Stability of Slow Cruising a Deep Vee Hull in Rough Water

[goboatingnow]

And heres what real deep V hulls can do.

http://www.youtube.com/watch?v=dctb7...e_gdata_player

Or another interceptor being " trialled"

http://www.youtube.com/watch?v=eLIzp...e_gdata_player

Dave

[Astral Blue]

Originally Posted by Tony B

Ed:

1) Is your boat considered a planing hull or a semi-displacement hull?
2) I am dieing to see a picture

With diesel, you should have a really good traveling range. And...........pretty maintenance free.
So, how big was your old fuel tank and are you still using it. I would guess that a 50 Gal tank would get you about 300 to 350 miles. If you went down to a 50 gal tank and the smaller size of your motor, I would think you have captured some extra room.

It is a planing hull. Photos of the hull are on Post #1 of this thread. Yes, increased range and decreased maintenance are the main factors driving this repower. I have actually decided to install a 40 gallon main tank and a 12 gallon aux tank. My original tank was 96 gallons. Yes, there will be plenty of extra room in the engine compartment. The new engine has a much smaller footprint and the extra room from fewer gallons of tankage will come in handy.

This project is extensively discussed and documented in the Bayliner Owners Club forums. Here are some links:

Victoria 2750 Repower

Victoria 2750 Diesel Repower - The adventure begins...

There were a handful of naysayers, but they disappeared toward the end of the thread.

BTW, registration is required in order to access the links above. The administrators invoked this recently in an attempt to increase membership.

Originally Posted by goboatingnow

Well this is contradicted by deep V RIbs which are planing and are excellent heavy weather machines. You should read DAg Pikes book on mobo heavy weather techniques. He prefer good planing hulls. ( and open the throttles)

Dave

I just ordered two of his books. I had never her of Dag Pike, but his 60 years of experience on the water is something to be listened to. Thanks for the reference.

Originally Posted by goboatingnow

And heres what real deep V hulls can do.

Or another interceptor being " trialled"

Dave

The interceptors are in a completely different class of boat. Pilot boats are truly awesome. Trust me, I will never find myself in those conditions with the boat I have. Taking my boat out there is kind of like off-roading with a Toyota Prius.

[Cheechako]

My Tanton 44 sailboat had a 4-108 in it. it weighed about 24000 lbs. the 4 -108 had no problem pushing that boat to hull speed well below max rpm. the average fuel burn for the extent of my ownership was .63 gal per hour. Then engine should push the bayliner to hull speed like it's not even there..... subject ot outdrive issues!

[Tony B]

Originally Posted by Cheechako

My Tanton 44 sailboat had a 4-108 in it. it weighed about 24000 lbs. the 4 -108 had no problem pushing that boat to hull speed well below max rpm. the average fuel burn for the extent of my ownership was .63 gal per hour......!

I have an Allied 39 ketch with a 4-107 which is the 37HP version. Boat weighs 22,000 lbs and I get similar results as Cheechako on mine and come to the same conclusion.

[Tony B]

Originally Posted by Astral Blue

.......This project is extensively discussed and documented in the Bayliner Owners Club forums. Here are some links:

Victoria 2750 Repower

Victoria 2750 Diesel Repower - The adventure begins.............

ED:

I joined the BOC and read your first link. I am very impressed with your research to confirm what we both already knew. I am at work and I wont get home for another week or so but I will find time to read your 2nd link out here.
The naysayers wouldnt be bad if they didn't find a need for insults to express their point. Fortunately only a small percentage of naysayers do that.
I quit going to TrawlerForum.com for that very reason. If you want to have a boxing match - let's dance, but on here everyone should try to be more civil.
I firmly believe you are going to achieve your goal of less fuel stops with increased range, greater fuel economy, less engine maintenance and an engine that wont quit, not to mention the safety factor of diesel handling vs. gas.
Have fun.

[Cheechako]

Originally Posted by Tony B

ED:

I joined the BOC and read your first link. I am very impressed with your research to confirm what we both already knew. I am at work and I wont get home for another week or so but I will find time to read your 2nd link out here.
The naysayers wouldnt be bad if they didn't find a need for insults to express their point. Fortunately only a small percentage of naysayers do that.
I quit going to TrawlerForum.com for that very reason. If you want to have a boxing match - let's dance, but on here everyone should try to be more civil.
I firmly believe you are going to achieve your goal of less fuel stops with increased range, greater fuel economy, less engine maintenance and an engine that wont quit, not to mention the safety factor of diesel handling vs. gas.
Have fun.

