What keeps Mercury from Seriously Updating its Sport Boat Engines?

[Dave 205]

I got to thinking about how time on this forum is a bit like being in a Chevy showroom in 1980. 305's, 350s, 454's, it's the late '70s all over again. The 4.3 is a lopped off 350 from 1988.

My understanding is Brunswick owns Mercury and Sea Ray. Any ideas out there on why our boats don't get modern high feature V-6 and V-8 engines?


This history on the 305 has a heck of a final footnote:

305The 305 5.0L variant of the small-block Chevrolet which was a 262 that was bored out and stroked using the crank of the 350 was introduced in 1975 had a displacement of 305 cu in (5.0 L) with a 3.7350-inch (94.869 mm) bore, and 3.4803-inch (88.4 mm) stroke. Many performance enthusiasts shun the 305 because of the availability of 350 engine, along with the fact that the same parts will yield much more power in a 350 cubic inch package. Due to the popularity of the 350, items like rebuild kits are more expensive for the 305. Still the 305 has considerable power potential to the broad selection of aftermarket parts that are readily interchangeable with the popular 350. Not all cylinder heads apply to this engine due to valves having bore interference or shrouding issues with the narrow bore of the 305 engine, but there are many LO3 setups that can produce over 300 horsepower from the right combination.
Induction systems for the 305 included carburetors (both 2 and 4-barrel), throttle-body injection (TBI), tuned-port fuel injection (TPI), and sequential fuel injection (GM Vortec).
The 305 was used in the following cars:

• 1976–1992 Chevrolet Camaro
• 1980 Chevrolet Corvette (California only)
• 1977–1993 Chevrolet Caprice (includes Impala)
• 1977–1986 Pontiac Parisienne
• 1976–1979 Chevrolet Monza
• 1976–1979 Chevrolet Nova (also GM X-body clones after 1976)
• 1976–1988 Chevrolet Malibu, Chevrolet El Camino, and Chevrolet Monte Carlo
• 1978–1992 Pontiac Firebird
• 1978–1980 Oldsmobile Cutlass (US Market only, Canadian market 1978–1987)
• 1991–1992 Oldsmobile Custom Cruiser
• 1981–1987 Pontiac Grand Prix
• 1975–1979 Buick Skylark
• 1977–2003 Chevrolet/GMC Trucks, SUVs, Vans
• 1991–1992 Cadillac Brougham
• 1978–1987 Buick Regal

After 1996, its usage was limited to light trucks and SUVs until the 2000 model year (vans and commercial vehicles until 2003) as the Vortec 5000. Currently still in production as a marine powerplant for Mercury Marine.

 

[Capt Skup]

Bottom line.. CHEAP!, GM is probably quite willing to keep producing the ancient engines for both Mercruiser and VolvoPenta, I would guess that the old, worn tooling has been paid for for decades. GM sells the engines to the above for $500.00 a piece, Mercury/Volvo slaps on couple hundred dollars worth of parts and turns around and sells them to us for thousands, clamped on their own boats we buy. Quite a deal. Now why do we settle for a 5.7 V8 that only puts out 300hp, when there are V6 under the hood of trucks with almost 400hp(Ford's Ecoboost). Most of the newer engines have either aluminum heads/iron blocks or all aluminum, requiring a closed cooling system, which many are not will to pay for. I have to wonder, how much longer can GM mill a decent block from the old tooling. I remember reading that the 454 cu tooling was so worn that GM told owners that 1 quart of oil every 500 miles was normal. I thought that Mercruiser bought the tooling for the 496/8.1 from GMC?

 

[Capt Skup]

I had the 5.0 V8 in a SeaRay 215EC, it was adequate as long as you were not carrying a lot of weight, took a while for the bow to come down on plane. Plus at about 200 hours it burned an exhaust valve and the head cracked. Lucky for me that I could do the repairs myself, bad for me that a Vortec head with valves was $650.00

 

[Presentation]

.....GM sells the engines to the above for $500.00 a piece, Mercury/Volvo slaps on couple hundred dollars worth of parts and turns around and sells them to us for thousands, clamped on their own boats we buy.

There is so much incorrect information in your post it really bothers me.

Just to correct a few things…..and there are more......

Mercury and Volvo do not buy engines from GM. They buy smallblock shortblocks (two different things) in the following sizes; 4.3L V6, 5.0L V8, 5.7L V8. Again, they are shortblocks only, not engines.

..... I thought that Mercruiser bought the tooling for the 496/8.1 from GMC?

Mercury is casting its own bigblocks at plant #17 in Fond du Lac Wisconsin. This is not old GM tooling, its lost foam casting, a very different technology then GM was using to make its bigblocks.

