Questions regarding GM V8 Marine Engines
Paul & Valerie Fowler
so that I can convert my nightmare boat into something that I actually
enjoy.
The original owner had an 898 Mercruiser, which I understand is a 305 with a
2 barrel carb. At some point, he blew the 305 and replaced it with a 350
with a 4 barrel.
Here are my questions...
Is there any visible difference between a 305 and 350, so that I can be sure
that there is a 350 in it?
Since I am having some carburetor problems, and one option is a new carb, I
want to be certain that I get the correct carb.
Can a 4 barrel from a car be made to work with a marine engine?
Is there any way to confirm that this is actually a marine engine, without
ripping it apart?
I probably shouldn't have bought this boat, but I do enjoy a good challenge,
and it was CHEAP!
Last question... Should this engine continue to baffle me, does anyone have
any idea what a complete rebuilt marine engine is worth? Just the engine, I
can install it.
BTW, it is in a late 70's Glastron V195. It tops out at 52mph on the speedo
and actually has a good skiing wake, which is surprising, considering the
weight of this boat.
Thanks Folks,
Paul Fowler
--
From the Home of:
Paul, Valerie, Lauren, Kyle & Gregory Fowler
Mailto:pvfo...@sympatico.ca
Capt. Mooron
"Paul & Valerie Fowler" <paul....@sympatico.ca> wrote in message
| Is there any visible difference between a 305 and 350, so that I can be
sure
| that there is a 350 in it?
Yes....
| Since I am having some carburetor problems, and one option is a new carb,
I
| want to be certain that I get the correct carb.
| Can a 4 barrel from a car be made to work with a marine engine?
A marine carb requires a flame arrestor
| Is there any way to confirm that this is actually a marine engine, without
| ripping it apart?
No... a marine engine may be built to allow even wear while operating at a
constant rpm. It will have water cooled exhaust and have a flame arrestor on
the carb.
| Last question... Should this engine continue to baffle me, does anyone
have
| any idea what a complete rebuilt marine engine is worth? Just the engine,
I
| can install it.
Price range even rebuilt will be in excess of $5000.
CM
Greg Moore
block, just behind the right head (when facing the front of the engine),
usually start out like '050...' That will usually tell you the block info
you need to some amount.
Now the harder chase.. It may be the 350, but depending on what year and
application it is from, the HP output it was designed for can be very
different.. Its cam, compression ratio, intake valve size, intake port
shape and piston top shape will all effect its output and the casting
numbers won't help with that. On the plus side, personally, I would take any
generation of 350 over the 305, just a better motor period.
Internally, there may be very little difference between your motor and a
marine version, depending on what he got it from. If it was a heavy duty
truck application, they will be extremely similar inside. If it was from a
late model pollution controlled car, there will be a lot of difference
(mostly in the heads, cam and intake). I'll assume he reused all the
external parts from the 305 such as distributor, alternator, starter etc, if
not, you'll need them. An automotive distributor will have a vacuum advance
pot on it and it cannot be made to run properly in a marine application, the
rest are fire hazards if not marine. For a carb, probably best to go with a
Holley Marine carb (marine carbs have overflows that dump into the barrels
as apposed to outside into the engine bay). Since Holley's are much easier
to adjust then a GM Q-jet you can make up for any miss-match in internal
parts better. Get a 600cfm or at max a 650cfm. If the existing carb has
vacuum nipples on it, then it isn't a marine version and is probably jetted
to cruise at 5% throttle, you will cruise at 50% or more opening. If it has
nipples, you will also have a hard time getting things to idle right since
it was made to use a vacuum advance on the distributor and boats can't use
one. If there are no nipples at all anywhere around the base of it, then it
is probably a marine unit, but maybe not made for the engine he used, or,
maybe just not working right.
Some questions for you...
Does the carb have nipples
What kind of choke does it have (electric, round heat pot, little box on the
intake)
What colour is the carb, or, can you see what kind it is (either a Holley or
a Rochester) (Merc always painted them black, no car was ever painted)
What kind of distributor is in the boat (or at least describe its size and
connections)
Is the intake aluminum or cast iron (scrape a bit of paint off if needed)
What colour is the engine, or if it has been painted, try to find some
colour under the black, usually blue or orange)
Do the valve covers use hold down bolts in the center or around the lip
(center means very recent engine, possibly Vortec)
Do the spark plugs go in parallel to the water or at a noticeable downward
angle
Greg Moore
"Paul & Valerie Fowler" <paul....@sympatico.ca> wrote in message
news:aOoQa.1346$104.1...@news20.bellglobal.com...
Greg Moore
You are telling him things that only distinguish a properly installed engine
in a boat. The jacketed exhaust, flame arrestor and so on are all direct
bolt ons to any engine, truck, marine, stationary or car.