I agree, way too much of that on this forum. I'm not sure the result will be great but what the heck... and ... "Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats"

[Tony B]

Originally Posted by Cheechako

...... "Believe me, my young friend, there is nothing - absolutely nothing - half so much worth doing as simply messing about in boats"

Ain't that the truth.
Now if we can just get Ed to put up a stick with some rags on it, he will be the man!!!

[Cheechako]

How about 2 bayliners bolted together with a stick and some rags?

[Tony B]

Originally Posted by Cheechako

How about 2 bayliners bolted together with a stick and some rags?

This is the kind of thinking and inovation that made our country great.

One of the things that had been repeated several times on this forum is that Ed devalued his boat. I strongly disagree with that. If he removed his engine and swapped for an outboard - that would have devalued it. But to swap for a diesel? I don't believe so. The boat will do everything it did before, except it will be at a slower speed and wont plane - maybe. Until he is finished with this project we wont know. I think he will at least get up into a semi plane if he wanted to - I think, but not sure. He has reduced weight in the rear by using a lighter engine and carrying less fuel.
Not everyone want to plane or pull water skiers. For river rats, he has in effect created a small, trailable pocket trawler. If the hull is well maintained I think he could get $15 to $20K for it.

[goboatingnow]

Originally Posted by Tony B

This is the kind of thinking and inovation that made our country great.

One of the things that had been repeated several times on this forum is that Ed devalued his boat. I strongly disagree with that. If he removed his engine and swapped for an outboard - that would have devalued it. But to swap for a diesel? I don't believe so. The boat will do everything it did before, except it will be at a slower speed and wont plane - maybe. Until he is finished with this project we wont know. I think he will at least get up into a semi plane if he wanted to - I think, but not sure. He has reduced weight in the rear by using a lighter engine and carrying less fuel.
Not everyone want to plane or pull water skiers. For river rats, he has in effect created a small, trailable pocket trawler. If the hull is well maintained I think he could get $15 to $20K for it.

That's 5k more then the cost of the repower? Which suggests that if he sold it previous for more then 5k he's up on your projections. I certainly call that devaluation.

The 4108 is very unlikely to be lighter then a gas engine.

As for planing , it will never do that. Those Bayliners required quite a push to plane, the hull isn't particularly efficient at getting out of the hole.

Sorry I just can't see the economic or engineering justification for this. fundamentally this is not a displacement speed hull it was never designed to be used so or a continuous basis. You could have repowered with a high performance diesel, got the economy of such , but still retained the ability to plane.

Dave

[David_Old_Jersey]

Originally Posted by Tony B

This is the kind of thinking and inovation that made our country great.

I wasn't going to post again on this thread - but couldn't resist a response to the above touch of jingoism, which I feel should read:-

"This is the kind of financial thinking that made (y)our country broke".

But as I said before - boats are not meant to make financial sense (mine included!), just deluding self (and on a Forum, others) by claiming otherwise for this project.

The irony is of course that I am the fella who is mulling over junking an old 4107 in favour of electric - at a cost of maybe £5k, just to see what happens (and I am not even an Enviromentalist )....with plan B being something shiney and new, and a tad smaller physically (access with the Perkins is a pig)......none of that makes any financial sense whatsoever .


One thing I forgot to mention performance wise is that on a fairly short motorboat hull with a wide beam and with little keel she will corkscrew a lot in any sort of following sea at displacement speeds - not always dangerous just have to stay aware at the helm. Don't want to get broadside in any sort of sea, especially if the boat is a bit rolly.

Comparing performance and / or handling characteristics of a displacement sailing boat to a motorboat is like comparing apples to oranges - the results are bananas .

