Putting a Turbo on a boat engine?

[Gryphon]

A friend and I were talking about the possibilities of creating a turbo setup for the 3.0L and 4.3L engines. He is currently in business making mass produced turbo setups for many GM engines for autos. With so many boats powered by a GM engine this seems like a possible area to expand to.

Does anyone make a turbo setup for a marine application currently?

If so, can you please provide a link.

What kind of interest do you guys think there would be for a bolt on turbo setup that would easily add 50HP to a 3.0L with an upgrade option in the +100 HP range?

Would most boats be able to handle the added power?

Do the GM marine engines use the same knock sensors etc as a car?

Thanks, will add more questions as I think of them.

 

[Mischief Managed]

Re: Putting a Turbo on a boat engine?

I'd think that if it was simple, it would have already been done. I know of no kits available and it's probably because of the heat of the turbo exceeding the Coast Guard allowable surface temperatures in the engine compartment, and the problems dealing with the water that mixes with the exhaust as exits the exhaust manifold. That said, turbos ahve been in marine use for years on diesels, so it's not impossible. Good luck.

 

[xxturbowesxx]

Re: Putting a Turbo on a boat engine?

id say if the engine was rebuilt with lower compression pistons and all the internals were forged then it wouldnt be much of a problem.. i think the engine would have to be built for top end power for it to really take advantage.. new valve springs high flow head.. and then engine management.. an fuel management unit now were talking about just more than a kit..

 

[Gryphon]

Re: Putting a Turbo on a boat engine?

Thanks for the info so far.

Just looking for feedback as we do not have much boat expereince between us.

If a kit was made it would be produced as a bolt on kit to sell, not just a one time kit.

As for the engines, you may be surprised what a stock block can handle, at least in the car engines. For example my 2003 Grand Prix went from approx 200 whp to 474 whp with a bolt on turbo kit. I changed rockers but never opened the engine otherwise, i.e. stock heads/cam/manifolds etc.

Thanks again for the feedback, keep the thoughts coming.

 

[HT32BSX115]

Re: Putting a Turbo on a boat engine?

Ok,

Now take that engine you have in your car that went from 200 to 474 HP and run it at 474 HP for say 30 min straight and see how it survives.

You didn't say what drive you have, but if it's an Alpha, it's good for about 300 HP at 4500 RPM or so.

It would be a contest to see which components break first.....The engine or the drive.


There's lots of Turbo'd marine engines. Just add money! (Most are diesel though)

Cheers,


Rick

 

[Gryphon]

Re: Putting a Turbo on a boat engine?

Once again this would be for a production kit and not just for any one boat. I was told an outdrive would be good for about 3-350HP. These kits would be set for +50 HP which I would assume stock parts may handle?

I do realize that my car is set to run the 1/4 or 11secs not 30 min. But again it has much more than an additional 50-100 HP going into it.

 

[xxturbowesxx]

Re: Putting a Turbo on a boat engine?

alot more stress in a marine application.. most engines are running at or near wide open throttle for long periods of time.. if you apply throttle to your car it may only take 15 seconds to get to cruising speed where there is much less force being applied to the car (wind resistance,hills.etc..) then you back off the throttle.. in a boat the resistance increases alot so the engine is working alot harder to hold a speed..

 

[newbster]

Re: Putting a Turbo on a boat engine?

Doesn't adding a turbo increase the efficiency of the engine? Given the fuel prices you might find that it starts to make more economic sense. Obviously, if you wish to make money selling them they will need to be an option for OEM. Thats pretty much the only way you will get enough scale to validate tooling and dev costs.

I would love to hear to what degree adding a turbo does increase efficiency. If you can demonstrate more than 10 % you will have a market.

 

[xxturbowesxx]

Re: Putting a Turbo on a boat engine?

a turbo increases the volumetric efficency of a motor therefore it acts as a larger engine and takes in more air.. its complicated but the more air you take you must add more fuel so in most cases it would decrease efficency..

 

[tommays]

Re: Putting a Turbo on a boat engine?

I think for the most part you will find belt driven supercharger kits as even merc racing does all there go fast this way as it avoides all the heat issues

 

[xxturbowesxx]

Re: Putting a Turbo on a boat engine?

i think a supercharger works great on most applications but on a 3.0 i would want something else because it takes power to turn the pulley and in most cases the hp gains arent worth the money.. if speed is important enough for you.. then your going to have to spend the money.. then a rebuild with new valve springs,retainers, high flow head, forged pistons and rods..then a turbo would be a great addition and would supply power to a 3.0liter to rev well into the 6k range and the head and valvesprings and retainers would allow revs that high for short periods..or you could just buy a 5.7 crate engine and outdrive and get more power without all the problems and work it might even be cheaper..

