Conference vicki::boats

    I think you would be much happier with a v6. much more power and to do
    some serious sking with a few people on board i think this is what you
    want. a v6  is a very dependable motor with alot of torque.on of the
    best out there is the 4.3 v6 chevy, merc i/o.
    

    The 3.0 litre engine brings a lot of weight to the table for not too
    many horsepower.  Last I looked they were 115 propshaft HP.   A 115 
    outboard weighs about 1/3 as much and in this size range (17') we're talking
    about a significant percentage of the boat weight.   So I would choose
    between a 115 O/B and a 4.3 I/O, like .-1 said.

    From the viewpoint of someone who qualifies as a full sized adult skier
    (210 lbs, 6'1"), you can't have too much horsepower. With both feet in
    a slalom ski I can *eventually* get up behind a 115 o/b on a 17' with 
    3 average sized adults in it. It's a workout. Dragging one leg I can
    get up behind a tired 90 o/b but there's no point in skiing with that
    setup. I've been behind a 140 i/o on an 18' with 3 adults and that was
    about as speedy as the 115 o/b. I would think a 140+ hp o/b would do a
    much better job. 
    
    I have a 260 hp i/o (350 cu" GM block) in a 19'. I can pull up 2 slalom
    skiers (400 lbs) with 4 adults in the boat. I'm very pleased with the 
    performance. I don't consider the fuel economy to be bad either
    considering I can cruise at 32 mph with 4 adults at 3000 rpm.
    
    When I was boat shopping I found a lot of good used Checkmates with
    ample horsepower i/o's. Most of them had the V-8's, or the big 4
    cylinders (190 hp). In any case, bring a slalom ski and try it out
    before your buy it.
    
    ~jeff 

    Some late breaking thoughts, 
    
    One thing you don't want to loose sight of is the overall weight of the
    boat & engine. My 19' weighs in around 3000# for boat,engine,and
    trailer. 875# of that is the engine and outdrive. So although I love my
    V8 I/O, I had to upgrade my tow vehicle to pull it. My second choice
    was an 18' Checkmate with a 190 I/O which weighed about 600# less than
    what I bought.
    
    If towing capacity is going to be an issue than you may want to look at
    outboards as they tend to weigh less that I/O setups. A 140 hp OMC o/b
    or a 150 hp Merc o/b on a 17' should do a nice job.
    
    ~jeff

    I had a 18 ft with a 120 hp I/O for 4 years. It would pull up a 220 pound 
    adult skier with three adults in the boat, but it sure would have been nice
    to have a little more power. I have to agree with all the previous 
    replies about a little bit bigger engine. 
    
     I would definatly look into the six cylinder 4.3 liter I/O!!
    
    
    				jeff b. 
     

    re .0
    
    Just to add my 2 cents...I would go with the 4.3 liter I/O. You will 
    be happy you did in the long run. The 4.3 has good torque/HP and gets 
    good fuel mileage.
    
    							-mike-

RE: .0

I'd go for an I/O about 170 Hp. I have a 120 on a 19'
Chaparral (heavy boat) and it does fine with one person 
in the boat. Depends somewhat on how heavy the 17 ft
is your looking at. A simple change in prop pitch might
do the trick.

To be really safe, I'd go for a 170/190 Hp. Much more
Hp gets too heavy. I'd also stay with the I/O. Economy
and dependability would be far more important to me
than a few pounds of weight. Plus I can work on the I/O
quite easily my self.

    I'm not a skier, but i've owned a few boats.
    
    The consideration in my mind is the H.P to Weight ratio.
    
    Obviously this doesn't include the trailer.
    
    Weight can be calculated in several. The boat, motor, fuel.
    Or the above + passengers. Since passengers are a variable
    i would exclude them.
    
    Here's a few examples: (they may not be accurate)
    
    Motor H.P   Boat/Motor weight           Ratio
    
    120              2000lb.                 16.6:1
    
    140               "   "                  14.2
    
    160               "   "                  12.5
    
    190               "   "                  10.5
    
    260 V8            2400                   9.2
    
    
    
    If these are close, the V8 may weigh more, but the ratio is better
    than the rest.
    
    Obviously an outboard would be better than the V8 because of
    its reduced weight. Also an outboards power curve is much better,
    it will get on plane faster.
    
    The advantage of the I/O is the engine is more accessible, and
    most people are more familiar with it. It definitley becomes
    a personal choice on which to buy.
    
