Alcanboats Forum

Hi folks

It has been a long time since there were any postings in the technical forum, so I though I would start a thread on my current project to repower Buster.

As some of you may know, I purchased Buster with one engine with a cracked block with the intention of repowering. I repowered the boat with a pair of Volvo Penta 4.3GXi engines with SX stern drives. I will declare that repower a success as it has been going strong since 2002. However, I am looking forward to a slightly different kind of boating in the near future and have some slightly different priorities now. To that end I am in the throws of repowering the boat with a pair of slightly smaller diesel engines.

Requirements
My primary requirement is to improve the range of the boat. I contemplated putting an auxiliary fuel tank in to carry another 50 to 100 gallons of gas. That looked like a relatively manageable option given that there is a large hole in the engine compartment where the generator used to be. But I had a concern about weight and a nagging suspicion that I might want a generator again at some point in the future. Given the higher energy density of diesel fuel, decided that it would be better in the long run to replace the engines with something more efficient. I didn’t mind giving up a little bit of performance, but I wanted to maintain the ability to get the boat on plane, so I was looking for something with appropriate output.

Having decided that I wanted to go diesel, I was immediately struck with sticker shock. A modern 200hp diesel engine seems to cost around $40K regardless of make, and I needed two of them. I wasn’t about to plop that kind of money into the boat, so I started the search for used engines. The requirements were complex
- Must be around 200HP (I was looking for anything over 170HP)
- Must be able to mate up to existing stern drives
- Must not be too heavy (I was prepared to accept up to 1000lb each)
- Must have relatively modern engine management (I was looking for efficiency)

These requirements narrowed the field quite a bit and generally had me looking for Volvo Penta D3 engines. The D3 was introduced in the early 2000’s and has been available in a ranged of output levels from 130HP to 220HP with minor changes in selection from year to year. The D3 doesn’t have the best reputation for reliability as it has an aluminum block and complex engine management systems, but I saw that as the price I would pay for efficiency and light weight. It took around a year of patiently watching eBay and scouring the interweb to eventually find a pair of D3-190 engines with low hours. Of course, the engines weren’t local. They weren’t even on the continent. The engines I found were in the UK at a place called Coastal Rides (coastalrides.co.uk) in Dover, Kent. They were really knowledgable and spent quite a bit of time on the phone with me to prepare a package including all the parts I would need to mate the engines to my existing drives. After they put the engines through a test run, they packaged the whole thing up and put it on an airplane for what was the most expensive shipping bill I have ever seen.

I obtained the engines in the fall of 2019 and I was supposed to start the repower work in the Spring of 2020, but then… COVID19.

I’ll add more to the story in a little bit.

Part II - Getting the Engines Home

In my previous posting, I described finding the engines in the UK. According to the records, the engines were initially installed in a boat as a mated pair.

As a side note, prior to embarking on this project I couldn’t have told you that that would be an important fact. Unlike my current configuration, the diesel engines are not completely independent of each other. There is a cable that connects the two engine management systems together to allow the engines to communicate with each other, and there are some instances where there is only one of something such as the scroll wheel that controls the digital dashboard.

Back to obtaining the engines.

I was pretty lucky about my timing because I was paying for the engines in British pounds. At the time, there was a lot of uncertainty because of the Brexit situation and the exchange rate was somewhat favourable. I might have been able to make the currency exchange more efficient that I did, but I just used a credit card to put a deposit on the engines and eventually paid the whole amount that way.

After paying a deposit the shop in the UK went about assembling a package for me and they test ran the engines in a test just the ensure all was well. In order to save money on shipping, they put the two engines on one pallet. It required removal of a few of the parts from one engine to allow the two engines to sit sufficiently close that the whole thing fit. Then they sent it via FEDEX air-freight. FEDEX engines? Are you crazy? It turns out that it wasn’t all that bad. FEDEX has a freight business that is relatively competitive. We spent some time researching shipping by boat, but it would have meant picking up the engines in Montreal or some other sea port. As it was, they were able to ship the engines to the Ottawa airport.

