On 10/11/2017 5:04 PM, wrote:
On Wed, 11 Oct 2017 13:10:58 -0700 (PDT), Tim
wrote:


2:51 PMIts Me
- show quoted text -
I just read about the Oxe. It uses a 2.0 GM diesel. According to the article is also costs twice what a 200hp Yamaha 4 stroke goes for. Ouch!
.....
Diesels 'usually' last longer than a gas job and are much more economical on fuel. But what you save in fuel costs probably don't over ride the massive up front expense of the whole unit. Bad trade off IMO.


===

Increased range because of greater fuel economy is the most common
reason for justifying the higher cost. Diesels use almost 50% less
fuel for the same power output, and have higher low end torque.


Which also allows bigger, more efficient props running at lower RPM.

On Wed, 11 Oct 2017 17:24:56 -0400, "Mr. Luddite"
wrote:

On 10/11/2017 5:04 PM, wrote:
On Wed, 11 Oct 2017 13:10:58 -0700 (PDT), Tim
wrote:


2:51 PMIts Me
- show quoted text -
I just read about the Oxe. It uses a 2.0 GM diesel. According to the article is also costs twice what a 200hp Yamaha 4 stroke goes for. Ouch!
.....
Diesels 'usually' last longer than a gas job and are much more economical on fuel. But what you save in fuel costs probably don't over ride the massive up front expense of the whole unit. Bad trade off IMO.


===

Increased range because of greater fuel economy is the most common
reason for justifying the higher cost. Diesels use almost 50% less
fuel for the same power output, and have higher low end torque.


Which also allows bigger, more efficient props running at lower RPM.


I was reading an article somewhere else that said the economy might
not make the difference in less than 10,000 hours. They also assume
higher maintenance cost, particularly with a belt drive. I am curious
how the belt is working out on the 7 Marine.

On Thu, 12 Oct 2017 00:33:16 -0400, wrote:

Diesels 'usually' last longer than a gas job and are much more economical on fuel. But what you save in fuel costs probably don't over ride the massive up front expense of the whole unit. Bad trade off IMO.


===

Increased range because of greater fuel economy is the most common
reason for justifying the higher cost. Diesels use almost 50% less
fuel for the same power output, and have higher low end torque.


Which also allows bigger, more efficient props running at lower RPM.


I was reading an article somewhere else that said the economy might
not make the difference in less than 10,000 hours. They also assume
higher maintenance cost, particularly with a belt drive. I am curious
how the belt is working out on the 7 Marine.

===

Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

---
This email has been checked for viruses by AVG.
http://www.avg.com

On Thu, 12 Oct 2017 08:34:00 -0400,
wrote:

On Thu, 12 Oct 2017 00:33:16 -0400, wrote:

Diesels 'usually' last longer than a gas job and are much more economical on fuel. But what you save in fuel costs probably don't over ride the massive up front expense of the whole unit. Bad trade off IMO.


===

Increased range because of greater fuel economy is the most common
reason for justifying the higher cost. Diesels use almost 50% less
fuel for the same power output, and have higher low end torque.


Which also allows bigger, more efficient props running at lower RPM.


I was reading an article somewhere else that said the economy might
not make the difference in less than 10,000 hours. They also assume
higher maintenance cost, particularly with a belt drive. I am curious
how the belt is working out on the 7 Marine.

===

Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

That must be one heavy sommich if 2 454s only get you 18 MPH.
The guy around the corner has a 36 (Donzi I think) with 2 250s on it
that will cruise in the 30s burning a combined 25-30 GPH or so (a
whole lot more at WOT tho)

On Thu, 12 Oct 2017 11:17:07 -0400, wrote:


Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

That must be one heavy sommich if 2 454s only get you 18 MPH.
The guy around the corner has a 36 (Donzi I think) with 2 250s on it
that will cruise in the 30s burning a combined 25-30 GPH or so (a
whole lot more at WOT tho)

===

A Bertram 33 is a much different boat than a Donzi: Heavier close to
20,000 lbs; Beamier; Windage from a full flybridge with enclosure;
Full cruising interior.

It would do 25 kts wide open with half fuel but I was concientious
about keeping the RPMs at no more than 3200 or 3300.

The whole point of my comparison excercise was to show that increased
fuel range with diesel is often the deciding factor as opposed to fuel
cost savings.

---
This email has been checked for viruses by AVG.
http://www.avg.com

On Thu, 12 Oct 2017 12:13:08 -0400,
wrote:

On Thu, 12 Oct 2017 11:17:07 -0400, wrote:


Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

That must be one heavy sommich if 2 454s only get you 18 MPH.
The guy around the corner has a 36 (Donzi I think) with 2 250s on it
that will cruise in the 30s burning a combined 25-30 GPH or so (a
whole lot more at WOT tho)

===

A Bertram 33 is a much different boat than a Donzi: Heavier close to
20,000 lbs; Beamier; Windage from a full flybridge with enclosure;
Full cruising interior.

It would do 25 kts wide open with half fuel but I was concientious
about keeping the RPMs at no more than 3200 or 3300.

The whole point of my comparison excercise was to show that increased
fuel range with diesel is often the deciding factor as opposed to fuel
cost savings.

