R25 engine choices

Of course if you want to really have the "best", pre oiling is an excellent idea. This is a pressure pump which is turned on before the engine is started and fills the oil galleries so that there is oil at every point as the engine fires its first stroke. I have always started the engine, let it run until oil pressure was up in the engine and transmissions (some of my larger boats have had oil pressure guages on the transmissions) and then put the boat in gear. Certainly in the RV world it is generally accepted that prolonged idling is not good for the engine (or your neighbors)--most 0n the road trucks have a "high idle" setting--as do some RV's. Realistically I would start the enginies, cast off the lines and go at an idle. It usually takes a minute or two to cast off the lines in a larger boat. But I would never start engines 10 or 20 minutes before shoving off.

I would be a little surprised that the range at 8 knots would be more than the range at 6.5 knots. Lets assume that the LWL of the C Ranger is 22 feet: With a sq root of this being about 4.7, 6.5knots is slightly over l.34 x sq rt LWL. This is an accepted magic number--beyond which a boat has to start climbing over its own bow wave (some minor variations according to the lenth to beam ratio, weight and hull form)--but it is a very good number. If you don't already own "The Nature of Boats, by David Gerr, it is a very good book to have in the library--so is "V oyaging under Power" by Bebee and Leishman. I have the first edition for fun, as well as the most recent edition, since I have had some experience with "Passagemaker", Bebee's boat.

At 8 knots you are at 1.7 x sq root LWL, and that is not as effecient as slower speeds. 9 knots will be less effecient yet. The less effeciency should mean less miles a gallon. For the Ranger 25, I would expect the best effeciency would be in the 5 knot range, but that is going to be too slow for most folks. It may be necessary to get long distance cruising.

I thought that someone had done detailed sea trials with fuel consumption, but I could not find that, which is surprising. I probably just missed it.

The "small" fuel tank is certainly a good question. If you are getting 5 miles a gallon (a gallon an hour at 5 knots) then you would expect a realistic range of slightly over 300 miles. That would make most of the PNW available. I figure at least 200 mile range to do Alaska in any boat.
 
LET ME START OFF WITH A BIG APOLOGY. I must have had my head screwed on backwards as I wrote the last message because I did not mean to use km (kilometers) when I meant nm (nautical miles) Since I read speed in knots, I think in terms of nautical miles and simply mislabeled them. Sorry if that confused anyone as it woud have me. Obviously - I screwed up big time. I will go back and edit the previous message to hopefully keep others from getting bad info.

However, as noted, the math is precise - the data less so. Even if read correctly off the charts, the curves have been fit to the data so any intrepretation of the charts will have an error factor.

Actually, it's all beside the point. Within a reasonable range for cruising speeds, the data would suggest something around 125 nm as a very conservative cruising range plus or minus whatever factor to be more precise or less conservative or more conservative or whatever one might wish to apply.

Some might think using only 2 thirds of the tank (50 gallons) as a basis is too little - others might like more of a reserve. Matter of choice and the local conditions - in this case the availability of fuel. Frankly, it's obvious that the best cruising range is at idle but who wants to do that.

Anyway, I will be interested in seeing some hard data when someone can produce better info based on actual use of the boat. Meanwhile, I will plan legs of no longer than 125 nm and recognize that there may be conditions where that is too long or where that is not a problem.

Oh - and thanks Thataway for your comments on warming up a diesel. Pre-oiling is out of the question as is pre-warming but I agree with you that letting the engine idle is not the answer despite the advice you see fairly regularly on letting the engine warm up. Glad to have some confirmation on that.
 
Old dog, I suspect we all understood that you meant Nautical miles--not a problem. The pre-lube pumps are not all that expensive. Is it worth the cost? It is arguable. If you run the engine regularly, there will be more oil in the galleries than if you let the engine sit for a week. This is probably one of the reasons that commercial engines last so much longer than recreational engines do.

You are correct that real time usage is the most important. If you look at the "Boat Test.com" tests on the C Dories, their numbers are significantly better than real conditions. The usual reason is that the boats are light, (small amounts of fuel, water, gear and people) they are new, with no bottom paint and clean bottoms, as well as in calm conditions. For example the TC 255 gets 2.78 nautical miles a gallon at 17 knots. with a range of over 400 miles. In reality most of us are getting 2 to 2.4 nautical miles a gallon.

