Hi Everyone,

As promised in EFI Fuel Plumbing - Best Practices, I will use this thread to chronicle the installation of a 5.3 LS engine into my Four Winns U17. I blame/credit Tim Moore and his Skater for inspiring me to start this project.

Here is the plan:

Engine
- Stock 5.3l LM4 engine from a Trailblazer
- Holley Fuel Injected Intake Manifold w/4150 throttle body. This moves the spark arrester from the front of the engine to the top. This helps with packaging in the small engine compartment…and I think it looks cool.
- Holley Fuel Rails to go with the above intake manifold.
- Holley HP ECU
- Truck Oil Pan, the LM4 oil pan is a bit shallow for my liking.

Mounting
- VP SBC bellhousing
- Custom fabricated front engine mounts. (I ordered a PAYR plastic engine to help in this effort)
- VP coupler that is used on their LS based engines.

Cooling System
- Johnson Pumps F6B-9 raw water pump. I’m planning on using an aftermarket harmonic balancer to drive it.
- Hardin Marine’s Closed Cooling System. Credit must be given to Scott Price at Hardin. He has answered all my questions quickly and in great detail. He definitely earned my business.

Exhaust
- Marine Power LS1 Manifolds
- Fabricated O2 sensor spacer

Here is the boat...


Stay Tuned,
Eric

The original rubber engine mounts were starting to show signs of wear. Volvo Penta used an oddball mount that would cost $250+ to replace. I decided to convert it to a mercury style mount and ended up buying these: http://www.hardin-marine.com/p-13539...ine-mount.aspx. Oooohhhh Shiny. I have to remake the stringer mounts for these too, but I don't expect that to be terribly difficult.

Here is the motor mount I designed to connect it all together. I'm currently planning to make everything out of 3/8" HSLA. I'm 3D printing all the parts before I spend money on steel and laser time. I should have those done next week to prove out the design.


More updates next week.
Eric

Cool project, good luck. I'm putting 2 5.3's in a 28 pc formula soon.

cool project, i got a lq4 that i plan on putting in my h210, ill be watching this for sure. cant wait to see how it goes

You won't even put one 5.3 into a Dodge Dakota.

Cuz I have too many of these damn boats to work on lol

Just an FYI, Summit makes an SFI Balancer that has the SBC/BBC bolt pattern in it. I used it on my LS swap into my Checkmate to run a similar Jabsco pump. The part # is SUM-C2500 http://www.summitracing.com/parts/sum-c2500. A less expensive alternative to the ATI's.






I then built a bracket that bolts to the stock A/C bracket location to hold the housing of the pump. I'll snap some pics when I go out and tinker with the boat later.

Very cool project! I have a U-19 that I bought new in 1996. I've been updating it for the life of the boat. Switched it to MPI sequential injection and larger injectors, SS headers, Edelbrock intake and throttle body. Also noseconed the Volvo Penta DuoProp gearcase. With all that, I've only seen 75 MPH on GPS. I would love to put a LS in it! Can't wait to watch your build! Cheers, David

Cool build, looking forward to it. I wish a lot of that stuff was available 6 years ago when I put the LS in my jet boat. Would have made life a lot easier.

Thanks Corey, pictures would be great. Thanks for the link to the summit damper too. I'm assuming you didn't use the keyway?


Very cool Taboma. I kind of regret not buying the U-19, but they wouldn't fit in my old garage. I love your Skater by the way.

I printed the engine mount yesterday. I'm happy with the design, just needs to be tweaked a bit more. (don't judge the bilge, you'll be able to off it in a few weeks.)



Next updates: Laser cut motor mounts. Machine new stringer mounts.

Eric