330 Excaliber to a 383 stroker- Anyone done it?

**gldslope** · 05-06-2012, 02:17 PM

383 Stroker

Originally posted by ffmedic74 View Post

Anyone converted a 330hp or a 343hp 5.7 chevy motor in their boat to a 383 similar to that that Indmar offers on Malibu boats? What would it take to do and what would be the costs?

Thanks!

I'm thinking about doing that exact project. I have. 2008 CC 211 with the EX343, and I think it's underpowered. I have been looking at various engine options and I think have finally settled on the 383. This particular crate engine is 460 hp.

**TX-Foilhead** · 05-07-2012, 07:03 AM

I believe that Mikeski looked into some HP upgrades a couple of years ago and determined it was close to impossible to break into the PCM computer to retune the motor. The easiest way is to buy another boat with a ZR 6 / 409.

**chris196** · 05-07-2012, 07:25 AM

Originally posted by TX-Foilhead View Post

I believe that Mikeski looked into some HP upgrades a couple of years ago and determined it was close to impossible to break into the PCM computer to retune the motor. The easiest way is to buy another boat with a ZR 6 / 409.

That may be true, but if you actually replaced the engine, you'd no longer be dealing with the PCM computer, correct?

**TRBenj** · 05-07-2012, 08:13 AM

Originally posted by chris196 View Post

That may be true, but if you actually replaced the engine, you'd no longer be dealing with the PCM computer, correct?

I believe the intent would be to swap out the 350 long block for the 383 long block, and keep all of the fuel, ignition and cooling components that came on the Excal.

The alternative would be to swap in your own aftermarket computer with a custom program on it, or revert to a carb.

**gldslope** · 05-07-2012, 09:06 PM

PCM Computer

I'm not too worried about the PCM computer. I am going to ditch that along with all of the associated wiring. Im going old school, a simple Holley. I don't have an exact plan, however, I have built a few engines back in my day of drag racing. So, what I want to build is an all aluminum stroker. I want a boat that is as light as possible for skiing, and can load up the ballast for boarding. It's pretty hard to empty out the weight of the cast iron block when it's time to make a slalom pass. My boat is a 2008 211, which nautique claims is a "certified" dual purpose boat, however, it is pretty heavy in the aft and makes too big of a wake. The block that I have my eye on is a Donovan and weighs about 100 pounds. Couple that block with a set of AFR 200cc heads, moderate compression 10/1 max, and a moderate but not too big of cam, and I think I will have a 475hp motor with lots of low end torque, due to it being a stroker. Last year, I cut a new exhaust hole in the back of the boat (wife was not too happy) and made from scratch a new set of down pipes to make a dual exhaust system. Link below is of the project last year if anyones interested.

http://www.petesdomain.info/dual_exhaust/pics.html

**Nautiqueman** · 05-07-2012, 09:46 PM

Kool! Awesome Job!

**crobi2** · 05-08-2012, 08:58 AM

@ Gldslope - Excellent!

I love how she says "there's water dripping out" (the exhaust) and you leap off and look UNDER the boat to be sure the water supply hasn't slipped off or something.

I can picture 99 out of a hundred of us doing exactly the same thing.

Sounds great - impressive work.

Please keep us posted on the stroker build. It would be nice if you could use the old fuel injection system/computer.

**obd666** · 05-08-2012, 10:55 AM

great job, that is way cool !

please do keep us abreast of the stroker build, am interested to see how it works out

**TRBenj** · 05-08-2012, 12:42 PM

Personally, Id be hesitant to dump all of the niceties of EFI on a boat thats <5 yrs old, but going to a carb is certainly the most straightforward way to tune a stroker!

There are several people with stroker motors in their (older) Correct Crafts over on CorrectCraftFan.com.

**ski4evr** · 05-08-2012, 07:49 PM

This would look great on top of a stroker!!! http://www.holley.com/data/products/.../largeHPSR.jpg

**Miljack** · 05-08-2012, 08:12 PM

Gld, awesome fab work! Have you had a chance to run it to compare if the new exhaust has helped the top end?
My question in all of this efi/PCM controller, if you just went with a custome ECM, could you interface it with the other systems and sensors in the boat? Wouldn't one need to tie into the "gateway" box to make the fly by wire work?

BTW, love the idea of the aluminum block and heads, would you also convert to closed cooling? Maybe not such a big deal if everything is aluminum and you're fresh water cooling?

**AirTool** · 05-08-2012, 09:14 PM

Originally posted by ski4evr View Post

This would look great on top of a stroker!!! http://www.holley.com/data/products/.../largeHPSR.jpg

Wow...that will definitely getch'your motor runnin'

Note the one shown in the pic is for a REAL small block Chevy from the good 'ole days...not the crap Vortec manifold/heads we have.

**Mikeski** · 05-12-2012, 05:22 PM

Yep,

I did some serious digging before I dropped the idea altogether for a variety of reasons. I did however install a set of eddie marine aluminum exhaust manifolds and would recommend you do the same. I even spoke with PCM about it and they said the stock tune was plenty fat to keep the motor from hurting itself if it ran a bit leaner.

I would not ditch the stock EFI system, there are plenty of guys that know how to make them work correctly and off the shelf software systems that would allow you to tune the ECM yourself. My motor is controlled by the MEFI 4b processor, if yours is drive by wire I believe that is the MEFI 5 processor. I would run the MEFI 4b, add O2 sensors in the exhaust elbows and run it in closed loop mode. Switching from open loop on the 330EX to closed loop on the 343EX allows them to run tighter fuel curves resulting in more horsepower.

The motor I almost put in my boat was going to be a dart block with Edelbrock aluminum vortec compatible heads bored and stroked to a 409 cubic inch motor. My target was to have over 400ft lbs of torque from 3000rpm through 5000rpm, with a peak around 500ft lbs around 4500 rpms. I would guess the motor would have made about 500hp. It's pretty easy to get there with 409 cubic inches and MEFI controlled EFI and ignition. I still have the spec sheet from Larry's marine engine in Arizona in case you are curious, email me if you want me to send it to you mikeskiw@gmail.com

I also considered a whipple supercharger. Either way I was looking at over $7k in hardware and ECM programming even if I did the installations myself. I had the cash ready to go but I realized it was a better decision to buy another boat which I did. I actually just sold that second boat since I didn't use it much in the past 2 years (2007-2011).

I use my boat for wakesurfing with fresh air exhaust. I also thought about cutting another hole and installing a second through transom port for full duals as you did but I don't want a loud boat. I still have a pile of 4" stainless steel pipe and mandrel elbows lying beside my shed with part of the exhaust already fabricated.

In 2009 my twin boys came into the picture and gobbled up most of the free time I had to work on my boat. This was a large factor in my decision to abandon this project. In 2011 I started working for a start-up company, between my 3 year old boys and my job now I have zero time for cool boat projects like this. It's crazy, I still need to find time to change my impeller and oil for this season. Luckily I have the boat functioning almost exactly as I would like it to function. That said, this thread makes me consider hauling the boat down to the whipple factory and have them add the supercharger.