CRAFT.
Bob Muse
Tom Murphy
Scibienski) writes:
>
>How come you guys always talk about the great wakes but never metion
the lousy
>handling/drivebility? Personally I would rather have a boat with a 1
inch
>higher wake which will allow me to give my buddies a straight ride. I
will
>admit, however, that with the way the new MC's waver in the course
(i.e. -
>unintentional doggy walk) the lack of spray at shortline can be a boon
to a lot
>more people. Too bad they never get there behind a Nautique, to
discover that
>there's no spray there either!
>
Oh how in pains me to say this....It's true, the Nautique has no spray,
even at 32 and 35 off. It's an incredible boat all around. Damn it!
Former MC fan. (Still love my '89)
Bob Scibienski
Any Nautique, 1991 or later
Bob S.
Bob Scibienski
redmiston
><snip - snip>
I think he's RIGHT!! That's why I bought a Tige 2002 :)
...rex
> I and 99% of my skiing friends love soft, easily crossable wakes first
> and foremost and most of the boating public wouldn't know whether the
> tow boat was walking on them or not. That's why this is a moot point
> and why MC will continue to outsell everybody. They are focusing on
> the larger market, most of whom really will never have to worry about
> "spray" either. And if a boat is good enough to pull the Pro Tour and
> a World Record, I'm guessing its good enough for most of us weekend
> pretenders.
>
> The comments on here that concern me more are those regarding 95/96
> ProStar reliability. My ProStar was bulletproof as have been those
> owned by my friends. However, recent negative comments, specifically
> about the LT-1, deserve valid research before buying.
>
> carver
Carver
Well I don't know about the supposed problems with the 95/96, but my
(recently departed) 94 ProStar tracked dead on in the course and
comparing its soft wake to a Nautique's hard one is like comparing
skiing over dental floss to skiing over a speed bump. Below 34mph a
Nautique's wake more closely resembles an I/O wake than a skiboat's.
Great boat, awesome tracking, big wake.
Personally, since my boat (and most other's boats I would guess) only
spends about 5-10% of it's life in a course, I am more concerned about
small wakes than the ProStar's tracking abilities (which Waterski Mag
incidentally has said is awesome in the course - Go figure?). And I
guess the skiers on the Pro Tour just continue to ski behind such a
"lousy handling" boat which, if it can't track at recreational line
lenghts (15-28 off), must just tear out all the boat guides at deep
shortline. And tell me, how did Wade get his World Record approved
even though the boat must have been "doggy walking" down the course and
his distance to center course must have obviously been out of
tolerance?
Carver
writes:
>
> It also must be noted that as a skier I don't believe in wakes
>unless at tricking or wakeboarding speeds, because if your holding
your
>edge and using your knees wakes should not be a factor at slalom
speeds.
> That's just my opions on this subject.
>
>Mark
I agree with you here if you assume that the small group of elite
skiers you probably interact with most are representative of the market
as a whole. Unfortunately they are only a small minority of the
boating public. Most people due to inexperience, age, etc. often have
difficulty with these things that come so simple to the serious skier.
I am a pretty avid water skier and I have only run the course at 15
off. I'm extremely sensitive to wake size, and most anyone I take on
my boat is even more so. Almost everyone I took on my 94 MC commented
on the soft wake and how easy it made skiing for them. Conversely, at
ski school, all three of us intermediate/beginners commented how the
Nautique wake at 32 mph was fairly large. The average recreational
skier wants to have fun and doesn't want to waste his/her time being
penalized because he/she doesn't have their hips all the way up to the
handle and their knees bent just so.
BTW, why have we left the Malibu Response out of this discussion. It's
probably a better ski boat than both of 'em.
carver
"Honey, have you seen the ProStar?"
CRMUSE
(Carver) writes:
>However, recent negative comments, specifically
>about the LT-1, deserve valid research before buying.
The problem with the LT-1 as far as I understand is the different heating
and cooling rates (which is directly related with expansion and
contraction) involving aluminum heads and a cast-iron block. This is a
problem in a boat due to the cold water that enters the cooling system on
a restart. This could concievably cause the head gasket to blow. IMHU
Bob Muse
MQualkinbu
a skier I'm concerned with tracking because at 32 - 38 0ff theirs not a
whole lot of room left and if the boats taking rope away from me by not
pulling straight it makes a difference.
My argument with MC is they will sell the public a non slot and
tell them it's going to be the same boat, if that's true why don't they
bring 1 to 1 trans to class C and other tournaments. I have'nt seen a non
slot at a tournament since 1979.
