DOLPHIN Repower By David Lorimer II

November 2021

DOLPHIN 47 Chris-Craft Commander From Cummins VT8-370M to Cummins QSB 6.7 380s with ZF 85A gears at 2.5 to 1 reduction, with Glendinning electronic controls.

In 2011 the oil change samples revealed antifreeze in the port engine’s oil. After a few

tests it was determined that we likely had a bad liner seal. Upon figuring out how much

rebuilding the VT8 -370M would cost vs replacing, we decided to try Bars Stop Leak

and run the engine monitoring its antifreeze consumption. This decision was executed

knowing that the engine would die a slow death.

Fast forward to 2020. After 9 seasons of decent oil samples the leak returned with a

vengeance. It’s about a 5-hour trip from the boat’s winter home to her summer slip. On

that trip the engine guzzled 1-1/2 gallons of antifreeze. We had been nursing it along,

not running over 1800 rpm, It still had good oil pressure, however, around mid-season it

started to produce greenish jelly at the crank case breather, this would definitely be that

engine’s last season.

Now, the major decision. Repower or sell? Repowering would be a ton of work, likely a

lost season and a huge expense. Selling her with a dead engine would be difficult at

best, at a huge reduction in value. If we sold her, then what, not having a boat was not

an option. Replacing her with the same model would likely be just trading problems and

new boats aren’t very attractive.

After working on DOLPHIN for 20 years we decided to repower. With what…. Despite

the VT8-370M’s issue with the leaking liners the Cummins engines were excellent. So,

I suppose we became Cummins fans. After hauling the boat for winter, I started

unbuckling the engines.

1. Starting to unbuckle the port engine

Fortunately, Chris-Craft designed a semi removable hatch large enough to remove the

entire engine with gears attached. However, the center of gravity of the engine was 2’

farther aft than the aft edge of the hatch coaming. I ended up having the rigging

company, which is part of the Marina’s family of businesses, make a “C” shaped lifting

hook to lift around the hatch coaming.

2 The lifting hook to lift the engines around the hatch coaming.

After removing the headliner and cutting the fiberglass on the perimeter, we were able

to set the hatch on the forward cabin top.

3 Headliner removed, corner supports installed, ready to cut the fiberglass to remove the hatch.

4. The cabin hatch cut out and removed

I put some thin strips of plywood around the perimeter to protect the fiberglass edge

from the engine as they were lifted out. The hatch was plenty long for the length of the

engine, but only about 3/4” clearance on either side.

Seth, with Lawson Rigging and Fabrication, came with his crane and crew and lifted the

engines out for me January 8.

5. Lifting the starboard engine out, approximately 3800 lbs, the hook is 6 X 6 box tubing.

What a mess after 50 years.

6. What a mess!.

I started removing all the old wires, fuel lines, and the engine mounts, generally

stripping the engine room bare. I removed about 75lbs of old wire and 45lbs of copper

fuel lines, a bonus at the scrapyard.

7. Almost 80 pounds of wire eventually removed

8. Approximately 45 lbs of copper plumbing were removed, mostly fuel lines

With the E/R striped I could easily get good measurements of the space I had to work

with. In January it was too cold to do much else.

I work aboard a ship at sea, and had to leave for work for a month. Aboard the ship I

had time to work on planning and research. The original intention was to use a pair of

remanufactured Cummins QSB 5.9s, an EPA tier II engine. Due to COVID the lead

time on the reman engines was 6 months. The new Cummins QSB 6.7, an EPA tier III

engine was only 2-3 months, and the cost surprisingly was nearly the same. Through

research I discovered Frank Truluck. Subsequently I learned he had 45 years of

experience at Cummins and now works at Southeastern Marine Power in Florida, a

Cummins dealer. They secured permission from the local dealer to encroach on their

territory, so Frank could submit a bid.

After numerous emails and calls working out the details with Frank, the engines were

ordered on February 4th, 2021. The final order consisted of a pair of QSB 6.7 380s with

ZF 85A gears at 2.5 to 1 reduction, with Glendinning electronic controls. This package

was very close in power and gear ratios to the old engines. The bonus was weight,

each package was nearly 1800 pounds lighter.