 

[Capt Skup]

Sorry it bothers you. If Mercury is not buying it's shortblocks from GM, than where are they getting them from? GM's former supplier? No difference, still a very old design. Supplier milling the blocks with new equipment? Where are the intakes and heads sourced from? Mercury may out of need, cast the 8.2 blocks, is that the only one? What bothers me is we, as the consumer, are paying a substancial amount of money for old, inefficient technology. A new SeaRay 260 Sundeck with a few options will easily top $75,000 but lift the engine cover and what do you see? A two valve, pushrod iron block GM designed, port injected engine. I just think that there are much better engines available that could be, as Mercury says, "Marinized" Well, sort of marinized.

 

[Presentation]

If Mercury is not buying it's shortblocks from GM, than where are they getting them from?

Mercury is buying smallblock shortblocks from GM.

The larger outboards are made at Mercury Marine in Fond du Lac Wisconsin, my home town.

The outboards engine blocks are cast in Fond du Lac at plant #17.

 

[Bugsy24]

You got to love FranK!!!! Shooting from the HiP!!

 

[MonacoMike]

Any ideas out there on why our boats don't get modern high feature V-6 and V-8 engines?

I'm not holding myself out as an expert but my logic says our boats need raw power and extreme strength to propel themselves and all our toys at a speed we find acceptable. Our boats put out and consume more power just getting on plane than most errand trips run around town. These marinized workhorses have been engineered for a few decades to provide this power. Comparing my boat and my tow rig power needs, my truck only hits higher RPM ranges (above 3K) for a few seconds while towing at near max capacity and rarely driving without a load unless I want to take off fast. My boat runs at greater than 3K for sometimes hours straight. This requires strength exotic metals may not handle or cost to much to handle it. In most motorsports at the recreational levels they still are not using "modern high feature V-6 and V-8 engines" except is rice burner racing.

The auto industry is playing with the politicians over fuel economy standard and to meet these standards they need cutting edge smoke and mirrors engineering to play the horsepower game in advertising and fuel games with the government at the same time. But you may get your wish as I'm sure the enviros are looking at the entire recreation sector. Hope you like it when it comes!

Bottom line answer: I'm not comfortable that "modern high feature V-6 and V-8 engines" can reliably power our boats. MM

 

[dicor]

I read an article once explaining why marine motors usually don't last as long as car motors. The explanation made a lot of sense to me. The writer explained that a car motor only uses about 15% of it's available torque due to the fact that once the car begins rolling it's relatively easy to keep it moving. A boat on the other hand uses almost all it's available torque all the time because you are always plowing thru water. It would be like driving your car up a hill all the time while pulling a 3000 lbs. trailer.
So I feel that motors made today put out a lot of HP but I'm not so sure they can handle the constant demand for torque. The last sentence is my opinion.

 

[CliffA]

let's not forget the relative simplicity of the engines as well....this allows most owners to perform at least some of the basic maintenance on the engines...if you are mechanically inclined you can perform the vast majority of the service and repairs....if the boats came equipped with the same highly advanced engines that autos and trucks have in them it would likely mean the vast majority of owners would be forced to start paying to have any work done to the engine....and we all know how expensive marine mechanics are not to mention the likely elevated parts cost from having to 'marinize' the components of the advanced engines....

Cliff

 

[dicor]

let's not forget the relative simplicity of the engines as well....this allows most owners to perform at least some of the basic maintenance on the engines...if you are mechanically inclined you can perform the vast majority of the service and repairs....if the boats came equipped with the same highly advanced engines that autos and trucks have in them it would likely mean the vast majority of owners would be forced to start paying to have any work done to the engine....and we all know how expensive marine mechanics are not to mention the likely elevated parts cost from having to 'marinize' the components of the advanced engines....

Cliff

I agree, with the the complexity of most new motors many mechanics have a socket wrench in one hand and a PC mouse in the other. Who knows maybe marine gas engines are on their way out and we may be looking at exclusively all Diesel marine motors which are inherently simpler and much more rugged. I'd love it if my 270 had a Diesel.

 

[Dave 205]

My curiousity on this started with my search for a used boat last spring. I was leaning toward trying to find a nice 4.3MPI - as it seemed more modern, potentially more efficient. When I came across a very nice 5.0 carb engine boat, I accepted it having the same horsepower, and figured that I might be part of a swan song for V-8 power sport boats.

I like to follow automotive tech, and some of the new V-6 engines quench my thirst for V-8 power, while being much more clean and efficient compared to older V-8s. Returning to boating was like returning to my high school / college days. Nostalgic, but perplexing at the same time. Ford, GM, and now Chrysler with its Pentastar V-6 have some really great new engines with great hp - but torque is off due to decreased displacement. The torque comments make sense to me.

By way of comparison:


My 2002 Dodge Durango 4.7 V-8 has 238 h.p. and 295 lb torque with a 5,600 lb tow rating.
New 2011 Dodge Durango Pentastar 3.6 V-6 290 h.p. 260 lb torque with a 6,200 lb tow rating.

