Mercruiser 3.7 question...

[Cheri Ann]

The boat we are in the process of buying (the Marathon I asked about a
week or so ago) puzzles me. It has a 3.7 litre engine (states 165hp on
plate). The guy told us FIRST that is was a 180hp. Apparently he was
wrong. Then he told us it was only a 4 cyclinder. Can't trust he knows
for sure...(Didn't find this info on the plate). Are these 4
cyclinders?

The guy told us it wasn't up to pulling water skiiers, and seeing the
horsepower I understand why!

Does it make sense that only a 165 hp would be put on a 23' boat? All
other boats I see this size (different make, though) have much larger
horsepower. Will we be sorry?!

Boat & motor can be seen at:
http://cutlassrestore.homestead.com/WeddingDay.html

Thanks in advance!
Cheri

[Wayne "Ratbo" Canino]

I looked at the picture and all I can see is that it *looks like* an inline
somethingotother.

Did you try counting the spark plugs. <running again>

-W

"Cheri Ann" <che...@erols.com> wrote in message
news:3D2D8CBB...@erols.com...

[Cheri Ann]

Okay Wayne...you better keep running!! :) (How fast can you run?!)
I shrugged off the "something wrong with Boo Boo?" comment, but I can't keep
letting you slide :)

Actually, I did realize after I posted that someone would ask me that...didn't
think it would be my buddy! Dumb us....no we didn't even look....figured we'd
check it all out better on a trip to the Marina without the owner there.

Yes, I need to go back and make the picture larger. I just made them all small
to fit them on the page. Actually, didn't plan on showing EVERYBODY, set it up
for friends and family to see. I thought it might help with my question now,
though...

[Cheri Ann]

Okay Wayne....I made the picture a little bigger. Can you tell anything by looking
now?

Cheri

[Wayne "Ratbo" Canino]

I can't, but that's more me being useless than the picture. My instinct is
that 3.7 litre would be a six, but someone here must know that. I'm an
outboard dood that knows what a 327/350 Chevy does - that's it.

-W

"Cheri Ann" <che...@erols.com> wrote in message

news:3D2D919D...@erols.com...

[Señor Chile Mas Grande]

Well, a 3.7L would be equivalent to approximately 225 cubic inches. The
largest automotive 4 cylinder I can recall off the top of my head would be
the old 196 cubic inch (approximately 3.2L) 4 cylinder that International
Harvester used to put in its old Scout....which was actually an IHC 392 cid
V8 cut in half. Most 4 cylinder automotive engines are 1.3L - 2.5L in size.

OTOH, 3.7L/225 cid would be well within the size range of normal automotive
inline 6 cylinder engines (normally, 3.0L - 4.0L). That fact, plus how long
the valve cover looks in the picture, leads me to believe this is probably a
6 cylinder inline engine.

"Wayne "Ratbo" Canino" <b17of...@nospam.hotmail.com> wrote in message
news:NAgX8.318432$R61.2...@rwcrnsc52.ops.asp.att.net...

[George Jefferson]

:I can't, but that's more me being useless than the picture. My instinct is

:that 3.7 litre would be a six, but someone here must know that. I'm an
:outboard dood that knows what a 327/350 Chevy does - that's it.

my instinct is that 3.7 number is wrong. All prepared to be corrected
but I've never heard of a 3.7 merc. The (only?) v6 is 4.3L and 3.7
is too big to be a 4cyl. Go take a look, if its a 4cyl anything
in a 23ft boat run away fast.
A ~180HP/4.3V6 is minimal, it will pull skiers but not real well.

[HLAviation]

>The boat we are in the process of buying (the Marathon I asked about a
>week or so ago) puzzles me. It has a 3.7 litre engine (states 165hp on
>plate). The guy told us FIRST that is was a 180hp. Apparently he was
>wrong. Then he told us it was only a 4 cyclinder. Can't trust he knows
>for sure...(Didn't find this info on the plate). Are these 4
>cyclinders?
>
>The guy told us it wasn't up to pulling water skiiers, and seeing the
>horsepower I understand why!
>
>Does it make sense that only a 165 hp would be put on a 23' boat? All
>other boats I see this size (different make, though) have much larger
>horsepower. Will we be sorry?!
>

Well, the 165 Mercruisers I know are the old straight 6 Chevys, nearly bullet
proof motors with a component to power ratio that won't let it blow up. The
170 hp (470 series) was a morphadite 4 cyl which was a cut in half V8 Ford.
I've worked on several boats with these and I am not impressed with them. The
165 6cyl is just a bit low on power for that size boat, but it's not bad for
taking 4 or 5 people for a cruise, just don't expect to haul ass. The boat is
gonna need trim tabs with this engine, more than likely, to be able to get the
bow down. The good thing is it gets some pretty good fuel economy.
http://hometown.aol.com/hlaviation/

[George Jefferson]

memory jogged by the photo, yes 4cyl and i think thats the engine they
always put closed cooling on for corrosion reasons. I'd be afraid
its hard to get parts for and hard to work on, but thats a guess.
You should talk to a local merc mechanic about it.

:Does it make sense that only a 165 hp would be put on a 23' boat?

well, not everybody wants to go fast and pull skiers. One thing
you should notice is that engine takes up a lot less space than a
v6 would.

:Will we be sorry?!

Depends on what kind of perfermance you expect.

