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GM 6.0L: LQ9 (GM Marine 6000) versus LS2 - Fuel Injected

calndux

calndux

Active member
As I stated before I live in Alaska...I can get the LS2 fairly cheap ($4000 for crate motor), but I can not get the boating MEFI-5, the marine wire harness, or a computer program to run it (that I know of).

I can buy a LQ9 (GM 6000) from Panther or Marine Power with their programs for around $9000 (including shipping).

I have been running a carbed 350 marine motor, but since I need a new motor I am weighing my options. I want the best value and reliability for the money.

If any of you guys run the cast block/Al heads with EFI please let me know how you like them.

Some for any of you guys that have tried the LS2 with EFI.

Also, If anyone is an expert or knowledgeable on the subject of the GM MEFI-5, marine wiring harnesses, and programs could you explain them to me. THe advantages and disadvantages. Like will a program for a LQ9 work for a LS2?

I guess I am leaning to getting another 350 due to cost, because I would like to have the LS2 with EFI, but no marine OEM has one now. Panther says they are working on one and so is Marine Power, but is it worth the wait? Could I even conceivably put my own together from a crate motor for a corvette that would be reliable enough?

I know waterthunder builds carbed LS2 engines and they sound awesome from what I hear on this site, but I would like an EFI version.

Sorry to ramble again, and Thanks,

calndux
 
Pleasurecraft Marine(PCM) makes a 6.0 l and a 496 CI with fuel injection for air boats. Diamondback and Alumitec use them. They are nice motors.
Just heavy for some of the Florida running, but very reliable.

Why are you set on fuel injection? When fuel inj Sh#ts the bed, you are SOL. With a carb you most likely will make it back home.

How much hp are you needing? Are you running a gear box?
The 450 or 500 hp carb LS2 motor is very reliable.

The PCM engines seems very reliable. Runs on 87 octane. They have cast iron cyl heads. The pleasurecraft marine engine will meet all of your needs if you want EFI.

http://www.pcmengines.com/levitator.html

I am impressed with the water thunder engines. They are top of the line.
I have been watching a guy run one for 1 yr now. He has only changed the oil. No problems. It runs great and it get a good work out!!!!
 
Almost every one up here and most of the folks I have talked to down south (limited numbers) say the EFI is the way to go....I am still trying to make up my mind, because I see the carb as something I can work on well enough to limp home and with the EFI/computer I might be stranded...The old 350 worked fine, but I would like to have a little more horsepower/torque. I guess I figured that this repower would need to last for several years (realistic goal??), and with most folks selling the idea of EFI, I wanted to check it out. Needless, I am trying to get educated on these airboat motors and I appreciate all the help.

Thanks.
 
Gary,
I would stay with a carb . The places we run , If you had a computer failure , well no pun intended but your up the creek without a ( motor), And our creeks are fast, And you know up here is not like the Florida boys playground ,It might be days before we see another boat. If we are way back in bush weeks, months years..... :D before you see another airboat. Call and talk to Randy at Alaska airboats Leonard has a new partner and they are now pumping out boats from what I hear .He might be able to get you what you need or call Dick in eagle river and see what he has.

Alaskatours
 
I agree with AlaskaTours if you have problems it may be a long time before you get help in Alaska. That why you always tell someone where your going and I carry a 406 PLB.

Sure you could have computer problems or electricial, fuel pump, starter, radiator or blow an engine anyone could cause you major problems. I personally don't feel worrying about an EFI going bad is a good reason for not buying a EFI.

Good Luck.
 
Good point rutting moose , I always give 2 people my destination and return dates if I'm not back 2 days after I say I'm going to come back I tell them you better come find me ......... :D , Where did you get your PLB . I priced those last year about $600 bucks Alot of money But my life is worth more than that.

Gary here is link to a Topic I started in Jan. About what tools to keep in the boat .I'm glad to say I have everything that was discussed in there .Minus the extra prop I had stored under the bow. That was an over kill... :shock:

Check it out..
http://www.southernairboat.com/phpBB2/v ... ox&start=0
 
Calndux

I have one of WaterThunders LS6's and it has tons of tourque and it pumps out 520 hp and it has a Carb and I have had zero prpblems with the engine and I agree with what your fellow Alaskins are telling you I would much rather have a carb at least you can work on it if the efi goes out your dead in the water I do Search & Rescue so I can not afford failures reliability is everything and I would say go with the LS SERIES ENGINE you will love how much weight it will take off your boat and run a 2.68 gearbox with it and a three blade Sensenich S series prop and you will be good to go
 
I built a 450HP LS1 for a guy in Alaska around two years ago. He called me once said he was amazed how well it ran and I have never heard back from him. He has a carb on his motor. I prefer a carb but I also build these engines with a Fuel injection. I like the carb because they are thousands cheaper, and have no computer controlled fuel. With electronic injection you have 8 injectors, a ECM box, throttle position sensor, map sensor, O2 sensor all of which can go bad and if you sink it plan on spending at least a grand to fix it. Like I tell everybody I don't care what goes wrong with a carb I will make it back in on my own.
 
