Anybody ever use an LS3 engine in marine application?
 

Maybe just a dream, but was wondering if anyone has ever swapped the Marinized LS3 into an application with Merc 6.2s.
Seems it would be a big increase in power....going to 425hp from 320hp. Not sure how the torque would compare, but this would be a pretty cool upgrade if you needed to repower.
Also, no idea how electronics would transfer...any ideas?

Thanks

6.2L LS3 Complete Engine Package - 425 hp - Michigan Motorz

I really like LS based motors. But for the price wanted (albeit a turn key motor), you'd be better off spending the same money on a big block.

There are lots of build threads on LS motors for marine apps. There are exhausts, carb intakes, conversion mount plates. Converting the efi is probably the most involved task

I have a twin turbo LS motor fuel injected. To me being able to buy a "junkyard" motor and install it in a boat (with a cam change) and make 330hp all day long was a win for me. That 330hp doesn't matter if its EFI or Carb, on that note there is hardly any saving with a carb by the time you buy a MSD box, intake and marine carb vs sticking with a factory computer and manifolds. I personal went with Holley HP efi as the Twin Turbos add some complexity to the system and I thought that would be the easiest way to go.

yes but there a lot of backyard a$$holes that cant figure out efi to save their lives. and you can usually get a carb running again in the middle of the lake, or worse yet ocean.

True but how many millions of vehicles are running around with modern EFI and how many of them are broke down on the side of the road because of a failure in the fuel system? Does Mercury even make a CARB motor anymore? Infact I have heard about way more MSD boxes failure then I have stock ECU or even aftermarker for that fact. You will need to run a MSD box to run the COP on all LS motors, unless you want to spring for a fancy Cam driven Distributor but then what's the point of the LS why not just run a BBC.

Also keep in mind changing jets is simply a key stroke away, add in 02 sensors and it can be adjusting while your driving to different temps and air denistys. Idle manure are way better with modern EFI special when you start going with turbo or superchargers.

to run a carb MSD not your only choice, daytona makes a slick setup, using one on my son's grudge LSX fox body mustang, they are great engines, but still very pricey marineizing them at this point..

Hello,

Would be such engine Chevrolet LS3 376/480 480hp V8 Crate Engine - 19301358 Partsworld Performance good for marine aplication, or it is to much oppen? I am scared about reverse watter.

That cam should be just fine,

https://m.summitracing.com/parts/nal-88958753

are you using an O2/ lambda sensor?

jeff

Not yet, I looking to buy this engine and marinise it, but electric kit include all needed sensors.
I belive claims there on this forum that 8.2 HO is monster, but I really like this small engines. This one with 480 hp look really pretty and we are more and more convinced to marinise it. I know, it will not be performance boat in standards from this forum, but I will be happy with 75-80 mph on our small paad kel boat. (cca 3.300 lb rigged, with drive..., only engine missing.)
Ready to ride will be less than 4.200 lb with this engine.

But the purchase price is coming down and findability (new word) of these engines is going up fast. Plus they are turning out to be very durable, and improve CG greatly when replacing big blocks. As such, they are gonna take over the market for marine engines. 454's are gonna be cheap and hard to sell real soon...

@ezstriper;
Perhaps it is such situation in USA. There in EU cost all engines like hell. If I marinise this engine, will cost me less than 14.000,-$ include taxes. Ok, I will need to be extremly creative to avoid strictly EU regulations, but it is possible. I want to buy Kodiak LSA or LS 6,2L DI L86, but no chance, they have no certificate for EU and it is impossible to import one of them in EU. Finally I am find LS3 from Marine Power which have certificate and imported in EU will cost me 19.999 $ include taxes. But today I am find this LS3 480 hp in England. I know how to marinise it, it will cost me less than all other engines and will have 480 hp with great torque (If it is curve on web page reall.).


Look:
- 400 lbft torque at 2.500 rpm
- 475 lbft at 4500 rpm
- 425 lbft at 5750 rpm

- 300 hp at 3.000 rpm
- 400 hp at 4.500 rpm
- 480 hp at 5750 rpm
- at 6.000 rpm still powerfull
And all this for 14.000$. It is not expencive if you ask me.

Nevertheless if I faill will losse 14.000$. Please instruction is this engine good base for marinise, or better to take 430 hp engine?
What mean in reall this 480 hp in compare with 430 hp at BBC?

Few of us have any feel for price and availability your side of the atlantic. I would stick with what is easy to get and replace...

More or less same storry. If break something bigg-finish for this season, nobody keep such parts on stock and must arrive directly from your land, but small parts are available every where. More easy is to buy Chevy automotive parts than Mercruiser parts. And marine parts from Mercruiser or Volvo really cost a lot!

Mercruiser parts are Chevy parts with black paint on them. For the most part. What do they use in Europe that is not a Chevy V8? Or basically nothing, because they're all small engines for 35 mile-per-hour boats?

