Weymouth 32 re-power D4 for Perkins HT6.354

[Episode]

In the process of re-powering my Weymouth 32. Current engines are still very sound, but conscious they will need replacing at some time in the future and looking for a little more power and economy - so have decided to bite the bullet now.

Boat appears to have been built around the existing engines so space (height) very tight. Have selected Volvo D4 180/HS45AE with Aqua/Python drive (to allow level installation). Anyone have any experience of this model of engine in this or similar vessel (Nelson type semi-displacement)?

Turning into quite a big job but will be worth it in the long run.

I will have two good HT6.354s (with Borg Warner 72 CR 1.9:1) for sale in the next couple of months. Approx 700 hours since full rebuild by Golden Arrow (under previous owner) bills for over £20K for rebuild. Turbos had further reondition in 2013. All pressusres (engine and box) and temps spot on book values. Complete with all instruments. Watch for advert in boats and outboards or drop me a line if interested nigelf@baf.globalnet.co.uk

 

[Latestarter1]

In the process of re-powering my Weymouth 32. Current engines are still very sound, but conscious they will need replacing at some time in the future and looking for a little more power and economy - so have decided to bite the bullet now.

Boat appears to have been built around the existing engines so space (height) very tight. Have selected Volvo D4 180/HS45AE with Aqua/Python drive (to allow level installation). Anyone have any experience of this model of engine in this or similar vessel (Nelson type semi-displacement)?


Turning into quite a big job but will be worth it in the long run.

I will have two good HT6.354s (with Borg Warner 72 CR 1.9:1) for sale in the next couple of months. Approx 700 hours since full rebuild by Golden Arrow (under previous owner) bills for over £20K for rebuild. Turbos had further reondition in 2013. All pressusres (engine and box) and temps spot on book values. Complete with all instruments. Watch for advert in boats and outboards or drop me a line if interested nigelf@baf.globalnet.co.uk

Big and expensive job, certainly not for faint hearted.

Benjamin (Fitzroy) is re-powering exactly the same type of vessel, Weymouth 32 in another thread here..Final comparisons will be real interesting. I assume you will be using the ZF with 2.43 ratio.

 

[Episode]

Certainly agree with your first three points! This boat will see me though to retirement (when I forsee - or is that dream of - a move to a gentleman's motor yacht cira 1930s) so this is a long term investment. The Weymouth is the perfect boat for us.

I have been following Benjamin's post with interest, as you say, final comparisons will be interesting. I aim to have this all done by early next year.

I think the 2:1 ratio is odds on at the moment - need to talk though with supplier next week before placing order. The 180 only revs to 2800rpm so not sure it will need the 2.43.

 

[volvopaul]

Not sure I'd have gone for that motor and the £££ involved. Please keep posting your progress, where and who is doing the work? I'm Solent based if your looking for someone to do the work.

I'd also have a chat with late starter I'm sure he could price you some engines to suit, I'd rather have the torque from a six pot engine as the d4s at 225hp without a supercharger take some spinning up to revs even in a sports cruiser. I'd make sure this reposed is a proper calculated job before you order the engines . You can't just repower based on hp ratings from the data sheet.

 

[Keith-i]

with Aqua/Python drive (to allow level installation). Anyone have any experience of this model of engine in this or similar vessel (Nelson type semi-displacement)?

I recently fitted a Python Drive to our Channel Island 32 which is not unlike a Weymouth. It was significantly cheaper than the Aquadrive and also slightly shorter in length which helped installation. Let me know if you want any info. Don't rush the alignment would be my advice!

 

[Episode]

Not sure I'd have gone for that motor and the £££ involved. Please keep posting your progress, where and who is doing the work? I'm Solent based if your looking for someone to do the work.

I'd also have a chat with late starter I'm sure he could price you some engines to suit, I'd rather have the torque from a six pot engine as the d4s at 225hp without a supercharger take some spinning up to revs even in a sports cruiser. I'd make sure this reposed is a proper calculated job before you order the engines . You can't just repower based on hp ratings from the data sheet.

