Hey Precision, Keep me posted on that kit. I have a lot of experience on swapping wet joint exhaust to merc dry joint exhaust on regular SB chevy engines.. It a little more complicated than just bolting it on.. Not sure if it will translate to an LS or not but let me know if you are interested in the info.

[email protected]

Chris

Really, all that effort in molesting your checkmate and going with carbs ??? What a waste when Holley has one of the best, & easiest to set up FI systems for LS motors money can buy!!! Your already there do it right for cripes sake !!!

So your first post on OSO is coming in here to be a douche? I have an idea, when its your boat, you do what you want. As far as "molesting" my checkmate goes, there really isn't anything changed. I am wiring everything with a factory mercruiser plug, my headers exit at the stock location, and I only had to move my motor mounts slightly. If I feel like putting a stock Merc motor back in it, I can have it done in a weekend no problem. So until you know a little more about me and how "right or not right" I do ****, why don't you just go ahead and **** yourself.

For the rest of you with positive interest in my little project, here is a little teaser pic of the 408ci LS2 mocked up for bracket manufacturing. I'll post more as I get it done and get my dyno numbers in the next couple of weeks.

http://s25.postimg.org/fnzukslz3/image.jpg

http://s25.postimg.org/tiy539ge7/image.jpg

Only a 20yr old juvenile resorts to name calling when confronted with constructive criticism. Grow up kid open your ears and shut your mouth, you might learn something.
Great pix and choice of technology till you get to the very top of the motor. I guess if you boat in OH where the chance of vaporlock is minimal a carb is fine. But go south or experience a lot of high humidity youll be wishing for a FI system.

Can you give us info on your Water pump/crossover? I am not very knowledgeable of LS marine plumbing.

Chris

I think your use of the term 'molested' is what got Corey fired off...and deservedly so.

If he was a 20yr old and decided to use a carburetor I'd be even more impressed !

Too many 'kids', even those who know how to tune/install EFI, fall over dead when presented with a carburetor. Sounds weird, but that's happening all over.

If Corey331 is more comfortable with a carburetor, then that's his best choice.

Many of us here, work on and tune FI all the time, for work even, and yet some of us still use carburetors. Far from 20yrs old - and far from being stupid.

Corey - some of us like what you are doing. Carry on.

No problem. There is a much easier way to plumb the system if you don't mind spending $2000+ on the Hardin Marine setup. Being a Engineer/Fabricator by trade, I decided to find my own way. That way was made much simpler with some parts from Moroso. A big problem in the drag racing world with LS motors is the cost of an electric water pump for these motors. So Moroso decided to come up with an adapter set up to be able to bolt on a BBC pump. Well I figured "Why wouldn't that work for a BBC crossover?". Now, when you ditch the factory water pump on an LS, you also get rid of a thermostat. So Moroso also built a remote thermostat housing and a bracket that mounts it to the front of the cylinder head as you see in the pic. This also uses a BBC thermostat housing, so the crossover kit from Hardin Marine bolted right up to the motor. The only mods I am doing is I am going to drill and tap the bottom of the remote thermostat housing to accept a feed line from the steam crossover out of the heads. Normally that just goes back to the radiator. For a sea water pump I am using a brass Jabsco pump that will bolt directly to the crank pulley. It should work out great, and I have a whole lot less than $2k in everything.

The motor has actually changed a lot since those pics were taken. I got rid of that Demon carb for an AED prepped Holley HP 750, I added a nicer 3" K&N arrestor and I fabbed up brackets to relocate the coil packs to the back of the cylinder heads to keep the motor clean looking. i am currently milling up a bracket to keep the water pump housing from spinning, so once that's on in the next week or so, I'll update with new pics. I also got my alternator mounted and am using a heim joint tension-er to keep that belt tight. As far as power steering goes, I am doing some experimenting there. I'll post up what I did IF it works, which it should.

Thanks man. It's going to take more than one ass hat that joins a forum for no other reason than to bash on my project to change my plans. Whats funny is that everything I have ever built has been EFI. My last Mustang was injected with a FAST setup and as you can see in the background, now I'm playing with a 87 Buick GN that is EFI. It only runs 10's on street tires, so I must not know what I'm doing, or know how to do it "right". But, my boats have always been carb'd (been boating longer than he thinks I have been alive) and I can honestly say that I have never been stranded on the water due to a faulty carb. Now,I can say that I have towed in more than one boater that couldn't get his boat to start due to some damn sensor not reading or going bad. But oh well, good thing is, its my project and the last thing I'm concerned with is making somebody on the internet I don't know happy.