Waterthunder":8o3gkkpt said:
nd I prefer a carb but I also build these engines with a Fuel injection. I like the carb because they are thousands cheaper, and have no computer controlled fuel. With electronic injection you have 8 injectors, a ECM box, throttle position sensor, map sensor, O2 sensor all of which can go bad and if you sink it plan on spending at least a grand to fix it.
Click to expand...


Waterthunder made several good points on the ugly side of EFI's.

What are all the GOOD, BAD, and UGLY side of CARB versa EFI??????
I know I've would like to know.
I main reason I like EFI is no DIESELING.........
 
well lets see if I can even come close on this one LOL
Carb: easy to fix (sorta), makes more power (supposedly) costs less(initially)

Efi with ecm: individual cylinder timing and fuel control, better economy, adjusts to changes in temp & humidity, costs more, almost impossible to work on in field, automotive ecm's do not like moisture, however the marine ones do just fine even submerged and drug behind the boat it is controlling.

There must be some reason the manufacturers spent all the time and money getting them in use and the marine folks adapted them to work in moist areas. It could be part of a vast right wing conspiracy movement I am not sure.

My last GMC truck had one and it went a 100,000 miles before it needed a tuneup or spark plugs. My current diesel chevy has one and of course I had to put the bullydog tri pup on it so i could smoke a brand new set of tires off of it in two weeks. I am not so sure but I think it does ok in the power dept.

I don't know maybe some one has some real world side by side comparisons we can take a look at. I am sure the manufacturers have them and they chose EFI with ECM's. I do believe the total power may be greater with a carb but so is the maint. I think most race classes exclude them although the little jap cars making all the big power certainly use them because a guy next door to me writes the programs for them computers.

Just a few thoughts on it
 
Give me a break 141. A carb is more self adjusting to atmospheric conditions AND IT DOESN'T NEED A COMPUTER TO ADJUST IT. I will state the DFI is more fuel efficient and makes slightly very slightly more torque at lower RPM's. Out of the hundred dyno shootouts I have read about over the past 15 years I have never seen a carb be beat it's simple. Here are the mechanics of it you have a A/F ratio which is optimum it doesn't matter how the fuel and air get's there long as it's atomized well at the correct A/F ratio. The main advantage of a DFI is the fuel can be shut of immediately by killing the injector this is a little harder to do with a carb. I have worked with people that have spent millions on building the perfect DFI system and it kills them to say it but they agree. They both do the same exact thing and one cost's thousands less and is much simpler that's the plus of a carb and the plus of fuel injection is better fuel economy and 5 to 10ft pound of torque on average under 4,500RPM and to me that ain't worth 3K FOR A COMPLETE SYSTEM. The other plus is when supercharging or Turboing the DFI is much simpler to set up and tune.
 
Now wait a minute Thunder, I have to change jets due to humidity, temp if I want a carb to be right on ... correct? I don't have to change injectors. How does a carb self adjust, I have never seen a mixture screw turn itself or a jet change while I was running. I would like one of those self adjusting carbs, all of them I have seen needed human intervention to adjust. I have to pull a plug and read it or hook up my wide band oxygen sensor to check the fuel air ratio and adjust accordingly, The ECM does all this on its own. I agree sensors are at times a pain but they do serve a purpose.

The future is here and it involves computers, just like the LS series(gen III) motors have replaced the others it is only a matter of time until ECM'S are standard on all applications except at the musems. General motors is dropping the 496 this year I believe, the major marine engine companies are scrambling to find a replacement. Times are a changing and not just with where we can run but what we run as well. I don't know crap about ECM'S but I will have to learn if I live long enough because they are the future. [/b]
 
Looks like this one could get interesting....I vote carburetor, preferably on A/C engine...but then again I am a dinosaur and so are my boats! :twisted:

Grant
 
You forget I build both motors Fuel injection or carb how many fuel injected motors have you personally built to date? I'm stating the both have advantages. Some people would prefer to spend 3K less and go with a carb, I feel 70% of airboaters will choose to spend less money. Oh ya ask someone on this site who had a $4,000 Arizona speed and Marine marine DFI. Arizona Speed has built more DFI marine motors then about anybody else. He had three problems in one year and burned a piston he took my advise and put a Holley on the new motor I built him not ONE SINGLE PROBLEM TO DATE. If you want a DFI he will be glad to sell it to ya. Chime in if you want Chris on your DFI 454! Oh ya I know another DFI system on an airboat that had a O2 sensor problem he burned some pistons around 10 hours. Both systems excel in areas the other doesn't I just find it odd that you probably haven't built a motor or even Owned a boat with DFI and your stating how their better. Are you about to start selling them? Well I have ran both and built both and they both have their place. If I had 3K to waste I still wouldn’t run one on my boat now my buddy’s DD 408 LS2 I installed a DFI and it runs great but he has more money to spend on the things that are not as advantages. I’m not wanting a debate I’m stating facts from hands on experience DFI’s are not the best way to go for most airboaters.
 