Also, to rebuild a marine engine is roughly the same cost as rebuilding a
truck engine and that can be done (block and heads) for around 1800 cdn,
bored, honed, valve job, new bearings, rings, pistons etc.. You may have to
add $100 or so for forged pistons, but not all marine engines used and, and
many performance land engines did.. Also, most automotive blocks can be
rebuilt to marine specs. Where the marine cost escalates is whats on the
outside, distributor, carb, manifolds etc and hopefully in this case, all
the 305 components were used as they would be direct fit, even the old 2
barrel carb would work with minor re-jetting to produce a 240hp 5.7 Chev.
Greg Moore
"Capt. Mooron" <over...@mooron.ca> wrote in message
news:d%wQa.41371$PD3.2...@nnrp1.uunet.ca...
Capt. Mooron
rebuilt marine engine.
In all honesty any mechanic could confirm engine type. I rebuilt a 318
Chrysler about 20 years ago and have forgotten most of what I learned with
that experience. I do remember marine parts and my choice of the Holly 4
barrel with flame arrestor. Velvet drive marine transmission. It was a
large block, truck engine. I rebuilt it with a mechanic buddy that
specialized in race car engines. He did it to learn.. so the work was free
but the machining and parts cost me plenty. Back then the cost was $1800 to
do it myself in his shop.
A rebuilt automotive engine is a different beast to a rebuilt marine engine
I think. The price I estimated is from experience with a friend's engine
transplant. Put "marine" on anything and the price climbs dramatically. I
doubt someone that has questions regarding a marine engine installation has
the contacts or has done the research to find a "deal". I assumed he was
looking for a drop in replacement with a matched transmission. I doubt you
will find a drop in replacement rebuilt with a warranty for much under $5000
installed. Heck... my friend just forked out $15000 for a new diesel
[installed] in his sailboat.
CM
"Greg Moore" <g...@sympatico.ca> wrote in message
news:qkzQa.1706$eP6.2...@news20.bellglobal.com...
Paul & Valerie Fowler
the same posting you were offered a case of beer for your excellent
assistance. I second that notion, and if we should ever meet, I'll go one
better and give you a bottle of Crown Royal!
To answer your questions to me, the carb has nipples all over it, which are
plugged. My understanding is that it came off of a Camaro. The engine
idles fine, and runs well, it is the whole starting thing that pretty much
began this year. I had aspirations to pull the carb myself and tear it down
over the winter, so I didn't bother to run any fuel stabilizer through it.
I think that I may be paying for that now.
The carb isn't painted black. It has an electric choke. Oh, it is a
Rochester Quadra Jet, but I'm not sure of the specific part numbers.
The engine is painted black. I am pretty certain that it is a marine
engine, just want to be sure if it is a 350 or 305. Yes I agree, I wouldn't
want a 305 from any year! The intake manifold is cast iron and isn't
painted black. I'm quite certain that it is from the camaro, as there are
some custom covers fabricated to seal some of the openings that were being
used for automotive applications.
The rocker covers are from the 305, and say 898 and all the other related
information on them. I guess rocker covers from 305s will bolt on to 350s,
but this is one of the primary reasons why I question if this is a 350 at
all.
The starter and distributor are marine units, as is the coil. I am pretty
certain that the alternator is a marine unit, but better look a little
closer!
It has the proper marine water cooled exhaust on it, and the shifter
brackets at the rear of the engine are all bolted on properly.
The spark plugs are parallel with the water - MR 43s (Brand new)
Here's what the problem is...
I can get it to start pretty well from cold, but if I turn it off after a
run, and let it sit for 15 - 20 minutes, it is almost impossible to start.
I am suspicious that the floats aren't blocking off the fuel supply properly
and it may be boiling the fuel through the jets and flooding the motor. At
the base of the carb, the 3/8 fibre gasket is there, which I understand to
be a method of keeping the engine heat from transferring to the carb.
However, I also understand that a marine carb has a smaller float chamber
and venting to also prevent the boiling of the fuel.
I have it idling at about 900 rpm. I can get it to idle lower, but it won't
start well at all if I do that. FYI, as I mentioned before, when it is
running, it is very smooth at all engine speeds. It does hesitate
momentarily when I hit the throttle and open the secondary barrels. I
suspected that maybe the metering rods weren't working properly, or
something wrong with the accelerator pump, but it does inject a lot of fuel
when I have tested it with the engine not running. Your comment re jetting
for 5% load verses 50% for boating has my interest now!
After I get the engine sorted out, I'll tell you about the shifting problems
and what I'm doing with those issues!!
Any additional information you can provide is appreciated.