The project seemed to start increasing in scope at this point. Digital screens for the

engines, required removing the gauges and new dashboards. Glendinning electronic

shift and throttles, new battery charger, new oil change pump, (the old pump only had

three valves so the gearboxes were excluded in that system,) all new fuel lines, new

primary duplex Racors, and new sound proofing. Consequently, more to remove and

figure out their replacement. I started with a 2” binder with specifications, plans, various

manuals and installation instructions or Marine Application Bulletins (MAB) from

Cummins, I quickly realized a 4” binder was needed. Some of the MABs from Cummins

were contradictory, Frank was fantastic about tracking down the correct answer from his

old colleagues at Cummins.

I ended up finding Libre CAD, a free auto cad program that made drawing engine

layouts, fuel and wiring diagrams very neat.

9 New fuel system drawing with free autocad program LibreCad

Editor Note: There is no photo 10

April first, home from the ship, and back to removal of the old….it was sad to remove

old gauge wires I installed back in 2004.

11. Removing the old engine and gauge wiring I replaced in 2004

The Morse shift/throttle cables and stands had to be removed to make way for the

Glendinning system.

12. Lower helm with the Morse controls and cables removed

And this is where a change order for the engines occurred, fortunately the only one. On

the lower helm, there were two shift throttle stands, the Glendinning would only be one

stand, with one lever per engine. I had planned to reconfigure the helm a bit and put

the Glendenning in the center, NOPE. There was not enough space between the helm

surface and the steering pump below for the Glendinning. I couldn’t lower the wheel

and raising the Glendinning stand was an ugly option. So, Frank was able to change

the order with Cummins and Glendenning to two shift throttle stands with one lever

each.

April also brought warmer weather, the boat storage building at Island City Harbor, in Sabula Iowa, is not heated. I could finally get in the bilge and start cleaning. I spent three days with a weed sprayer filled with Simple Green, a scrub brush and garden hose.

13. Degreased after 3 days of scrubbing with Simple Green.

Then three more days with an angle grinder fitted with a sanding disc and finally a

random orbital sander.

14. Stripped bare, ground and sanded smooth, ready to paint.

I was determined that all the rough and very painful shards of fiberglass would be

eliminated.

I made 1/4” plywood boards for the Engine Room overhead, painted both sides and

fixed the Soundown to them, carefully wrapping all the edges with Soundown’s foil tape

and making an even spacing of the attachment screws. Then I could relocate the 110v

LED E/R lights. The original Edison 12v E/R lights were replaced with 12v led flood

lights. Then the soundproofing could be installed on the aft bulkhead. The hydraulic

steering reservoir and the aft shower drain pump (with new hoses) were installed on

aluminum spacers from McMaster Carr, so the sound proofing wouldn’t be compressed.

I also cleaned up drain plumbing from the aft deck sink and removed the potable water

filler for the engine heat exchangers, to streamline the installation.

I had removed the batteries and all associated wires. Chris-Craft had some inefficient

ways to wire the engines. They had the port engine grounded to the starboard bus, a

port-starboard ground bus tie, and a third ground bus, and the battery location was

terrible. I spent a lot of time figuring out where everything would fit and how best to lay

it out for function, maintenance, safety, and visual appeal. Part of the battery wire

redesign was having the wires concealed in wire ways as much as practical. I ended up

fabricating two boxes to hold the battery disconnects and large ampere 12V breakers. I

used a local company, Premiere Metals of Eldridge Iowa, to laser cut, powder coat and

laser etch the labels on aluminum covers for these port and starboard electrical boxes.

The 3/4" deck boards were sagging badly after years of 8D batteries sitting on them, so

new deck boards with 2”x 2” oak stretchers underneath for support were fitted. I was

able to get two coats of white on the entire E/R bilge and new centerline deck boards by

the end of April.

Editor Note: No photo 15

16. After the second coat of white.

During the whole month of April, I was getting updates from Frank on the engine

delivery. Apparently once assembled as a basic engine they are shipped to the factory

upfit center for the marine options to be installed and then tested. Of course, all during

COVID with the associated truck freight shipping, delays multiplied. Finally, the day

before going back to the ship for a month, the engines arrived with no damage!

17 Finally arrived with no damage

Cummins has all kinds of installation parameters that you must meet in order to pass

the sea trial and sign off on the installation for the warranty to be valid. This sea trial

was omitted from less reputable bids! Some of the considerations were:

Exhaust back pressure less than 5” Hg. Cummins shared an exhaust back

pressure calculator and we determined we would meet that requirement.

The old engines had a 2-1/2” sea strainer and the new required a 2”.