    I'm a V8 fan, it will certaily work less for this application,
    i wouldn't put MILAGE in this equation. For the hours you'll
    use it, the cost difference won't be enough to worry about,
    in the end, the V8 will outlast the others anyway.
    
    
    JIm 
    

    Well, I have been looking at new boats for the past few weeks and I have
    enjoyed it but it has been a challenge clearing up the confusions of
    makes, layouts and (most of all) engine/power choices. I have been
    looking in the 19'-21'foot range, for a boat to be primarily used on
    Lake Champlain in Vermont and something I will keep for quite a while
    since I am moving up from a much older boat. The budget is in the
    $14-18 K range (will be buying it with my father). I have been looking
    at Sea Rays, Maxum's, Wellcraft, Four-Winns, and Sunbirds (also ran
    into a VIP). Based on perceived value and taste I have been leaning
    toward the Maxum. I have found a number of '91 boats (obviously the
    best deals) but would order a '92 to get the right boat for the long
    haul if I had to. The make several versions of a 21' (actually 20'7")
    which look about right. We are leaning to the bowrider version, which
    comes in a front/rear facing seats with two jumpseats on either side of
    the engine cover OR a bucket seat/rear bench/sunlounger configuration. 
    We are leaning toward config. 1 above. 
    
    I have found both of the config's above in left over '91 boats. Here is
    where the engine issue complicates it. The rear jumpseat config. has a 
    4.3L, 175/155 (crankshaft/propshaft) I/O, while the rear bench config.
    boat (actually their "sport" version) has a 5.7L, 260/230 I/O. Both are
    great prices. The rear jumpseat config could be ordered as a '92 with a 
    5.0L, 200/180 I/O, but more $$$.
    
    The boats weigh about 2450 lbs. with the 4.3 and the 5.7 (according to 
    Mercruiser spec sheet) adds  about 100lbs (805 lbs up to 905 lbs). I am
    concerned that the 4.3 in this boat will be too little for large adult
    skiing with 2-4 folks on board, or will be marginal. I have rented a
    19' Baja with the 205/185 4.3 (4 barrel carb vs. 2 barrel) and skied a
    large adult with 5 on board with very good success. I like the 260/230
    but am concerned about weight/ecomomy  and it being
    the second-choice boat configuration. The 200/180 '92 order may be
    optimum (Maxum does not offer the 205/185 4.3L) but the '91's are great
    prices ( the 260/230 is about $16K with galvanized trailer, full canvas, 
    etc.). Very sharp looking boat.
    
    What are your opinons of these options (particularly the 175/155 4.3L)
    including experiences with the two configurations (front/rear facing
    with rear jump seats VS. buckets/rear bench). Any help with this issue
    will be appreciated. Thanks.
    
    Larry

    
    	Larry,
    
    	I have a '88 205 Fourwinns with a cuddy front. The engine is a 175
    	OMC, with a steel prop 16" pitch X 15" dia. The boat weights aprox.
    	2800 with gas another stuff, then 2 adults brings the weight up
    	some 3100 lbs. I have has no problems skiing, the boat does between
    	35-37. With out a skier the boat does 40. The 4.3 engine is a 
    	small power house, it provides good torque (see pass issue in
    	trailer boats for 4.3 comments).  My neighbor has a '88 Bayliner
    	19' with a 260 engine. His boat will do between 50-54 on the water.
    	So are you looking to go real fast or by matching the prop to the
    	boat, you will be able to have a lighter weight engine, save some
    	$$$ on gas and still be able to ski. 
    
    	Good luck
    
    

    I have a 19' Larson Cuddy with the 4.3 merc and it pushes the boat
    along just fine. apx. 50mph.  Not really sure because the wife yells
    at me. (+:}    Although I have not pulled skiers yet I have pulled
    my friend on a knee board with seven adults onboard at the time. 
    The larson has the back-to-back seats and also the rear jumps.
    I like the back-to-backs because they fold out as sunloungers. Also
    the cushions on the rear jump seats can be lifted up to meet with 
    the engine compartment so that you also have a rear sundeck.  The
    boat I have also comes in the bench seat fashion.  I think with the 
    bench/buckets you loose out on seating capacity but gain leg room.
    although since you are looking at a bowrider you should have plenty
    of seats.   
    Not sure where you are from but you may want to look at the Larsons
    I have had no problems with the boat or the dealer.  Actually I was
    at Marine USA the other day and they had a bench model of my boat
    (DC190) on the showroom with a price of $13,200 (I think) including
    trailer and such.   You may want to give them a try if you havn't
    
    
    Colin
    

    For my $.02,  I'd rather have the horsepower on demand.  It is very
    costly to add horsepower later if you find that originally didn't get
    enough.
    
