FUEL BURN

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skipperjon

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I need to move my boat, a 1998 Luhrs 290 Open, from Puerto Penasco, Mexico to San Carlos, Mexico on the Sea of Cortez.
It's about 300 miles by water. Got a quote from a boat transport of $1,900 to pull it on my trailer. I think it's a lot of money since it's only about 350 miles by land.
That part of the world has very few places where fuel is available. On my route there is only one in Kino Bay which is about 200 miles south of Puerto Penasco.
I'm concidering doing it by water but am not sure if I would have enough fuel to make it.
The engines have been completely rebuilt with 10 hrs on them. They are 350 Marine Power, 320hp each.
What would be my most economical speed to make this trip? Slow cruise, trolling (8 knots), or even running on one engine at a time? Going slow is not a problem for me.
Obviously, I would pick the right weather window.

Thanks for all advice.

John
 
I could give you a nice "rule of thumb guesstimate", but frankly, what you need is to gather accurate fuel consumption data for your particular boat. Especially if you are going to "push the envelope".

If I were considering a trip, and in order to make that trip it would be necessary to use "extreme fuel conservation measures" then I would cancel the trip. Most of the boats I have had or been involved with had about a 300 nm -straight line- range. The catch is that you need to allow for unanticipated heavy seas/current and nav errors. This is when you use those "special fuel saving procedures", not when actually planning the trip. If you can't do it "the normal way" then you should likely look for an alternative.

In any event, you must have accurate fuel consumption data for your particular boat, under various conditions. Then you need to plan the trip under standard cruise, and include a fuel safety margin. Without that information, I cannot suggest you even try the trip.
 
You can purchase a few extra 5 gal gas containers or a bladder to extend your range? With either there are a few safety things to do as well if you go this route?
 
"That part of the world has very few places where fuel is available. On my route there is only one in Kino Bay which is about 200 miles south of Puerto Penasco."

...And what if you pick up contaminated fuel? That would be a big concern for me, regardless of how mechanically well the boat is.

It may be a case of uncertainty vs. certainty of getting your boat to your destination, tough choice. Sounds like it could be a neat trip though. Good luck in your decision.
 
Until I put a fuel flow monitor in my boat, I assumed I had lower fuel consumption per mile at lower rpms. Surprised myself and found that no matter what speed i cruise, it's about 1 mpg. The only question is how fast I want to get there. 100 miles is about 100 gallons wethere i'm at 20 knots or 10 knots. What is the fuel capacity of your boat? 250 to 300 gallons?
 
Lets see, a maximum range trip on rebuilt engines. Where do I start? First I would want more than 10 hours on an engine before I take it out in waters without immediate aid availiable. Second, with newly rebuilt engines your fuel range is just one issue. How about oil consumption? Finally, your range with rebuilt engines may be greatly effected by the state of the engine break in. Your range may improve as everything seats in but it may go down if seating goes poorly. Simply put, you don't have the conditions sufficient to get a good read on what is going on. I used to ferry single engine airplanes from the West Coast to HNL. Without 50 hours on the engine, and a damn good read on the seating conditions of the engine you cannot possibly have an idea on a quality fuel consumption reading on your engines.
 
i agree, such a long run on fresh rebuilt with limited or no facilities is risky...

as to best economical speed, it's hull speed, probably aroudn 7.5 to 8kts. go 20% over that and you'll b urn 50% more, at least.
 
According to the spec sheet your boat has a fuel capacity of 302 gallons. Unless you are going to carry a good bit of fuel in cans/bladders you shouldn't even be having this conversation.

Even under labratory conditions you are at "bingo" fuel. Throw in a bit of wind, waves and current and you are out.

I used to run a Luhrs 32 a few years ago and I can tell you for a fact that, beacuse of weight and other factors, they are not noted for their fuel efficiency.

Unless you are going to carry about 100 extra gallons I wouldn't even consider it. IMHO

Regardless of fuel, as others have said, I wouldn't even consider it until those engines have more hours on them.

Bob
 
One thing to consider when getting a quote for trailering is not the distance from point A to point B; rather A to B back to A. Unless the driver is able to pick something up at B he will charge for his return. It seems the price is expensive at $1900 considering you have a trailer.
The trip by water if I read correctly is 200 miles for the first leg and then another 100 miles to the final destination. A rule of thumb when boating is 1/3 tank fuel out, 1/3 for return, and 1/3 for reserve. If you can't go the first leg without using less than 2/3's, then you are pushing your luck. You need to figure out fuel milage to get an idea if it's safe to attempt. The rebuilt engines have 10 hours on them; should be broken in by now. I would run them hard to make sure everything holds up prior to leaving.
 