From the Home of:
Paul, Valerie, Lauren, Kyle & Gregory Fowler
--
From the Home of:
Paul, Valerie, Lauren, Kyle & Gregory Fowler
Mailto:pvfo...@sympatico.ca
"Greg Moore" <g...@sympatico.ca> wrote in message
news:qkzQa.1706$eP6.2...@news20.bellglobal.com...
Paul & Valerie Fowler
Thanks for your information. Perhaps I needed to provide more information
to you as well. Please see my response to Greg Moore.
This is an I/O, rather than inboard, therefore, a velvet drive doesn't
apply. Beautiful tranny though, we had that in a Mastercraft ski boat with
a 351 Ford engine. Beautiful engine also...
I bought this boat as a cheap way of getting my family on the water.
Unfortunately, I no longer have access to the family boat, and have a huge
problem with being in debt for a boat, so I went cheap, knowing that I am a
pretty good mechanic and willing to learn about marine engines. I have read
the shop manual cover to cover.
With regards to this boat, I have a few options that I am currently weighing
out as follows:
Continue to press on with it, replacing defective or un-suitable parts with
proper units. To do this, I need to know exactly what I am dealing with, so
a few well placed questions will get me some assistance from better
mechanics than myself. I can also get an idea of what the costs will be.
By the time I replace 10 different parts, I might have been better to spend
the money to buy a complete re-build. I know of a few places that I can get
engines, or take my engine.
Perhaps I should unload this boat, and buy a newer one. I know many more
things to look for now. Unfortunately, I have a conscience, and wouldn't
feel right selling something that doesn't work to someone else. I wish the
guy who sold this boat to me had the same morals! So, if I do sell the
boat, it will be in working order.
Anyway, keep the comments coming, and the suggestions, any info I can get
helps.
Thanks,
Paul
--
"Capt. Mooron" <over...@mooron.ca> wrote in message
news:nPzQa.41413$PD3.2...@nnrp1.uunet.ca...
joe
might sound steep, but when i turn it over it sounds like a mean machine, it
was worth the money !
"Capt. Mooron" <over...@mooron.ca> wrote in message
news:nPzQa.41413$PD3.2...@nnrp1.uunet.ca...
Jets
I have a Glastron 19 footer called a Sea Rider, a V194. Its the closed bow
jobbie. I bought it with a frozen (as in ice) block. On of my neighbours
gave me a 350 block to replace the 305. I added rings, bearings and a gasket
kit. I bought one manifold and re-used the 2 barrel carb. I did not bore the
engine. I spent less than a grand. The previous owner said the boat ran
"nearly 50" with the 305. I doubt it. The best I can do is 45 on the 2
barrel. That 2 barrel is special. it is small and its "marine" It is
designed to make 175 HP on a 305 and usually gives 160 on a dyno. You can't
suck enough air through it to let the 350 wind up. There is no 240 HP in my
boat. I have a 4 barrel and manifold just waiting for next year. The
"marine" is important. Marine carbs are designed to overflow into the engine
and not the bilge to prevent the big bang. the same goes for spark shields
on alternators and starters. Some of us take risks...
52 MPH tells me you have a 350 with four barrel. You need it. The 305
engines had a problem cracking in the block along the cam. 350s are
bulletproof. The limiting factor is the gearing. 300 is the absolute limit
for the 898 drive.
I am curious as to what RPM and pitch of prop you are using.
You can reach me at this e-mail, or at jett...@forces.gc.ca
"Greg Moore" <g...@sympatico.ca> wrote in message
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Rich
way to identify the size of your GM block is to run the casting number on
the back of the engine. Any good automotive engine rebuilder can tell you
what size the engine is when you give them the number found on the backside
of the block above the bellhousing and below and just to the side of the
distributor area. Marine engines typically use a little "hotter" cam grind
and have brass or stainless oil galley and freeze plugs and there are some
other minor differences like the recirculation water pump, etc. One very
important thing to always keep in mind is that anything fuel or electrical
used on a marine engine must be marine specific. For your own safety, never
consider using automotive items to replace marine starters, alternators,
distributors, fuel pumps or carburetors. The electrical articles are
designed to prevent stray electrical sparks from traveling into the bilge
area where flamable fluids or fumes are present. Fuel items are designed so
they do not discharge raw fuel into the bilge. They use hoses or vent tubes
that dump any excess fuel from broken diaphragms, stuck floats, etc., back
into the engine flooding it out, instead of into the bilge. Enjoy your new
boat but please remember for your own safety and that of others around you
to be sure to use marine parts every place that is necessary.
Rich Homan
Engine Systems Specialist
rho...@go2marine.com
945 Hildebrand Lane NE Suite 220
Bainbridge Island, WA 98110 USA
877-780-5670 Fax 206-780-5673
www.go2marine.com
.
"Paul & Valerie Fowler" <paul....@sympatico.ca> wrote in message
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