MV 2272, S/C Ecotec 2.4L, Scott 752

[AKLiving]

The project:

SeaArk OB jet conversion to inboard jet. I have been slowly working on my boat for a year or so now with the next step to start converting to an IB.

The boat is a 2272 MV SeaArk with a 115/80hp outboard jet. This is way under powered which has been fine for the most part. Fuel economy has been OK when light at 2.7mpg and worse than some V8s at 1.9mpg when loaded (no where close to max load capacity). Current running wt of about 1,600lbs. 

So.... I'm embarking on an estimated 2-3 year conversion depending on time and funds and time to complete it. Right now I'm done working on it until spring break up.

Work done so far:

First was adding some semi-dry bow storage that would keep stuff out of the way and provide a huge hunting/fishing platform. The frame is riveted angle aluminum and some left over 3/4" marine plywood.
Over the aluminum flooring and bow I added some exercise foam mat you can pick up at any store. It's inexpensive, light, soft, has good grip, doesn't seem to absorb water, and made the boat a lot quieter.
Next was changing from center rear console to a full walk through windshield at about 8' from the bow. Enough room to carry an ATV if needed.
Originally I was going to paint it the same SeaArk green but after using an aluminum etching primer it was a close enough match. New paint wouldn't have matched the faded green anyway. Prepped with vinegar after washing and the primer has held up to quite a bit of wear and tear.
The windows I cut from acrylic and installed myself. I may have saved $400 but it was such a pain to install that I don't want to do that again. The windows were probably 1/16" or so too big.


Parts for the conversion I have right now
It's not an exhaustive list since there are other posts for that.

Donor LE5 from 2007 Pontiac G6, ~56,000mi
M62 Supercharger
LSJ throttle body
Supercharger pulleys/tensioner
Fuel pump - Hayg
Scott 752 jet, 19-19 impellers, 110 and 114 inserts, hydraulic trim, hydraulic revers
Heat Exchanger - 3/4" in 1-1/2" copper pipe (aka 20mm in 40mm)

What I have to still get:
Base tune for 2.4l Supercharged
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

I will need some help tuning and plan on getting HPT and learning how to use it.

So, here are some photos documenting the original setup to where I am right now in the build:

[AKLiving]

The Deck and Windshield

[AKLiving]

Flooring and how it looks now

[AKLiving]

What is going in.

The jet is a stock photo (obviously) with mine on the way. It will have hydraulic revers and trim.

Pictures of the donor car and prepping the motor. When I get the supercharger on I'll post more pictures.

I was thinking of painting the engine the same boat green, leaving it natural aluminum or the Scott jet blue. I'm open to suggestions.

[mof]

Great project.

First thought, you will need to fit a nice long smooth delta bottom to the hull to ensure smooth clear solid water is delivered to the jet. The centre strake/fold in particular may aerate the water to the jet and hamper performance. Hamilton publish details of hull design to get best performance. Your scott unit will thank you for getting this part right, and this is hard to fix if you get it wrong.

Second, have a search for underfloor heat exchanger. 20mm copper pipe inside 40mm copper pipe. 1 metre per 100hp is the rule of thumb. Easiest and cheapest heat exchanger you can get, virtually un-blockable.

[AKLiving]

Great project.

First thought, you will need to fit a nice long smooth delta bottom to the hull to ensure smooth clear solid water is delivered to the jet. The centre strake/fold in particular may aerate the water to the jet and hamper performance. Hamilton publish details of hull design to get best performance. Your scott unit will thank you for getting this part right, and this is hard to fix if you get it wrong.

Second, have a search for underfloor heat exchanger. 20mm copper pipe inside 40mm copper pipe. 1 metre per 100hp is the rule of thumb. Easiest and cheapest heat exchanger you can get, virtually un-blockable.

Thank you the the advice. I won't be doing the aluminum work on the hull. I will trust the work to a guy that's done this many times before and has experience on good delta dimensions. I believe he takes out the center ridge a ways further up as well. I understand the importance of getting that right and it's too hard to adjust once it's done so I'm hands off on that one.

I have seen the under floor heat exchanger and will keep that in mind. I definitely like the idea of it being difficult to block up. I run mostly glacial fed, extremely silty water and not even filters or sand traps cans get all the silt out.
Do you have any reason I shouldn't go with a plate style exchanger?

[mohawk]

under floor tube is just so simple and works so well. they take up no space in the engine bay and if you cant weld, you can still buy the bits from a plumbing shop , cut and fit it  then get your local plumber to braze it together .
itsa no brainer realy.

[daveb]

The hull looks too flat(not much deadrise) for a jet pump from what I see.

[Paul]

The hull looks too flat(not much deadrise) for a jet pump from what I see.

The pump will still work but handling will be poor.

[AKLiving]

There are lots of very shallow deadrise boats around here and they work but like Paul said they handle poorly. Poorly I guess depending on how you look at it. I definitely can't carve through a corner. I have learned how to handle my boat and approach it similar to car drifting. I slide in corners and throttle out of them. It slides so much now that I don't expect it could get much worse. Clearly it isn't any fun in rough water but I don't have any whitewater around here.


Most of my boating is in water like this:
The only way to tell which image is water is by the bow in the picture.

[LBD]

http://www.nzjetboating.com/yabbse/index.php?topic=29895.15

It will be interesting to see how much this slides... 6 degree dead rise so pretty flat.. but no strakes at least not just now.

I am hoping the slight tunnel at the front will help arrest some of the front drift.... maybe.

But then, performance handling is not the aim.

[LBD]

Have you any idea of the weight of the boat... with or with motor?

[AKLiving]

Have you any idea of the weight of the boat... with or with motor?

I haven't weighed it but estimated running weight with the outboard is 1,600lbs. I don't think I would be too far off on that considering how much I was hauling on my last trip and still got on step with 80hp at the pump. I plan on getting a weight before I put the new engine in.
The Ecotec weighs almost the same as the Yamaha 2 stroke I have on it now. So, I'll gain the weight of the pump and doghouse. I'm taking out the rear benched so overall I should gain less than 100lbs. I'm not too worried if I gain more though. The power gain will be around 200hp and a much better pump.
Believe it or not with the change I will be gaining considerable floor space because of removing the rear benches. See the shallow draft picture to see what's coming out in the back. I'll get a better photo when they come out.

[AKLiving]

Look what arrived today.
I love winter but waiting until spring breakup is going to be painful.


Thank you Tyler Myers at Outlaw Eagle for getting me set up with an awesome pump.


At least I can pass time this winter while still being on the lakes and rivers.   

[AKLiving]

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.