On Thu, 12 Oct 2017 14:59:28 -0400, "Mr. Luddite"
wrote:

On 10/12/2017 2:13 PM, Bill wrote:
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.


I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel. The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.

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

On 10/12/17 4:53 PM, wrote:
On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel. The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.


I thought it was the result of a combination of factors, including
higher compression ratio, more heat content of the fuel, higher turbo
boost pressure, and greater heat content of the fuel, and continuous
pushing of that fuel into the cylinders.

On Thu, 12 Oct 2017 16:22:23 -0400, "Mr. Luddite"
wrote:

On 10/12/2017 4:03 PM, wrote:
On Thu, 12 Oct 2017 13:11:11 -0400, "Mr. Luddite"
wrote:

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.

OK but these days an engine will easily go 5000 hours or more in a
car. There are plenty of 200,000 mile Hondas, Toyotas and even Ford
trucks around and most got pretty shoddy maintenance in the last half
of their lives.
Cars usually get junked because things other than the engine go bad.
Hell my 71 Jeep 304 had 170k miles on it when I sold it (running) and
same with my 69 Corvette. Those were old technology detroit iron
running 70 miles a day on the beltway plus my "around town". Both had
the **** kicked out of them.
Neither were in salt water tho. I suspect it is corrosion that kills
I/Os, at least that has been what I saw.




I don't think you can compare the wear and tear of say, a GM 350 V8 used
in a car with the marine version of the same engine. Unless you are
just trolling around all the time, the marine engine is working at or
near full load and at relatively high RPM compared to the car version.
The car version, cruising down the highway with the torque converter
locked up is only turning about 1600 -1800 RPM at 60-65 mph and is only
developing maybe 20 or 30 hp to do it.


You never rode around with me in my Corvette I suppose. That was
before the Maryland cops figured there was money in speeders and there
was virtually no speed limit on the beltway after dark.
I have made lots of trips at or near WOT(140 mph or so)
I also ran it pretty hard all the time.

My Chevelle had a 456 rear so 70 MPH was around 4500 RPM
The Corvette was a 336 so it was a bit lower at 70.
My Honda is turning ~4k on the interstate (75-80). The V-tech kicks in
at 5000 RPM and I feel it a lot, just running up and down US41.

My boat certainly has an easier time of it.
Engine sp Time[h]
- 1000 r/m 125
1000 - 2000 822.9
2000 - 3000 101.7
3000 - 4000 175.4
4000 - 5000 51.1
5000 - 6000 0.4
6000 - 7000 0
Engine ho 1276

On 10/12/2017 5:12 PM, wrote:
On Thu, 12 Oct 2017 16:22:23 -0400, "Mr. Luddite"
wrote:

On 10/12/2017 4:03 PM, wrote:
On Thu, 12 Oct 2017 13:11:11 -0400, "Mr. Luddite"
wrote:

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.

OK but these days an engine will easily go 5000 hours or more in a
car. There are plenty of 200,000 mile Hondas, Toyotas and even Ford
trucks around and most got pretty shoddy maintenance in the last half
of their lives.
Cars usually get junked because things other than the engine go bad.
Hell my 71 Jeep 304 had 170k miles on it when I sold it (running) and
same with my 69 Corvette. Those were old technology detroit iron
running 70 miles a day on the beltway plus my "around town". Both had
the **** kicked out of them.
Neither were in salt water tho. I suspect it is corrosion that kills
I/Os, at least that has been what I saw.




I don't think you can compare the wear and tear of say, a GM 350 V8 used
in a car with the marine version of the same engine. Unless you are
just trolling around all the time, the marine engine is working at or
near full load and at relatively high RPM compared to the car version.
The car version, cruising down the highway with the torque converter
locked up is only turning about 1600 -1800 RPM at 60-65 mph and is only
developing maybe 20 or 30 hp to do it.


You never rode around with me in my Corvette I suppose. That was
before the Maryland cops figured there was money in speeders and there
was virtually no speed limit on the beltway after dark.
I have made lots of trips at or near WOT(140 mph or so)
I also ran it pretty hard all the time.

My Chevelle had a 456 rear so 70 MPH was around 4500 RPM
The Corvette was a 336 so it was a bit lower at 70.
My Honda is turning ~4k on the interstate (75-80). The V-tech kicks in
at 5000 RPM and I feel it a lot, just running up and down US41.

My boat certainly has an easier time of it.
Engine sp Time[h]
- 1000 r/m 125
1000 - 2000 822.9
2000 - 3000 101.7
3000 - 4000 175.4
4000 - 5000 51.1
5000 - 6000 0.4
6000 - 7000 0
Engine ho 1276


High RPM for engines designed for them doesn't hurt but "lugging" them
sure is.

Running a boat is closer to continuously lugging the engine for hours on
end if cruising somewhere. That's where the diesels have the big
advantage. They are made for it.

BTW ... your Honda is turning 4k RPM at 75 to 80? That seems very high.
Once the torque converter locks up (assuming your Honda is an auto and
has one) cars today usually are running closer to 2K or maybe a little
more at that speed. That's my experience anyway. The new Canyon I
bought has an eight speed transmission and a lock up TC. At 65 mph I am
turning about 1800 RPM.