I will say as a driver I liked the 94s better than the 95s and I
say that more from a functional point of view. It's very easy to make this
observation after you have replaced a few buoys in the water or had to
pick up a trick rope after being released.
linda
Tom Murphy
I think that the Powerslot issue has become based in emotion rather
than anything else. With the fuel injected 300+ HP motors, a 1:1 still
has plenty of power for 36MPH slalom. Ask Mike Morgan, he ran a handful
of bouys at -39.5 at our record tournament in '94 behind the 310HP 1:1
Mastercraft. I believe that I can give a better pull with this boat
because the throttle is easier to precisely control. I guess it depends
on your driving style.
MQualkinbu
I can only go on the scientific facts, the power slot will track
better and here is the proof. A 14 X 18 prop will travel farther in a
single rotation than a 13 X 13 thus creating a stronger hold on the
course. Think of the prop has having 3 levers and the more leverage you
can get on your columm of water the better the boat will hold speed and
track.
I guess I could bring up another issue here and that is horsepower.
On a small block V8 look at your maximum hp specs. Chevy will be 310 hp at
5000 - 5400 rpms, Ford will be 310 hp at 4600 - 5100 rpms, which is not in
your skiing speeds. Some boats will never achieve the full 310 hp.
I think when the truth be, were all being mislead by the marketing
genious of our sport.
Mark
Tom Murphy
writes:
Well....the Powerslot is a power feature that simply gets the engine
into it's power band, and don't get me wrong, it does that extremely
well. I have an '89 240HP 'slot and wouldn't dream of running a 1:1
with this engine.It's probably 14" DIAMETER willget slightly more
"traction" but that would be because of the increased surface area of
the blade, rather than the pitch, but that has no effect on tracking.
My original argument about "feeling the skier" related to throttle
action rather than tracking anyway. My point about horsepower is just
based on the fact that the EFI 1:1 RATED @ 310HP is as strong a pull as
the 240HP Powerslot (both very strong). I just find it a little easier
to adjust to the skier with the 1:1, probably because less power makes
the throttle a little less touchy. By the way one of our lakes is very
short and it's no problem getting up to 36MPH in plenty of time.
There's is most certainly nothing wrong with the 'slot, I was just
bringing up a point that I thought would be pretty novel. I also think
that the big jumpers would prefer the extra pull of the 'slot.
Tom
Barefootr
better and here is the proof. A 14 X 18 prop will travel farther in a
single rotation than a 13 X 13 thus creating a stronger hold on the
course.>>>>>
Mark,
I don't follow your train of thought. It would be my understanding
that if a prop rotated more revolutions per distance traveled, than more
applicable torque would be shown.
An easy analogy for me would be a car in 1st gear travels 5 mph at
1000 rpm, and it's very tough to stall it.....but the same car in 4th gear
travels 30 mph at 1000 rpm, and stalls at the slightest resistance.
Are we not taking into account the reduced geared transmission of the
boat? With that in account, the larger prop should not travel any further
than a 13x13 behind a 1:1 tranny.
Am I missing something here?
Bare. :)
RAIBERT RJ
>> I guess I could bring up another issue here and that is horsepower.
>> On a small block V8 look at your maximum hp specs. Chevy will be 310 hp
at
>> 5000 - 5400 rpms, Ford will be 310 hp at 4600 - 5100 rpms, which is not
in
>> your skiing speeds. Some boats will never achieve the full 310 hp.
>> I think when the truth be, were all being mislead by the marketing
>> genious of our sport.
YES! horsepower = Torque x RPM x (scaling factor). Some boats usually
don't even reach the maximum advertised RPM required to reach that BIG
horsepower number!
Yes we must remember the true factor when considering the holding power of
a particular motor/boat combination. It is most important to have peak
torque at the skiing speeds of 30-36 mph. It is even more important that
this Torque curve be as "flat" as possible holding this peak torque as
long as possible.
How can that torque be multiplied? You guessed it, a gear reducing
transmission--the powerslot for MC and Power Plus 1.23:1 for Nautique. MC
still exclusively qualifies the Powerslot even WITH the LT1 for AWSA
tournaments. Nautiques come standard with the gear reduction and CC with
the GT-40 multi-port with the standard gear reduction transmission the
AWSA qualified towboat.
RJ
MQualkinbu
Your own anology is hopefully going to show you how this works. A car
traveling in first gear at 5 mph at 1000 rpms is hard to stall, a car
traveling at 30 mph at 1000 rpms stalls very easy. Why is this, very
simple gearing; in first gear the ratio for the gear is 4 to 1, very hard
to stall and multiples of torque. The car in 4th gear has a ratio .75 to
1, very easy to stall.