I do understand the diesel thing. My buddy used to captain a bigger
Bertie with 2 6-71s in it for a rich guy (46 or 50 sumpin?). Nice
boat. Winter at Pier 66 and summer in Annapolis. He gave it all up for
IBM and a family. There were IBM guys who said they would have just
swapped jobs ;-)

wrote:
On Thu, 12 Oct 2017 12:13:08 -0400,
wrote:

On Thu, 12 Oct 2017 11:17:07 -0400, wrote:


Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

That must be one heavy sommich if 2 454s only get you 18 MPH.
The guy around the corner has a 36 (Donzi I think) with 2 250s on it
that will cruise in the 30s burning a combined 25-30 GPH or so (a
whole lot more at WOT tho)

===

A Bertram 33 is a much different boat than a Donzi: Heavier close to
20,000 lbs; Beamier; Windage from a full flybridge with enclosure;
Full cruising interior.

It would do 25 kts wide open with half fuel but I was concientious
about keeping the RPMs at no more than 3200 or 3300.

The whole point of my comparison excercise was to show that increased
fuel range with diesel is often the deciding factor as opposed to fuel
cost savings.

I do understand the diesel thing. My buddy used to captain a bigger
Bertie with 2 6-71s in it for a rich guy (46 or 50 sumpin?). Nice
boat. Winter at Pier 66 and summer in Annapolis. He gave it all up for
IBM and a family. There were IBM guys who said they would have just
swapped jobs ;-)


My friend has a 39’ Luhrs. Twin Cummins. They are heavier than a gas
engine, but I bet not that much more than a 454. Unlike a 6-71.

On 10/12/2017 9:51 AM, Keyser Soze wrote:
wrote:
On Thu, 12 Oct 2017 00:33:16 -0400, wrote:

Diesels 'usually' last longer than a gas job and are much more
economical on fuel. But what you save in fuel costs probably don't
over ride the massive up front expense of the whole unit. Bad trade off IMO.


===

Increased range because of greater fuel economy is the most common
reason for justifying the higher cost. Diesels use almost 50% less
fuel for the same power output, and have higher low end torque.


Which also allows bigger, more efficient props running at lower RPM.


I was reading an article somewhere else that said the economy might
not make the difference in less than 10,000 hours. They also assume
higher maintenance cost, particularly with a belt drive. I am curious
how the belt is working out on the 7 Marine.

===

Here's a real world example of the diesel vs gas engine trade off. Our
old Bertram 33 had a 320 gallon fuel tank which seems like a lot but
it had 454 gas engines which burned 35 gallons per hour. Cruising
speed barely reached 18 knots on a good day. Doing the math, you come
up with a safe fuel range of less than 140 miles, not enough for
offshore canyon fishing in the NY area. Converting to diesel engines,
the burn rate drops to about 20 gallons per hour, and cruising speed
climbs to 23 knots or so, for a fuel range of around 300 miles. That's
a big difference in the capability of the boat and has nothing to do
with the price of fuel or reliability.

---
This email has been checked for viruses by AVG.
http://www.avg.com



About $75,000 to $100,000 for removal of gas engines, engineering,
plumbing, new pair of 250 to 300 HP diesels. If gasoline is three bucks a
gallon, the conversion would cover 25,000 gallons of gasoline. Ouch. 😀


THere's something about gas engines running for hours at 3,600 to 4,000
RPM that disturbs me, even though I realize they have cams, etc., that
are designed for it. Seem to remember the general rule was 1,000 to
1,500 hours before a rebuild.

I have the same problem with land yachts. Had a large Pace Arrow
motorhome with a big ass gas engine that I thought would explode
climbing the hills out on Rt. 84, heading for Florida. At a certain
size/weight diesel is the only way to fly.

On Thu, 12 Oct 2017 10:52:37 -0400, "Mr. Luddite"
wrote:

THere's something about gas engines running for hours at 3,600 to 4,000
RPM that disturbs me, even though I realize they have cams, etc., that
are designed for it. Seem to remember the general rule was 1,000 to
1,500 hours before a rebuild.

That must have been a "rule" made when engines were still "detroit
iron". Once the Japs showed us you can make a better engine, all of
them will run many thousands of hours.
My Yamamerc 60 had over 3000 on it with no indication it was in need
of anything. I got rid of it because of all of the other $200-500
screw on parts that were nearing end of life.

On 10/12/2017 1:05 PM, wrote:
On Thu, 12 Oct 2017 10:52:37 -0400, "Mr. Luddite"
wrote:

THere's something about gas engines running for hours at 3,600 to 4,000
RPM that disturbs me, even though I realize they have cams, etc., that
are designed for it. Seem to remember the general rule was 1,000 to
1,500 hours before a rebuild.

That must have been a "rule" made when engines were still "detroit
iron". Once the Japs showed us you can make a better engine, all of
them will run many thousands of hours.
My Yamamerc 60 had over 3000 on it with no indication it was in need
of anything. I got rid of it because of all of the other $200-500
screw on parts that were nearing end of life.



I wasn't referring to outboards. Was talking about I/Os that use car or
truck engines like the popular GM 350, 454, Ford 460, etc.