Anyway, that deffo my last post on this thread

[Astral Blue]

Originally Posted by Tony B

ED:

I joined the BOC and read your first link. I am very impressed with your research to confirm what we both already knew. I am at work and I wont get home for another week or so but I will find time to read your 2nd link out here.
The naysayers wouldnt be bad if they didn't find a need for insults to express their point. Fortunately only a small percentage of naysayers do that.
I quit going to TrawlerForum.com for that very reason. If you want to have a boxing match - let's dance, but on here everyone should try to be more civil.
I firmly believe you are going to achieve your goal of less fuel stops with increased range, greater fuel economy, less engine maintenance and an engine that wont quit, not to mention the safety factor of diesel handling vs. gas.
Have fun.

I am astonished at the number of people that rush to judgment yet fail to educate themselves on very important aspects of what they are contesting. This failure and at this magnitude does not lye on the naysayer per se, but is a reflection of our civilization. We live in a society where a radio talkshow host with the IQ of a fire hydrant and the candor of a used car salesman has the ability to sell ice to an Eskimo on the "merits" of his/her pervasive arrogance packaged in a form that appeals to and solicits a positive response from his/her audience. This is found on too many forums. BOC is not immune from this; but I must admit things have gotten better over the years.

Forums have served as an invaluable too in helping me become better educated about boats and have helped me share this knowledge with others. But sadly, many people fail to see the value in this use; and rather use it for self fulfillment. However, I doubt they find themselves fulfilled after clicking on the "submit reply" icon.

Originally Posted by goboatingnow

That's 5k more then the cost of the repower? Which suggests that if he sold it previous for more then 5k he's up on your projections. I certainly call that devaluation.

The 4108 is very unlikely to be lighter then a gas engine.

As for planing , it will never do that. Those Bayliners required quite a push to plane, the hull isn't particularly efficient at getting out of the hole.

Sorry I just can't see the economic or engineering justification for this. fundamentally this is not a displacement speed hull it was never designed to be used so or a continuous basis. You could have repowered with a high performance diesel, got the economy of such , but still retained the ability to plane.

Dave

The GM 350 that was previously on this boat weighed over 1000 lbs. including the manifolds, risers, heat exchangers, and bell housing. The Perkins 4.108 weighs 460 lbs.!

My prior fuel tank was made of heavy gauge aluminum and had a capacity of a hair under 100 gallons. Setting aside the weight of the tank, a full tank of fuel would have weighed 700 lbs plus the tank with my old fuel tank; and now, a full tank now weighs 280 lbs plus the weight of a much lighter tank.

The new engine and new fuel tank will shave about 1000 lbs from the weight of the boat!

There is economic sense in this repower. I have yet to see a boat in as good of condition as mine that has been well taken care of as mine has, not to mention having a new transom for under $12K in this market and in my geographic region. That's the price with a standard gasoline power plant. With the brand new Diesel engine, the boat will sell for well above $15K if I were to sell it today (after the repower is complete). And with having plans to keep it for a long time, I can depreciate the cost of the repower over a decade and still manage to lose very little resale value. Over a decade, I will have 2000 to 3000 hours on this engine; and that is hardly significant for a Perkins 4.108. On the other hand, 2000 to 3000 hours on a high performance Diesel is something I stay away from if I was in the market for a boat. A Volvo D3 or D4 or a Cummins or Isuzu equivalent that has been run at high RPM's for that many hours is going to be yearning for a rebuild.

Not everybody wants to be up on plane. I was on a friend's boat yesterday cruising down the San Joaquin River (comfortably at 7 knots). I passed by dozens of boats in the 28 foot range. Only 2 of them were on plane. This is in a speed unrestricted navigation channel, not a no-wake zone! The majority of the boats I have seen in this size range over the past few years have been cruising at or slightly above displacement speeds. The cost of fuel is actually forcing people to get away from the "lets hurry up and relax" mentality.

I have never really paid too much attention to the cost of fuel for my own boating experiences because it is an insignificant part of the cost of boat ownership. Replacing a starter can easily cost more than it does to fill up a tank. A haul-out, outdrive servicing, and bottom paint job has the equivalent cost of three years of fuel.

The math is not really that difficult to demonstrate this is cost effective. Goboatingnow, I invite you to break down the cost of this repower versus a high performance Diesel repower and demonstrate I'd be ahead of the game if I repowered with a high performance engine. If cost is the only factor to consider, the answer is obvious. But I'm not driven by cost alone. I'm driven by the love for my current boat and wanting to make it suit my cruising needs, not to appease a segment of the market I never plan to appeal to. Like I've said to others, what you are suggesting is that I would need to repower and use the boat in a way I don't intend to so I can appease future prospective buyers.