Here are 4 stand alone DFI systems and one were trying to run on a Duramax in stand alone format. One of these designs I was personally involved with the RnD AND testing let alone working on a airboat cruise mode. The other design I did the first proto type testing on also It will be on the market and available shortly! Like I said I like both but it depends on who and what the owner wants


IMG_1398.JPG
 
that looks like a whole bunch of stuff that would over welm the average gear head give me a holley i still got my weather station notes i can change jets between rounds
 
Calndux---I'm running a 0540;but, if I was looking for a "car motor" for my airboat it would be as simple as two words---Carb. and Waterthunder
 
Thank you guy's you help make my point. DFI is a great thing but it's also making something that is proven 100% reliable and making it many more times complex then it needs to be and ten times more exspensive. A $350 Holley or a $3,500 DFI that is a big differance for that kind of money you can realy upgrade a motor. I enjoy building engines for the average airboater which most of them will prefer the cost and proven reliability of the carb nothing wrong with either. Me myself I understand and work on both and I prefer the carb. On 98% of any new technology I always jump on the new stuff but with the DFI's I'm not sold yet until somebody truly writes a self analyzing stand alone system that never has to be fine tuned by somebody with a lap top.
 
Didn't say anything about a stand alone system. I was referring to a whole system that monitors the fuel and timing for each cylinder and adjusts it as needed.

Nope never have built one or owned a boat with one yet, I said that I know nothing about them other than what the manufacturers say. They are the future as a whole system not a stand alone that is a half a system and you get half results from it. the pistons wouldn't have burned if all the parts were there and were working. As for reliability well I don't run over cars on the roads because they quit and there sure as hell is a lot of those systems out there last time I looked under a hood of a car or truck.

the system I am referring to is built by mercury marine and I believe they have a little experience at it last time I checked. I don't have to assemble a motor they do it and they test it and they warranty it. The check engine light says if a problem exists and if you ignore it it goes into limp home mode so you can't hurt your engine. i believe you were working on that for your engines as well in case it got too hot were you not?

the computer senses the load and delivers the fuel neded as it is needed and ajust the timing for each cylinder as needed and gets yopu your best fuel economy possible under the load at the time.

Yep I can change jets as well but a lot of folks can't we are getting more and more people in airboats who don't work on engines at all, they can benefit from a whole system monitoring the engine, I beleive that is what an ECM is an engine control monitor, nothing stand alone about it , a whole system monitoring your engine and its needs and adjusting it as needed.

Nope I am not selling them and not planning on selling them I agree each has its virtues and each has its draw backs and each is built for a certain type of individual situation or person using it. The three thosand isn't wasted if it is invested in a whole system and the whole system is used and it keeps your engine running like it is supposed to with no input or work from you, most folks these days take their car to the dealer when the check engine light comes on and that is the type of person who is buying the 50,000 dollar airboats. they want them running and running right when they want to go and workuing on it at the ramp or in the swamp is not an option, Maybe I will start an airboat tow service so when the check engine light comes on they can call and get towed in to the garage. LOL

You didn't address the self adjusting carb? I have never seen one of those, do you have one or a part number for one? I think that would be really cool and you probably could sell a lot of them. I have worked on holleys, demons, carters, edelbrock now, rochestors, webbers, and none of them have been self adjusting.

As for 100% reliable I just had the brand new demon which came with red gaskets dissolve a gasket within 15 minutes of it first use, that is not 100% reliable and I and stan were stumped about the clogged jets because I run filters and water seperator and it was a brand new system and no trash should have been in it but it was because the gasket dissolved. My point is nothing is 100% reliable and more and more people can't work on a engine at all. Those who can are very fortunate and can probably rig something up to get home. I most of the time carry a stock HEI dist. to put in my boat in case the MSD box goes out again like it has before, However most folks can't change a dist. especially on the water in the swamp. So what difference is it if it is the MSD box or the ECM that goes out? none your still done for the day and on the rope back to the dock if you can't fix it and don't have the parts.

All the new cars require a computer to fix them, my new truck had the CD player quit working, the dealer had to re-flash my computer and it was fixed, A damn cd player is controlled by the trucks computer go figure. So the laptop is no stretch every technician I know has one or a desk top mounted on their tool box.

Computer controlled engines are here, they are making great horsepower and they are reliable they just haven't been put on airboats YET but wait a few weeks one is coming The future is here and I have seen it. It looks pretty good especially if someone thinks a jet is a plane. LOL
 
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