To put this perspective in the boating world we have to think about
the wieght of the boat and what's called the prop columm. A 1 to 1 trans
will use a 13 in columm, a gear reduction will use a 14 in columm. The
larger the columm the more wieght it can support. A good example here is
would you rather stand on and have your wieght supported by a 10 inch tree
stump or a twenty inch tree stump. Which will support you better the
larger or the smaller diameter, thus the same principal works with props.
Another point here is the prop travels further in a single
rotation, when you use the larger prop. A good point is brought up when it
is said, the smaller prop is turning faster so it must be stronger,
unfortunately that also means more slippage and less wieght carrying
ability, due to decreased columm size..
I hope this explains what your asking, but if it does'nt leave
another message and I will try to clarify.
Mark Qualkinbush
Jack Mills
market, they no longer try to produce the best boat for skiing. Looks
and PR is more important! That is why they went to the totally
unfunctional windshield in 85, and the LT1 engine (95)that produces
it's peak torque way above the RPM needed for skiing. As far as being
used in the Pro Tour; they would use a bayliner if it had the largest
sponsership support. Mastercraft has been responsible for a great
deal of innovations over the years, but they new hull does not track
well, but finally has a good spray at the price of a killer rooster
tail at 22 off( espically for women and kids). As far as the
reliablity of the LT1, very few of the eastern region promo boats
have escaped engine or acessory failures last year. 94 was a bad year
for correct craft, now it is Mastercraft turn to take the heat; maybe
the new malibu with the scorpion engine will the new "killer combo".
P.S. I have owned two mastercraft and three correct craft depending
on who had the best boat.
Jack Mills
RAIBERT RJ
> To put this perspective in the boating world we have to think about
> the wieght of the boat and what's called the prop columm. A 1 to 1 trans
>will use a 13 in columm, a gear reduction will use a 14 in columm. The
>larger the columm the more wieght it can support. A good example here is
>would you rather stand on and have your wieght supported by a 10 inch
tree
>stump or a twenty inch tree stump. Which will support you better the
>larger or the smaller diameter, thus the same principal works with props
I don't know where this guy comes up with stuff about greek building
columns and tree trunks--I though we all was talking about torque,
horspower, speed, and all that good stuff, however our wives or
girlfriends(we better not have one of each), and friends would all be lost
in this "torque talk" and tell us all we are boring guys for conversing
about such issues and tell us that this is not good stuff to talk about.
Enough of the hot air. I believe the 13" column vs the 14" column may be
better described as a tree branch. I would rather be standing on the
thicker branch because it would support my weight(and after this winter I
need all the support I can get) much better.
THE BOTTOM LINE IS THAT MASTERCRAFT and CORRECTCRAFT HAVE KNOWN FOR YEARS
THAT A GEAR REDUCTION IN THE TRANSMISSION PRODUCES MORE TORQUE. A LARGER
PROP(14/18 FOR MC AND 14/16 FOR CC) THEN CAN BE USED TO KEEP THE RPMs
LOWER(SAME AS 13/13 PROP WITH 1:1 TRANSMISSION).
P.S. Sorry for the capital letter, just wanted to make a point.
RJ
Chip Broecker
>> Jim Lince wrote,
>> You are comparing the LT-1 against what engine specificially and
>> further, what torque is needed at 36 mph, vs. what the LT-1 puts out at
>> that speed, vs. other engines?i.e Where are your facts? Jim, YOU have to have the facts because YOU are defending
MC.
> Always treat the marine applications like a farm tractorExactly. Even Caterpiller makes a better boat than MasterCraft.
> The best thing to do here is go directly to engine
> manufactures and ask for their data, that will give you the real truth
> about specs on which engines are strong in skiing speeds.
> Mark is quite right here demanding that Jim and other MC owners go get the facts to
counter his assertions. MC either doesn't have engineers, or has lame ones that
don't understand that the Prostar might be used for pulling Waterskiers at say
36mph. Also, the powerslot does not make any difference when it comes to this
analysis, and it's gear ratio was chosen at random. And he has a clarity of vision
that is seldom seen in a non-engineer; peak torque is the only consideration in the
choice of an engine, and all engines should be run at their peak torque RPM all the
time.
As an owner of a 96 MC LT-1, I repent. I am sure that I was in dementia when I
thought I loved it. Based on reading anti-MC posts, I realize now that I have been
in denial and should seek treatment. Perhaps someone will take pity on me and make
a low offer for my MC, so I can get a real skiing boat that wasn't designed by a
bunch of buffoons and rammed down the throat of the largest segment of ski boat
buyers.
Any offer above 5,000 US accepted. Best offer wins, by midnight on the date of this
post.
Best, Chip
Charles Hill
>
>Any other "Facts" (and I use the term very loosely) about Mastercraft
>you can share, Jack?
