LakeBoat4

New here and hope welcome. I posted on another thread and told to start my own tread in this section.

Got an LS total new build in the works and think the LS is the way of the future without Mercury involvement at least for the engine.

Is there a 10 post threshold to be able to post photos? If not how are photos attached? Everyone know if there are no photos it doesn't exist.

Brad Christy

LakeBoat,

Yes. Ten post threshold. Just spam this thread, or some other dead thread, until you get to ten. Then you're golden

Eagerly awaiting pics. My nephew, who works for me, is all-in on LS builds, and we have spoken at length on them here at the shop.

Thanks. Brad.

Wildman_grafix

I am going to be following, getting close to reposer time and it sure seems like LS/LT would be the way to go in the 500-600HP range. Just make 10 posts total, this is your thread just do it here,,,, count down 10,9,

Heck GM builds these base motors and sends to marine power and Kodiak to marinize it the rest of the way.

https://marinepowerusa.com/engines/6-2l-lt4-sportpac

https://www.kemequipment.com/marine-...#product-title

Tartilla

I'm pro LS, but what is the real advantage of an LS vs BBC engine?

​​​​​​LS vs SBC is a no brainer. But the costs to switch everything to LS is considerable.

Now LS to BBC, what does the LS bring to the table?
​​​
LS larger Cam bore size ++++

Similar weights when BBC has alum heads
​​​​​
BBC has far better CID potential.
​​​​​
LS has more FI support etc.
​​​​​
Not really seeing the benefit for a 600hp BBC for an LS.

Interested in perspective.

Wildman_grafix

I thought the all AL LS/LT was closer to 200-300lbs less?

For me smaller footprint helps some.
Pretty sure valve train geometry is better.
Intake and combustion design is better.
I am sure there are a ton of little things that may not mean much in boats and at this power level. Things like a better block design etc.

The biggest downside would be what you Brought up, pretty easy to do 540 in a standard deck BBC.

I would love to see a comparison of the fuel burn and component life of one of the motors I posted above and a similar power 540 BBC.

I am sure ILMOR did the before deciding on doing their 650Hp LT4.

https://www.ilmor.com/Marine/High-Pe...percharged-650

Tartilla

Iron LS blocks are relatively heavy. Bare iron BBC are about 219lbs ish with main caps.

BBC cranks are likely a bit heavier.

Valvetrain on LS is hands down the winner.

Modern design BBC heads are pretty good with chamber design etc.

Agreed on smaller footprint of LS/SBC, but the BBC is not really that much bigger. But when inches count...it may make the diff of changing plugs...or not...

I was always pro SBC/LS. Until getting deep into BBC, the raw iron size benefits.

F-2 Speedy

iTrader: (6)

Dont you have to pull the heads to replace lifters on the LS platform ?

c0ncEpT

When using OEM blocks, Yes.

LakeBoat4

What are the advantages of a LS::
1) NEW technology
2) Super parts availability
3) Weight savings, I don't agree that a BBC block is only 219lbs. There is roughly 500 lbs difference between a BBC and LS. Iron blocks, Aluminum heads each.
4) The BIG one: Power Density. Cube to Cube Lbs to Lbs there is no comparison
5) LS was designed with Forced Air Induction to begin with. Block geometry is Superior especially with aftermarket blocks and heads.
6) Smaller footprint,
7) Revised firing order, more even power pulse, easier on the crank.

Points to start with

I am Old School and don't like change but embrace the New Tech out there. Got two 572 BBC in the machine shop now for total rebuilds, waiting on parts. Side buy side the LS wins hands down. My little LS is a 427 and makes the same power.as my BBC's on 91
Let talk about some of these points. I hope there will be more LS marine builds to come.
.

LakeBoat4

Post 5
Countdown for photos