[Astral Blue]

Originally Posted by David_Old_Jersey

I wasn't going to post again on this thread - but couldn't resist a response to the above touch of jingoism, which I feel should read:-

"This is the kind of financial thinking that made (y)our country broke".

But as I said before - boats are not meant to make financial sense (mine included!), just deluding self (and on a Forum, others) by claiming otherwise for this project.

The irony is of course that I am the fella who is mulling over junking an old 4107 in favour of electric - at a cost of maybe £5k, just to see what happens (and I am not even an Enviromentalist )....with plan B being something shiney and new, and a tad smaller physically (access with the Perkins is a pig)......none of that makes any financial sense whatsoever .


One thing I forgot to mention performance wise is that on a fairly short motorboat hull with a wide beam and with little keel she will corkscrew a lot in any sort of following sea at displacement speeds - not always dangerous just have to stay aware at the helm. Don't want to get broadside in any sort of sea, especially if the boat is a bit rolly.

Comparing performance and / or handling characteristics of a displacement sailing boat to a motorboat is like comparing apples to oranges - the results are bananas .

Anyway, that deffo my last post on this thread

Making financial sense should never (in my opinion) be the overwhelming motivation behind thinking outside the box. People step outside the box because they are not comfortable or content with what is in the box. If the fruit from the tree tastes bitter, you are not obligated to continue eating fruit from that tree. In fact, you are not obligated to eat fruit at all if you find a better source of food.

All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.

Arthur Schopenhauer, German philosopher (1788 – 1860)

[Tony B]

Originally Posted by David_Old_Jersey

I wasn't going to post again on this thread - but couldn't resist a response to the above touch of jingoism, which I feel should read:-

"This is the kind of financial thinking that made (y)our country broke".

Maybe you should think before you criticize. My statement was obviously made in jest of the Originally Posted by Cheechako
How about 2 bayliners bolted together with a stick and some rags?
As for my country, I have pride in it as I do myself. Enough pride to display my profile and not hide behind the anonymity of the internet.
My country's problems were financially created by greed and not by innovation.
But as I said before - boats are not meant to make financial sense (mine included!), just deluding self (and on a Forum, others) by claiming otherwise for this project.
Yes, you probably are deluding yourself with your jealousy and negativity shows through very well.

The irony is of course that I am the fella who is mulling over junking an old 4107 in favour of electric - at a cost of maybe £5k, just to see what happens (and I am not even an Enviromentalist )....with plan B being something shiney and new, and a tad smaller physically (access with the Perkins is a pig)......none of that makes any financial sense whatsoever .


One thing I forgot to mention performance wise is that on a fairly short motorboat hull with a wide beam and with little keel she will corkscrew a lot in any sort of following sea at displacement speeds - not always dangerous just have to stay aware at the helm. Don't want to get broadside in any sort of sea, especially if the boat is a bit rolly.
Question: Will this boat react any differently at displacement speed, which he normally travels at, with a small diesel than the old gas engine or even a paddle wheel for that matter? This is a propulsion system and not a stability system that is being replaced.

Comparing performance and / or handling characteristics of a displacement sailing boat to a motorboat is like comparing apples to oranges - the results are bananas .
True, thats why I didnt compare performance as far as stability is concerned. I think you make up your own arguements from something that is not there.

Anyway, that deffo my last post on this thread
Good, there is enough negativity already out there.
Have a good life. Tony B

I might have let this slide had you not made a disparaging remark about my country

[Tony B]

Originally Posted by Astral Blue

..........The new engine and new fuel tank will shave about 1000 lbs from the weight of the boat!...........

I had no idea there was that much of a weight difference.
Shaving 1,000 lbs from the stern of your boat will definitely have some effect on stability and planing - even if not a full plane, just the dropping of the stern prolly wont be as severe.
I should have such problems. That means that if you wanted to rebalance the boat you would prolly have to take on around another 100 gals of drinking water. Damn. LOL. With the added space you now have, that should be easy to do. Custom fit fiberglass tanks.
Anyway, you wont know for sure until you do your test runs. Much easier to add weight than to remove weight. A Naval Architect should be able to tell you exactly where to place the weight to achieve the stability performance you want.