>
>BTW: The scorpion has a very unreliable valvetrain and I've heard that
>there's going to be a recall on the engines soon right in the middle of
...rest of blatant fabrication deleted...
>
>(now, I totally made this up, but it's the very crap Mastercraft endures
>over and over here).
>
Jim, I read your post with interest until I realized how offended I was by
your hypocrisy and irresponsible posting of this potentially damaging "rant".
I am very reluctant to express this, because I have always been one to praise
the freedom of self expression the net allows, and I ususually ignore flames,
but let's try keep our posts limited to our opinions and not be so hostile to
the boat manufacturers. You just escalated the type of discussion you were
trying to bash. OK I'm truly sorry for my own ranting, If you must respond,
please to so by e-mail.
Thanks,
Chas
--
Charles S. Hill (Charlie or Chas) "Barefooters walk on water."
oooO Oooo ch...@uceng.uc.edu hil...@picard.ml.wpafb.af.mil
( ) ( ) H(513)252-5001 W(513)255-3622
( ( ) ) http://waterski.net/
Robert Plamondon
You people out there trashing the LT-1 had better re-do your homework.
It's an outstanding engine! And to the guy claiming that the '94 Eastern
Promo boats were unreliable due to the Lt-1, you REALLY need to re-do
your homework. Anyone who knows anything about Promo boats knows that
all '94 Promo boats had the 275 TBI Engine with PS tranny. In fact, I
bought one!
Besides (you Nautique owners trashing MC's), Us MasterCraft owners can
change out our so called unreliable engines anytime we want, BUT YOU HAVE
TO DRIVE THAT UGLY BOAT FROM NOW UNTIL YOU SELL IT!
Just kidding, Sort of. They're all great boats, they just are built with
a different set of priorities. I've heard Nautiques are better at
tracking but the 2 I've driven don't track as good as my '94 MC.
Man, this is almost as nasty as the Chevy/Ford argument!
Later, Rob
Bob Scibienski
reduction long before any skiboat companies came along. Concerning the 13" vs.
14" analogy, I agree in part. Where I disagree is that it soould NOT require a
14" limb to support my wife's weight!
Bob S.
Bob Scibienski
tournament boat with the GMC 6.2 diesel under the hump. Now this is an engine
with mucho torque (I own a PU with one and love it). On the other hand it only
puts out 130 hp. So lets find out how this boat behaved with skiers in tow
(keeping in mind that they would have the extra weight of the gas mask added to
their mass). Anyone out ther ever drive one. Weigh in and tell us the low
down! Lets get to the bottom of this question!
Bob S.
Doug Leno
|Enough of the hot air. I believe the 13" column vs the 14" column may be
|better described as a tree branch. I would rather be standing on the
|thicker branch because it would support my weight(and after this winter I
|need all the support I can get) much better.
Seems to me that weight support isn't the real reason why larger props
are used. The support of your weight is the job of the hull, no? The
job of the column is to propel the boat so that the hull becomes a
planing body.
A larger column certainly has the potential for accomplishing a greater
acceleration force to the boat, simply because it represents a more
efficient prop/water interface. This potential may not be realized,
however, if the engine isn't strong enough.
To me, the larger prop is like using a bigger rowboat paddle - you can
move more water per stroke but you won't actually go any faster unless
you are strong enough.
A small, high-velocity water column could provide the same nominal force
(and therefore "weight support") as a large, slower column but the real
benefit of the larger column, assuming that it has enough torque behind
it, is that dynamic forces external to the boat (i.e. rope tension)
have a lesser influence on the boat.
Now to digress -- could someone tell me what is the affect of a larger
prop on the wake itself? Seems to me that the larger column might
translate into a flatter propwash or even a softer wake.
|THE BOTTOM LINE IS THAT MASTERCRAFT and CORRECTCRAFT HAVE KNOWN FOR YEARS
|THAT A GEAR REDUCTION IN THE TRANSMISSION PRODUCES MORE TORQUE. A LARGER
|PROP(14/18 FOR MC AND 14/16 FOR CC) THEN CAN BE USED TO KEEP THE RPMs
|LOWER(SAME AS 13/13 PROP WITH 1:1 TRANSMISSION).
Exactly. The combination of a larger prop and a reducing transmission
is where the benefit is.
The gear reducing tranny does two things: It provides torque
multiplication AND (possibly) allows the engine to operate in an rpm
range where more nominal torque is available from the crank. It becomes
evident then, that if you want a given boat to travel at a certain speed
with its engine at the peak of its torque-vs-rpm curve, that there is
one and only one prop size and gear ratio combination that will
accomplish your goal. Whether or not that magic operating point is
actually implemented in real towboats I have no idea, but it was fun to
think about it :-)
Doug
--
Doug Leno Hewlett Packard Disk Memory Division
do...@boi.hp.com Heads and Media
Slalom7777
motor with no trouble. It holds speed better than the GT 40. I am a
loyal CC owner and am tired of all the lies. i still like CC better and
always will but do not slam MC. it is a fine boat and the LT-1 is a
little better than ours.
