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I hope this is OK to post here. It's not a car project but it is an ecotec 2.4l LE5 supercharged build.
This was inspired by many posts on this forum as well as other sites where you find the ecotecs being used. A special thanks most recently to AlexBC and his https://www.cobaltss.net/forums/2-0l...etboat-315976/ and to https://www.cobaltss.net/forums/how-...through-80620/.
I've read through countless builds, how-to's and other forum posts to learn a lot with more to learn. I felt I needed to contribute and hopefully this will help someone else.
The project:
SeaArk OB jet conversion to inboard jet.
After my last hunting trip I hit the absolute limit to my current setup. I have a 2272 MV SeaArk with a 115/80hp outboard jet. We had 2 guys, gear for a week of hunting/camping, and about 750lbs of moose onboard. I had to redistribute weight several times and still barely got on step. Max speed was about 20mph up river. Overall I go 1.9mpg and barely made it home with 5 gallons to spare with an hour of initial downriver on my 9.9 kicker. Thats worse than many V8 inboard setups.
So.... I'm embarking on an estimated 2-3 year build depending on time and funds to complete. Right now I'm done working on it until spring break up.
Parts for the conversion (bold I still need):
It's not an exhaustive list since there are other posts for that.
Donor LE5 from 2007 Pontiac G6, ~56,000mi
M62 Supercharger
Supercharger pulleys/tensioner
Fuel pump - Hayg
Scott 752 jet pump - on it's way from a shop in Canada Wire harness - stand alone from CBM, AFI, or dyi Driveline - Spicer 1310 or 1350 close couple, middle slip Wideband - AEM 30-3033 Fuel Regulator Marine exhaust - jetboatbase.com Fuel Injectors - Bosch 42# split cone spray Water-to-Water heat exchanger - probably plate type, raw water to coolant
I will look at getting HPT and learning it before seeking some help with tuning. There isn't anyone around here so I'll look for help on a base tune to start with. I figure HTP will allow me to tune and create logs for help in getting it dialed. The closest dyno is an 8 hour drive away and I don't even know if anyone Alaska can dyno an engine not in a car/wheeled vehicle.
So, here are some photos documenting the original setup to where I am right now in the build.
Original setup. The boat. 2272 SeaArk. Currently powered by a 115/80 Yamaha OB jet.
Added a full console about 8' back. This is the current setup and still drafts about 8" or less depending on load and distribution.
Donor engine. 2.4l ecotec from a 2007 Pontiac G6. 56,000 miles.
Almost ready for cleaning. Considering painting either same color as the boat or SDM blue to match the pump.
Bolt on parts. I won't be keeping the injectors.
Stock photo. One on the way with hydraulic reverse and trim.
Last edited by AKLiving; 11-06-2016 at 08:16 PM.
Reason: adding links
I've search and searched. Found an LSJ build and talk about a finished 2.2 supercharged boat but I have not found a 2.4 jet boat build. I know, not a huge difference. If you find that LE5 jet boat build please let me know. That would be great.
Would it not be easier to just add another outboard engine? If your goal is to fabricate something unique and unusual, your project makes sense; otherwise it is a bit crazy (crazy can be cool) to solve your capacity issues. I believe anything can be done with enough time / money / motivation; I don't see any reason your project can't be done =)
Would it not be easier to just add another outboard engine? If your goal is to fabricate something unique and unusual, your project makes sense; otherwise it is a bit crazy (crazy can be cool) to solve your capacity issues. I believe anything can be done with enough time / money / motivation; I don't see any reason your project can't be done =)
It would be a whole lot easier to just go with another outboard. I've wanted to do this project because it is somewhat unique and challenging. Being underpowered was just the incentive to start the conversion now. There are many pros and cons to both setups and heated debates in both camps. It's all about personal preference. Easiest isn't always very much fun.
I don't know anyone where I live that would be competent to tune my engine and the closest city is 250 miles away.