I planned to use the same size 8D batteries with a Blue Sea battery combine

solenoid. The amps from 1 8D met the minimum requirements.

There were three fuel system requirements, supply restriction less than 5” hg,

fuel return pressure less than 8” Hg, and fuel supply temperature less than 140F.

These requirements created some questions…..The old fuel lines were 1/2”

supply and 3/8” return, and supported the old engine’s needs, but at what level of

fuel restriction and pressure? A colleague at work, who is a hydraulic engineer,

worked up a spreadsheet on the fuel system values. We concluded at a 1/3 fuel

tank level or lower, with the same size fuel lines considering the lengths, fittings,

and filter restriction that we would be very close or possibly over those

requirements. We decided on 5/8” supply and 1/2” returns, using Parker 221FR

fuel hoses (USCG and ABS approved for commercial marine use) with Parker

JIC fittings. I was determined to have DRY fuel connections; I was tired of the

flared copper connections being damp in some places. The final fuel

requirement originally posed no concern, fuel lower than 140F, unfortunately the

High-Pressure Common Rail fuel system can return fuel to the tank as hot as

175F. With a 200-gallon tank that fuel was going to get hot, possibly too hot. So,

a fuel cooler was included in the original order so it would be covered under the

warranty. (Everything on the original invoice would be included in the engine’s

warranty.) I also liked the idea of cooler fuel in the tanks not heating the aft cabin

as much, and the safety of a lower fuel temperatures for fire reasons. Without

the cooler, if the fuel supply temp exceeds 140F the engine’s computer derates

the power to prevent damage to the fuel pump due to the lower lubricity of the hot

fuel. Cummins also requires no fuel valve in the return system, so the valve at

the top of the fuel tank was removed, this facilitated a new 1/2" drop fitting that

accommodated the larger return lines with no restriction. All the fuel lines and

fittings came from Brooks at HydraDyne, in Charleston, S.C.

Most of the parts of the puzzle were figured out and waiting for me when I got back

June 2nd. The first order of business was to make a template of the engine mounts

location. Without the template it would have been impossible to measure in three

dimensions accurately once, let alone 8 times. Frank had warned of Cummins drawings

being inaccurate for this phase. He was right, the drawing dimensions did not add up.

We figured out the error thanks to a supplemental drawing for the ZF 85A gearbox,

otherwise I would have located the engine mounts 1-3/8” too far forward. Once the

template was built, I took some aluminum box tubing and machinist squares clamped to

the engine to verify the dimensions were accurate.

The old shaft couplings had male alignment bosses, as did the new gear flange. Scott

Wolf, a friend and fellow boater, has Fostbinder Fabrication, in Moline Illinois. He

removed the male boss on the shaft flange and machined it to the correct tolerances as

a female. He also increased the size of the flange bolts from 1/2"to 5/8” to match the

new gear flange, bigger bolts meant bigger heads, so scallops had to be milled into the

outside perimeter of the shaft flange.

With the template verified it could be bolted to the modified shaft coupling and installed

on the shaft.

18. Old modified shaft coupling bolted to the engine template with the 8 degree down angle of the

ZF85A gearbox to locate the engine mounts

Then the new engine mounts were located. This was not too bad as the old engine mounts were nearly the same width as the new mounts. The aft mounts on the ZF gearbox and were taller than the stringer, so I had to build up the stringer, somewhat straightforward, but then it got ugly! The forward mounts were much lower than before. The new engines had an 8-degree angle built into the ZF 85A. This was desired so the engine sat in the boat nearly level. The dilemma was how to cut squarely 6”-8” off the original stringer, from the inboard side, as there was not enough room outboard for the various saws to fit. After a lot of measuring and what ifs, I was able to screw a piece of aluminum box tubing to the stringer as a guide and buy a huge Makita circular saw that

would cut 4-3/8” deep. The outboard stringers were more difficult. The guide had to be screwed to the piece I was cutting off and the heavy saw held up to the guide, otherwise it wouldn’t fit.

19 The engine mount template in place, port side, before morticing the aluminum plates.

Now the actual engine mounts could be bolted down. Originally Chris-Craft used lag screws to secure the engine mounts, unfortunately lag screws are no longer are acceptable to Cummins. It was decided to drill through the stringer and use 1/2” grade 8 all thread and hardware in fine thread. I also made 3/8” x 4” x 8” aluminum plates for the engine mounts to sit on distributing the forces on the fur stringers. The outboard stringer was more challenging. Due to the deadrise of the hull it was shorter. For the original lag screws to have enough grip the outboard stringers have another chunk of wood inside the hollow fiberglass beam. This made installing the backing washers and nuts more difficult.