It may be that other aspects of the automotive systems allow for the increase in towing with the decrease in torque.

 

[Steve Craig]

let's not forget the relative simplicity of the engines

You nailed it Cliff. Reliability & relative ease of maintenance/repairs.

Buddies of mine are non-boaters but heavy into street rod building. Everything from a '35 Chev, '53 Chev, '29 & '32 Ford etc.
Built from the ground up.
They buy used GM LT-1 & LS-1 engines out of late Corvette, Camaro, even a Roadmasters.
Computer controlled, make gobs of power in stock form, love to rev., plenty available & extremely reliable.
I'm thinking this would be an easy swap into a boat with a 5.0 or 5.7. Not sure on the exhaust manifolds but sure sounds worth looking into.

 

[MonacoMike]

I'm not comfortable that "modern high feature V-6 and V-8 engines" can reliably power our boats. MM

These comments haven't won me over to the newer is better. They probably can't take the heat in an enclosed bilge while producing the torque required. MM

 

[CV-23]

The thing that always amazed me was Mercury charging $40,000 for a Blue racing motor. You can build one with the best parts (Merlin, World Power, Stainless Marine, etc) and not spend $40,000. Factory motor prices are way out of line as well as the new boats they offer. $225,000 for a 28' boat! I'll keep my paid for 1990 with a real 454/7.4L.......a Generation 6 454 Vortec would be a nice upgrade though but with a 4bbl, Mike.

 

[Kingsfr]

This topic is, also, of interest to me. I, too, wonder why boat manufacturers don't use some of the modern engines found in today's cars and trucks. They have much smaller, lighter, more fuel efficient engines producing the same and more H.P. My boat has a 6.2L 320H.P. engine. A Chevy Camaro, as an example, has a 3.6L V6 that produces 312 H.P. and 278 ft-lb of torque. Its 6.2L engine makes 550 H.P. and 550 ft-lb of torque.
Are there any mechanics or techs that have the answer? Is it that the newer designed engines can't run for long periods of time at higher RPMs, or do they not generate the amount of torque needed to push boats through the water, or is it a cost thing? Something else? Everyone seems to have an opinion, but what's the reason from those in the know.
Does anyone know anyone who has repowered their boat with a modern automotive engine?

 

[CliffA]

You nailed it Cliff. Reliability & relative ease of maintenance/repairs.

Buddies of mine are non-boaters but heavy into street rod building. Everything from a '35 Chev, '53 Chev, '29 & '32 Ford etc.
Built from the ground up.
They buy used GM LT-1 & LS-1 engines out of late Corvette, Camaro, even a Roadmasters.
Computer controlled, make gobs of power in stock form, love to rev., plenty available & extremely reliable.
I'm thinking this would be an easy swap into a boat with a 5.0 or 5.7. Not sure on the exhaust manifolds but sure sounds worth looking into.

today's advanced engine electronics are designed to maximize fuel efficiency and control emissions while at the same time keeping enough HP and torque for the application....this approach works well in a car or truck that will experience variable loads on the drivetrain...on a flat surface there is very little power needed to keep a vehicle moving once the mass gets moving...the advanced electronics will allow the engine to muster up enough power to get the vehicle moving, then as the demand decreases on the drivetrain the electronics will throttle back the engine into its most economic and environmentally friendly mode...as hills or rough road surfaces are encountered and the demand on the drivetrain fluctuates the electronics will adjust the power from the engine accordingly...the demand on the powertrain in a boat is VERY different...the boat powertrain almost always has a high level of demand on it while the boat is moving....this is due to constant 'push back' and drag from the water against the hull...the engines must be designed to deal with the type and level of demand that will be placed on them...a modern GM 350 in a car making 400 HP and 400 ft/lbs of torque with elaborate electronic controls would likley die a quick death if it were placed in the hostile environment of a boat engine bay where the ambient heat is almost always high and the demand is also always high and sustained for long periods of time....a boat engine must be designed to be reliable at sustained high loads and for prolonged periods of time.....there is no need for the advanced electronic controls on a boat engine since the engine will not experience the fluctuation in load as a car engine will...

 

[Steve Craig]

Cliff,
Well written.
I agree, simple is better.The current breed of marine engines seems to be there.
I'm getting educated.........slowly.

Cheers

 

[CV-23]

I'm sure todays new engine variable cam shaft timing would also swallow alot of water with boat exhaust systems. I bet the Ford V10 would work in my 270 but it's only 310hp....no improvement there, Mike.

 

[Steve Craig]

Just sold a '71 Buick 455 I rebuilt with the intent on putting it in my Skylark. Original 350 has plenty of power & I decided to rebuild it & keep it with the car.
The 455 stock specs. were under-rated from the factory @ 360 HP, TQ 510. with an 800 CFM Q-Jet.
That would certainly make the boat go!
As Cliff wrote, however, I'd likely need to keep the engine cover off & my fingers crossed.