I started out looking for a slightly more powerfull direct replacement - lazy 6 cylinder, 6 litre around 180hp, but there appears is little out there that will physically fit or suit - most modern 6 cylinder engines produce way more hp than I need. Toyed with the idea of Perk Sabre (225) but that is more power than the boat was built for and would take some major work on floor stucuture, wheelhouse furniture. That would soon eat up the relatively small saving on purchase price. I am looking for new rather than rebuild. Did you have an alternative in mind?

Selection of D4 (I am proposing the 180hp version which tops out at 2800rpm) was on more than simply the HP. They have also been put forward as solutions by three separate yards (all of whom offer a range of engines), accepting that they could all be wrong or have other motivations (bigger margins). However, according to hp and torque curves the D4 180 produces more of both, than my current engines, at all points across the full rev range. On this basis, if coupled to right box and props I would have thought they would be suitable. If they produce more hp and torque at all points of the rev range is there any reason why they would not spool up at least as quickly as the current Perks? I think the D4 turbo cuts in at much lower rpm that the Perk, where little is happening until 2000 rpm. Certainly be interesed to hear of you think otherwise.

Also looked at modern Nelsons to see what they were using. The ones built in Holland (slightly larger and heavier than the Weymouth) come with a twin D4 option (albeit with twin D6 as an option). Seaward appear to use the Yanmar equivalent.

 

[JSYmartini]

The previous owner of my Askham 35 re powered with Perkins M300ti's (278 hp iirc)
He said there was several occasions when they thought they weren't going to fit but they did...just.

There's a pair for sale in the Channel Islands at the mo, with ZF boxes, instruments etc, 1400 hours (I think), £5750 each.

I'll dig out the newspaper advert again if anyone's interested

 

[Latestarter1]

I started out looking for a slightly more powerfull direct replacement - lazy 6 cylinder, 6 litre around 180hp, but there appears is little out there that will physically fit or suit - most modern 6 cylinder engines produce way more hp than I need. Toyed with the idea of Perk Sabre (225) but that is more power than the boat was built for and would take some major work on floor stucuture, wheelhouse furniture. That would soon eat up the relatively small saving on purchase price. I am looking for new rather than rebuild. Did you have an alternative in mind?

Selection of D4 (I am proposing the 180hp version which tops out at 2800rpm) was on more than simply the HP. They have also been put forward as solutions by three separate yards (all of whom offer a range of engines), accepting that they could all be wrong or have other motivations (bigger margins). However, according to hp and torque curves the D4 180 produces more of both, than my current engines, at all points across the full rev range. On this basis, if coupled to right box and props I would have thought they would be suitable. If they produce more hp and torque at all points of the rev range is there any reason why they would not spool up at least as quickly as the current Perks? I think the D4 turbo cuts in at much lower rpm that the Perk, where little is happening until 2000 rpm. Certainly be interesed to hear of you think otherwise.

Also looked at modern Nelsons to see what they were using. The ones built in Holland (slightly larger and heavier than the Weymouth) come with a twin D4 option (albeit with twin D6 as an option). Seaward appear to use the Yanmar equivalent.

There is nothing wrong with your thought process, since demise of Yanmar 4LH and Perkins Sabre stuff a cheap waste of space choices are very limited and whilst I make a point of having nothing to do with Volvo Penta engines the D4 would on the face of it appear to fit the bill very well but only if installed with care.

If we take your current motors HT6.354 145's you have not mentioned if they are handed with one motor being contra rotating, in that case likely you have two BW72CR 2.1:1 boxes alternatively if both engines normal rotation you will have a 1.88:1 and a 2.1:1 to give you contra rotating props. If we cut to the chase with a rated speed of 2,400 rpm your shaft speeds are currently in the range of 1,200 to 1,260 rpm.

If we take Volvo D4's 180's with ZF transmissions and go with 2:1 reduction ratio your shaft speed is 1,400 rpm writing off your current propellers at a stroke. If you were to use a deeper ratio 2.43 shaft speed will come down to 1150, only requiring a small increase in pitch which would also take account of slightly reduced displacement.