Does anyone have any suggestions on someone that would be able to come up with a stand alone tune for my type of setup and provide remote tuning? I plan on getting HPTune and have been learning it and checking out the demo mode.
I have tuned both supercharged and turbo converted 2.4 Cobalts, it's not bad at all. If you have HPT I'd be glad to take a look and help out where I can.
I have tuned both supercharged and turbo converted 2.4 Cobalts, it's not bad at all. If you have HPT I'd be glad to take a look and help out where I can.
Standalone might be a little bit different. Im not sure they use the stock ecu. A lot of the MEFI gm ecu standalones i see advertise as speed density. Tuning SD on a e67/e37 is a little different, but doable. Either way im interested to see the file.
I've tuned SD on a megasquirt in my Tercel. If you understand how an engine works and have access to the software, tuning is tuning IMO. I can tune anything if I have access and time to learn the software. You get faster with experience but the basic theory is always the same.
I definitely understand how to do it. I was simply stating it might not be the exact same process as an e67. I would hope that they arent using an e67 for SD just because the coefficient based stuff can be a pain. Hpt is making it easier though. Still wouldnt be bad.
Thanks for the responses. It's 30 below out this week so I'm lacking motivation right now especially not having a garage. At least I see there are people that can work with me remotely. That's VERY encouraging. I know the e67 is used as a stand alone in off road buggies so this application shouldn't be much different.
I'll probably wait until I get a spacer made for a wideband before tuning or just swap a regular exhaust for out of the water tuning.
It's hard having almost all of what I need to start working on this and just stare at it. I love winter but this year I can't wait until spring.
The E67 is used in a lot of 2.4 powered boats or any stand alone application that uses
electric throttle.Edit cal with hptuners or efilive. Mefi ecu is an E67 with different firmware to run manual throttle or different
crank trigger wheels.
Most of the boats use keel cooling to keep a closed system and be able to also have a heater. Questions, Give me a call 909 910 3867. Steve
Last edited by EFIHARNESS; 12-08-2016 at 08:48 PM.
Like Steve mentioned, we can configure your 2.4L with the stock LSJ TB on the E67. We've done a ton of 2.4 SC setups and have real good tunes all the way up to 60# injectors.
What are you going to do for cooling? We now offer a wet manifold for both the intake and exhaust.
-AFI
I planned on building a copper pipe inside a copper pipe water-to-water heat exchanger run along the bilge area for closed loop cooling. Simple and from what I hear the people using this method that they are near impossible to clog. Even though I will be using a sand trap the waters I run are so silty you can't get it all out.
I had planned on getting a true marine aluminum exhaust manifold from a company in New Zealand that marinizes ecotecs. It is a water jacketed exhaust.
I didn't see your wet exhaust manifolds on your web site. If you have more info on these I would appreciate it since I haven't purchased an exhaust yet. I have seen ecotecs from AFI that were on airboats but setup that wouldn't work on an inboard boat.
Spring is around the corner and I'll want to make sure I have the engine running well enough before I decommission my boat for the conversion.
The days are getting longer an I'm getting restless. Wanting to do something for the boat I figured I could mock up the heat exchanger. Using the 20mm in 40mm method here is what I have before soldering. Being in the US I used 3/4" in 1-1/2" copper pipe. It's 10' so using the 1m per 100hp I should be good for 300hp. I don't have a drill press or confidence in drilling 3/4" hole in elbows like others have so I used reducers. Local supply is limited living in Alaska but the shop had two 1-1/2" x 3/4" x 1-1/2" tees. Well they had 3 but I needed 4 so decided to keep it uniform and the other 2 ends have 1-1/2" tees with 1-1/2" to 3/4" reducers.
Total was $155 - not bad.
I'm so thankful my wife didn't even give me a hard time for doing this in the living room. She must know how anxious I am to get back to working on the boat project.
Advice wanted.
I have both LE5 and LSJ throttle bodies and need to decide which to use.