20. Installing the forward engine mounts starboard side, the small access holes for the washers and locknuts are visible on the outboard mount.

On June 15th the rigging company was back to set the engines. This time they brought the counterweights which allowed the computer controlled 100-ton Liebherr crane (their smaller crane was out of service) to have more boom in the air.

21. The port engine lifted by Lawson Rigging and Fabrication

This made it easier to maneuver the engines as we were setting them in the boat. We had the first engine hanging with the gear end slightly lower and maneuvered it into the cabin.

22. Lowering the port engine in through the hatch

Then turned it 90 degrees and lowered into the E/R and slowly set on the aft mounts.

We stopped and repositioned ourselves in the bilge and then the crane slowly lowered

the engine onto the forward mounts.

23. Port engine sitting on her engine mounts

The Starboard side was nearly as easy, but the oil change fitting on the gearbox was

going to be too close to the stringer. So, with the rigging crew and crane waiting, I

quickly added a jic elbow.

The next day I started to line up the engines. This was too difficult to accomplish by

myself. There was too much back and forth, measuring the flange with the feeler gauge

and bumping the adjustment. Close was good enough for now.

I moved on to the seawater plumbing which I had removed, to the seacocks in the demolition phase. Fortunately, the seacocks were replaced in 1998 with new Apollo ball valves. I kept the old 2-1/2” strainers and reduced them to 2” fittings after the strainer,

all in bronze. The fuel cooler presented a problem. It is 16” long. It had to fit in between the strainer and water pump intake. Cummins also required that the seawater intake stay wet. They suggested a trap like bend in the hose. This requirement was going to be ridiculous both practically and visually. The solution was to use a bronze flapper style check valve. I also included plumbing to winterize the engines with a fitting in the side of the boat that is connected to each engine and generator. Over the years I was tired of slimy green antifreeze all over the E/R for winterizing. Now winterizing consists of closing the seacock and opening the winterize circuit and connecting the sump pump to the hull fitting. Putting the sump pump in the tank at the exhaust stack and filling the tank with antifreeze, start the pump and engine, circulating the antifreeze through the system adding to the mix to get -40F protection. Now I can do the winterizing solo without a mess in the E/R

24. Starboard water intake tree, 2 inch on the left with the check valve, dropping into the fuel cooler. On

the right the winterizing valve with the new winterizing connection in the hull side.

Unfortunately, it was the end of the month and time to go back to work.

August 2, back aboard to finish? I originally wanted to be finished by August but,

there was still quite a long list to accomplish.

The engines each arrived with their various wiring harnesses, plugs, and Customer

interface Boxes (CIB) Then there was a third box with the Glendinning control heads,

wiring harnesses, and brain box. At the end of the previous month, I verified everything

was present and correct, but only had time to install the Glendinning brain box. I

located it inside the wiring trunk in the guest cabin just below the helm. Chris Bernard,

a good friend helped pull all the wiring harnesses for the engines and Glendinning’s to

both helms. Cummins did a surprisingly good job marking all the components, male

and female plugs that were color coded and different, so they only went one way.

However, Cummins engineers were baffling in their design. They wanted three separate

switches to enable, start and stop the engines. They allowed me to use my original key

switch to enable or key on and start. Frank was helpful verifying the wiring change with

the application engineers, so I didn’t fry anything expensive. I still must have a separate

momentary stop switch. The engineers explained they want the engine shut down while

the brain is still enabled to capture all the data. It took nearly three days to connect

everything and properly bundle and secure all the wiring harnesses neatly. I had to

modify the dash for the screens and wanted time to layout a new dash so I made a

temporary panel to cover the old mess and hold the screens. I am still contemplating

the VDO Veratron Oceanlink 7” LCD screens, user configurable to show all the engine

data on one screen instead of three different pages on the 4” Cummins screens.

On to the fuel system. I installed the required water in fuel sensors supplied with the

engines to each Racor and labeled them, so later if port #1 Racor alarmed I knew which

one it was. I found a cool pressure/vacuum and temp sensor from

TransducersDirect.com that communicates via Bluetooth to an app on one’s cell phone.

It has user configurable gauges with alarms, so I will get an alarm on my phone for fuel

filter restriction at a setpoint I choose.

