LS1 or LT1 Marinizing

hi everyone... first time boat owner here...
as of today i'm the proud owner of an 89 Bayliner 2855 Contessa ( cruiser ).
theres a couple of questions i have regarding the engine that is currently in the boat. Its powered by a single Volvo 260 V8 and Volvo 280 Outdrive, but im worried about its reliability since it has quite a bit of hours logged ( 3789hrs to be exactly ) on it. The Outdrive will be upgraded to a DP unit, i already have talked to someone about this and will be getting a reman unit that will be plug and play with the curent setup, that will only require the drop out the existing unit and reinstalling the new DP unit. The only thing i'm confused on is the ratios where the DP unit is available in 2 flavours : 1.95:1 and 2.30:1

The reason behind all this is that i'm planing to spend a LOT of time on this boat with the wifey and kids and i want it to be reliable!

also i never really liked carburators (im a licensed automotive tech) so im hopping that i can get rid of it.
Looking to repower it with newer LS1 or LT1 Engine or get a custom 350 built with vortec heads and ITB's, but wondering what will it be required to marinizing most engines. Also i can keep an open loop cooling system since my boating will be done in the great lakes.

as far as the fuel system i will be using an speed density system that i will build/program ( www.msefi.com )

 

If reabilety is the question get a two engine setup and/or go for diesel engine.

The danger off fire is also reduced with diesel. A turbocharged diesel do a god job compared to a none turbo gasoline and is also cheaper to runn. I gues the fuel cost is moust boaters concern this days.

 

the reason being is that i have someone that is offering to sell me a LS1 for $250.

also some other guy owes me some $$$ and has a built 350 with 4bolt mains wiseco pistons, carillo rods, billet crank, balanced and blue printed, L71 heads and Weiand stealth ram intake almost for free

 

http://www.stainlessmarine.com/smallblock.html

http://www.crusaderengines.com/parts60.html

http://www.malibuboats.com/Default.aspx?pageID=52

I also think you might find something here
http://www.mastercraft.com

The rest you can find just by looking trough this forum.
I gues some parts like generator and heat exchanger(if your curent engine is not raw water cooled) from the engine you have.

 

if you desided on the dp drive just go with the package only question is 5.7, 6.0, 6.2, 8.1 liter engine and it comes complete wiring harness, fuel pump, ecu, exhaust manifolds, everything just drop in no worries and it has a warranty

 

I would go for the LS1! and the higher ratio with that big of a boat. Should be sweet. Only thing I'm not sure about is if Jacketed exhaust manifolds are available yet? Should be! Sweet!

 

why does everyone think that water jacketed manifolds are hard to build ????

all you really have to do is build a JIG from the original manifold and then use then take a gaskets to a machine shop and have them make a 1/2" thick flange, but making sure that only th holes and bolt patern are cut out leaving you with a rectangular flange that the ends will be beveled at 45'.
when this is done mount it into the jig and fab up the pieces that hold the exhaust log on and the engine piece. once the is done using scheduelle 40 or 20 ( for better heat transfer ) SS weld-el's tack up the internals. with a lil bit of math and geometry equal length runners can be achieved as well.
once everything is tacked up and everything looks good it can all be welded up, leaving only the enclosure for water jacketing. the second last step would be drilling the holes and welding in the bosses for the water fittings and zincs. Fill her up with water and pressure test in an eclosure to at least 25psi since an automotive coling system will peak ant only 15Psi and on an open cooling system will most likely be less ( speakin about my own boat here )

Note: the reason why i bolded out the test in an eclosure is that i seen enough ppl get hurt and could have been prevented easily. if you have a weak weld and a plate lets go you have a better chance if the manifold is an enclosure, if a hose lets go you wont end up with a nasty whip mark ( seen it done a couple of times, even though was laughin so hard i was in tears i was happy that that wasnt any worse and hopefully next time that person would think twice before doing again )

Same procedure can be done to water cooled turbos exhaust housings, or even better if no engine swap has been done and manifold can be used, machining of an adapter plate for the use of twin turbos.

heres a couple of words of wisdom:

- if you dont know how to use a TIG this job is NOT for you since a good hand and some skill you can get nearly perfect welds with proper penetration and less chances of having a poor weld when done by a trained hand.

- make sure that the JIG is nice and strong since the heat from the welds will try and move.

- Do NOT rush. take you time on welding everything up since you only have one shot at it since taking it appart will be a lot of grinding

Good Luck and Happy boatin

 

I fully agree! Some people don't have the time, knowledge, or desire to build stuff, But it's what I do also. The coolant system pressure is less of an issue if you are running an open water cooling system however with a nice aluminum LS1 I would probably prefer closed cooling. Just protects your investment a little better. Do you have heaters on your boat to extend your boating season? can be done with raw water also but closed a little easier on cores.
Light engine with a real reliable 450HP potential.

I'm doing home made tri-Y headers for my 489 BBC but it's closed water cooled with a radiator and keel cooling on an airboat so I don't need jacketed.

 

working with a friend that is in the HVAC industry to do a complete unit since this boat wont win any races, but want it to reliable, quiet (i cant belive im saying this since my VW used to have a staright 3" from the turbo back with no cat ) and fuel efficient ( hence from carb to EFI )if i do go with the LS1 then i will convert it to closed loop and use a heat exchanger, this was i can add in an electric valve to extend my boating season

yesterday was 32'C and today its rainy, crappy and 14'C

anyways...
theres a lot of room in the engine bay so im gonna add a 10KW Generator to add some convinience on the water.

 

heres a couple of pics...
first ones the boat and the second is the 260 Volvo/Penta motor
as you can all see theres lots of room since this boat has a wide bow ( 10' )

 

I'd go with the LT1 over the LS1, because all the marine accesssories from the 260 V8 will bolt right up. I'd pick a caprice/impala LT1 with iron heads over the camaro/vette aluminum headed version, for two reasons: the caprice/impala cam is ideal for a boat application, and the iron heads are optimized for lower rpm operation. Many police cars and taxis have logged 250,000 miles on their LT1 engines before needing an overhaul.

 

Unless you plan on putting in a closed cooling system, your nice aluminum motor will corrode away before you know it. You also need to install a proper cam. Don't forget about ignition protected electronics (spark proof). The higher compression will probably lead to detonation too.

Boat motors are always under load unlike cars. Completely different operating conditions.