When the engines arrived, I rented a trailer (after making sure FEDEX could load the engines for me) and drove out to the airport. First stop was the FEDEX office to pick up the customs paperwork. Then over to the Border Services office to pay the taxes. The Border Service people took a little bit of time to figure out the right codes for marine diesel engines (used), but eventually determined that there were no duties, registration fees, inspections, safety certificates or other paperwork things. I paid the taxes and got the form that allowed FEDEX to release the engines to me, so I went back to the FEDEX office and handed them the paperwork.

The FEDEX folks were happy enough to load the engines for me, but I needed to wait for a bit while they found a forklift operator. I backed the trailer up to a big loading bay door and eventually a forklift appeared with a crate on the forks. The forklift operator was very skillful and was able to load the crate just forward of the trailer axle so the trailer would be stable. I knitted the crate to the trailer with some rope to keep it from sliding around and headed home.
When I got home with the trailer, I realized that I had a bit of a problem. I needed to unload the engines from the trailer. I undid all the rope and hopped in the trailer to slide the crate out. This is when the brilliant move of putting two engines in the crate came to haunt me. It should be noted that these are, in fact, very light weight for diesel engines. Just because they are light for diesel engines doesn’t make them light in absolute terms. Each engine weighs around 600lb, and by simple math, a pair of them weighs 1,200lb. I’m moderately strong, but that crate was simply not going to move with raw muscle power alone. I found a suitable length piece of lumber and used it as a lever to lift the back edge of the pallet and inch it forward in a bit of a ratcheting action. I got the whole thing to the back of the trailer to the point where it was teetering onto the tailgate. I slid the pallet down the tail gate and it came to a halt when the first edge hit the ground. Once again my muscle power failed me, so I took the easy way out and used the power of the car to pull the trailer out from underneath the crate. Success! The crate with the engines was now inside my garage.

Dave, will you have the repower completed for the 2021 boating season?

Cheers

Hi Jim

The repower is well under way right now and I am expecting it to be done for the upcoming season. I will type up an update with more details, but the current situation is that the old engines are out and the new (used) engines are in the engine compartment, but not fully mounted or hooked up. I am expecting to see them started up in the next week or so.
Cheers
David

Repower Part III - solving a few mysteries

One of the things that had me a little concerned about the new (used) engines was the engine management system. The engines that I bought are 2008 vintage. They have the Volvo Penta Electronic Vessel Control (EVC) system, but it is the dash-C variant (EVC-C), which makes it obsolete. You can still get parts, but it is really difficult to find information on how to hook it all up. Would I need a new binnacle? Would I need to add electronic shifters?

When I uncrated the engines and started exploring the situation, I found that I had gotten pretty lucky with the specific engines I had purchased. Each engine had a black box on a short umbilical wire that looked like the sort of box that would contain electronics. Mounted on the black box was a small arm on a pivot. The arm had a hole in the end that looked just about right for a throttle cable. A little web sleuthing confirmed that this was indeed the throttle control and it meant that I wouldn't have to replace the binnacle and I didn't need to convert to electronic shifters. I was almost disappointed as I had a few minutes at the helm of Limitless which had the full electronic control package and saw just how slick it was. Oh well, on to the next issue.

Next issue… I spent a fair bit of time trying to guess whether or not the 1.79:1 gearing of the SX stern drives would be OK and whether or not I would be able to use the existing props. My first estimation was that the existing stern drives and props would work just fine. One of the biggest issues in trying to make this determination was the lack of accurate information about the gas engines that were being removed. For the diesels going in, there were torque curves, fuel consumption curves, specific output formulas and all sorts of info to determine what the engine would do. For the gas engines, there was one number to work with - 225 horsepower. It wasn't even clear what RPM they would put out that horsepower, let alone a torque curve. The gas engines probably reach peak horsepower at an RPM somewhere around the recommended maximum of 4,400 to 4,800 RPM. The diesels are supposed to max out at 4,000 RPM. Just on the basis of RPM, it would appear that the gear ratio or propellor pitch would need to be changed, but this was complicated by the fact that the diesel engines are down 35HP from the gas engines. So I started to postulate that the gas engines at 4,000RPM might actually be very similar HP and torque to the diesels which would mean that the gearing and props may just work. In the end, I decided to change the gear ratio ever so slightly, so I scoured eBay and came up with a couple of 1.66:1 ratio SX drives in good condition. I'm still crossing my fingers, but I am hedging my bets a little bit. My current props have a fairly high pitch already, so if there is some chance I need new props, I wanted to go down in pitch and not up.