    With the bigger engine you have the choice to throttle back for economy
    and have plenty of power for the "get up 'n go" times.  
    
    So, if there's not much money difference, I'd opt for the 260/230.
    
    Good Luck,
    
    Tom
    

    
    re:.9  "for the long haul" does that = longevity.
    
    if so you answered your own question, get the V8..
    
    JIm.

    
    I spoke with a guy on the river the other day and he was driving an
    18' Larson and mentioned that the 4 cylinder I/O in his boat was
    rated 200hp, but I neglected to get into the details. Is this true?
    
    Does some manufacturer offer a 200hp 4 cylinder marine engine? Sounds
    like it might have a damn good power-to-weight ratio....
    
    Rick
    
    BTW: I'll stay with my 351ci for now....

    I believe Mercruiser makes a I-4 that's rated at 185 h.p. (my cousin
    had one in a 19' stingray-did about 50mph!)  Perhaps it's this engine
    with a 4 bbl?
    Doug

��               <<< Note 882.15 by TOTH::WHYNOT "Malibu Skier" >>>
��                              -< Just a guess... >-
��    I believe Mercruiser makes a I-4 that's rated at 185 h.p. (my cousin
��    had one in a 19' stingray-did about 50mph!)  Perhaps it's this engine
��    with a 4 bbl?
��    Doug

    There used to be a MerCruiser 485 which was a 220 c.i. four
    cylinder aluminum block (cast by Mercury Marine) with a ford
    460 head.  (One head from a V8.)  It was (very
    optimistically) rated at 185 crankshaft horsepower.  Dropped
    from the lineup about two years ago.  Power output was close
    to the V6, and buying the GM V6 block was cheaper than
    casting the Al block.

    The 485 started life as the 470 which I think was rated at
    165 horsepower.  Also, 185 was the high-output rating, there
    was a lower rating with a smaller carburator.

    I don't know of any four rated at 200 crankshaft horsepower,
    and definatly none with 200 propshaft rating.

    Straight from my 1991 Mercruiser pamphlet:
    Alpha Models
    Model  propshaft HP    comments
    -------------------------------------
    3.0 L      115     181 cubic inch in-line four cylinder, 2 barrel carb
    3.0 LX     135     high perf. intake and exhaust, 2 barrel carb, 181
    4.3 L      155     2 barrel carb, 262 cubic inch V-6
    4.3 LX     175     4 barrel carb          "
    5.0 L      180     2 barrel carb, 305 cubic inch V-8
    5.0 LX     205     4 barrel carb          "
    5.7 L      230     4 barrel carb, 350 cubic inch V-8
    
    Bravo Models 
    
    Model  prop. HP   drive           comments
    -----------------------------------------------------
    5.7 L   240      Bravo 2        4 barrel, 350
    7.4 L   300      Bravo 1 or 2   4 barrel, 454
    D183    140          "          183 cubic inch diesel
    D219    170          "          219 cubic inch diesel
    D254    200          "          254 cubic inch diesel
    
    Magnum models
    
    model    Prop.HP     drive            comments
    ------------------------------------------------------
    350 MAG    240       Alpha 1          5.7 liter V-8
    454 MAG    350       Bravo 1          7.4 liter V-8
    502 MAG    390       Bravo 1          8.2 liter V-8
    
    Performance Products
    
    Model     Prop HP     comments
    -------------------------------
    HP 425     385        454 cubic inch, 4 barrel
    HP 465     445        502 cubic inch, 4 barrel
    HP 500     465        540 cubic inch, 4 barrel
    HP 525SC   490        454 cubic inch, 4 barrel, supercharged?
    HP 575     525        540 cubic inch, 4 barrel
    

Re: 525SC, yes Mercruiser has a line of Supercharged engines, I thought I had
mentioned that somewhere in here. I don't remember the details anymore, but
they were reviewed, installed in Wellcraft Scarab Thunder series boats in 
Boating (I think) magazine. It was a recent edition with a Sunseeker (the
reason I bought it) on the cover. If memory serves there are three: the 525,
a 600, and an 800 Hp model. The 525 and 600 are custom jobs, but are still
offered with a short warranty. The 800 is all yours from the moment it leaves
the dealer. I'll try to remember to bring the mag back from the Cape if any-
one is interested in more details. Cost? Forget it, if you have to ask..... :-)

    Mercruiser used to make a 170 hp (2 bbl), and a 190 hp (4bbl) inline 4
    engine. It was 3.7(?) liters, or about 225 cubic inches. As I was told,
    it was based on one half of the Ford 460 big block V8. At .83 hp per
    cubic inch it's a very strong motor and by no means a lightweight unit.
    