One of the factors not taken into account in the engine curves, is the prop slip. There will be more slip at the higher speeds, as well as more power (and fuel used) per each incrimental increase in speed. In my experience in some boats--an increase in boat speed of one knot is equal to doubling the fuel consumption!
 
Ok, so refraining from running the engine at a constant lower RPM range by periodically increasing the throttle per Bob's suggestion is really to manage carbon deposits. Correct?

Has anyone thought about additional fuel capacity? I know Mac brought along an extra 5 gal bottle on his Alaska trip. But what about something more permanent? Is there any room? If so, where?

Tim
 
thataway":175ycwox said:
Of course if you want to really have the "best", pre oiling is an excellent idea. This is a pressure pump which is turned on before the engine is started and fills the oil galleries so that there is oil at every point as the engine fires its first stroke. I have always started the engine, let it run until oil pressure was up in the engine and transmissions (some of my larger boats have had oil pressure guages on the transmissions) and then put the boat in gear.
Click to expand...
On my tractors and equipment with diesel engines, I leave the fuel shut-off, then crank the engine until it has oil pressure. Then start it. I do this especially in cold weather and it the engine has not been started for a while.

Don’t know if this is a possibility with the Yanmar engine, but if it is, that is a way to get oil into the top of the engine before starting.
________
Dave dlt.gif
 
You can do what Dave suggests, if your engine has a selenoid fuel shut off. I did this occasionally with my Cat's--hit the stop buttom and the start at the same time. Not sure how much oil pressure one gets with this--but it will get some oil up into the galleries if the engine has not been run for some time--and you have plenty of starting batteries.

For whatever reason this has not been real popular in the boat crowd--and it may well be fear that you can run down the batteries when starting the mains.
 
I have a question about fuel management relating to issues about storage, condensation, bacteria problems, etc.

Is it better to have one large tank or would a confuguration with a day trip tank and a larger one for cruising be advisable. The issue is that keeping a 150 gallon fuel tank full all the time, especially when you might only use 50 gallons on a day trip, requires that you carry 150 gallons of fuel, 1,200lbs, around with you all the time.

With two tanks you have to have a switching system, sending units, filters, and gages for both hense double the potential for mechanical problems.

With a partially full tank that is not used regularly, there is the potential for condensation, and other problems. Any thoughts?

Note: a 125 mile range for Alaska is not enough. For example, if you want to go from Wittier to Motnague Island to fish halibut, you will never get back with only 125 miles worth of fuel. Also it will take you 8 hours to get there and 8 hours to get back at R25 speeds.
 
I agree with dtol, that 200 to 250 miles is desirable for an Alaskian run from the WA area.

We have usually had several tanks. There are some who feel that it is not all that important to keep tanks full. I cannot keep my tanks full on the TC and no problems with that. I didn't keep my diesels tanks full.
http://www.yachtsurvey.com/myth_of_cond ... _tanks.htm
Is an article by David Pascoe on fuel tanks and condensation.

We have only had one boat with a day tank. A day tank is an excellent idea, too bad that more boats don't have them.

Fuel management requires several things--one is preservatives: Stabil or Pri G or D, plus Startron. The second is re-circulation and "polishing" We had a fuel pump and the polishing system in all of our diesel boats, even the racing sailboats with small diesels. The fuel pump can transfer fuel between tanks, it will allow rapid bleeding of the injectors and filters.
Some engines, like the 2 stroke GM diesels and the Ford Lehmans, recirculate the diesel thru the return lines. Some diesels do not recirculate a lot of fuel, and some are not run often. For these engines, it is advisable to run the polishing system regularly to remove algae,(which grow at the water fuel interphase), remove moisture and any impurities in the fuel.

I mentioned in another post that I got salt water in one of my fuel tanks. Having another equal size thank, allowed me to switch to that tank, then filter, remove the water and polish that fuel. Eventually I ran it into the other tank, and pulled the man hole on the tank, so I could get into the bottom and siphon off any debris and then clean the bottom with paper towels, to be sure I had the tank absolutely clean.
 