 

[Limited-Time]

Re: Putting a Turbo on a boat engine?

Turbo's make power in mid to upper RPM ranges. A boat engine needs low end for a good hole shot. Unless the Turbo is coupled with a Land and Sea (no longer in business) shifting type prop you would be hard pressed to prop the boat.

 

[Liquid_force]

Re: Putting a Turbo on a boat engine?

Turbo's typically perform best at mid to high rpm because that's where they're most productive in a car. I'm fairly confident that an adjustment of sizes of the turbine and compressor could lower the usable range pretty significantly (at the cost of upper rpm usability), but that seems to be the least of the problems with turbocharging a boat.

FWIW - I have seen turbo diesels in some bigger speed boats (24-26').

 

[JCF350]

Re: Putting a Turbo on a boat engine?

The first and most obvious thing is that turbos and marine manifolds work at cross purposes. For the turbo you want the HOT gases from the exhaust while a marine manifolds primary role is to get rid of the heat as fast as possible.

They make "after coolers" for turbos that are for boosting turbo output (denser gases).

Also why does the trucking industry keep calling inter coolers -- after coolers?

 

[Liquid_force]

Re: Putting a Turbo on a boat engine?

they're between the turbo and the engine intake aren't they?? Seems pretty "inter" to me.

 

[bayliner in elkmore]

Re: Putting a Turbo on a boat engine?

yes the intercooler is designed to lower the temp of the intake charge therefore increasing the amount of fuel the computer will put into the charge making for optimal air/fuel ratio allowing for the best performance. but i agree neat idea but too much engine compartment temp, better off supercharging but keep in mind the integrity of the loweer unit!!

 

[45Auto]

Re: Putting a Turbo on a boat engine?

Started to make a nice write-up with RPM and speed vs HP charts and all, but figured I would give my theory real quick instead!

Bolt a 50HP turbo to a 135HP 3.0. Now at max RPM it has 190HP. So you have to prop it like a 190HP 4.3. Say go from a 19 pitch to a 23 pitch. Now when it's off the turbo trying to accelerate at low RPM it's a real over-propped dog. So try dual turbos (like Nissan, one smaller than the other) to get some additional power down low. Now you can use the 23" prop, you have the low end equal to a 4.3 to turn it. Why not just drop in a 4.3? Probably way cheaper and more reliable. The turbo should theoretically get slightly better fuel economy since it's more volumetrically efficient (using the free exhaust heat to make power) but it wouldn't come close to offsetting the additional complexity, engine loading, and additional failure mode potential when I'm way out of sight of land and the storms are coming in .....

Turbos work nice on small car engines because they don't develop any boost if they're not under any load. Your turbo-charged Grand Am probably still cruises at 70 MPH at 2000 RPM or so, making almost no boost because it only requires 15 HP or so to maintain that speed. Unfortunately due to the difference in drag between air and water a boat would need the HP increase across the whole RPM range (unless you go to a variable pitch prop like Limited-Time said). You could do it with a small turbo-charged engine but boats really need the low-end torque to accelerate. Now if you just developed a cheap 2 or 3 speed transmission to go along with the turbo it would be real interesting!

 

[JCF350]

Re: Putting a Turbo on a boat engine?

Because the cooler is AFTER the turbo. "-)

Turbo terminology is pre cooler= before the turbo unit
...............................inter cooler= between the turbo and the engine
...............................after cooler= between the exhaust manifold and the
..................................................turbo unit.
You almost never see an after cooler mounted because there is very little gain in boost (usually more than compensated for by modern designs).

they're between the turbo and the engine intake aren't they?? Seems pretty "inter" to me.

Yep! Sure is. Always has been (at least for the 30+ years I've been dealing with them).

 

[JCF350]

Re: Putting a Turbo on a boat engine?

yes the intercooler is designed to lower the temp of the intake charge therefore increasing the amount of fuel the computer will put into the charge making for optimal air/fuel ratio allowing for the best performance. but i agree neat idea but too much engine compartment temp, better off supercharging but keep in mind the integrity of the loweer unit!!

Intercoolers in a boats use raw water to cool the air. They are not air to air coolers. Superchargers will also benefit greatly by using an inter cooler also.

 

[JustJason]

Re: Putting a Turbo on a boat engine?

VP has aftercoolers in alot of their desiels.....
it has nothing to do with HP.... it has more to do with keeping the temp's down in the engine box....
The biggest issue with TCin boats is the heat..... you need to keep that exhaust cool... and cool it quickly.