    ~jeff

    After a bewildering couple of weeks of touring the boat dealers and
    coping with seemingly endless manufacturer/configuration/engine/color
    conbinations many impressions are formed. In the engine area, all the
    dealers seemed to have, order, and rave about the 4.3L V6 offered by
    both Mercruiser and OMC. Many of them had felt that the 140/115 4-cyl.
    was underpowered and brought alot of weight to their 19-21 foot boat
    lines. They also had alot of customers who did not want to move the
    next step to a V8. About a month ago I rented on Lake George a Baja 
    190 with a 205/185 4.3L, 4V Yamaha I/O. The boat was a real rocket 
    and until I looked under the engine cover I thought it was a small V8.
    Most manufacturers offer the 200/180 5L GM 305 CI or Ford 302 CI 2V
    engine as the next step up from the 175/155 2V 4.3L, while only some offer
    the 205/185 4.3 LX as the next step. I do not know if this reflects
    availability of the 205/185 4.3L or what but this would seem to be a
    terrific mid-range engine (lighter than the 5.0L, good economy at most
    ranges where the 4-V is only running on the primaries, yet more punch
    than the 2V 4.3L when you want it). Maybe it will become more common in
    the future. Anyway, the dealers seem to really like the 4.3L and order
    alot of boats with the 175/155. This is the top engine in the 18'
    length boat, with the 200/180 5.0L as the top in the 19', and then the
    260/230 5.7L option available in the 20 and 21'. SeaRay seemed to have
    the widest engine options on most of their boats. Perhaps this is one
    of the reasons their prices are higher.
    
    Larry
    looked

This seems to be an appropriate note to ask your advice & experience:

This wknd we decided to get a Limestone 24 (23'10"L x 9'2"B, 4700 lbs), 
deep vee (22 degree deadrise), and three engine options to consider:  230 
hp, 260 hp or 330 hp, all Mercruisers.  It's a very solid and capable 
boat, known for excellent seakeeping rather than top end, and unusual in 
that the engine is amidship, with a 5' jackshaft from rear of the engine, 
under the sole, through the transom to the lower unit.  Heavily 
constructed, there have been no complaints about the jackshaft vs rear 
engine configuration, so that's not an issue.

I've driven the 230, and it's a bit weaker than I'd like.  So, 260 or 330?
Am I correct in understanding the 260 is a 5.7l (350 ci) and the 330 a 
7.4/454?  My questions fall in three areas:

1)  PERFORMANCE:  Do any of you have experience with similar size/weight
boats with either of these engines?  The builder doesn't really talk about
top end performance, but I gather it's around 38 kts (44 mph) for the 260,
and perhaps 41-43 kts (47-49 mph) for the 330 -- both plenty fast for what
we intend.  Do these numbers sound reasonable to expect?  Any information
on relative fuel economies?  9gph @ 28kts @ 3000rpm for the 260 was
quoted; would the 330 be much worse at a similar boat speed?  (How much
heavier is the 454 over the 350?) 

2)  MAINTENANCE/LIFESPAN:  A larger engine usually is less stressed than a 
smaller one for the same boat speed, but I wonder about added heat build-up 
with it.  And much worse fuel consumption.  Are there any significant
service differences? 

3)  DESIGN PROBLEMS/FEATURES:  Since there's a good used market in this 
model, we'll likely look very closely at what available (save some $$$ if 
possible), and that means looking back over nearly 10 years of production
models. Are there any significant "break points" in terms of desireable
features becoming available in either Mercruiser size which I'd do well to
get if possible?  (Y'know, they stopped the lower unit gear lube leak in
the '88 XYZ model,...stuff like that.) 

Which one would you choose?

Thanks for your help; there certainly seem to be a lot of knowledgeable 
I/O owners among you!

John.

    How about the 5.9l Cummins turbo-diesel?  I think that may be an
    optional engine.  A bit more weight, but that's offset by
    smaller fuel load for the same range.

    re .20
    
    If you think the Baja 190 w/205 4.3L Yamaha was a rocket...try that
    HP/weight ratio combo, in their 17' Sunsport - very quick!
    