David
acss...@acs.eku.edu
> <<<<<I can only go on the scientific facts, the power slot will track
> better and here is the proof. A 14 X 18 prop will travel farther in a
> single rotation than a 13 X 13 thus creating a stronger hold on the
> course.>>>>>
>
>
> Mark,
> I don't follow your train of thought. It would be my understanding
> that if a prop rotated more revolutions per distance traveled, than more
> applicable torque would be shown.
> An easy analogy for me would be a car in 1st gear travels 5 mph at
> 1000 rpm, and it's very tough to stall it.....but the same car in 4th gear
> travels 30 mph at 1000 rpm, and stalls at the slightest resistance.
>
> Are we not taking into account the reduced geared transmission of the
> boat? With that in account, the larger prop should not travel any further
> than a 13x13 behind a 1:1 tranny.
>
> Am I missing something here?
Maybe... if they are indeed geared identical (overall ratio of trany and
prop), the larger prop might still have an edge due to increased blade
area assuming there was sufficient power to take advantage of it.
It would probably be simplier if we were comparing props where only one
variable changed. In this cas there coule be 3 differences... tranny
gearing, prop dia and prop pitch. As a general rule of thumb I would
"guess" that to a point lower overall gearing improves tracking and to a
point larger blades improve tracking. The 2 examples are differing
compromises that strive to reach the same goal.
Dudley Cornman
Systems Programmer
Academic Computing Services - EKU
ACSS...@ACS.EKU.EDU
********************************************************************
*** When it comes to boats... ***
*** I'd rather have a new boat than a used boat... ***
*** I'd rather have a Baja than a Bayliner... ***
*** I'd rather have a used Bayliner than no boat at all... ***
********************************************************************
acss...@acs.eku.edu
> THE BOTTOM LINE IS THAT MASTERCRAFT and CORRECTCRAFT HAVE KNOWN FOR YEARS
> THAT A GEAR REDUCTION IN THE TRANSMISSION PRODUCES MORE TORQUE. A LARGER
delivers is a better word
It actually multiplies the torque of the engine.
> PROP(14/18 FOR MC AND 14/16 FOR CC) THEN CAN BE USED TO KEEP THE RPMs
> LOWER(SAME AS 13/13 PROP WITH 1:1 TRANSMISSION).
When you increase the pitch you are in effect dividing the torque from
the engine.
So gear reduction and increased pitch are offsetting factors if they are
applied in equal amounts.
Larger prop dia. also offsets gear reduction. If the rpms truely remain
the same in all these different setups then the combination of the
larger dia. and increased prop pitch is exactly offsetting the gear
reduction. So why do the gear reduced boats perform better?
Jon Zeeff
>larger dia. and increased prop pitch is exactly offsetting the gear
>reduction. So why do the gear reduced boats perform better?
In theory you can just spin a small prop faster, but at some point
it will just sit there and cavitate. So you gear it down and put
on a bigger prop to get more bite.
GORDON JENSEN
>
>In theory you can just spin a small prop faster, but at some point
>it will just sit there and cavitate. So you gear it down and put
>on a bigger prop to get more bite.
>
engine) for tourny and other runabout size boats is somewhere around
2,500. By best, I mean most effecient. So as in the above, the
larger, higher pitch prop turning slower (the optimum RPM range for the
boat load) will be more effecient than the 1:1 smaller diameter lower
pitch prop. A real small prop turning really fast will be very
ineffecient.
Gordon
Bob Scibienski
I have pretty much stayed out of this thread except for a few attempts to inject
some humor but I have now decided to go ahead and throw my own 2 cents worth in.
To begin with, I think that the drive setup has very little to do with a boats
tracking behavior. If anything I would expect a "stronger" drive train to make
the boat more difficult to keep dead center. If you are getting a stronger
push, then every time the skier alters your direction with his pull you will
travel farther in that new direction before you can compensate. You may argue
with this but that's the way I see it.
