Great Thread! Fixing to do an LS swap in a Century!

Does the Century look like a Fountain?

If you ever have any questions, PM me. I'll shoot ya my number!!!

I did finally talk to Brent at BBlades this week. He was a huge help and made me feel a lot better about how much weight I lost out of the transom and how we can make the boat perform. His exact words were "I don't care if it comes from the nose, middle or stern, taking that much weight out of a boat is always a good thing! We will make a prop that will make it work.". He thinks a worked Bravo 1 prop is still my best bet. So I'm going to try a stock one first.

Also, one little hiccup I had was with the coolant crossover set up I was running, which was pretty much a factory setup on the front two corners only that ran into the bottom of the thermostat housing. In a factory set up it runs back into the radiator which keeps coolant flowing through the heads at all times. In my set up, the water was dead heading into the t-stat housing until the t-stat opened up. So I think I was getting steam pockets forming in the heads which is also where the temp gauge sending unit is. Cause I would get intermittent high temp readings. So now I am putting on the Trick Flow coolant crossover set up that runs all four corners and I am going to dump it into the hose that carries the water out to the thru-hull fitting in the transom for the dry exhaust. This way I will always have nice cool water running through the heads. In my head this seems like it should work. I guess I'll find out when I put it on this weekend and try it out!!!

Any new updates or other projects?

I finally got mine running really well last season. I did make a few changes though. After spending most of 2016 chasing cooling issues, I pulled the motor so I could take it apart and check everything over. When I did, I found #8 cylinder was scored. It looks like I might have sucked something in when I was fighting my reversion issues. So I ordered a new piston and rebuilt everything. This time I went with an iron block. I did this thinking the added weight (96lbs) might help me balance out the boat more and, when I took the aluminum block apart, it was full of corrosion even though the engine had at most 10 hours on it and all of those on the hose or in Lake Cumberland. I also broke down and bought the Hardin Marine accessories, but I am running them as an open cooling set up, I wish I would have done that from the start cause man, it was nice to just bolt them on, plumb it in and take off. They work awesome. I am extremely glad that I added the weight of the iron block and billet accessories back into the boat. The thing handles awesome now!!! What surprised me the most was how much better it handles in rough water than it did with the 454 in it. I was honestly thinking it would have been the opposite. Now I am in the process of playing with props. At the end of the season I was running a 24p Bravo. It was carrying the boat very well and handled great, but I wasn't quite getting the rpms out of it I wanted. So next spring, I'll keep on playing with it. But for now, here's a pic of her the last time I had it out last year at the Caesar Creek Shootout in October. She airs out pretty good!!!

https://s25.postimg.org/4czz38gen/Running_3.png

Man, looks awesome in the water. What horsepower do you think you’re getting? I’m wanting to upgrade in the next couple of seasons and thought of replacing my 350 mpi’s with LS motors but honestly will probably only need 450hp per side. I’m told my boat runs out of hull much over 80. Just not sure if the expense would be worth it over stroking my current motors.

The tune that’s in it made about 575hp on the dyno so maybe 540-550hp with the accessories on it. 450hp should be super easy out of an LS for ya.

while on this thread, if anybody is interested, I have a 408 LSX complete engine, eagle forged crank, rods, weisco pistons, GMPP CNC ported heads, ported Victer Jr. intake, BT cam, valve train, pro systems custom carb, Daytona Electronics box/harness, over 600hp om 93 email me @ [email protected] or 540-786-8111 if interested...Rob

Bringing this thread back, there is a wealth of information in it. As one of the original post questions was getting a LS based engine into a boat with a Mercruiser 5.7L I had a few more questions. I have found a 97 Bayliner 2050SS 5.7L Alpha GenII that is in good shape but needs carb and distributor among other things for less than $500. Seems to me you guys have solved most of an a LQ4 6.0L swap problems already. Trying to keep this somewhat economy swap as someone previously stated.
The Break down:
Use SBC to LS conversion motor mounts
Use flywheel from 5spd LS
3 of the 4 bolts line up but the 4 isn't exactly needed
Use Stock truck ecu can be used and converted to open loop so no 02 sensor issues with water in exhaust
Use Pleasure Craft iron exhaust manifolds and risers
Cam from stock truck LQ4 should be ok with water reversion at 114 to 116 degree LSA
Add Trunion kit for durability
Add Moroso LS Rear sump oil pan
Add electric fuel pump
Wire Harness will have to be done piece by piece using old harness and truck harness

Questions:
Use the water pump in the Alpha gen 2 and go raw water?
Interrupt switch for reverse on Alpha GenII?

I have a friend who is a LS tuner and the conversion of the ECU wont be a problem. The cooling system is where you guys get a but fuzzy. I will only be using this boat in freshwater. Some say with iron block and aluminum heads will cause corrosion with raw water and to go closed cooling and add a heat exchanger, and those are expensive at hardin marine, so is their pump. others say raw water. can you use the water pump in the Alpha and if so do you keep the stock truck water pump or put a pulley in its place? Thanks for this thread as is, as someone stated earlier there is a lot of good information and many contributors.