whats truly needed to swap an ls engine
10-20-2019 | 07:20 PM
#271
Registered
Joined: Jun 2018
Posts: 420
Likes: 35
From: Michigan
Originally Posted by [email protected]
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.
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.
11-15-2020 | 07:56 AM
#273
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Joined: Oct 2019
Posts: 5
Likes: 0
I have been following this thread for a long time. Lots of good info. I now have a 93 searay 220 BR 350/A1 and a semi low miles 5.3l with entire harness and ecu that I pulled out of a running driving truck. Attempting to do this reliable and cheap which usually dont go hand in hand. Had a few questions.
1. Are you guys using the oem gm ps pump for yours alpha? Or alpha pump?
2. Can I run dry exhaust through the alpha? As in out the prop? I wanted a captains call set up, can it be done dry or would it melt something. The pcm and harding manifolds are pricey. Was thinking of buying ls forward facing turbo headers adapt them backwards and ceramic coating them.
3. Will I have to get a sea pump? Only going freshwater. Lots of lakes in maine lol. Will the alpha raw water pump be enough to cool a stockish LS? Also, if I use raw water I then don't need a heat exchanger? Even though there's tons of room, raw water cooling appears much simpler.
thank you!
1. Are you guys using the oem gm ps pump for yours alpha? Or alpha pump?
2. Can I run dry exhaust through the alpha? As in out the prop? I wanted a captains call set up, can it be done dry or would it melt something. The pcm and harding manifolds are pricey. Was thinking of buying ls forward facing turbo headers adapt them backwards and ceramic coating them.
3. Will I have to get a sea pump? Only going freshwater. Lots of lakes in maine lol. Will the alpha raw water pump be enough to cool a stockish LS? Also, if I use raw water I then don't need a heat exchanger? Even though there's tons of room, raw water cooling appears much simpler.
thank you!
09-08-2021 | 01:24 PM
#275
Platinum Member
Joined: Jan 2005
Posts: 1,156
Likes: 518
From: Owen Sound Ont.
I have looked at this more than once, I actually have a couple of NASCAR Spec LS2's just waiting to be built for a boat. I figure around 10g's each to dress and install the engines, heat ex-changer, oil adapter, headers, flywheel, oil pan, engine mounts and front dress. No actual engine or ECU. I'm sure with some creativity it could be done for less.
09-08-2021 | 04:48 PM
#276
Platinum Member
Joined: Feb 2001
Posts: 4,294
Likes: 1,458
From: Virginia Beach
The torque curve of the traditional SBC/BBC is better suited for a boat. A 5.3L LS is not going to gain you anything, and the cost of a supercharged LS is nuts. There have been some threads - good ones too - but you'll find that there's a lot involved in getting usable power out of them that justifies the cost. Just my thoughts.