    The 205/185 HP 4.3L has a very good HP to weight ratio for most boats
    in the 17'-20' range. 
    
    							Good Luck!
    							  -mike- 

RE: .22, 
>>>    How about the 5.9l Cummins turbo-diesel?  I think that may be an
>>>    optional engine.  A bit more weight, but that's offset by
>>>    smaller fuel load for the same range.

(Assuming you were replying to the Limestone 24 question,)  Do you know 
the engine weight and horsepower?   The 260 yields ~18 lbs/hp, and I don't 
think we'd want to go above 20 lbs/hp.  The weight is a concern, since I 
don't want to have to lift the hull another inch or two -- that'd use up 
still more power, and start a vicious cycle of wanting more power.

BTW, in talking with another dealer (and owner) since posting .21, it
seems 350ci/260hp is considered the optimum engine for that boat.  (And 
the 230 is a 305ci; you probably knew that already.)  The 454/330 really
matters mostly at the top end, where it adds a bit, and at the gas pump,
where it also adds a bit (or two).  Apart from what I'd presume to be a
>$5K (???) premium for diesel power in that size, I'd much prefer it
despite slower acceleration and probably lower top speed.  But add in more
than a modest weight penalty, and it probably isn't practical for
real-world use in this boat. 

J.

��(Assuming you were replying to the Limestone 24 question,)  Do you know 
��the engine weight and horsepower?   The 260 yields ~18 lbs/hp, and I don't 
��think we'd want to go above 20 lbs/hp.  The weight is a concern, since I 
��don't want to have to lift the hull another inch or two -- that'd use up 
��still more power, and start a vicious cycle of wanting more power.

    Model	High Output Power	Weight		Max. Fuel Cons.

    6BT5.9-M	210 BHP @ 2600 RPM	1090 lbs	11.2 gal/hour
    6BT5.9-M1	250 BHP @ 2500 RPM	1130		12.4
    6B55.9-M2	300 BHP @ 2800 RPM	1170		16.2

    Weights include heat exchanger.

    It was the Shamrock that I was thinking of, which offers the
    Cummins diesel option in a 24' boat.

    The 454 ci engine may still be your best choice if your going to
    run this boat with a lot of weight in it, people and/or gear.
    I have a 25 ft Proline with the 454, top end is 33 knots or so when
    light, it will do 20 knots at 3300 rpm. Now I add all my tuna gear,
    bait, ice, 166 gal. fuel, marine growth, I need to run at 3700 rpm's
    to get 20 knots. 
    As for diesel, I'd love to have a Volvo tamd41 i/o. I wouldn't look
    at a Cummins.
    
    Steve

    re: note 882.24
    
    I believe that the 260 HP and the 230 HP are really the same 350 cubic
    inch engine.  The 260 HP is being measured at the crankshaft versus
    the 230 HP being at the propshaft, in other words there is a loss of
    30 HP in the I/O unit.  The same Mercruiser engine with a Borg-Warner
    inboard tranny only loses 10 HP to the gear box because it's a straight
    thru drive.  It's important when comparing different boats/engine
    combos that the HP figures they are quoting are all the same.  Industry
    standards are getting away from quoting crankshaft cause it doesn't
    take into account drive losses.
    Wayne

    Good point - what's particularly confusing is with used boats.  People
    (naturally) state the engine HP as it is given on the engine (or
    otherwise communicated when the boat was purchased).   So you see
    any boat more than a couple of years old with the popular 350 cid
    engine listed as 260 hp, which is 230 propshaft thesedays.   
    
    To make it more confusing there is also a 230 *cranskshaft* 
    (one of the variants of the 5.0L 302 block) which is something like 200
    hp at the propshaft.   So if you see "230 hp" you really have to ask 
    questions...

re: .28,
Jim,  that's very helpful...thanks.  I'm convinced the dealer is talking
shaft output, not at the prop, which makes his "305 ci" with 230 hp and
350 ci with 260 hp make sense. 

Wherever it's measured, my point of reference is the performance I 
experienced with the smaller of those two engines, and I know we want 
something with at least another helping of Wheaties added.  The comment on 
the 454 is also useful; right now I'm trying to track down more info on a 
rumor I heard that the 454 in that installation is tight, and may tend to 
get much hotter.  FWC is the culprit, but of course we'll opt for it.

I'm definitely going to investigate the diesel option, though those 
weights may limit us.  As may the physical dimensions, as it needs to fit 
in the standard engine box.  The 454 is reportedly a rather close fit.