Now, concerning the "advantages" of gearing. First of all, according to David
Gerr in "The Propeller Handbook", total blade area is the single biggest factor
in delivering power to the water. The larger the prop diameter the larger the
blade area. Second, to push a 2500 pound boat at a given speed with a given
skier in tow requires that the propeller accelerate a given mass of water per
unit time. It doesn't matter whether the prop is a 13X13, 14X16 or 14X18, the
mass of water moved will be the same. However, the bigger props move more water
so they can achieve this at lower RPM. This allows the propshaft to be run at a
lower RPM to yield the same endpoint. However, in each case the total mass of
water being accelerated is the same and thus the force pushing the mass of the
boat etc. is the same. The bottom line is that the actual forces involved are
identical regardless of the prop details. Third, gearing allows the engine to
run in the same RPM range regardless of the prop. The bigger the prop, the
greater the reduction to achieve the same endpoint.
So, you asked, why do gear reduction boats work better. I offer several
suggestions. First, there are significant parasitic losses of power involved in
turning things in a viscous fluid like water. I'm neither a math head nor an
engineer but I would guess that these losses increase disproportionately to
actual increase in RPM. Thus I would guess that the smaller, higher RPM props
waste more power. Second, the gear reduction tournament boats actually operate
in a slightly different RPM range. In my experience, towing a 36mph skier in
the course, a 1:1 boat averages 3600 RPM, a 1.23:1 boat needs 3800 RPM and a
1.5:1 boat needs almost 3900 RPM. Thus the gear reduction boats are in a
slightly different part of the power curve and it is probably a more efficient
part. Third, because of the gear reduction, when a skier pulls the boat down
the actual "cost" in RPM is less than with a 1:1, by the factor of the
reduction. Finally, when comming out of the hole, the gear reduction boats
reach their "power" RPM range sooner than a 1:1 boat. Thus the actual power
required to pull a skier up is acheived slightly sooner, which is perceived as a
stronger pull.
Well, maybe three cents worth : )
Bob S.
Barefootr
different RPM range. In my experience, towing a 36mph skier in the
course, a 1:1 boat averages 3600 RPM, a 1.23:1 boat needs 3800 RPM and
Bob, I disagree with this. I expected to see a difference in rpm ranges
between a geared boat and a straight 1:1 boat, but I have not seen
anything close to it. Most of the rpm's differences that I've ever seen
are 100-150 rpm, which can be easily attributed to the tachometer
tolerances.
acss...@acs.eku.edu
> evident then, that if you want a given boat to travel ata certain speed
> with its engine at the peak of its torque-vs-rpmcurve, that there is
> accomplish your goal.
This statemement as you presented it is not true... something more like
the following would be more true, but still not a hard fact.
It becomes evident then, that if you want a given boat to travel at a
certain speed with its engine at the peak of its torque-vs-rpm curve,
that there is one and only one prop size PER gear ratio combination that
will accomplish your goal... ASSUMING THAT YOU DON'T CHANGE ANY OTHER
FACTORS LIKE BLADE SHAPE, BLADE RAKE, BLADE MATERIAL, ETC.
I can readily provid an example from the i/o world that would disprove
your statement. I can easily dial-in my Torque-Shift to match about any
fixed pitch prop that you deem to be "the one and only".
As for inboards...
I contend that it might be possible to build a 13 x 13 that would
perform ABOUT the same as a 14 x whatever by increasing the blade
surface area of the 13 x 13 to approximately equal that of the 14 x
whatever and tinkering with blade shape and rake. I imagine the two
props would look considerably different.
Bob Scibienski
snip
>Bob, I disagree with this. I expected to see a difference in rpm ranges
>between a geared boat and a straight 1:1 boat, but I have not seen
>anything close to it. Most of the rpm's differences that I've ever seen
>are 100-150 rpm, which can be easily attributed to the tachometer
>tolerances.
snip
Bare - is that with a skier in tow? All I can say is that this has been a
consistant observation of mine over several boats. I agree about the tach
differences - a buddy has a Nautique essentially identical to mine but they
differ by 100 rpm. However, if you compare these ranges, the powerslots are
always higher than the PCM's which are always higher than the 1:1's (again, in
my experience). In fact, I have driven one '96 Prostar which needs almost 4000
rpm to hold a good shortline skier in tolerance, and from the sound I think it's
really turning that fast. That said, it really is a minor point. The essense
of my post was that at skiing speeds all of these boats are putting out the same
forces to the water.
Bob :-)
acss...@acs.eku.edu
>>the same in all these different setups then the combination of the
>>larger dia. and increased prop pitch is exactly offsetting the gear
>>reduction. So why do the gear reduced boats perform better?
>
> it will just sit there and cavitate. So you gear it down and put
Is this point really being reached/approached by any of the ski boats on
the market?
Hammrski
>Um excuse me, what's your point here? That the LT-1 can't be used
>for skiing? That's the stupidest comment I've ever heard. That's like
>stateing that because a manufactuer stopped putting in 454's and started
>using 350's (with less torgue) then the boat can't be used for skiing.