On 10/12/2017 5:05 PM, Keyser Soze wrote:
On 10/12/17 4:53 PM, wrote:
On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up.Â* A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory.Â* A CumminsÂ* 5.9L diesel by
comparisonÂ* is 1200 lbs or 515 lbs heavier.Â* Twins would mean a weight
difference of over 1,000 lbs.Â* That's quite a bit, even for a 39' boat.

Major difference is:Â* The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year)Â* while the diesel CumminsÂ* develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel.Â* The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.


I thought it was the result of a combination of factors, including
higher compression ratio, more heat content of the fuel, higher turbo
boost pressure, and greater heat content of the fuel, and continuous
pushing of that fuel into the cylinders.


Probably all you mentioned ... oh and also the greater heat content of
the fuel in case you forgot. :-)

On Thu, 12 Oct 2017 16:53:30 -0400, wrote:

On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel. The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.

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

Looks like Krause cut'n'pasted something to show his exceptional knowledge of diesel engines.

On Thu, 12 Oct 2017 17:49:16 -0400, John H
wrote:

On Thu, 12 Oct 2017 16:53:30 -0400, wrote:

On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel. The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.

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

Looks like Krause cut'n'pasted something to show his exceptional knowledge of diesel engines.

===

At least it was boating related. :-)

On 10/12/17 6:06 PM, wrote:
On Thu, 12 Oct 2017 17:49:16 -0400, John H
wrote:

On Thu, 12 Oct 2017 16:53:30 -0400, wrote:

On Thu, 12 Oct 2017 16:42:10 -0400, wrote:

I was curious so I looked it up. A fully dressed 454 with cast iron
heads weighs 685 lbs from the factory. A Cummins 5.9L diesel by
comparison is 1200 lbs or 515 lbs heavier. Twins would mean a weight
difference of over 1,000 lbs. That's quite a bit, even for a 39' boat.

Major difference is: The 454 develops 450-500 lb-ft of torque at 3200
RPM (depending on year) while the diesel Cummins develops peak torque
of 610 lb-ft at 1600 RPM

The extra torque probably comes from the longer stroke in the diesel.
(4.0" vs 4.75")
They make gasoline engines "square" or even over bore to reduce the
reciprocating forces of a longer stroke for a given displacement
It lets them run at higher RPMs.

===

I believe the extra torque is mostly a result of the higher
compression ratio in a diesel. The higher ratio effectively increases
the duration of the power stroke compared to a gas engine.

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

Looks like Krause cut'n'pasted something to show his exceptional knowledge of diesel engines.

===

At least it was boating related. :-)



As opposed to nothing boating related from WD-40 Herring, aka
Limp-a-Long Johnnymop.

On Thu, 12 Oct 2017 17:47:17 -0400, "Mr. Luddite"
wrote:

On 10/12/2017 5:12 PM, wrote:



I don't think you can compare the wear and tear of say, a GM 350 V8 used
in a car with the marine version of the same engine. Unless you are
just trolling around all the time, the marine engine is working at or
near full load and at relatively high RPM compared to the car version.
The car version, cruising down the highway with the torque converter
locked up is only turning about 1600 -1800 RPM at 60-65 mph and is only
developing maybe 20 or 30 hp to do it.


You never rode around with me in my Corvette I suppose. That was
before the Maryland cops figured there was money in speeders and there
was virtually no speed limit on the beltway after dark.
I have made lots of trips at or near WOT(140 mph or so)
I also ran it pretty hard all the time.

My Chevelle had a 456 rear so 70 MPH was around 4500 RPM
The Corvette was a 336 so it was a bit lower at 70.
My Honda is turning ~4k on the interstate (75-80). The V-tech kicks in
at 5000 RPM and I feel it a lot, just running up and down US41.

My boat certainly has an easier time of it.
Engine sp Time[h]
- 1000 r/m 125
1000 - 2000 822.9
2000 - 3000 101.7
3000 - 4000 175.4
4000 - 5000 51.1
5000 - 6000 0.4
6000 - 7000 0
Engine ho 1276


High RPM for engines designed for them doesn't hurt but "lugging" them
sure is.

Running a boat is closer to continuously lugging the engine for hours on
end if cruising somewhere. That's where the diesels have the big
advantage. They are made for it.

BTW ... your Honda is turning 4k RPM at 75 to 80? That seems very high.
Once the torque converter locks up (assuming your Honda is an auto and
has one) cars today usually are running closer to 2K or maybe a little
more at that speed. That's my experience anyway. The new Canyon I
bought has an eight speed transmission and a lock up TC. At 65 mph I am
turning about 1800 RPM.

Dunno about the Honda but that was what I remember, though it might be
more like 80-85. We go fast down here. Next time I am out I will look.
It is a 5 speed and I am talking about 5th gear.

If your boat motor is "lugging" you have the wrong prop. Outboards
should still suffer from the same problems tho and the commercial guy
here gets 6000 hours or more out of his 175 Zekes. (Single, pushing a
38 foot pontoon)
I will admit he understands protecting his equipment and he is not
running WOT all the time, neither do most of the people I know.
Assuming the technology of Japanese outboards is similar to the cars,
they do redline them a lot lower tho.
My F70 redlines at 6300, enforced by the ECU and the Prelude is more
like 7400, not enforced by anything. but a red line on the tach