Talk of turbochargers 'cutting in' is all vaporware, not sure what turbochargers you have, but even with Holset 3LD's the 6.354's produced squat all boost, and whilst D4-180 has a nice solid looking torque curve starting at 2,000 rpm, it is a 3,7 liter motor and common rail fuel system will make it feel real spunky IF THEY ARE GIVEN A CHANCE with a sufficiently deep reduction ratio.

Purchasing engine/transmission as a package makes total sense, leaves you out of any torsional compatibility and complex warranty issues however there are other agendas, suppliers will steer you to what is on the order board, not what is necessarily 100% correct for your application, tread with care. Have seen jiggery pokery with manipulated re-quotes and increased lead times all aimed at driving potential engine order toward an engine spec which is on the order board but not 100% correct for the application.

Done right this has potential to be a real sweet set up.

 

[MYStargazer]

This is fantastic. Two Weymouth 32s of about the same age - both being repowered, but with two different approaches, and, I suspect, two somewhat different budgets! This is truly the kind of thing this forum is for.

Please, please take some pictures of yours as-is and during and after the repower. I take hundreds for use as a reference later on and to help others. It costs nothing and is well worthwhile.

 

[Episode]

There is nothing wrong with your thought process, since demise of Yanmar 4LH and Perkins Sabre stuff a cheap waste of space choices are very limited and whilst I make a point of having nothing to do with Volvo Penta engines the D4 would on the face of it appear to fit the bill very well but only if installed with care.

If we take your current motors HT6.354 145's you have not mentioned if they are handed with one motor being contra rotating, in that case likely you have two BW72CR 2.1:1 boxes alternatively if both engines normal rotation you will have a 1.88:1 and a 2.1:1 to give you contra rotating props. If we cut to the chase with a rated speed of 2,400 rpm your shaft speeds are currently in the range of 1,200 to 1,260 rpm.

If we take Volvo D4's 180's with ZF transmissions and go with 2:1 reduction ratio your shaft speed is 1,400 rpm writing off your current propellers at a stroke. If you were to use a deeper ratio 2.43 shaft speed will come down to 1150, only requiring a small increase in pitch which would also take account of slightly reduced displacement.

Talk of turbochargers 'cutting in' is all vaporware, not sure what turbochargers you have, but even with Holset 3LD's the 6.354's produced squat all boost, and whilst D4-180 has a nice solid looking torque curve starting at 2,000 rpm, it is a 3,7 liter motor and common rail fuel system will make it feel real spunky IF THEY ARE GIVEN A CHANCE with a sufficiently deep reduction ratio.

Purchasing engine/transmission as a package makes total sense, leaves you out of any torsional compatibility and complex warranty issues however there are other agendas, suppliers will steer you to what is on the order board, not what is necessarily 100% correct for your application, tread with care. Have seen jiggery pokery with manipulated re-quotes and increased lead times all aimed at driving potential engine order toward an engine spec which is on the order board but not 100% correct for the application.

Done right this has potential to be a real sweet set up.

Thank you this is all proving very useful.

Current engines are handed (ie one contra rotates). Contrary to what you would expect, this means the 72CRs have slightly different reduction ratios 1.9 and 2.1 I think (I don't have the figures to hand). Therefore, current props are different sizes (pitch and dia) which rights them off for whatever I fit. Disadvantage is cost but advantage is it give me a free hand on prop size (up to a max dia of 24").

Given this my thinking was that a similar reduction ratio (2:1) coupled to the rights props (a question in itself) would produce a similar "feel" to the boat i.e. no faster at tickover, not having to rev up to silly rpm to get moving, with a couple of knots extra for cruising and top end.