25. Bluetooth vacuum sensor for Racor filter restriction displayed on an app on ones smartphone

Cummins suggests 10-micron primary filters, but with Racors that are oversized, the

fuel restriction difference with the 2-micron filter is negligible. We usually get fuel

directly from the truck bypassing the questionable fuel from marinas and have always

used 2-micron size with no clogging issues. In order to get the various fuel lines the

correct length I pulled them through their route and marked them. I was able to borrow

a hydraulic hose saw from my ship; it looks like a deli meat slicing blade on a small Skil

Saw. It cuts the wire braided hose cleanly with very little smoke or debris. Once all the

lines were cut, I pulled them back through their routes to verify the correct length.

26. All the fuel lines cut length, laid out to mark the ends, before cleaning and installing the fittings

The lines went to Motion Industries in Davenport Iowa to have foam plugs blown

through to clean them. And finally, have their JIC fittings installed, no hose clamps!

The lines were capped to prevent contamination on the final installation. I also marked

all the ends with their location and color-coded tape with flow direction. Subsequently,

the fuel line installation was relatively easy, however securing the lines neatly was very

time consuming.

27 Port side fuel cooler

28. Port and starboard duplex Racors with water in fuel sensors installed. I added mini stainless steel ball

valves and plugs on the drains

I was concerned that fuel flowing around the system could cause a static charge. I was

not convinced the original copper grounding strap was adequate to properly ground the

fuel tanks. So, I ended up running a #4 gauge wire from the new ground bus to both fuel

tanks.

The CIB was slightly larger than a shoe box. All the wiring harnesses from the engine, gauge screens, Glendinning and boat terminal strip connected here, an ugly bird’s nest. The box couldn’t be too far from the engine due to the engine harness length. I had a conundrum…. where was this going? I ended up with a compromise solution after

rearranging the forward deck support. To protect and neaten the wires I made a box to enclose the CIB and its connections with one side open to access the engine reset breakers.

29. Starboard CIB with its enclosure box to protect and conceal the wires, New generator fuel valve,

relocated near the filter.

I was excited to discover after removing all the crap from the engine stringers all three 8D batteries would fit side by side between the stringers.

30. Building the battery box and installing the port and starboard breaker and disconnect boxes

This changed the battery wiring plan. Now I could have ONE main ground bus instead

of two and a bus tie, which I could locate on the athwartships beam with the batteries

just aft. Then the Battery disconnect and breaker boxes forward of the beam. This

completely concealed the battery wires. I ended up buying a manual hydraulic wire lug

crimper, like a small port-a-power, it can put 11 tons of force on the hexagonal crimp. It

came with various sized dies for wire sizes up to 4/0. It even imprints the size of the Die

used on the lug.

31. The hydraulic wire lug crimper, capable of 11 tons of crimping force

After mounting the disconnects and breakers in the boxes on spacers, the boxes could

be installed and the passages connecting them drilled.

32 Installing the disconnects and breakers on spacers so they are flush with the cover

The new lug crimper made the wiring fun and was well worth it! All the lugs are tinned

copper with enclosed ends by Ancor, with adhesive lined shrink wrap to seal them, and

Ancor type III tinned marine wire.

33. The interior of the port 12v disconnect box

34. The interior of the new battery box, maind ground bus, and Blue Sea battery combine solenoid

partially installed

35. Port CIB, disconnect and breaker box

36. Starboard CIB, disconnect abd breaker box

The old battery charger was 24 years old, so I decided it was time for replacement.

Pro-Mariner, the manufacturer of the new charger, recommends breakers for each of

the independent 12v outputs. I should have at least a fuse for each of the remote

meter’s sensing wires. The Blue Sea combiner automatically combines port and

starboard engine batteries when it senses a charge on either battery. The starboard

engine has a 12v alternator connected to the starboard battery as one would normally

expect. The curve here is the port engine has an isolated 24v alternator connected to

the 4 8D inverter batteries only. This leaves the port engine battery without charging

while underway, so the combiner charges the port battery when the starboard engine is

running. But on shore power or when the generator is running the combiner connects

the two as designed. In this situation, you want the new smart charger to sense each

battery bank separately. Fortunately, the Battery Combiner has a wire in its design to

override the automatic combine function and force the port and starboard batteries to be

separate. In order to provide 12v to this separation circuit automatically, I installed a

tiny solenoid to energize the override, separating the batteries when the battery charger

was working. Consequently, I designed a small panel to hold the output breakers,

meter breakers, indicator light for the combiner, and the solenoid.

