eddiemotor

Check out Hells Canyon Marine Jet Boats or White Water Customs.

Raylar

As the one marine engine company who brought a complete 550HP LS based engine to the market in 2007 and did quite a bit of expensive development and research I can say that these LS marine engine threads always seem to get a little streched and hyped sometimes.
For a little example the air boat link, the company seems like an expeirenced air boat engine builder, but where in the world do they come up with a 376 cubic inch pump gas LS engine that will make 550HP normally aspirated at 5800 rpms! GM's supercharged LSA engine barely gets there an it takes 6500 rpms for that. Its really easy to make claims, its another thing to back them up with independant dyno tests!
The LS engine platform is an excellent engine. With enough $ and expert builds larger cubic inch versions can get to good high torque and horsepower numbers with proper endurance engine builds to be called good long life performance marine offshore engines. They can certainly do the job in certain boat applications such as JIMKID'S LS marine engines do in his Skater. Lets be real here and have him let you know what those 750HP @6800 rpm LS's of his will cost you complete bobtail built and configured exactly as his are done.

Next, please keep in mind that in small jet boats and such these engines can be excellent powerplants as the power and torque available from them in 376 - 406 cubic inch versions to give great results in these smaller lighter boats.
If they are used in 24-27 ft single engine offshore type hulls or 30-35 foot twin engine offshore type hulls they will need to be freshwater cooled and need to produce over 500lb/ft. of torque at 4000-4500 rpms and provide similar 500HP power at 5600-6200 rpms to be considered enough power to push these hulls at BBC comparable acceleration, speeds and cruise speeds. Yes, I know the supercharged versions can do this horsepower and torque numbers at cruise rpms (4000-4200 rpms), but only in boost and you can't expect these supercharged engines to have any good life if they have to cruise for hours in BOOST!

These LS marine engines will still have to do this with comparable costs to the currently available BBC engines that do this reliably and regularly on a reasonable cost basis. There are two reasons this is slow to happen so far in this industry. One, the performance boat market is slower than cold snot for the last three years and two, not many engine companies have created LS engines of this size, reasonable cost basis and type to fill the almost non-existant offshore engine need. Hope this changes in the near future for all of us.

Best Regards,
Ray @ Raylar

Wasted Income

Ray, thanks for the feedback...it's definitely thought provoking....however, I am surprised it took you that long to chime in.

Though you didn't answer my original questions from the first post of the thread.
You claim that:
Is this purely speculation? Educated guess from your years of experience? Factual data from a running boat equipped with an LS?

Have you ever equipped a sterndrive with one or two of your 550 hp LS packages? If so, did you compare it back to back in the same boat with a similarly priced or powered BBC?

That was my initial intent of the thread. To get some facts on how the LS engines actually run in-hull, and not to bench race or dock race as you put it. I just find it extremely hard to believe that with all the LS engine packages offered for sale, that nobody has tested them on the water, and is willing to provide results. Did all these companies build these for show pieces? Bragging rights?

So far, the only one who has shared any empirical data of how they work in a sterndrive application is JIMKID, and it seems that they work pretty well, albeit at a rather high assumed cost.

bdubs

I agree there is not much of a market for the LS from engine builders like Raylar. The pricing just doesn't work out.

But for a DIY guy and the right boat, It could be a great combo, and cheap.

MikeyFIN

Invested ? In their GM iron long blocks that GM designed in the early 50's and 60's when they considered whale oil for lubrication....

I don't buy that more than Volvo Penta being the inventor of the outdrive despite patenting it.

JIMKID Motorsports

look on the cover and the back cover of this mouths sport boat mag mast has you guys covered

Wasted Income

Hey Raylar...do you have any input to the questions posed in post #88?

Also wondering what kind of testing you did on your LSM550...if you did anything like the guys at Mast did in the video below?

I'd be curious to know if Mast did any in-hull testing? 10 mins WOT at peak hp, 10 at peak tq, and 10 mins WOT while lugged...back to back, to me, is impressive.

[youtube]http://www.youtube.com/watch?v=7YtkD8CXnW8[/youtube]

biohzrd

Not to bring up an old post, but I thought some of you may be interested to know about these. Have a set on my 5.3l converted truck engine. I am running a MSD 6ls, Edelbrock Performer RPM intake, and 750 cfm carb with a LS6 cam/springs. Puts out right at 380hp/380lbtq. I ran this setup all last year without a single problem. By the way, this is a junkyard pullout that has 60k miles on it prior to marine use. I have not gone into the motor at all. Factory bearings, rings, head gaskets. Plus the Gen III engines use o-ring style silicone gaskets, and I have not experienced any of the nagging small leaks I did with my older 5.7 350.


http://www.skidim.com/prodinfo.asp?number=R028023

http://www.skidim.com/prodinfo.asp?number=R029016

bdubs

Looks like a nice start to some turbo manifolds.

Lets see some pics of your set-up.

biohzrd

When I get back State side I will get some up