Gas Powered DEs

BillD

Admiral
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Portsmouth NH, boating out of the mighty Merrimack
Boat Make
25 Terry Jason with Cummins 370 power
Always curious,

Who on the forum has gasoline powered DEs?

What size and make of hull?

What engine and hp?

What gear and ratio?

What size prop Diameter and pitch ?

What are the different cruise speeds and at what rpms ?

Thanks,

Bill D
 

captchuck

Lieutenant Commander
Joined
Dec 4, 2011
Posts
186
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Location
Long Island
Boat Make
26' Seaway
1984 26' seaway
5.7 mpi mercruiser
300 hp
2:1 spinning an 18x17 3 blade acme with some cup
2800-16 mph
3000-17.5
3200-19
Wot @31
I average about 1.6-8 mpg on a cruise
 

jwalka51

Captain
Joined
Nov 28, 2012
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Location
Newport R.I.
Boat Make
26' Webber Cove lobster boat.
26' webber cove , set up as a lobster boat.
350 gas, 220 hp In front of steering bulkhead
1.9:1 gear, borg warner
18x18 four blade, (over propped, But I dont care, I bought the prop to work with the re-power I am doing soon)
15-15.5 mph @ 2600
20-22 mph @ 3200 rpm
cant get more than 3200-3300 turns out of her
Not sure about fuel consumption
cant wait to put my little john deere and twin disc in her.
 

pugsley

Captain
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Dec 12, 2012
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used to have a 350 in a 35 bruno, 2.57:1 with a 21x19
did 12 at 2800, and 20+ wide open, 4400 i think.
 

Sailorgp

Commander
Joined
Nov 1, 2011
Posts
498
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Location
Great Lakes
Boat Make
Sisu 26
26' Sisu
5.7 Chevy 260hp Holley 4bbl
1.88 Borg Warner Velvet Drive
17 x 15 4 blade
WOT 4,200rpm 20 knots
cruise 2,700 12 knots @5 gal/hr
 

BillD

Admiral
Joined
Sep 1, 2011
Posts
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Location
Portsmouth NH, boating out of the mighty Merrimack
Boat Make
25 Terry Jason with Cummins 370 power
1984 26' seaway
5.7 mpi mercruiser
300 hp
2:1 spinning an 18x17 3 blade acme with some cup
2800-16 mph
3000-17.5
3200-19
Wot @31
I average about 1.6-8 mpg on a cruise

26' webber cove , set up as a lobster boat.
350 gas, 220 hp In front of steering bulkhead
1.9:1 gear, borg warner
18x18 four blade, (over propped, But I dont care, I bought the prop to work with the re-power I am doing soon)
15-15.5 mph @ 2600
20-22 mph @ 3200 rpm
cant get more than 3200-3300 turns out of her
Not sure about fuel consumption
cant wait to put my little john deere and twin disc in her.

used to have a 350 in a 35 bruno, 2.57:1 with a 21x19
did 12 at 2800, and 20+ wide open, 4400 i think.

28' Cape Dory Power Cruiser
Original 275 hp Chrysler
19 kts at 4,400 rpm wot
12 kts at 3,200 rpm cruise

26' Sisu
5.7 Chevy 260hp Holley 4bbl
1.88 Borg Warner Velvet Drive
17 x 15 4 blade
WOT 4,200rpm 20 knots
cruise 2,700 12 knots @5 gal/hr

Thank you all !

Keep them coming !!!
 

Bill

Founder
Joined
Aug 30, 2011
Posts
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Location
Hull, Ma
Boat Make
27 Terry Jason
Would be nice if we could get a couple of guys with the same boats and do a gas/ diesel cost comparison so we could see at what point a diesel becomes worth the initial investment. I realize that this wouldn't work or be practical in boats over 28. But for smaller boats why do we install diesels?

The initial investment is around 4 times the cost of a gas engine

The price of diesel is more than gas

Diesels weigh more

Gas is quieter

Diesels last longer

Diesels get better economy usually by 30%

Diesels increase resale value of the boat

So, tell me your thoughts. We've had this discussion before but I think we should rehash it out.
 

