Princess 35 project

[kdtran]

So, 1 1/2 years ago we decided that we had grown out of our Windy 9800 and started looking for a replacement.
Having spent a large proportion of my childhood aboard Princess', a 1986 model P35 caught my attention. The boat, originally delivered to Switzerland equipped with two petrol engines on sterndrives, had been imported to Norway in 2000 and re-powered with VP AD41P-A engines and DPE sterndrives. Good boat, reliable engines, decent cruising speed, 5 births and at the right price she ticked all boxes.



Putting 40+ years of motorboating experience, 20 years professional marine experience and all common sense aside, I looked at the boat, fell in love with the nice interior and made a deal with the seller.
In retrospect I must admit that it was NOT my brightest moment, as the boat turned out to be in significantly worse condition than what I had imagined.

During the 220Nm delivery trip, I suffered an engine stop due to a broken fuel pipe, clogged fuel filters due to diesel bug, and more worrying an escalating fresh water leak from the port engine.
Four weeks after taking over the boat, the port engine was loosing 1 liter of fresh water per hour, and it was all ending up in the bilge.
As engine access is "rather" tight on the sterndrive version of the P35, I decided to lift the boat out of the water and remove the engines for a light overhaul, expecting to have her back in the water within a month or two.
How wrong I was...

With the engines out, I got the chance to have a proper look around the engine room to assess the actual status of the technical installations. My conclusion: the boat was in a right mess.




Stringers had been cut to make room for the oilpans of the diesel engines, leaving the core material exposed and hence drenched with a mixture of oil, diesel, coolant and water causing osmosis on the inside of the hull (..), the engine foundations had not been plastered in properly resulting in 4 water soaked pieces of wood underneath a layer of fiberglass, the autopilot pump had never been attached to the bulkhead and was laying loose in the engine room, there were electrical cables going no-where and everywhere, the diesel heater sounded as it was exploding every time it was running, the water tank was leaking heavily, engine room insulation was hanging loose all over the place, the steering hydraulics was leaking on the flybridge, leaving a nice slippery layer of hydraulic oil on the starboard side of the boat, navigation lights were not working as they should, front windows were leaking water, the exhaust pipe from the gas-powered fridge had been disconnected from its original outlet, and in stead been re-routed to terminate behind the port side cockpit settee, mice had at some stage made a nice little nest in one of the ventilation houses behind the starboard cockpit settee but had luckily moved out, etc etc.
I seemed that for every panel I opened I found a new set of surprises.

Fortunately, I had the skills, time and money to undertake what was turning out to be a major project, and selling a wreck of a boat at less than what we payed for it was not an option for neither me nor my family.
9 months and close to 1300 man-hours after being lifted out of the water, the boat was back in her home port complete with new pantry, serviced engines, new wiring, new engine insulation and much much more.




Finally we could start enjoying boating again!
Yeah, right..
Or rather, we DID enjoy a 3 week summer vacation and a few short day-trips in the autumn, but in December of last year we experienced low and fluctuating oil pressure in the port engine.
I opened the oil filter for inspection and found fragments of white metal in it. Realizing that the engine would require a complete re-build we were forced to make some decisions. Both sterndrives were in need of a re-build, one engine required a complete re-build, the starboard engine had higher running hours than the port engine and had lived the same life as the port engine leaving me wondering how long it would last.

End of story: we decided to go for a re-power and the boat will now be equipped with 2x Volvo Penta D4-260 engines and DPH sterndrives.

I have published a project thread on the Norwegian forum baatplassen.no, and here you can find some more pictures of the work performed so far, and might learn some Norwegian at the same time
http://baatplassen.no/i/topic/129740-prosjekt-nødvendig-oppgradering-av-princess-35/?page=1

If any of you are interested, I will also post some information in this thread covering the re-power process.

All the best from Norway-

 

[Murv]

Wow, what an undertaking! Thanks for sharing, I'm certain there will be plenty of interest in your thread.

 

[jimmy_the_builder]

That's quite a big project! Great stuff, thanks for posting (and well done). Hope the repower solves your woes (although this can't have been a cheap option, I imagine). Look forward to hearing more about the project.

 

[oldgit]

Well done you............ a real mountain of work there.
Those engines and outdrives should make that boat fly.
Largest repower knew of previously was with a pair of KAD 44 but on shafts.
Wondering about max hull speed on the Princess 35 and stability after that ?
Do have a photocopy of the original MBM boat review which was tested with both Cummins and Volvo engine options.
About 22-23 knots at WOT.
Main whinge was carpets not bound and rusty under sized stainless fastenings.

Have got the very basic owners manual supplied with the P35, if you need any pdfs of interior wiring.
do keep us up to date.