Talk of turbo cutting in was reference to the relatively square and long troque curve for the D4 ie it is not all happening at the very top end (which is what I want to avoid). Perks have 3LDs and you are right they don't add much in the way of boost. When mapped against the D4, the HT's torque curve is not as long or square, I did find this surprising given ther are nearly 6lts. The modern Perks' curve (say the M150) does not compare (accepting what people have to say about the M series) and produces spades of torque from very low rpm. A reflection of the fact that the 6.354 is a 50 year old design

The formula I have (from the excellent Prop Handbook - Dave Gerr) points towards a ratio of about 2:1.

Given I can (have to) choose new props is there any advantage to a higher reduction ratio? The prop curve will still only meet the power curve at one point.

 

[Barleycorn]

Don't want to pee on your parade, but the Perkins 6354 is a bombproof engine, and as it is still used in so many machines I can't see getting parts for it will be a problem for many years. We have used it in farm machinery and had machines with 10 to 15 thousand hours on them, and still going fine. I really can't see that changing the engines will ever be cost effective in terms of fuel saved or value on the boat. They will have mechanical CAV fuel pumps so you can easily get the fuel settings changed on these. If your engines have only done 700 hours they are hardly run in. I would sit on the money ready to put it towards the Silver Ormidale!

 

[Latestarter1]

Don't want to pee on your parade, but the Perkins 6354 is a bombproof engine, and as it is still used in so many machines I can't see getting parts for it will be a problem for many years. We have used it in farm machinery and had machines with 10 to 15 thousand hours on them, and still going fine. I really can't see that changing the engines will ever be cost effective in terms of fuel saved or value on the boat. They will have mechanical CAV fuel pumps so you can easily get the fuel settings changed on these. If your engines have only done 700 hours they are hardly run in. I would sit on the money ready to put it towards the Silver Ormidale!

These are horizontal HT6.354's as well as one being a contra rotating engine, not to mention the fact that they will certainly have hydraulically governed CAV DPA injection pumps.

Scavenge pumps for horizontal engines NLA, water pumps for contra engines NLA, as are camshafts and genuine Delphi parts for hydraulic governed DPA pumps. Dot2 6.354's are unsociable, smoke at start up, rear main oil seals leak, as any owner of a turbocharged Perkins knows they are weak on head gaskets. Exhaust manifold is raw water cooled and has limited life in sea water and replacement expensive, add to this with a horizontal motor manifold failure is a potential sinker.

I can think of two specific cases recently where owners purchased boats with T6.354's spent decent money, around £14K having engines re-built on vessel purchase hoping for trouble free boating. One owner having engines re-built in 2009 has not completed a single season without a breakdown, the owner of second vessel has been living with smoke, oil leaks has had head gasket failure right in the middle of the season.

Boating should be for enjoyment.............I can see EXACTLY where OP is coming from.

 

[Episode]

Don't want to pee on your parade, but the Perkins 6354 is a bombproof engine, and as it is still used in so many machines I can't see getting parts for it will be a problem for many years. We have used it in farm machinery and had machines with 10 to 15 thousand hours on them, and still going fine. I really can't see that changing the engines will ever be cost effective in terms of fuel saved or value on the boat. They will have mechanical CAV fuel pumps so you can easily get the fuel settings changed on these. If your engines have only done 700 hours they are hardly run in. I would sit on the money ready to put it towards the Silver Ormidale!

Much of what you say is correct. This will never pay for itself but if I wanted to make money I would never have taken up boating ): This is a long term "investment". My Perks are sound but will need replacing idc and do take quite a bit of work, notwithstanding the rebuild. Some parts are hard to come by and others cannot be had for love nor money. Remember these are the horizontal version and one contra rotates. Some parts for the latter need to be machined up from scratch and this is certainly never cheap and not always easy if the original is past using as a model. Failure would take the boat of action for months (very important to me). After long hard thought I have drawn the conclusion that now is the right time for this. Re powering (any option) is not going to cost any less if done in 2 or 5 years. My aim is to have good, reliable engines that will be good for many years.
Excellent choice with the Silver Ormidale.

 

[Latestarter1]

Thank you this is all proving very useful.