Don't know about the rest of Alaska, but you can easily do the Inside Passge from Seattle with the 75 gallon tank - depending on how you cruise. I won't list each stop (unless you want them), but we covered the follwoing distances between fuel stops:
129 miles
83 miles
75 miles
96 miles
97 miles
71 miles
80 miles
119 miles
187 miles (crusing at 6.5 knots, included Tracy Arm)
71 miles
128 miles
78 miles
80 miles
97 miles
114 miles
93 miles
78 miles
72 miles
94 miles
84 miles
Total fuel 873 gals, total distance ~ 2200 miles

Mac & Linda on Island Ranger
 
Thanks Mac. I'm sure I contributed to the concern previously but I wouldn't hesitate to make the trip with the R-25. When we did it a few years ago with a slightly larger boat, fuel was not a problem although it looks we did like you did - we refueled at every opportunity. We had 150 gallons of capacity in a boat that burned about twice as much fuel and ran on the top half of the tank almost always.

Some more information like yours and we'll be able to make a good estimate of fuel consumption.

The numbers are interesting.
 
Just had the engine serviced (350 hours) and Jerry adjusted the idle down to 600-650 rpm. I think it has been idling up around 800. Could be it is a little too slow - it rattles things about. But it sure does make a difference! I think there is a chance it will troll slow enough now - maybe not for pinks, but probably OK for Kings and for sure silvers. I'll try this afternoon....

Mac
 
Thanks for the numbers--I would be interested in your stops. Sounds like you cut it really close. 75 gallons at 2.5 miles a gallon (which your mileage figures to be) is 187.5 miles--I understand that you dropped the speed down to get better mileage.

What would concern me is the head winds, head seas and adverse currents. I prefer to have at least a 15% margin. The three trips we made to Alaska, we had 300 gallons in a vessel which made 6.5 miles a gallon...Thus we were not dependant on finding diesel at each stop.
 
Well...we tried trolling today and....

The good news -our crab traps had a good harvest - I'm boiling up the 8 crabs we collected today. And...with the idle down at 600 - 650, we can troll at 2.5 kts or so.... it sure is thumpy though. The speed was perfect for silvers - maybe a little quick for kings and way to fast for pinks. A trailing bucket worked pretty good...but we didn't catch any fish (except one shaker).

Mac
 
If you really want to troll for long times with these engines, I would suggest a trolling valve, if they are available for this transmission.
 
I already checked with Ranger Jeff - and no - the trolling valve isn't available. I'm probably going to go with a small kicker mounted on the swim step, but can't find a motor mount that will fit and not interfere with the dinghy when it is mounted on the weaver davits I already installed. I mounted the dinghy up tight so there is no gap between the swim step and the dinghy, so I would need to cut away the swim step to use the motor mounts (they all have a lip that hangs over the swim step) I've found so far and I just hate to cut things!

Mac
 
Somewhere I saw a swim step with a quick release mount. Not sure how it would fit on the Ranger 25--I'll see if I can remember/find where it was.
Basically involved with thru bolts and captive nuts on the underside of the swim platform. You would have to bolt it and off, but that is fairly quick with a socket set. Probably can be done with two captive bolts, and two removiable bolts.

I am not too surprised that there is no trolling valve. We had to bump the tranny in and out of gear on the Cal 46--a real pain!--finally ended up rolling out a little genoa just enough to give steerage way, but it limited the course one could take!

Agree that the outboard is the next best thing--sea anchors/drogues are too much of a hassel when trolling and offer some danger of fouling the gear in the prop.
 
There are a couple of other possible options to slow the speed for trolling. The cheapest option (which I see a lot of out here in the Puget sound) is to simply tie a 5 gallon bucket off of each midship cleat. It's a little redneck, but it does work. Similarly one can do the same with a drift sock or small sea anchor. I'd find any of the above to be a bit of a PITA but it does work.

What I'd suggest is trying to find a way to adapt a trolling plate to the transom. Most of these are designed to be bolted onto an outboard, but maybe you could find one that could somehow be adapted to work. Without a clear picture in my head of how far back the prop is from the end of the transom, it's hard to say if this would work.
 
Thanks for the ideas. I'd love to find the removable / quick release mounting bracket. That would be perfect. I've searched - and searched....

I tried dragging buckets - too big a pain - in the way.

I had a trolling brake on an earlier boat so I am familiar with 'em. The prop is pretty deep and the rudder is behind it, I can't picture how it would work.

Thanks again. I might try utilizing a spacer under the bracket I found so that it is sits higher and then I wouldn't have to hang it over the step. But I still like the removable idea the best!

Mac
 
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