LS vs Big Block
03-24-2013 | 12:13 PM
#44
Pirate of the Chesapeake
Joined: Aug 2006
Posts: 4,330
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From: North Point Creek, Md.
I do know that the stock bottom end will handle almost 1000 HP.I think they may be the future common marine power.Notice mercury racing is now getting away from the old BB chevy style engine.JOHN SR
03-24-2013 | 12:54 PM
#46
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Joined: Jun 2006
Posts: 117
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We need some Turbo LS motors in a large twin application. I really think they would be a really awesome setup.
I already have superchargers but do the math on a pair of CMI's and you could have a good start on a twin turbo set-up using cast iron manifolds.
I already have superchargers but do the math on a pair of CMI's and you could have a good start on a twin turbo set-up using cast iron manifolds.
03-24-2013 | 02:30 PM
#47
Charter Member
Joined: Apr 2000
Posts: 285
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From: Draper, Utah
I had a 28 Daytona with twin Whipple charged SBC that ran 149mph on GPS. This was a 2002 boat. The motors made over 800hp each and tons of TQ. Everyone said the boat would not go over 100 mph. They were wrong. Would love to see a smaller skater with supercharged LSX.
It's all about power to weight. Cats do great when the loose a few pounds.
I wish merc Racing would have taken on the LSX
Eric if your reading this come on and give us a light weight 600-700 HP LSX.
MP
03-24-2013 | 02:30 PM
#48
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Joined: Jan 2006
Posts: 3,859
Likes: 791
From: St. Pete Beach, FL
Before the LSx crowd gets the panties in a bunch, I have owned a couple in automotive applications. One of my younger brothers has a LS2 based forged 402 ported LS3 headed .620ish cammed nasty iin his 05 GTO. Every time I drive it I think man, this thing is stupid fast. It pulls low 11's in the 1/4 and he drives it to work almost every day. He has 50K on this build and other than being really hard on valve springs ( square lobed hydraulic rollers do this) it has been super reliable.
GM never built an LSx over 427 CI for a reason. The LSx engines can be spun up and produce great HP but that alluminum block will not hold up in a marine application. Big tourqe LSx engines are built off of the iron block LQ9 truck engines and have lots of boost applied. They can handle that well in a automotive application but a marine application put stresses on an engine from idle on up that the LSx engines were not designed for. When you start talking about aftermarket blocks and unlimited CI's everything changes but yet stays the same. What it really comes down to is cost to repower. Most people can reuse all of their accessories when repowering with a healthier BBC. Making the swap to an LSx engine will require all new accessories, i.e. exhaust manifolds, accessory drives and brackets, engine pounts, bell housings etc. This will double the cost of making the swap.
GM never built an LSx over 427 CI for a reason. The LSx engines can be spun up and produce great HP but that alluminum block will not hold up in a marine application. Big tourqe LSx engines are built off of the iron block LQ9 truck engines and have lots of boost applied. They can handle that well in a automotive application but a marine application put stresses on an engine from idle on up that the LSx engines were not designed for. When you start talking about aftermarket blocks and unlimited CI's everything changes but yet stays the same. What it really comes down to is cost to repower. Most people can reuse all of their accessories when repowering with a healthier BBC. Making the swap to an LSx engine will require all new accessories, i.e. exhaust manifolds, accessory drives and brackets, engine pounts, bell housings etc. This will double the cost of making the swap.
03-24-2013 | 05:55 PM
#50
Registered User
Joined: Aug 2012
Posts: 614
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From: Charlotte Mi.
HOLY SMOKES!!! Thats fast in a 28' cat. Ive had people tell me a 31 cat is sketchy over 115-120. Your crazy!! I will not be over 100 in my cat until I attend a high performance boating class.
