466 diesel burn rate

[rlamb]

We are buying a 2004 466 with the 75 HP Yanmar. I have to run it up the CA coast and wondered what is the best cruise RPM and expected speed and hourly burn rate others have experienced. I know all will vary some but wanted others experience to factor in my plans
Thx
Roger

 

[Mikem]

I have a 2003 466 with that engine. The fuel curves are pretty accurate. Stay above 2000 rpm so the turbo doesn't load up. If I remember correctly at 2100 rpm it is about 1.3 gph at a little over 6.5 kts SOG. Now, at WOT the consumption at 3500 rpm jumps to 3.6 gph. Flat water, no wind I do 8.8kts at 3500 rpm. The experts say to run the engine at 75% to 80% of WOT. One thing to be wary of is the termination of your fuel pick up tube. In other words even though the book says 100 gallons what is your usable fuel? I had a friend with a 460 that ran out of fuel but still had 40 gallons in the tank because of the incorrect length of his pick up tube.

 

[rlamb]

Fuel burn

Great info - thAnk you!

 

[Mikem]

Re: Fuel burn

4JH2-HTE76 4.193.42 2.90 2.351.98 1.281.02
ModelHP3800360034003300320031003000280027002600250024002200

 

[Mikem]

Re: Fuel burn

ModelHP38003600340033003200310030002800270026002500240022001GM109 .61.54 .43 .36.3 .2.152GM2018 1.221.07 .88 .73.62 .4.283GM3027 1.811.59 1.29 1.09.89 .56.43JH238 2.281.82 1.50 1.261.03 .72.523JH2-TE47 2.712.19 1.84 1.51.25 .81.644JH251 2.812.3 1.93 1.641.37 .95.774JH2-TE63 3.532.93 2.46 2.061.69 1.13.924JH2-HTE76 4.193.42 2.90 2.351.98 1.281.02

 

[Bowedtoothdoc]

I am pretty sure we have the same engine and fuel capacity. You may want to have a look at this thread to get some additional information.
http://forums.hunter.sailboatowners.com/showthread.php?t=155124
Also as mentioned above that 75% to 80% max rpm is the recommended cruising rpm. There according to the chart at 2800 rpm you are looking at around 2 gallons per hour. If you back down to 2200 rpm you are almost half of that at just barely over 1 gallon per hour. My question, Is it bad for the engine to run for hours on end at 2200 rpm? This could save allot of fuel!

 

[kemahflash]

Running your jh3te

Cruising at 2000rpm is ok if you remember to run it up to 3500 rpm for a period

 

[Mikem]

One may also just clear the engine by putting it in neutral and running the throttle up and back several times.

 

[patrick17440]

I have made the run up the Baja coast twice from Cabo San Lucas to San Diego
which is about 800 miles, also known as the Baha Bash. Alot of wind, current and head
seas on your nose. My H460 with the 4jh2hte 75hp turbo at 2200rpms ran 6-6.5 depending
on sea conditions burning about 1gal/hr. At 2800rpms, 7.5-8.5 burning about 2gal/hr.
Boat has 3 blade max prop. When you run up the coast, fill one water tank. The boat
has 5 tanks and you really don't want to carry an additional 1600lbs of weight with
200 gals of water

 

[Ivan]

To Mikem:

It is not correct to say "clear the engine by opening and closing the throttle several times in neutral". The Yanmar manuals and all advisors are clear and consistent that you must run the engine at near to wide-open throttle for 1/2 to 1 hour periodically, which is the ONLY way to prevent the cylinders from glazing, which happens when the engine is lightly loaded for long periods. This happens to all diesel engines. If you don't do that you will find that de-glazing the cylinders is very expensive, and an easy and completely preventable condition.

 

[Don Lucas]

It is not correct to say "clear the engine by opening and closing the throttle several times in neutral". The Yanmar manuals and all advisors are clear and consistent that you must run the engine at near to wide-open throttle for 1/2 to 1 hour periodically, which is the ONLY way to prevent the cylinders from glazing, which happens when the engine is lightly loaded for long periods. This happens to all diesel engines. If you don't do that you will find that de-glazing the cylinders is very expensive, and an easy and completely preventable condition.

I don't think it is clear at all. I believe my manual says to throttle it fully and then back it back down and repeat for 3 times.

 

[Alan Gomes]

I don't think it is clear at all. I believe my manual says to throttle it fully and then back it back down and repeat for 3 times.

Here are some quotes on the stopping procedure from three different Yanmar manuals. As you'll see, the suggestions are similar though not identical in all cases.

From the Yanmar GM/HM Workshop Manual (p. 44): "Note the following items when stopping the engine. 1. Place the transmission in neutral, then allow the engine to idle for five minutes before stopping the engine. 2. Momentarily raise engine speed to blow out any residue in the cylinders, then pull the engine stop knob or lever."

From the Yanmar Service Manual (1GM, 2GM, 3GM) (p. 11-11): "1. Before stopping, put the clutch in NEUTRAL and run the engine at approximately 1,000 rpm for about 5 minutes. 2. Before stopping, temporarily raise the speed to the rated speed to blow out residue in the cylinders. Then stop the engine by pulling the engine stop lever to cut the fuel."

From the Yanmar GM Series Operation Manual (p. 38): "1. Reduce the engine speed to low idle and put the shift control lever in NEUTRAL. 2. Accelerate from low speed to high speed and repeat five times. This will clean out the carbon from the cylinders and the fuel injection nozzles. 3. Allow the engine to run at low speed (approximately 1000 rpm) without load for five minutes. 4. With the key in the ON position, pull and hold the engine stop know until the engine has come to a complete stop. After the engine has stopped, turn the key switch to OFF."

Hope this helps.

 

[Don Lucas]

didn't help me, I didn't need any help

 

[Alan Gomes]

didn't help me, I didn't need any help

Didn't say you did! I think it rather supports Mikem's original point, with which you agree.