I guess somebody hasnt been around boats long enough to have heard of all mercs FI vapor lock horror stories...

Corey, we all know how well carbs don't work.. can't wait to see yours not work too!

lots of carb bashers here...not much to go wrong with a carb, and the newer ones like quickfuels are very adjustable thru out the entire band with a 02, I do not blame you at all for running one...sometimes getting the EFI right and keeping it that way can be a real pain...

im interested to see the performance vs the bbc. see how much the numbers actually change. I have been contemplating doing this on my next project just not sure if I want to spend the money since I have all the bbc stuff though.

At what point does the LS motor have to give way to the BBC? I would be willing to bet an LS motor will blow away a 330hp 7.4 and a 365hp 454 Mag. It would probably beat a 415hp 502 mag. I am thinking the Merc 525 will be where the big blocks start gaining on the LS but I would bet the LS would perform better below that. LS Engines are awesome and move a ton of air. Cant wait to see the results of this build!

My original goal was to build this and try to equal the power numbers of a hp500 but with a 400-500 pound weight savings. I know a guy with my same hull that had a hp500, so I'll be able to compare the numbers. Although my engine builder and quite few other people tell me I'll be well over 500hp, I'm not counting on it. Time will tell here shortly. I took measurements for the wiring harness to my Daytona ignition, so once that gets here, it's off to the dyno. I'll keep ya posted on what it does.

The HP of a big block is easy to match. The torque is not. That being said, the LS series of engines are torque monsters for their size. The dyno results will be interesting.

especially being a stroker it might equal the torque. if it does and makes the number hp wise it might be a viable replacement with weight advantages. only thing is a stroker isn't going to be super cheap I know the bbc stuff isn't either but it is more available and easier to obtain.

I'm pretty sure that even being a stroker, it won't hit the torque numbers of the big block. Even if it comes close to the number, it will be higher in the RPM range. But I think I will be able to overcome that with the combination of the weight loss (we all know how different our boats act with just us in it compared to a load of people) and the fact that I will be able to run a smaller prop since I will be cranking it to 6500 rpm. I think the dyno will really tell the story of how its going to act. On a side note, my stroker kit really wasn't as expensive as you might think. The expensive part comes in with the lack of a used parts market for marine stuff. so everything I bought was new. Actually, I had more in my headers than I did the stroker kit, lol.

Cory, speaking of torque, and I agree with whats been said about the lack of here, wouldn't the performer style intake been a better choice in your app ??? saw a LS manifold test a while back and thought those had a more torque in the mid ranges ??

That was actually the intake I had originally picked out. But in talking with Bob Madera when specing my cam and my local engine builder, they both said the Victor Jr. would be better. They thought that the dual plane Performer would probably make a little more torque down low, but not enough to offset how much power I would lose up top. My heads and cam are designed to pull up to 6500-6800, and the performer would choke out at 6000. Bob also said he could close up the lobe separation a little since I am running headers that doesn't allow water to mix in with the exhaust until the transom and that would really make up for the low to mid range power I will lose with the Victor.

gotcha...Bob would know

true on both points and I hope youre right cause im hoping this thing runs like a scalded dog lol

For anyone looking to do the LS swap, I recently finished up testing a version of our CAN-2-CAN marine gateway for the LS and Duramax. As posted on page 1, you can simply ditch the factory LS MAF setup and switch to speed density by EFIlive tuning. That should run ya about $300 or so. Now all the GM wiring harness and ECM remains intact, and the gateway we built for the Holley EFI guys will convert all the gauges to your favorite digital display or Livorsi gauges. That covers the electronics side for cheap, leaving more $$ to buy some good marine headers and marine alternator.

Just a little update, finally got this on the dyno and I was very pleased with the results!!! 572.3hp 566ft-lb!! This was on a very conservative tune as I am just as concerned with reliability as I am with performance. There isn't much doubt in my mind that it could make 600 with some more timing, but I am less worried about making a dyno number than I am having a great summer on my boat!!!

Video of it idling
https://www.youtube.com/watch?v=CaB0H2uw5JE

One of the first pulls, made 560 I think.
https://www.youtube.com/watch?v=lOUTehkQt20

From outside through mufflers. Damn thing sounds SICK!!!! Can't wait to hear it through my Lightnings. This was the 572.3 pull
https://www.youtube.com/watch?v=sGyRDXxjftk

I was amazed at how damn good this motor sounds. Its super crisp on the throttle response and idles at 800rpm like a dream. I have been busting my ass all this week to get the rigging in the boat done so I can drop it in.