[Cheri Ann]

Thanks SO much for your help! I really enjoyed the way you compared it to car
engines. Believe it or not, I understand those alot better than boat motors. :)

(I've helped totally tear down and rebuild automotive motors)

While surfing around I have discovered some posts from others running this
engine on a 21' boat. They seem to complain of not much speed and having a hard
time getting on a plane with a load. This boat was such a good deal (cheap)
that we couldn't pass it up. Maybe later we can replace with a mercruiser
engine with more horsepower.

Cheri

[bomar]

Here is a link to an ebay auction of a 165 hp Merc engine....has pics of the
beast.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=1843223859

"Cheri Ann" <che...@erols.com> wrote in message

news:3D2D8CBB...@erols.com...

[Cheri Ann]

Thanks for all the info!
Chaz does remember also seeing on the plate: 244 cu. in
Does this help to narrow down?

Cheri

[Jim Kelly]

The 3.7 Mercruiser is a 4 cylinder engine of Mercury manufacture except for
the cylinder head. It has the same bore and stroke as the 460 cid Ford V8
and uses the Ford cast iron cylinder head. The block is cast aluminum which
is one of its oddities since a cast iron block with an aluminum cylinder
head is more conventional in 4 cylinder engine design. The engine has
several other unique features such as a direct camshaft driven water pump
and a water cooled voltage regulator in the charging system.

This engine was available as the standard 3.7L rated at 165 hp and in later
models uprated to 170 hp. It was also available as the 3.7 LX, initially
rated at 180 hp and later uprated to 190 hp. The standard versions were
equipped with a 2bbl carb while the LX versions had a 4bbl. All models, due
to the aluminum block, had a closed cooling system.

These engines were produced in relatively large quantities and parts
availability is not a problem. They were also fairly reliable with the
exception of the charging system. The water cooled regulator system is
prone to failure but retrofit kits are available to install a conventional
charging system.

Regarding performance, their horsepower and torque curves come close to
matching the earlier (non-Vortec) 4.3 GM marine conversions despite the fact
that the 4.3 is a 6 cylinder. A 22 footer is at the upper limit of the boat
size that these engines would perform acceptability in.

If the boat suits you, in my opinion, you should not allow the fact that
it is equipped with this engine dissuade you from purchasing it.

[Cheri Ann]

Hi Jim!

You have explained it in terms that I understand very well. Thanks so
much for taking the time out to write this :) We've always owned an
outboard so we were clueless on these. You have given us alot of
information about these motors. You have quite a bit of knowledge on
these!

The owner did admit to us that it wasn't made for pulling skiiers, just
crusing around. He just gave us SUCH a great deal on the price, paid up
the next two months for the dry dock, and other extras. I'm glad you
think we should still purchase it. It's too hard to pass up.

Cheri

[Jim Thompson]

Mercruiser 3.7 Liter 224 cubic inch (165-190 HP) engines were built
during 1986-89. 4 cylinder engines.

Jim

On Thu, 11 Jul 2002 09:48:43 -0400, Cheri Ann <che...@erols.com>
wrote:

[tedk]

Hello,

I have this same motor in my 19' Larson Delta Cuddy (if you have the
165 3.7Liter straight 4 cyl). I'm in Lake Erie so the closed cooling
is nice to avoid Zebra muscle entry into the block. Also, keeps a
constant motor temp once it warms up. I ski off the back, but mine is
4' shorter/lighter. Could always use a few more H.P. but economy is
excellent. B.T.W. 460 Ford 7.4 liter / 2 = 3.7 liter inline 4. Mine
runs well for a 1986 model. Its hooked to a Alpha 1 drive. Mine had
points/condenser setup, but it's now much better with $90 upgrade to a
electronic ignition system. Took about 1/2 hr. No points/condensor
to change, and the timing is always set right. Be sure head is clean
and free of rust chips (being iron) when changing plugs. Don't want
to let bits of iron into the cylinders.

Ted
Jim Thompson <ji...@jimthompson.net> wrote in message news:<9rjuiu0lj25aps76e...@4ax.com>...

[Lloyd Sumpter]

Ah, yes, the 170: The Frankenstein of marine engines. Basically Merc.
sliced a V8 in half (the head, pistons, etc. are the same as a big-block
(7.4l)chevy V8)

OK engine, but you might have trouble finding parts for it, and 3.7 is
WAY big for a 4-cyl - it will vibrate.

Lloyd

[HLAviation]

>Ah, yes, the 170: The Frankenstein of marine engines. Basically Merc.
>sliced a V8 in half (the head, pistons, etc. are the same as a big-block
>(7.4l)chevy V8)

The head I had had Ford casting marks.

http://hometown.aol.com/hlaviation/

[tedk]

Hey HL,

Where/what should I look for to identify mine as Ford heads (See my
prev post). It is a "Ford" stamp, or some certain number, etc?

Thanks,
Ted
hlavi...@aol.com (HLAviation) wrote in message news:<20020722171343...@mb-me.aol.com>...

[HLAviation]

>Where/what should I look for to identify mine as Ford heads (See my
>prev post). It is a "Ford" stamp, or some certain number, etc?

The one I had had the FORD emblem you know and love cast into the head under
the vave cover, i forget exactly where, but it was obvious when I had the cover
off.
http://hometown.aol.com/hlaviation/

[tedk]

Thanks, I'll look for the symbol the next valve cover removal I do.
(not yet done, and hopefully not for a long time!)

tk
hlavi...@aol.com (HLAviation) wrote in message news:<20020726142622...@mb-mc.aol.com>...

[The Loner]

The symbol is under the cover.

--
The Loner

"tedk" <watersk...@yahoo.com> wrote in message
news:7ba63254.02072...@posting.google.com...