saw those at the IBEX show, pretty much stopped me in my tracks. Those headers look expen$$$ive :eek: :D


Not looking for that though, i am simply looking to build under 500HP for a nice reliable runner. Personally i dont need 1200+ HP in a 27. Also not looking to buy engines i have a builder in mind already that is well up to the task. Right now i am just looking at options on the various LS blocks/heads/induction available and wondering what is the best starting point.

Mast has a good start....30 mins of WOT...

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

Sounds cool to say it but realistically that should be no biggie for any performance marine engine. Heck Merc 525's in SV and SVL have gone entire seasons hour after hour at WOT with only basic maintenance/oil changes. Most of our races are half hour to forty five minutes min. They ought'a be able to turn the lights off an go home for the night, shut 'er down in the morning :D :cool:

That motor is pretty sweet though if i had the means to go new that would probably be on the short list for sure. There was actually a surprising amount of LS based engines at IBEX. Heard that the emissions reg in the coming years was going to be all engines under 500hp. . . . . . fingers crossed on lots more of these.

Dave, I agree completely. I used to work for Merc in Fond du Lac in Plant 12...I worked in the ITC (indoor test center) area as an engine development engineer and ran tests with engines running literally hundreds of hours of WOT for hours at a time and then idle for hours at a time, then back and forth many times. Clearly a marine engine needs to be robust enough to handle the duty cycle imposed by boaters.

I think that Mast is just in the first stage of proving the performance and durability of the LS platform for marine use...because really, as of right now, there isn't much hard data and facts out there regarding LS engines in marine applications.

Glassdave did you ask the price?

Has Doug ever built a 30 with a rudder? I think it's a great idea.

well all your hard work payed off cuz i think some of us can be pretty rough on these things. I think the 525EFI is an one incredible piece of work. Unfortunatly it wasnt till i got back when i started about thinking about LS motors for the Mag or i would'a payed mor attention . . . . guess I'll hafta keep my eyes open in Miami (if i make it down)

didnt get a chance. These were actually quite a few with LS's in there display.

CMI makes a nice unit but a little pricey. There are lots of cast manifolds available too. We've been using LS engines for years in aluminum jet boats up here. If you want to make your own the cheapest route is GM performance parts. They've really done a good job of keeping parts prices down to help promote the platform. The LS3 is a great starting point if you want an all aluminum engine and will make 500hp with just a cam swap. Personally I like the LSX 376 forced induction package. It's got a tougher rotating assembly and 9:1 compression. With a cam swap it'll make just a bit under 500hp but live on cheap gas. The LSX 454 was tested for 50hrs straight WOT between peak torque and peak hp without issues. If you're going to run a blower on any of the production engines with cast pistons be careful with the tune up... :eek:

Here's some out of the crate LS7's with only a cam swap. As usual I think Weismann was ahead of the curve running LS's years ago. I'd like to hear an update on his experience with them. Sounds awesome! [YOUTUBE]http://www.youtube.com/watch?v=EFZP9G3K-CE&feature=related[/YOUTUBE]

Awesome vid Haxby!! Thanks for posting.

I agree that the 525 is amazing...hoping my next rig will have one.
My development work was primarily reliability related on the Verado and a couple other outboards...the REALLY cool stuff (525, 1075, etc) were all across town up on the hill at the Merc Racing plant.

Pretty sure the LSX376 has the same internals of the LS3, just with the stronger block.