I don't have injectors yet and originally was looking for 42lb bosch but may be able to get 60lb at a better price.
The RPM limit will be set at 5,000 rpm for safety reasons.
The M62 currently has a stock pulley but possibly 2.8 in the future after it's running well.
My harness is currently set up for LE5 TB but I have re-pinned connectors before so changing it for LSJ shouldn't bee too hard. They are both 8 pin I believe.
My question is with a low RPM limit and thus much lower demand for air and fuel needed would there be any need for the LSJ TB and 60lb injectors?
Advice wanted.
I have both LE5 and LSJ throttle bodies and need to decide which to use.
I don't have injectors yet and originally was looking for 42lb bosch but may be able to get 60lb at a better price.
The RPM limit will be set at 5,000 rpm for safety reasons.
The M62 currently has a stock pulley but possibly 2.8 in the future after it's running well.
My harness is currently set up for LE5 TB but I have re-pinned connectors before so changing it for LSJ shouldn't bee too hard. They are both 8 pin I believe.
My question is with a low RPM limit and thus much lower demand for air and fuel needed would there be any need for the LSJ TB and 60lb injectors?
I would think the 42's would be maxed out or close to maxed out going with even a 3.0 or 2.9" pulley. If you go with the 60's you have more wiggle room and the 42's won't really offer any advantage besides maybe being a bit easier to tune for idle.
Do you know the size difference between the LSJ and LE5 TB?
I was concerned a little about tuning at idle after hearing that more than once. That's one reason I considered the 42lb injectors.
A boat can spend a lot of time at or near idle and there isn't a neutral so there is always a load on the engine. I'm not sure if that would help or make it harder since there would be a higher fuel use at idle rpm.
When you say near maxed out on 3.0 or 2.9 are you looking at it from a car application that revs to 7k and beyond? It seems like the demands would significantly more at 2k+ rpm above what my motor will see.
I haven't seen anyone posting duty cycles at lower rpm. That data would probably answer my question.
Last edited by AKLiving; 03-16-2017 at 08:00 PM.
Reason: missing part of sentence
For the supercharger use the lsj throttle body. Depends on how high youll rev as to what injectors youll need.
Thank you. I was going that route until someone that has a lot of experience but not on this forum much said it would be easier to stick with LE5 TB and the LSJ wouldn't provide gain with the airflow I need at lower RPMs. I wanted to ask here because this appears to be the biggest resource of people that own or have owned supercharged 2.4's. It seemed like a theme that increased boost isn't always better without adequate airflow. I haven't performed this much modification before so I'm absorbing info like a sponge and sometimes need to wring a little out.
I was concerned a little about tuning at idle after hearing that more than once. That's one reason I considered the 42lb injectors.
A boat can spend a lot of time at or near idle and there isn't a neutral so there is always a load on the engine. I'm not sure if that would help or make it harder since there would be a higher fuel use at idle rpm.
When you say near maxed out on 3.0 or 2.9 are you looking at it from a car application that revs to 7k and beyond? It seems like the demands would significantly more at 2k+ rpm above what my motor will see.
I haven't seen anyone posting duty cycles at lower rpm. That data would probably answer my question.
Higher RPM than you I suppose but it would suck to buy the 42s and end up needing the 60's. I would think a load increasing fuel use would make it easier to idle on larger injectors. I have a crappy idle (could be my tune) with 2.2 engine and turning the AC on levels it out.
Theres another guy that put an lsj in a boat, revved less than 5k and used 42s. Try to find his thread.
Thanks for the reminder. I know who you're talking about and looked up the thread. 62% duty cycle with 2.6" pulley on an LSJ. I should be fine with 42 lb injectors.
Thanks for the reminder. I know who you're talking about and looked up the thread. 62% duty cycle with 2.6" pulley on an LSJ. I should be fine with 42 lb injectors.
What octane was he running with 2.6" pulley did you see?
11-06-2016, 08:07 PM
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