I really appreciate all those resposes. It seems that the consesus is to do it by land. Most likely this is what I will do eventually and I will tow it myself with an escort behind me.
I do trust the engines as they are now, but since I do not have a way to monitor the fuel burn yet, I'm hesitant to undertake such a voyage. The engines should be fully broken-in by now, they were run on a dynomometer after the rebuild and the shop, which by the way specializes in rebuilding marine engines, told me that no further braking-in is necessary.
All of the responses had valid points and I thank all.

John
 
quote:
Originally posted by skipperjon

I really appreciate all those resposes. It seems that the consesus is to do it by land. Most likely this is what I will do eventually and I will tow it myself with an escort behind me.
I do trust the engines as they are now, but since I do not have a way to monitor the fuel burn yet, I'm hesitant to undertake such a voyage. The engines should be fully broken-in by now, they were run on a dynomometer after the rebuild and the shop, which by the way specializes in rebuilding marine engines, told me that no further braking-in is necessary.
All of the responses had valid points and I thank all.

John

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Good luck and, whatever you do, be safe! :)

Bob
 
You could trailor it part of the way, then bring it to a boat ramp and finish the trip by boat...? eh?
 
are'nt you going to have to pay someone to drive the trailer to the new location anyway?
 
There is no way reman engines with 10 hours are broken in. It may be a very good shop but unless you are OEM with very expensive optical measuring equipment for each component there is not a chance in the world.
 
I agree even my new engines were not considered broken in until I had 50 hours on them. Things can happen and If I were you I'd prefer to put additional time on the engines incase something unrelated to the engines but part of the overall system fail. As far as running on one motor unless you can freewheel the other prop (neutral won't cut it) you could have problems with the V drive or transmission. IMO this is to long a trip on a set of remans with 10 hours on them. Carrying diesel fuel in a bladder tank is one thing but gasoline I wouldn't do it. Where would you put the bladder and adding the additional fuel weight will hurt fuel coinsumption. Are the engines under the cockpit on that boat? If so where would you put the fuel bladder?

Bill
 
On Fishing boats in the pacific we used 5 Gal per hr, per 100 hp.
Using that formula your boat, at cruise is gonna use about 35 Gal per hour. (on paper)
With a safe usable fuel capacity of 290 Gal's, (out of 302 Capacity) that's only 8 hours of cruise time.
Can you make 300 miles in 8 hours?

Assuming you were able to lay up when the weather got into your face, you could leave early AM when the sea if flat, cruise till those winds kick up shortly after noon, lay up till the winds died down and the sea flattened out again and continue.
That'd get your best distance per Gallon.
 
Five gph per 100 hp is a number for four cycle diesels, Thudpucker, and the Marinepower engines that skipperjon has are gassers. His gph would be more like seven.

Also, gas engines seem to keep the same burn per mile regardless of speed. Diesels can vary up to four to one getting especially good when the boat runs at 3/4 hull speed.
 
He needs to make 200 miles as that's the mileage to the first available fuel. He would need to be able to make that with 2/3 of his fuel. The no time engines are a different matter though.
 
quote:
Originally posted by vic33004

are'nt you going to have to pay someone to drive the trailer to the new location anyway?

Click to expand...

The plan was to sail the boat to it's destinaton, then take a bus back to pick up the truck and trailer.
John
 
quote:
Originally posted by Billylll

I agree even my new engines were not considered broken in until I had 50 hours on them. Things can happen and If I were you I'd prefer to put additional time on the engines incase something unrelated to the engines but part of the overall system fail. As far as running on one motor unless you can freewheel the other prop (neutral won't cut it) you could have problems with the V drive or transmission. IMO this is to long a trip on a set of remans with 10 hours on them. Carrying diesel fuel in a bladder tank is one thing but gasoline I wouldn't do it. Where would you put the bladder and adding the additional fuel weight will hurt fuel coinsumption. Are the engines under the cockpit on that boat? If so where would you put the fuel bladder?

Bill

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According to the transmission owner's manual, it is ok to run on just one engine. It will not hurt the "HURTH" transmission.
No, I would not want to carry extra fuel anywhere on deck.

So it's overland we go.
John
 
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