Arather small princess dwarfed by its bigger and newer cousins in St Kats Dock in central London.
The keen observer will probably notice the biggest crime possible to commit on the The Thames........a non matching fender.

 

[NBs]

Hi,

Really impressive reform, a huge project to do it yourself, many work would not have been done, but not you, cool to share your work here. After the start, I hope you have casual and enjoyable miles in the future.

NBs

 

[MrB]

If any of you are interested, I will also post some information in this thread covering the re-power process.

100% yes please. :encouragement:

 

[markc]

Great project, thanks for sharing! I can only imagine the terrible feeling you had as you started to reveal more and more problems. Looking forward to seeing more

 

[ari]

Wow, amazing! Yes, definitely do keep us updated, I'd love to hear how you're getting on.

 

[ari]

Well done you............ a real mountain of work there.
Those engines and outdrives should make that boat fly.
Largest repower knew of previously was with a pair of KAD 44 but on shafts.
Wondering about max hull speed on the Princess 35 and stability after that ?

Bear in mind that Princess offered the Princess 35 with big V8 sterndrive petrols. I forget the horsepower but I think 235hp each. So not dissimilar power through sterndrives to the D4-260.

One interesting aspect might be the weight though, those D4s are heavy engines, heavier than the KAD 44 I think (which I never quite understood since the D4 is 4 cylinder and the KADs were all 6 cylinder...)

 

[oldgit]

Bear in mind that Princess offered the Princess 35 with big V8 sterndrive petrols. I forget the horsepower but I think 235hp each. So not dissimilar power through sterndrives to the D4-260.

One interesting aspect might be the weight though, those D4s are heavy engines, heavier than the KAD 44 I think (which I never quite understood since the D4 is 4 cylinder and the KADs were all 6 cylinder...)

Not sure that The Princess 35 ever had a V8 option as standard ,mebbe just the V6 and 135 HP four pot option ?
Do know a boat or two appeared with a single VP petrol, presumably for river use.
Doubt the outdrives around at the time circa 1985 ie the 270 and the rarer 280 would have been able to reliably handle that amount of power.
Not sure how much power the 290 was designed to cope with, especially pushing 6 tonnes of flybridge around ?

https://www.princess.co.uk/about-us/princess-heritage/

 

[ari]

It definitely had a twin V8 petrol option. Just can't recall exactly the horsepower, but over 200hp.

(Plenty of Eighties boats with 200hp+ petrol engines and outdrives - the 5.7 litre V8 was normally 260hp, both Mercruiser and Volvo Penta).

 

[oldgit]

Now got me wondering what on earth all that space under the the P35 saloon was filled with, sans engines.
all the spare parts and tools need to keep the outdrives from disintergrating suppose ?

 

[kdtran]

Now got me wondering what on earth all that space under the the P35 saloon was filled with, sans engines.
all the spare parts and tools need to keep the outdrives from disintergrating suppose ?

Please don't ask..

There's eons of space there, but probably due the rather large amount of petrol originally stored underneath the saloon, Princess had decided to mount the batteries in the engine room just below the sliding doors and whoever re-powered the boat had the "sense" to mount the actuators for the EC system just underneath the hatch opening, making it nearly impossible to get in and out of the engine room.
All that's sorted now though, and as can be seen in my "baatplassen.no" thread, I have moved the batteries out of the engine room to the same location as they have on the shaftdrive versions of the boat.
So currently, the space underneath the saloon is filled with the following:
Batteries, Fuel pre-filters (original engine room mounted filters have been moved and replaced with Separ 2000/10 filters), Watertank (same as on the shaftdrive version, but mounted against the forward bulkhead), two aluminium fuel tanks mounted in same location as on the shaftdrive version (prob. replacement put in as part of the engine re-power in 2000), 70 liter hot water tank, waterpump, huge homemade genset box with tiny genset inside which will be removed permanently in the very near future.
As we have 3 children, I was considering using some of the space for an extra "cabin"/bed with access from the dinette area, but have changed my mind.

 

[kdtran]

I must say that I am impressed by the response to my thread. Cheers!

I mentioned in my opening post that I have spent a large proportion of my life aboard Princess'.
My parents (or should I say my Father as my Mother, 47 years and 9 boats down the line still refers to their boat as "that bl##y boat) started their boating career with a Folkparker 21 in 1971 with me only being 2 months old. They then moved on to a Project 31 in 1973, this was replaced by a 30DS in 1983, replaced by a P33 MKII in 1987, replaced by a 415 in 1992, replaced by a 430 in 2000, replaced by a P50 MKI in 2003 before he/they converted to a Fairline Targa 62 GT in 2006 and at the age of 81 moved down in size to a Beneteau Oceanis 13.80 last year.

