And stronger valve springs.

And a 23° degree split camshaft with stock GM intake lobe.

Neat but mostly useless IMO. Ls7 heads are damned good as is. After market Ls7 heads are even better, I have an ETP/Mast headed 427 with a hydraulic roller and reasonable valve springs and thats 700hp so this thing needs make damn good power to make any sense. I'm guessing the mercury engine cost alot more than this.(and yes it can be built for marine duty for not too much more.) http://www.mastmotorsports.com/view.php?id=155&c=4&s=6

Pretty neat but seems they are spending a lot of money for almost no reason.

As stated you could make right at or close to 700 on pump gas with a hydraulic roller cam.

Be cool to see what they do with it though.

This would have to be an improvement that someone other than mercury could use as currently mercury doesn't even offer an LS based engine.

As others have pointed out the current engines are really good so to justify the mercury pricing it really has to deliver something great.

Its nice that mercury has joined the 21st century since nearly every other marine engine manufacturer ((PCM,Crusader,Volvo,Illmor,MarinePower) etc has been using LSx engines for years..All of them have engines that make 400 or more hp..No fancy heads, superchargers,etc..
But Mercury can not compete with them on the same engines because of the insane prices it charges boat manufacturers who use their engines so they come up with these uber expensive heads to make it seem like its "their" engine.. Look at the new V6 they came up with,, spent a ton of r&d to produce an engine
more expensive than anyone elses base LSx motor yet making less hp and tq and using Mercury specific parts so they can rape you there later as well.. If it wasnt for the fact that the insane prices are hidden in the overall price of a new boat and paid with financing of said boat they would not be able to sell many engines..

Let's see. 15° - 12° degree valve angle (depending which you use), super effecient combustion chambers, raised intake runners, and mid 300 (to upper)cfm ports from the got damn factory.

For a small block !

Massive power from small cubes. Heads ready to take on big cubes.

What the hell is not too like ?

Wish they'd spend the money and do same type heads that fit the Chevy gen VI big block.

Screw the 4 valvers. No $$$$ need.

I believe Mercury stated a few years ago after they developed the new 1350 that they feel the weak point of the GM engines is the overhead valve train combinations. I'd assume this is why they may be developing a overhead cam set-up for the LS.

You can stoke these now to 380".

I know i'm going to get a bashing but seriously why the love for big heavy lifters and pushrods? Overhead cams and lighter valve train are soooo much better suited for the high rpm abuse we give our dinosaurs. You can buy an entire NEW 420hp / 400ft. lbs of torque weighing only 444lbs total ea, for what some guys put in their heads alone. The fuel saved while idling through no wake zones alone...

http://www.fordracingparts.com/parts...KeyField=11829

or

http://www.fordracingbyspeedshopdire...6007-a50xs.htm

Some day.... Closed cooling and dry exhaust.

probably cause a stock ls2 makes almost same power and more torque at the same rpm for $1500 less with those old school heavy lifters and pushrods..
to a manufacturer marinizing engines $1500 a unit is huge..
There is also the fact the coyote is approx 3" wider than big block chevy and approx 6"+ wider than a small block.. Thats a lot of real estate in a twin engine boat..
__________________________________________________ __________
GM LS2 Crate Engine
Part No: GM-LS2CR
Price: $5,899.00
The LS2 produces 400HP @ 6500 RPM and 400lbs/ft of torque @ 4400 RPM
__________________________________________________ _____________

5.0L 4V COYOTE 420 HP MUSTANG CRATE ENGINE
M-6007-M50*
Suggested Retail Price
$7,399.00
420 horsepower @ 6500 rpm and 390 ft.-lb.+ of torque @ 4250 rpm