Current engines are handed (ie one contra rotates). Contrary to what you would expect, this means the 72CRs have slightly different reduction ratios 1.9 and 2.1 I think (I don't have the figures to hand). Therefore, current props are different sizes (pitch and dia) which rights them off for whatever I fit. Disadvantage is cost but advantage is it give me a free hand on prop size (up to a max dia of 24").

Given this my thinking was that a similar reduction ratio (2:1) coupled to the rights props (a question in itself) would produce a similar "feel" to the boat i.e. no faster at tickover, not having to rev up to silly rpm to get moving, with a couple of knots extra for cruising and top end.

Talk of turbo cutting in was reference to the relatively square and long troque curve for the D4 ie it is not all happening at the very top end (which is what I want to avoid). Perks have 3LDs and you are right they don't add much in the way of boost. When mapped against the D4, the HT's torque curve is not as long or square, I did find this surprising given ther are nearly 6lts. The modern Perks' curve (say the M150) does not compare (accepting what people have to say about the M series) and produces spades of torque from very low rpm. A reflection of the fact that the 6.354 is a 50 year old design

The formula I have (from the excellent Prop Handbook - Dave Gerr) points towards a ratio of about 2:1.

Given I can (have to) choose new props is there any advantage to a higher reduction ratio? The prop curve will still only meet the power curve at one point.

I have zero experience of the D4 at any rating and you are are obviously having discussions with people who have. I have been involved with a number of four cylinder Yanmar 4LH re-powers two were replacement of Perkins 6.354's, using a slightly deeper reduction.

Absolutely no point in comparing anything with Perkins Sabre data sheets they are products of 25 degree test fuel fantasy.

I am also a disciple of Gerr which leads me to reach my conclusion, diameter not pitch is king with your hull type. I am not suggesting that your prime path will not work only that deeper may work a tad better. I would be interested in Volvopaul's take as he is intimate with the engine.

Good luck

 

[Episode]

Thanks, will certainly explore higher ratios and welcome input from anyone with direct experience.
In answer to other earlier questions. Supply and all installation will be done by single approved Volvo dealer. More expensive but much greater in terms of clarity around warranty. I will do much of the stripping out.
Appears that 180 is not available off the shelf so should be no issues with incentive to supply old stock/incorrect pairing.

 

[MYStargazer]

More thoughts on your options here... http://www.ybw.com/forums/showthrea...mmins-Conversion-Thread&p=4345256#post4345256

 

[NF1]

Apologies for resurrecting an v old thread. However, as I started it I think I can justify it In short, I completed this project in 2015 (D4 180s installed by Golden Arrow). Really pleased with engines and installation, it has transformed the boat. Servicing has been done by GA, but now engines are out of warranty I am looking at other options for servicing. Boat now in Chichester area. Any recommendations? Is Volvo Paul still in business?

Thanks

 

[Greg2]

A post about the project with any pics that you have would be of great interest.
@volvopaul is still in business and occasionally frequents the forum.

 

[NF1]

Thanks. Unfortunately, as it was done by contractors the job was pretty much a photo free zone. I have some end result photos I will dig out. A bit of detail if of interest or value to anyone considering similar.
It was a big job! I did consider doing some work myself, but in the end I had everything done by Golden Arrow. A decision I certainly don't regret. Quality of work was superb and v good at staying in touch and involving me in decisions.
Any replacement engine was going to be a very tight fit (originals were horizontals) and so lots of measuring and remeasuring before quotes and contracts.
Removing the old engines was harder than expected. We factored in roof soft patch, furniture, wheelhouse deck etc. What we did not foresee was that every bolt securing mounts to bearers had been welded in place. Clearly something done at time of build.
Engine bay totally refurbished and fuel tanks cleaned.
Evey thing mechanical or electrical relating to engines replaced. New shafts (one had a v slight bend) in higher grade steel and new dripless stern seals.
Floor bearers replaced (wood to ali) to provide a little more height in bay.
New control panel, fabricated to look like the old one (all the right gauges, albeit a little more modern).
I will dig out the pics and post the conclusion later.

 

[Greg2]

Sounds like quite a job but one well done. The result must be very pleasing!