replace mercruiser 888 with smaller engine
I want to replace the old Mercruiser 888-- 188 hp, alpha 1 sterndrive--
on my 23 ft cruiser with a smaller, new 3 liter 135 hp unit with
generation 2 alpha outdrive.I don't need to zip around at planing speed. Can the conversion be done without major trauma? Will the existing transom hole be OK. What about engine bearers, steering etc. Your advice appreciated |
mongo
Jan 16
2006
|
| Thank you everyone. But my 888, is 30 years old. It is in urgent need
of replacement. It is NOT for fuel-saving economy I am conemplating
re-powering to a smaller engine. It is because the old merc runs on 7
cylinders (rusted exhaust manifault killed the 8th with salt water),
has very bad blow-by. We seldom do more than 5 knots in the rivers
lakes where we cruise, and NEVER go at wide open throttle.
Thanks all |
mongo
Jan 18
|
| Get a replacement engine that bolts in. What is it you have, a 302? I
think you can still get those. I suspect the 351 is also a bolt in. And
don't get a 4 cylinder. That is too small an engine for your boat. "mongo" <tedareno@optusnet.com.au> wrote in message |
James
Jan 18
|
| If all you want to do is about 5 kts just put a small outboard on a swing-up
bracket on the transom. You could get a used one and have it installed for
a lot less money than the cost of the project you propose. Matter of fact,
you could buy a new aluminum skiff with a new OB and still save money, IMO. |
Butch
Jan 18
|
| 23 ft boat with a smaller engine means the engine will have to work extra
hard to go the same speed - even if that is slower.
Not to mention the ability to get out harms way is better with a larger
engine in particular getting out of the way of an oncoming storm.
Same principle as with a pickup truck, often a v8 will get BETTER mileage
than a six cylinder at highway speeds.
Keep what you got and make sure you keep it in top tune, with the money you
save you can easily justify the best mechanic once a year. |
Gorf
Jan 17
|
| Well ... first off, will you not be paying about $10K for that new
engine/outdrive? That's a lotta gas money ... or ... how much do you
expect to save on fuel? For me, I run just on plane at about 2100 rpm
which according to the power curves is about 90 hp. |
bowgus
Jan 17
|
| That's really nice on paper, but you arn't figuring the torque factor. I think what your result would be like putting a Toyota 4 cyl. in a
Chevy Suburban. that 888 will do more at 1/2 throttle than the 3.0 will at
full.Especially on a boat that size. to get the max performance out of
the 3.0 you'll have to turn at about 4000 RPM, and if you try to over
prop the boat to get the rpm down, you'll do nothing but lag the engine
go slower and suck more fuel. I have a 3.0 *(140 h.) in an 18 ft. fiberglass ChrisCraft, and my
brother has a 20 ft Century with a a 4.9 (292 cube 6 185 hp.) he and I
can run the same speed, I'm pulling 500 RPM minimum. more than he and
his boat uses less fuel If it was my boat, (and I know it's not) I'd leave it alone. |
tschnautz
Jan 17
|
| What about engine bearers, steering etc. No hardly any is the same. except the bellhousing mount on the outdrive |
tschnautz
Jan 17
|
| It'll be a hassle and expensive. If you want to go slow then just do it
with the motor you have. It's not like you will save a bunch of gas just
because you swap out for a slightly smaller engine. Boats use a lot of gas
no matter what the engine. Unless you are having problems with the 888. In
that case you could replace it with a more modern engine. Just about
anything will connect to the outdrive. At worst you may need a new
bellhousing. I believe the new 4 banger uses a front engine mount, where
are the engine mounts on your 888? Not many accessories will move so you
will need to buy a lot of stuff. I'm assuming you don't care about resale
as your crusier is possibly underpowered already and putting a smaller motor
in it will reduce it's resale. In any case there is no reason to replace your early alpha with the 2nd
version. The differences between the two alphas is trivial. "mongo" <tedareno@optusnet.com.au> wrote in message |
James
Jan 17
|
| first off, why do you want to convert? if it's for economy, I think
you'll be disapointed.
just my opinion. I think you will find more "trauma" than you wish to put up with. |
tschnautz
Jan 16
|
| Why do you say I'll be disappointed if economy is involved? |
mongo
Jan 16
|