With the engines in hand and new (used) SX drives I continued to source all the other bits and pieces I thought I might need. My goal was to assemble a repower "kit" that would hopefully not have anything major, or even minor, missing. My hope was that this would avoid any unnecessary delays once the boat was pushed into the shop and the repower work started. As I indicated in my first posting, the repower was supposed to start in the Spring of 2020, but the COVID shutdown threw that plan out the window. As the COVID shutdown progressed, it seems we figured out new ways to work and in the late fall, the repower work got started. I'm not doing the work myself, so I don't really have a blow-by-blow description of what's going on, but I have seen the occasional picture of the green engines in Buster's engine compartment.

Dave

Looks exciting!

Looking forward to seeing you on the water again this year.

Cheers


Jim

Celebration! I saw video of the engines running. They were only started for a few seconds, but it shows that they are hooked up at least somewhat correctly and the electronics are working. The boat now waits until Spring launch to see how well it all works together. This repower is being done on the cheap, with a lot of stuff coming from eBay. It all looks pretty good on the surface, but you never know what lurks under the covers. I am now imagining all kinds of possible issues between the engines and the stern drives. Bad bearings, broken gears, leaky valves, plugged passages. They wouldn't stop the engine from firing, but they could sideline the boat for a long time.

Speaking of doing it on the cheap, I saw the invoice for the installation. I was very curious to see the list of parts that were needed as I had worked pretty hard to assemble everything I though would be needed. I think I did a pretty good job as there were no big surprises. However, there were a LOT of parts still needed that I hadn't considered. Things like filler hose for the fuel tanks. The tanks were being removed to weld on fuel return fittings for the diesel engines. The 50 year old filler hoses were simply cut off to remove the tank. Putting back the tanks required replacing the filler hoses and that stuff is not cheap. So, while no one thing was super expensive, there were a lot of little things.

Regardless, the engines are in and the boat is back in the yard waiting for the lake to thaw. I am super excited to get down to the boat and see the green engines in their proper homes. I am anticipating the next set of problems dealing with the electronics, propellors and other things that were best guess at the time. More to follow in the Spring.

hows things going with the re-power? I bought used twin 300 outboards for an Allwest I'm rebuilding but with fuel costs I'm wondering if I could get away with a single 320 hp Volvo diesel inboard and sell the twin outboards before I go through the trouble of podding it.
I was hoping to see how yours works out as a gauge or an opinion.
cheers Paul

Hi Paul

In a nutshell, the repower was mostly successful. I ran into trouble with the used engines from eBay, but gradually got things going. A fuel pump here, a turbocharger there and everything was good until one of the engines gave out near the end of the season. In principle, the pair of D3-190 engines were a pretty good choice for the boat. I was able to get the boat up on plane at wide open throttle and it would do a little over 25MPH, but was slightly over-propped and would have been faster with a better prop selection. The brilliant part, however, was the fuel economy at low speed, so it was clearly going to meet my goal of better range.

But... then I sold the boat. Not just on a whim. We moved across country to British Columbia and taking with boat with us just didn't make sense. So, Buster's new owner has fixed her back up and renamed her and is enjoying her in her new home.

Would a single 320 diesel be a good choice? I'm thinking it would be just a little shy on power to get up on plane unless the boat were really lightly loaded. The single would have a little less drag and put the prop deeper in the water, so it stands a chance of performing well, but if you were looking for planing performance, you might go slightly bigger. If you are happy at displacement speeds, then you might go smaller. These are just opinions though and I could be way off.

Good luck whichever way you go.

David

ok thank, I have a line on 3- 2018 Volvo D-4s for 20k with 3500 hours. legs and controls but I'm not so sure on how much actual fuel savings I would get compared to the outboards/ maintenance.
tough call