Thanks for your inputs.

J.

    Rough engine/drive dimensions:
    
    Small block (305/350):
       length from transom (at crankshaft centerline) to forward most part
          of engine = 37 inches
       width = 29 inches
       height = 20 1/16 inches
       weight: 
              305 with Alpha drive = 893#
              350 with Alpha drive = 907#
              350 with Bravo Two drive = 1008#
    
    Big block (454):
       length from transom (ditto note above) = 39 inches
       width = 32 
       height = 21 1/16
       weight:
              454 with Bravo One drive = 1113#
              454 with Bravo Two drive = 1148#
    
    Wayne

    Isn't the smaller small block V-8 302 CID, not 305?  (5.0 litres).
    
    Interesting to note that the "big block" 454 isn't really that much
    heavier than the small block.
    

RE: .31 
>> Isn't the smaller small block V-8 302 CID, not 305?  (5.0 litres).

No, the smaller of the two Chevy small blocks is the 305.  The Chevy 
302 was the original (~1968) Z28 motor, long since out of regular
production. 

Present Chevy small blocks come in 305/350 flavors.  Fords are 302/351.

Interesting to note that Ford is coming out with an "over the counter"
streetable high performance 351.  HP rating is up around 375(!), price 
hadn't been announced at the time Hot Rod magazine covered the story.  
It's supposed to be available this fall.  Should be interesting to see 
how it will work in a marine application, such as a Ski Nautique.

Rick

    
    
    302= ford
    
    305= gm
    
    351=ford
    
    350= gm.
    
    personally if i had to chose, i would take the 350. the 454 is a PIG
    
    also with regard to diesel, you would have to go turbo, and it would
    cost more than the boat and trail and all the gear, and gas you would
    be using for a lot of years.
    
    the 350 or 351 will meet your requirements, and be around for awhile.
    
    there was definitely some knoweldgeable info here.
    
    
    JIm.

    Even though I'm a Ford car fan (5 liter Mustang GT is my dream car), I
    believe that the Chevy 350 with the 4 bolt main is the best engine ever
    made.  It is bullet proof and easily modified.  Parts are available
    anywhere and are generally less expensive than other makes.  
    Just my opinion.
    Wayne

	From the '92 rumor mill....

	There is a 280 HP PCM unit.  I have no details regarding the
block that is used or whether it will have fuel injection.

	R

RE: .33,

>>>    also with regard to diesel, you would have to go turbo, and it would
>>>    cost more than the boat and trail and all the gear, and gas you would
>>>    be using for a lot of years.

Yes, I agree; the interest alone on the additional investment might 
cover the additional fuel consumed; shorter range is a reasonable 
trade-off, given that we should get over 200 useable miles on full tanks.

This information, both knowledge and opinion, has been extremely helpful. 
Unless something new hits the docks this winter, I think we'll go for the
350 with 260 shaft hp. 

The bad news I discovered is that the Limestone 24 Runabout used market
has mostly dried up, and all '91s have been sold.  Guess we have to look
at new. 

John.

My '83 260 chevy has those lighter heads which tend to burn out exhaust valves
and seats at 400-600 hours.  I don't know if it's been corrected or is still
an issue.  Something to check out before you buy (please post results).

Dave

    
    
    Re. .38, are you positive of this. Lighter heads.....
    
    Please explain
    
    JIm.

In  the first half of note 844.* I trouble-shot a problem on my 260.  One of the
noters suggested looking to see if I have the scallop head (cheaper ones).

That night I looked thru my merc shop manual and found a tech tip on how to
determine if you have the heavy head or the lightweight head.  By looking at
the edge to see if it is scalloped.  

So its for real and I understand that the lack of lead in todays gas is the 
culprit for the "premature"  valve/seat problem.  

I don't know when/if merc has addressed this issue, but its sounds like you 
have a current list of contacts to address this issue.  I will be looking for a
newer boat and I would like to know what year to look at to avoid this.

Please read the first half of note 844 and post what you think/find.

Dave

    
    	Regarding engine size and so on, what is your insurance company
    	quoting for rates. In their eyes the bigger the engine, faster the
    	boat goes equals a greater risk, so it will cost $$$$. Plus they
    	will look at your experience and if boating courses have been
        taken. 
    