>You are comparing the LT-1 against what engine specificially, and
>further, what torque is needed at 36 mph, vs. what the LT-1 puts out at
>that speed, vs. other engines?
>
> That's right, Porsche is no longer interested in making the best
>driver's car because the engine produces it's "peak" torque above
>usual speeds. Nevermind, that at usual speeds, it's as quick as any
>other.
One difference, the porche has gears and you can utilize the horsepower by
leaving it gear a little longer, hittting the horspower/power band while
doing so.
A direct drive boat does not have gears and will not let the engine rev.
up to it's potential if the peak horsepower is beyond the max. rpm of the
boat.
Hope this clears this up a little.
Correct Craft all the way!
Jim
Doug Leno
|> It becomes
|> evident then, that if you want a given boat to travel ata certain speed
|> with its engine at the peak of its torque-vs-rpmcurve, that there is
|> one and only one prop size and gear ratio combination that will
|> accomplish your goal.
|This statemement as you presented it is not true... something more like
|the following would be more true, but still not a hard fact.
|It becomes evident then, that if you want a given boat to travel at a
|certain speed with its engine at the peak of its torque-vs-rpm curve,
|that there is one and only one prop size PER gear ratio combination that
|will accomplish your goal... ASSUMING THAT YOU DON'T CHANGE ANY OTHER
|FACTORS LIKE BLADE SHAPE, BLADE RAKE, BLADE MATERIAL, ETC.
Oh my, a thousand appologies. I had better do better wordsmithing next
time, indeed. thanks much for pointing that out!
I was assuming all of the things you mentioned in caps, but really
should have simply said "prop speed of advance" instead of "prop size",
which is far too general.
Certainly, if you fix the boat speed and engine rpm, then the other two
paramters are mutually dependant and form unique pair combinations.
Thus, there is one and only one propeller speed of advance per gear
ratio. I'm using the term "speed of advance" to refer to prop distance
traveled per rotation. Assume, of course, identical conditions.
sorry about that.
Bob Scibienski
snip
I'm using the term "speed of advance" to refer to prop distance
>traveled per rotation. Assume, of course, identical conditions.
>sorry about that.
snip
Doug -
I believe that the propeller people use the term "pitch" to describe this
particular parameter.
Bob S. : )
Jim Lince
>
> Jim Lince wrote,
> You are comparing the LT-1 against what engine specificially,
> and
> further, what torque is needed at 36 mph, vs. what the LT-1 puts out at
> that speed, vs. other engines?
> market for towing applications. Your ft lbs of torque is 330 at its peak
> and has tremendous curve, thus not sustaining torque. I'm not saying the
> LT-1 is a bad engine, but it is not a good pulling engine. You can go to
> any Chevy dealer and grab your RPM torque ratio versus horsepower and
> you'll find that it's a great race engine as long as you can keep your
> RPMs over 5000 with no drag or wieght resistance.
>
> That's right, Porsche is no longer interested in making the best
> driver's car because the engine produces it's "peak" torque above
> usual speeds. Nevermind, that at usual speeds, it's as quick as any
> other.
> this anology. This car has no low end torque, would this car be as quick
> if it had a trailer with some drag behind it. The answer is it would loose
> quickness and become very weak.
> Always treat the marine applications like a farm tractor
> when it comes to pulling, torque, horsepower, gear ratio, and RPMs,
> comparing to racing engines will not work. Our envioment demands an engine
> that achieves all these elements in skiing speeds and tach range.
> You are comparing the LT-1 against what engine
> specificially, and
> further, what torque is needed at 36 mph, vs. what the LT-1 puts out at
> that speed, vs. other engines?
> The best thing to do here is go directly to engine
> manufactures and ask for their data, that will give you the real truth
> about specs on which engines are strong in skiing speeds.
>
> Mark Qualkinbush
330 ft lbs is not "no torque" or even low torque by any V8's standards.
My Dodge Ram 1500 4x4 1/2 ton pickup truck (that pulls my Mastercraft
quite easily I assure you) does not have this much torque and it also
has a curve (as all engines do). If you want that much low end torque,
go buy a diesel.
Here you go again, "The LT-1 is actually the weakest engine in
the upper end market for towing applications". Compared to what? I say
again, compared to what?
News alert, all you people need to trade in your 350's for
Cummings diesels, because your 350's don't have enough "sustained"
torque throughout the power range to support a skier at 36 mph.
Mark, please go look into barefoot boats and 200hp outboards
(with not nearly the torque of any V-8) and please tell that crowd that
these outboards are terrible pulling engines...