Oh yeah, to the asshat that said I was "molesting" my boat, after doing some fine measuring, I don't even have to drill new holes in my stringers to mount the damn thing. It will literally "drop in" with the motor mount conversion brackets I bought.

Very nice! Would you be willing to post the dyno graph? I would be interested to see where the motor makes peak torque and how fat the torque curve is. Also, I am a little confused looking at your previous posts, is this a 6.0 or 6.2?

I'm at work and don't have the graphs with me. But it made peak hp at 5900rpm and torque peaked at 4600rpm. The torque was what surprised me. It came on pretty strong and just kept climbing. It almost matched the hp curve. I think this will be a very strong motor in the midrange. It made 500 ft-lb at 3500 or 3600 and at 6000 rpm it was till at 493 ft-lb.

As for the motor, it started as an aluminum 6.0 LS2 but was bored .030 and stroked to a 408ci. So roughly 6.7L now.

I love it. I am building a 408 for my Corvette right now. Ported LS3 heads, LS3 injection setup, Cam Motion cam. Those are good numbers for a water friendly cam profile. I am curious how longevity will be with the longer stroke and aluminum block in a marine application. Can't wait to hear your results when it is in the boat.

How much are the headers?

Was that you they were referring to on ls1tech that could do sleeve jobs? These aluminum 5.3s from trucks should become plentiful, how much to get one sleeved?

I think you need to stick with aluminum blocks to realize the weight savings, and then spin them up to higher RPMs so you can go faster! Some rockin naturally aspirated 700hp would be awesome and so light compared to a blown big block that only revs to 6000.

Your project is really awesome. Sorry for the all questions. I really want to do something like this so I'm trying to figure out what it would cost. Thanks.

They are about the same price as new BBC headers from Lightning. I believe I had about $2600 in them with the options I selected on them.

No problem man. If you ever have any questions, just shoot. I have no problem sharing what I have learned!!


One thing I will tell you is create a budget.... then almost double it. LOL. There is a lot of small stuff that I never counted for. -AN fittings and things of that sort. Plus things came up along the way where I spent a little more than I normally would have just because I wanted a little "bling" factor. Stuff like $350 billet valve covers and what not. I will say this, between selling my stock 454, a lot of the other BBC parts I had and stock stuff off of the LS motors I bought, I had less in this build than I would have if I would have bought a fresh or low hour hp500, and that was my main goal. and, somebody could have done this build for a lot less money than I did. A stock rotating assembly with upgraded rod bolts will handle 700hp. Also a set of stock heads work great, but I went with the CNC ported heads, mostly because I got a killer deal on them. Also, there are manifold options out there that are quite a bit less than a set of headers, but I figured, if I'm doing this, I'm going to do headers.

One other thing I wanted to mention is the cooling set up that is rigged with rubber hose was strictly for the dyno. I would never put anything that jenky looking into my boat. In the boat, the remote thermostat housing will actually be mounted to the back of my back seat. That will do two things. One, clean up the front of the motor even more, and two, it will allow me to build stainless -AN lines from the adapters to the housing that are equal in length ensuring I have the exact same water pressure to both sides of the engine as well as equal lines to the headers.

How much for stainless?

I have no idea. I know I'll never be in salt water, so I didn't even price them.

Maybe I need a fresh boat to complement the salt boat.

any updates?

Single digit temps have kept me out of the barn, but I have been working in the garage building brackets and stuff to get the motor ready to drop in. Also had to machine my valve covers for more pressure relief. I think they turned out pretty good. I'll post up some more pics as I get stuff completed. Its supposed to be 60 degrees here the next few days, so hopefully I'll get a lot done and drop the motor in here very soon.

I hope to see you on the lake this summer, I'd love to see this in person, such an awesome build.

Keep an eye out for me, I'll be in the white and pink Checkmate. Our place is on the Southfork just past Burnside State Park launch ramp, but I run the entire lake. Make a lot of trips up to Conley (my girls love to get ice cream there) and have quite a few friends that hang out near the dam, so I'm all over. Flag me down if you see me!! I love talking boats and meeting new people!!

http://s25.postimg.org/7zushaw5b/image.jpg