BillD

Admiral
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Location
Portsmouth NH, boating out of the mighty Merrimack
Boat Make
25 Terry Jason with Cummins 370 power
Would be nice if we could get a couple of guys with the same boats and do a gas/ diesel cost comparison so we could see at what point a diesel becomes worth the initial investment. I realize that this wouldn't work or be practical in boats over 28. But for smaller boats why do we install diesels?

The initial investment is around 4 times the cost of a gas engine

The price of diesel is more than gas

Diesels weigh more

Gas is quieter

Diesels last longer

Diesels get better economy usually by 30%

Diesels increase resale value of the boat

So, tell me your thoughts. We've had this discussion before but I think we should rehash it out.

Bill,

I your 25 T Jason gas is the "$smart$ move". Granted you are going to replace the 460 Ford with a reman 460.

Me, doing fresh gas in your 25 T Jason I figure Crusader 6.0 MPI, ZG63A 8 degree down angle gear 2:5.1 ratio 1.5" shaft swinging a 22X22 prop.
 

Raider Ronnie

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Boat Make
33 Flowers.

captchuck

Lieutenant Commander
Joined
Dec 4, 2011
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Location
Long Island
Boat Make
26' Seaway
I think diesel vs gas in a smaller boat has a lot to do with what kind of hours you put on the boat. I personally put around 150 hours a year on the boat. When I priced out repowering with both it was an easy ten thousand more for diesel. For me I rarely look at resale value I simply look at its value to me.
 

BillD

Admiral
Joined
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Location
Portsmouth NH, boating out of the mighty Merrimack
Boat Make
25 Terry Jason with Cummins 370 power
I think diesel vs gas in a smaller boat has a lot to do with what kind of hours you put on the boat. I personally put around 150 hours a year on the boat. When I priced out repowering with both it was an easy ten thousand more for diesel. For me I rarely look at resale value I simply look at its value to me.

Gas versus diesel in a small DE you should also consider the weight. The weight differential could be +/- 300 lbs or so if you are considering a small block gasser versus an 225 JD or Cummins 6BT.
 

finaddict

Lieutenant Commander
Joined
Sep 2, 2011
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Location
salem, MA
Website
stores.ebay.com
Boat Make
Nauset
29 Nauset costal

What size and make of hull? 29 ft Nauset

What engine and hp? 350 mercruiser 260 hp

What gear and ratio? borg warner no clue on the gear/ration

What size prop Diameter and pitch ?

What are the different cruise speeds and at what rpms ?
400 rpm = 1.2 knots
1200rpm = 6 knots
1800 rpm = 8 knots
2800 rpm = 10 knots
3200 rpm = 13.2 knots (cruise) 0.75 nautical miles/gal
3600 rpm = 16.7 knots (WOT)
 

Bill

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27 Terry Jason
I guess I should investigate before I speak . I thought marine diesel was more expensive than gas at the dock . Ya I think a huge factor is application . I am not going to be using this boat commercially , it's simply "because I want one" boat. Ill be taking it to the bank etc but maybe once a week if that. The next thing besides the upfront cost is the noise. I couldn't inagine standing next to a 4bt. I haven't heard a 225 JD . Didn't know that about insurance either.

What are the drop in prices for a 225jd?
 

Raider Ronnie

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33 Flowers.

jwalka51

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Location
Newport R.I.
Boat Make
26' Webber Cove lobster boat.
You should look into a 150 John Deere. When I was looking for an engine for my webber cove 26, I originally thought that I wanted a 220. But after standing next to one, I realized that it was too large an engine to put in my boat. So I ended up getting a john Deere 4045 rated at 150 HP.
Dont get me wrong, the 220, 6068 engine would fit, but there would not be alot of room after that thing went in.
 

pugsley

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Dec 12, 2012
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What size and make of hull? 29 ft Nauset

What engine and hp? 350 mercruiser 260 hp

What gear and ratio? borg warner no clue on the gear/ration

What size prop Diameter and pitch ?

What are the different cruise speeds and at what rpms ?
400 rpm = 1.2 knots
1200rpm = 6 knots
1800 rpm = 8 knots
2800 rpm = 10 knots
3200 rpm = 13.2 knots (cruise) 0.75 nautical miles/gal
3600 rpm = 16.7 knots (WOT)

you are way over wheeled.
 
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