    	My .02 
    
    	Mike

    Well, since my original question  in .9, we decided to go with the '91
    Maxum 2100SSL (20'8") with the 260 Mercruiser. The deal was really
    unbeatable and with any of the other options I was paying more for less
    boat/engine. The dealer will also winterize and store it for the winter
    since I need to do some mods to my father's garage before the new one
    will fit. The bad news is I HAVE TO WAIT UNTIL NEXT YEAR TO USE IT!!
    Anyway, I can wait and will be looking forward to Spring. I also based
    some of my engine decision on longevity of a bigger engine not working
    as hard, having the extra ponies when needed, and the fact that, for
    the amount of use the boat will actually get each year, the extra gas
    cost will not be significant. The bucket seat/rear bench/sunlounger
    layout actually seemed to have better engine accessibility as well as
    having all passengers facing forward, with the bow for extra seating
    when really needed. The Maxum seemed to be a really good value. The
    insurance was a real concern of mine, but turned out to be not as bad
    as I had heard horror stories about. $265 per year for liability/boat
    and trailer.
    
    Anyway, Thanks for all your inputs, ideas, and opinions. As always they
    were a big help. Thanks again.
    
    Larry

    What about outboards on off shore boats.  I have heard by various
    people that outboards/deisel is the only way to go.  They are more
    ecconomical and last longer.  Does anyone have any experiences as to
    power requirements for a 25' 5860 lb boat.  It will weigh more with 250
    gals or gas and 3-4 people.  
    
    Mfg specs say 41-44 mph with twin 150 outboards and 45-49 with twin
    200's.  I'm sure that is with one person and one gallon of gas.
    
    I don't want to overpower as I do a lot of trolling but also will be
    running off-shore and would like enough power if I need it.  Fuel
    economy is also a consideration; but it certianly takes second place to
    safety.
    
    Gordon
    

    Well I'm sure you'll get a lot of outboard vs I/O argument in here.
    
    Outboards probably last longer (fewer moving parts).
    Outboards probably are *not* more economical.  I believe their fuel
    consumption is higher in general, and their initial cost per HP is
    also higher than an I/O.
    
    Some people use propshaft HP to weight ratios as some indicator as
    to how fast a boat might go.  A rule of thumb seems to be that a
    1:20 ratio pushes a planing hull in the 30-35 range (assuming some
    non-weird prop pitch and a realistic load like 3 people and 1/2 tank).
    If you apply that metric, 41-44 seems to be stretching it for your
    example which is pretty close to 1:20 with the twin 150's.  The
    equation is most definitely non-linear so I couldn't even begin to
    extrapolate about the 400 hp, but I have a friend with a 4000 lb
    boat with 330 hp (1:12) and I think he tops out in the 45-49 range.

FWIW, I'm looking at a 4700 22-degree deep vee which can hit 40-41 mph 
with 260 hp I/O.  With the 330 hp I/O, they say it does 45-46.  Another
customer with money to burn bought the same hull and had a custom O/B
extension built, to which a pair of 200 hp Johnsons were installed--they 
claim he get into the high 50's with that combo, which is probably due 
partly to longer length and lighter weight as well as the added power.

The flatter the bottom (aft in particular), the less power to drive it a 
given speed.  Deep vees given up in top end some of what they gain in 
softer ride.  Width, number and placement of planing strakes can also 
affect the equation.

J.

    You engine experts must know the answer to this one...  What is
    the main difference between the 305 and 350 "small" block V-8s?  Their
    external size is the same and their wight is pretty close.  Was
    the 305 bored/stroked to 350, or is it a different block altogether
    (someone mentioned 4-bolt main bearings on the 350 earlier as another
    difference, or did I read it wrong?)
    

    The stroke is the same (3.48). The bore on the 305 is 3.87.  The bore
    on the 350 is 4.001.  You cannot tell the difference between any of the
    Chevy small blocks unless you know what to look for or you check the
    casting numbers.  The 305 had a bad problem with heads that would
    crack.  If the bottom of the head where it bolts to the block is
    scalloped rather than straight, keep away from it or swap heads
    (many others will fit).  The 350 HD (and possible the 400) was the only
    Chevy small black available with 4 bolt mains (there is also a 350 with
    two bolt mains).  There is not a consensus that the added expense of
    the four bolt main engine is worth it especially in a boat where the
    RPM's shouldn't go above 4500.  Engine failures generally occur in the
    rod or the rod bearing, not by the main web letting go.
    Wayne

    Thanks.   Reason I asked is that if you look at any boat where you have
    a choice between the 5.0L and 5.7L engines, there is no weight
    difference and the incremental cost is marginal, leading one to ask
    why wouldn't you usually go with the 5.7L (assuming it was within the
    max horsepower for the boat)?  The gas consumption would be higher at
    a given RPM but as has been said a lot in this file, that doesn't
    necessarily mean anything since at cruise the bigger engine would be
    turning fewer RPMs.   This assertion is also borne out by the fact that
    you see *many* more 5.7L engines on the used boat market than 5.0L. 
    