37 Three bank 50 amp Pronautic battery charger and its outout and remote meter breaker panel,

partially installed

38. New flybridge helm configuration with start and stop switches, Cummins ED4 gauge screens and

Glendinning controls

39. New temporary lower helm configuration, working on new lighted switches and VDO 7 inch Ocean

link screens and split Glendinning bases

Cummins has a procedure for the first start up or after a fuel filter change to run the

priming pump 6 times to completely prime the filter and fuel system. They Caution DO

NOT prefill the filters. They only want fuel sucked through the primary filters and

subsequently the engine last chance filter entering the fuel pump and HPCR in order to

prevent any contamination.

Chris Bernard came up to help with the final alignment of the engines within 0.005”.

After nearly 2 hours we were happy with the initial alignment on the port side at 0.002”.

The starboard side took half the time with similar results. Cummins wanted the engines

realigned after the boat was floating and had a run underway a few hours.

The 4” dry portion of the exhaust was rather daunting. Facing the front of the engines

the exhaust exits the turbo on the left side, great for the Starboard side, a short “s” turn,

but the port side was going to have to make a 180-degree bend, cross over the back of

the engine and drop into the custom mixer.

40. Fabricating the starboard dry exhaust s turn

41. Port 4 inch dry exhaust making the 180 turn. Fuel lines marked and capped and partially run

I used turbo flanges from Seaboard Marine in Oxnard, California and was able to use

stock 4” long radius stainless steel elbows from McMaster Carr, then into 4” stainless

tubing. This connected to a custom stainless-steel water and exhaust mixer from

Seaboard. Justin took my sketch and fabricated the mixers with an extruded bell

design. I don’t weld, so Chuck from Lawson Rigging and Fabrication, came over and

helped fit the pieces and welded them together. Both Justin at Seaboard and Chuck at

Lawson are artists with their welding skills. Once the exhaust was welded it needed

supports that had to go to the engine, so the engine/exhaust unit was isolated as a

single unit for vibration. To support the exhaust Chuck and I were able to use the

factory rear engine mount holes to hold stainless steel angle stock that went up to tabs

and doubler plates on the exhaust tubing. The mixers connect to the existing exhaust

with 6” high temp silicone hump hoses for vibration isolation and new hoses connecting

the fiberglass exhaust components, all with double stainless t-bolt clamps.

42. Port exhaust and supports partially finished, Custom mixer and hump hose in the background

One of the t-bolt clamps on the exhaust mixer holds small butterfly bracket, made by

Justin at Seaboard Marine, that holds the exhaust high temp switch. Cummins sends a

switch that closes at 250F, too high for my taste, so I replaced it with one that alarms at

180F, before any exhaust components are damaged.

While I still had the hose saw from the ship, I pulled all the oil change hoses, the same

type as the fuel lines, and got them made up and secured in place. Since the engines

and gears were filled with oil at the factory I will connect them during the first oil change,

once the sumps are drained.

Cummins wanted all the cooling water to go out the exhaust stack. Originally Chris-

Craft dumped a good portion of the engine’s cooling water overboard through a bypass

midships port and starboard. They likely did this to reduce the exhaust back pressure,

but that calculator from Cummins indicated this was unnecessary. Over the years I

grew accustomed to checking for cooling water midships after starting up the engines.

Considering the exhaust stack was partially submerged and under the swim platform,

checking for water flow there was impractical. I plumbed in the bypass with a ball

valve.With this valve half open it turns out the exhaust stack temps do not exceed 100F,

and I still have the desired visual confirmation of water flow midships.

Sunday August 29th, I only had two days left and desperately wanted to test run the new

girls before going back to the ship for a month. By noon I had finished the cooling water

discharge plumbing, connected a garden hose to my hull side winterizing fitting, lined up

the valves, turned the key on, climbed into the engine room and pressed the start switch

while opening the water valve.

Vroom, the port engine started instantly!!!!Exhilarating!!!

The CIB has the same gauge screen as each helm. Checked through the numbers, so

far so good! Climbed around checking for leaks and all dry. Went to the helm and tried

the throttle, it works. I shut her down and tried the same procedure on the starboard

side, relieved to have the same successful results.

The following day I disconnected the dry portions of the exhaust and delivered them to

Iowa Illinois Taylor Insulation, my boat neighbor Jim Groves’ business, in Northwest

Davenport. They represent the company that makes the removable insulation blankets

for exhaust systems.