I don't even know why I bother with this *crap*,
Jim
MQualkinbu
Jim Lince Wrote,
(Here you go again, "The LT-1 is actually the weakest engine
in
the upper end market for towing applications". Compared to what? I say
You ask compared to what? The Indmar Monsoon, PCM GT 40 and
Merc Black Scorpion and in this application the LT 1 is the weakest. If
we were runnning a race with differentials, gearing, and other power aided
devices I would take the LT 1, but were not. Again I said it once I'll say
it again it's not what I say it's what the manufacture specs specify on
their products. Why did Chevrolet feel it was needed to develop the Gen 1
heads, for torque and the pulling enviroment.
(Mark, please go look into barefoot boats and 200hp outboards
(with not nearly the torque of any V-8) and please tell that crowd that
these outboards are terrible pulling engines..)
I don't have to, they have lower units with gear reduction
and different drive angles. They are great pulling engines. An example
here is a Merc 200 uses a 1.86 to 1 gear ratio, thus instant torque
multiplication. I'm not trying to put anyone down or any one engine I'm
just trying help people understand the concepts of marine applications and
how all the components fit together.
Mark
Jeffrey P. Jones
>
> MQualkinbu wrote:
STUFF DELETED SINCE I DON'T LIKE THE TONE OF IT
> >
> > Jim Lince wrote,
> I don't even know why I bother with this *crap*,
> Jim
Well Jim, it not really the Mastercraft as a boat. The boats is fine.
It's the people who drive them. They are a bunch of drunks. That is a
fact. Now CC owners are a group of angels. We don't drink and we ski
better than MC owners. This is particularly true when we ski behind
Mastercrafts. We have learned to cross through the NO WAKE ZONE and
can thus handle anything a MC has to offer. Can we talk about what truck
is best now? OH we don't need to, I own a Ford so it must be the best.
Besides, you know people who drive Chevy's are a bunch of drunks.
Oh please Mr Meloon can we have good weather here soon so I can ski?
Jeff
--
This message is meant to inflame only Jim.
http:/cyp.medicine.rochester.edu:8080/jones_group.html
Jim Lince
Hey I'm not the one going around slamming brands...or stating that one
is better than the other --- you must have me confused with someone
else. Jim
Jim Lince
>
> Jim Lince Wrote,
> (Here you go again, "The LT-1 is actually the weakest engine
> in
> the upper end market for towing applications". Compared to what? I say
> again, compared to what?)
>
> You ask compared to what? The Indmar Monsoon, PCM GT 40 and
> Merc Black Scorpion and in this application the LT 1 is the weakest. If
> we were runnning a race with differentials, gearing, and other power aided
> devices I would take the LT 1, but were not. Again I said it once I'll say
> it again it's not what I say it's what the manufacture specs specify on
> their products. Why did Chevrolet feel it was needed to develop the Gen 1
> heads, for torque and the pulling enviroment.
>
for pulling skiers while stating that Mastercraft no longer is
interested in making the best boat. Later on you said it's the weakest
in it's class. Fine, have a ball. I'll go trade in my LT-1 for a V-6
I/O with a 1:8 transmission and I'll show em then won't I?
I should have seen it when I saw the words "Mastercraft is no longer.."
I give,
Jim
RAIBERT RJ
>> Fine, have a ball. I'll go trade in my LT-1 for a V-6
>>I/O with a 1:8 transmission and I'll show em then won't I?
My V-6, 4.3L has been a great engine for all applications. My family and
friends have really enjoyed the boat and skiing behind it. Besides, I
could not afford the big buck for the MC and LT-1. Maybe in a couple of
years I will be able to get one. However, I also am confused about these
engine issues and think I will wait for the Gen 1+ head design(I like GM
engines because they are good and GM signs my paycheck) in the multi-port
motor to come to the Mastercraft boats.
RJ
Mark Kovalcson
MasterCraft is not a family owned business and the bottom line is bucks,
I think their emphasis on family boats is getting the best of them and
that as of 1995 they are losing their quality control and building an
ugly boat. I really love the way the 91-94 ProStars handle, unlike the
current trend towards riding higher out of the water.
Question how many real tournament ski boat companies are building
competition for ski doo's ?
Sorry, I couldn't resist.
LesC4
Wrote: <<<Now that MasterCraft is not a family owned business and the
bottom line is bucks>>>
MasterCraft has not been family owned since 1984 when the Coleman Company
bought them from Rob Shirley. So how could this have a affect on the
bottom line recently.
Why not built personal watercraft? SeaDoo owns a Celebrity a major I/O
manufacturer and Mercury Marine is about to introuduce their new line of
PWC's. Maybe MasterCraft was ahead of thier time.
Les Clark
Midwest MasterCraft Dealer
Le...@aol.com
Les Clark