    What do 4 bolt mains have to do with web failure in an engine, or, is
    that your point?  Would 4 bolt mains affect the liklihook of rod
    bearing failures? 
    
    
    

    My info comes from some of the local motor heads here in NIO.  My
    point (actually their point) was that something else will usually
    let go before the mains come apart.  It doesn't matter if it's two or
    four bolts.  I've had four small block Chevy engines go bad from 
    over revving for long periods of time in my old Jeep (5.36 rear-end
    gears).  It was the wrist pin in the piston that started to rap.  I
    never actually broke a rod or anything dramatic like that.  I
    personally would rather have an engine designed for use in trucks
    (4 bolt mains) given the choice no matter what my local motor head
    experts tell me.  
    Wayne

    Whats the red line RPM on a 350 Chevy 4 bolt main engine ? (stock
    engine)  Whats the max rpm one would want to run a 350 at on the
    highway... that is hour after hour such as cruising on a highway?
    
    I have a 4 bolt main in my truck and on the highway I run 3000 to 3200
    RPM at 55-60 MPH.  
    
    Thanks,  Jeff

      The Max RPM's that my engine (Indmar Model 300SP, 350-4 bolt) is spec'd
    for is 4800.  Although I'd have to take the prop off to ever reach
    that...;^)   WOT with a 13X13 prop is about 4200 RPM, and tranny
    gearing is 1:1
    
    Doug

RE: Redline

There's big difference between the redline for short bursts, and the
redline for extended cruising.  A stock 4 bolt main Chevy should take
6000 rpm for a few seconds, assuming the valvetrain is up to snuff.
For extended highway or marine cruising I would think you'd want to 
limit rpms to <3500.  The engine will stay together at higher speeds, 
but engine wear is also GREATLY accelerated at higher rpm.

RE: The difference between a Chevy 305 and a 350

The major difference is in the profit for Chevy!  The two motors are 
basically identical, with the only differences being bore and possibly 
different camshaft profiles.  I'd be willing to bet it doesn't cost 
Chevy more than a few dollars more to build a 350 than it does a 305.  
But they sure charge a lot more, knowing that plenty of people will pay 
the difference for the extra performance.  This happens a lot with 
outboards too, most engine configurations are used for 2 or 3 different
hp ratings, with the only difference being a larger bore or different 
port sizes.  It doesn't cost 'em a cent more to bore a motor an extra 
1/8" for 5 or 10 extra hp, but it means several hundred dollars in extra 
profit. I've seen an old Mercury outboard where the major difference 
between the 40hp and the 50hp was that the 40 had a throttle stop, 
limiting the carb opening.  

Rick

    re: .-1  It's the same story in outboards.  And it's funny that you
    (Rick W) should bring this up because the engines on your boat and mine
    (90 & 115 OMC o/b) are a perfect example.  In this case there isn't
    even a displacement difference so even the pistons are identical
    between the two engines.   The carbs also appear to be physically
    identical, so the only differences left are port sizes and maybe
    jetting.  Yet the retail price of the 115 is around $1000 more than the
    90.   The 120/140 is another example.

    
    its in the cfm of the carb.....
    
    JIm.

    Rick, you could swap motors with Jim when he's not looking.  Then
    swap the engine covers so he thinks he still has a 115 HP.  He'll be
    in the notes file next spring asking for advise on why his boat
    all of a sudden got so slow.
    Wayne

    You'd think OMC would at least make the deception more plausible by
    putting the 115 in a slightly bigger package - but in fact they are
    identical housings.
    
    So the question is, if Jim B is right, you gotta be able to buy a
    couple of 115 carbs and install them for less than what OMC gets
    for the difference between the 90 and 115.
    
    This seems too easy.  Must be a catch.
    

    
    In addition i would think an intake manifold would be needed,...
    
    The lower end gearing and prop might be larger..
    
    I think someone said the difference was about $1000. i think
    
    carbs, manifold, prop would add to more than that, not really
    
    sure about the lower unit...
    
    JIm

    Might not need the manifolds if they simply used the ever popular
    restrictor plate under the carb.
    
    Carl