And then back to work for the month of September. So close, scheduled to launch

October 5th.

October First, I got an early flight home so I could pick up the dry exhausts and new

heat blankets from IITI that Friday afternoon. Saturday, David Smit and I reinstalled the

exhausts and wrestled the new heat blankets into place.

I had some details to clean up; like installing a resistor in the CIB to tell the engine

control module there was a signal from the fuel gauges I don’t have and to connect the

rudder angle indicator to the starboard ECM. This alleviated the two nuisance alarms on

the ECMs.

43 Like most of our boats, no fuel gauge, had to add a resistor to trick the engines software to stop a

nuissance alarm

Remember that Cummins Sea trial, the gentleman at Cummins who conducts this had a

family crisis. His wife was pregnant with twins and the entire family had COVID,

eventually all fine! Consequently, I’m still waiting for that formal sea trial.

Without the formal instrumented sea trial, I had another issue to solve. Now I needed to

set up some test gear to check the installation myself. Vacuum and pressure gauges

for fuel restriction and pressure, vacuum gauge for seawater restriction, a fluke

pressure/vacuum sensor for the exhaust back pressure with a custom copper tube as a

heat sync to protect the fluke sensor from the 750F exhaust temps, and a four-channel

thermocouple device for exhaust stack temps top and bottom on both sides

simultaneously.

44. New flooring from Race Deck, the fluke meter in the middle right for measuring exhaust back

pressure. 4 channel thermocouple top middle for exhaust stack temps after the water mixes

October 5th, LAUNCH, the marina kept tension on the slings, and I tied her securely in

the lift pit. I started the generator, no issues with its new battery wiring or new fuel lines.

Then started each engine, checked gauges, for leaks, and water flow all good, then

tested the shifts and the directions were correct. All the wiring from Cummins and

Glendinning was truly plug-and-play, astonishing!!

Robert, one of the gentlemen working for the marina, went with me for a short test run.

Once out on the river Robert took the helm while I went to the E/R. He could see my

directions on the closed-circuit video cameras. Everything looked good on the gauges

and all the test gear…. and they were so quiet! We ran back and forth with RPM up and

down starting the very non-technical break in procedure. Cummins claims no break in

is required!?! But Frank and others helped determine a conservative break in plan.

The following day off to Moline 50 miles away. On the trip up that previous fall the noise

in the center of the main saloon was 83 decibels at 1800 RPM, with the new engines

and soundproofing at the same RPM the noise was only 72 Decibels. Most of that was

from the exhaust tubes resonating on their hard mounts, yes another project.

Due to my schedule and winter, DOLPHIN was only in the water for 20 days, but we

clocked nearly 40 hours underway. At 25 hours the gearboxes got their oil and filters

changed, and I could connect half the oil change hoses. The shaft couplings were

unbolted, and alignment rechecked, indeed minor adjustments were needed.

The main saloon headliner and hatch need to be finished. The lower helm reconfigured

with custom Contura V switch actuators and switches, the tops of the switch with a

dimmable backlight symbol, and the bottom of the switch a dimmable indicator from

New Wire Marine, in Charleston, S. C. The shafts are out for precise straightening on

the huge shaft straightener my father made years ago. Also aligning the struts and

replacing all their bearings. The propellers aren’t quite big enough, only getting 88%-

90% load so hopefully adding a bit of cupping will work, at the prop shop now.

Some Interesting numbers to contemplate:

705 hours involved for the repower so far!

82 trips to Sabula, Iowa from Moline, IL, or 9020 miles driven.

11 decibels Noise reduction at 1800 RPM.

3600 lbs weight reduction.

2” draft reduction.

Boat planes at 100-150 RPM lower with undersized propellers.

30% decrease in fuel consumption, better numbers after props adjusted hopefully.

We should have repowered DOLPHIN years ago, but I wouldn’t have possessed the

knowledge or the resources then. I am extremely grateful to Frank Truluck, at

Southeastern Marine Power in Florida. Frank is unbelievably knowledgeable about the

Cummins engines; he was always quick to answer my numerous questions or find an

application engineer or old colleague who could. Frank could have sold the engines

and walked away, instead he provided invaluable support throughout the entire project.

45. Notice the big 'C" below the Chris Craft star. Cummins supplied a stainless steel logo with each

engine

46. Engine room photo