We have there all small block and bigg block which have EU certificate. Mostly in reed for Volvo and black for Mercruiser, but in specialised marine shop cost spare parts much more than same automotive parts. Market in my place is not so bigg and all unusuall parts must come from somewhere out, bigger expencive parts come directlly from USA or from magazine in Belgium or Neatherland.
For example peopeller Maximus cost in my region more than catalouge price in USA plus taxes and cusstom and no go to buy it in one week. More easy and much cheaper is directly personall import from USA...

Nevermind, I am not expert for purchase and forget this complains. My interes is to buy quality engine.

Hello,

What about flex plate and flywheel?
Is it flexplate enough for LS3, or better to change it with flywheel?

Hello,

Is it neceseary to change pistons or other engine parts to crate engine LS376-480 marinisation or can we just keep originall parts?

Switch to a flywheel.
the pistons should be fine. Run the coolant at a minimum of 160 degrees F.
Do not apply full load until the engine is warmed up.

Jeff

Thanks for all suport there!
Will report on spring what will come out!

when I talk about marinizing, talking about, water pump setup, exhaust, etc that stuff is pricey for LS at this point

This spring a local guy was hounding me to install a ls3 in his boat, couldnt find a source for stock cooling system parts that came on some boats, manifolds , heat exchanger, motor mounts, pulleys/cooling pump appeared to be around 7000$ from hardinl. labor to retrofit it all, running engine, etc and it was north of 10,000 no mwtter how you dice it

My numbers are higher.
I expect just few cents less than 11.000 euros with taxes, except my and brothers work, but this is our hobby. Tell me for cheaper engine with 480 hp? No go to buy new marine engine with 400 + hp there in EU for less than 15.000 euro inclusive taxes. GM claim 495 hp with classic headers for LS367-480 engine and with marine headers like Kodiak or Marinepower, will gain another few hp. I know, at the end will go down for 5-10 hp becouse of more fuell pressure-seccurity for pistons, but at the end will be at least 460-470 hp at 5800 rpm on prop. This engines have probably better mileage than bbc (Better compression, 300# less weight...) and this 11.000 euro is not so much if is all this true.
By light pad kell boat, 27 ft long, or 29 LOA, with less than 4400# ready to ride it is 475 lb-ft probably enough for happy ride. And this torque is almost same betwen 4.300 and 5.000 rpm. with MSA surface drive, ZF 1,56 and labbed Maximus 26" I expect maximum speed arround 80 mph and best mileage close to 50 mph.

Is it unreall?
Is it expencive?


p.s.
Last days I hear a lot about diferent clearences, diferent gaskets... betwen street and marine engines. I understand if use direct cooling, but is this true with closse cooling and if you have in your mind heating time before full power?
What lambda numbers need to keep to avoid pistons burning?

my point exactly...great engines, have 2 race cars running them...will be great marine engines when more people do the marine parts

Yes I have 2 6.0 LQ9 s in a 30 ft cat 400 hp each out of 2005 Cadillac Escalades Was a big project.Used all components from donor vehicle.Sent computers out to get Vats removed.Stripped wire harness of un nessasary wires.Found Exhaust manifold from a friend (PCM Marine)
Engines require closed cooling. But they run great. Easy on fuel 2 of these burn the same as 1 BBC Took about a year to put them all together.

Plavutka, spring has passed. How did it turn out?
I have a similar project coming that don't need a ton of torque and will like lighter engine.
Anyone else who can share some new experiences is appreciated.

Hello,


We have all equipment there, but no time to put it together. Hopefully will put boat in water in september or october.
Marinising of LS3-480 is simply, we made time "mistake" with boat modification. We want to cover surface drive and propeller with integrated swiming platform and this aditionally half meter plus paint of all boat take us hughe time.


There I have two questions:
- have anybody experiences with durability of Hempel Ocean Gloss paint? We paint it with true white. Quite tricky to made mirror surface but nice when finish.
- we have exhausts http://californiamarine.com/images/c...rge/123215.jpg . Will be neceseary to tune originall software of engine becouse of this exhausts and will it bring or take few of claimed 495 bhp?


@Scandinavian, if you bring on propeler same rpm like by 8,2 HO you have much better troque like by 8,2 HO.
New 430 hp Volvo Penta is in fact marinising LS3.
Crate engine LS3 with 13 kg fliwhell and with out of marine eqipement have 200 kg.

Marine engines are about TQ not HP, they are cammed differently, different clearances and certainly the electrical system are built for a marine environment, this includes everything from ignition, to charging, to a simple starter they all need to be different). I'm sure the modifications can be done to make it work but certainly at a cost!

Not agree.


1.) If you look torque on prop by same prop rpm, you have better prop torque by LS3 than by 8,2 HO. Therefore you need to use B1 with 1,5 for BBC and 1,65 for LS3.
LS3.480 which we will use have 12% better torque than LS3.

2.) LS engines are cooled with cooling liquid and do not need any internall modification becouse salt water.

3.) Electronic it is electronic and hard to belive that "marine" aplication have diferent materiall than car aplications. One more coat of cable warnish and that is it more or less.
Starter and alternatos we buy speciall for marine aplication, but strictly becouse of safety and not becouse of environement...