Both my father and I are keen DIY'ers and we both hold engineering degrees from UK universities, so there might be cause to claim that the apple does not fall far from the stem in this case. He does however think I am a lunatic for taking on this project, though still being supportive as he had similar experiences with his P415 which he also ended up re-powering.

Thread drifting finished, it's time to get back to the topic.
With the decision made to re-power, the old engine installation was put up for sale as re-build projects, both were sold within one week and arrangement were made to have the boat lifted and stored for the re-power.
Having "ripped the boat apart" last year, I at least new what I needed to do to remove the engines and the removal process was very much easier this time around.
Removing the old installation also gave me the chance to get rid of some surplus wiring from the now no-longer-to-be-used-by-me EC system as well as old instruments.


The new installation will have 2x 4" color LCD panels at the main helm and 1x 4" color LCD panel on the flybridge instead of traditional dials, and I will move the overhead 9" Raymarine MFD to the port side of the instrument panel at the main helm. The old Raymarine C80 plotter mounted next to the instrument panel will be replaced with either an IPad Pro 12.9" or by a pc based chartplotter and 15" monitor.
The IPad solution has the advantage that it can connect to the Raymarine MFD giving a mirror image of this, and I can also use it on the flybridge, so if finances permit this looks to be the preferred option.


In the engine room, all connections were loosened in preparation for the lift-out. The aft seating was also removed though I did regret using Tec7 when putting it in place last year, as cutting it loose cost me 1 breadknife and 2 spatulas. Final step was to remove the engine room hatch, dismantle the charge air coolers and trim of 2cm from the lower part of the hatch opening, and a couple of hours later the engines were out.


As can be seen in the pictures above, the hatch opening is the same size on my boat as in the shaftdrive versions of the P35, so there is not a lot of space available. To make matters more challenging, the D4 engines are wider and taller than the AD41's, so I have spent a considerable amount of time with AutoCAD comparing the dimensions of the engines.
The pictures below show the D4-260 in white on top of the AD41 in pink. Compare this with the top-view picture above (pic. no. 2 from left) showing the edge of the hatch opening and part of the port side AD41, you can see that the new engines will be a tight squeeze!


The new installation is approx 200kg heavier than the old one, so I have specified the D4's with extended bell-housings and exhaust gas risers, bringing the CoG 5cm forwards compared to the AD41 installation.
VP specify a recommended minimum C-C distance of 95cm between the engines, but I only have 83cm available (..) giving a minimum clearance of 2cm in one area but hey, clearance is clearance and houses can be re-routed to improve this if needed.
I will most probably also have to make a new bracket for the starboard ECM (Engine Control Module) lowering this somewhat, re-locate the starboard crankcase ventilation filter and re-locate the port seawater strainer or put in an inline strainer aft of the engine-mounted strainer but these are sacrifices I can live with.
I did consider other engines, but due to the weight of the boat, I need high-torque engines and considered 3-liter units (e.g. D3-220, Mercruiser/VW 3 liter-270hp, or Hyundai Seasall 270) to be unsuitable for the application for this reason.

With the AD41's the boat reached a fully loaded top speed of 25.2 knots @ 4000 rpm, but to be able to see over the bow, she needs a cruising speed of more than 22 knots.
Also, being stern heavy, she is very sensitive to the effects of following seas, or at least that was the case with the AD41's. Following seas with a wave height of 0.5 meters would bring the cruising speed down from 22 to 17 knots with the rpm dropping from 3700 to 3400.
The D4's should give me a top speed in the region of 33 knots, and a comfortable cruising speed in the region of 25-27 knots and as the torque of these engines is considerably higher than that of the AD41's I am hoping to be able to run at 2800rpm (700rpm below max), giving a fuel consumption of approx 50 liters/hour @ 25 knots as compared with 60-70 liters an hour @ 21-22knots for the AD41's .

W.r.t my current undertakings; to be able to install the DPH transoms I need to make some modifications to the transom holes. Basically this consists of adding 2cm of height in the lower parts of the DPE holes, and approx 5cm of material in the top. Princess had used high quality teak veneer (or equivalent) as distance material in the transom, and there had been some water ingress in the lower parts of this.
I have therefore cut away some of the fiberglass on the inside of the transom, removed the de-laminated parts of the distance material and drilled 8 holes (7mm) in the outside keel area in an effort to remove as much water as possible from the distance material.



I currently have a de-humidifier and a heater fan running in the engine room and will let this run for a week or two prior to applying new wood sections and fiberglass.
More than 90% of the distance material has its structural integrity in place, so with the addition of some layers of 400 kg/m^3 webbed fiberglass strips and 300kg/m^3 "normal" fiberglass cloth the structural strength of the transom should be well within acceptable limits.

To be continued.