53MY Owners: What's your cruise & burn?

[stormchaser]

I'm trying to figure out what RPM is appropriate for cruise? I sorta figure there are 2 cruise speeds...most fuel efficient (which would be somewhere around 9 knots?) and the manufactuerers "suggested" cruise rpm? Ive got 871TIs.

So, what RPM do you cruise at, what engines do you have, and what's your burn rate?

 

[SKYCHENEY]

I have 6v92's but with the same gear ratio and props as you would have so this info should be about the same.

1300rpm 9.5kts 12gph
1450rpm 10.5kts 18gph
2050rpm 15.5kts 36gph
2300rpm 17.2kts

 

[stormchaser]

How do you get 15+ knots at 2,000rpm? Sounds like you are on plane at 2,000? Im not and just pushing a LOT of water and going about 12knots. Do you open her up wide to get her up on plane than back off? How low acn you drop the RPMs and stay on plane?

 

[Pascal]

at slower speed, there is a huge difference in fuel burn with very small sped change. Hull speed is 9.2 on the 53, try going 10.5 and you will probably burn 30% more fuel. Slow down 1/2 knot and save even more, as long as your TIs stay warm...

sometimes it really helps to throttle up to 2100 or 2200 to get the boat up and then back to 2000. it dep[ends on the boat, its weight, props and critically bottom / running gear condition, you'd be amazed to see what just a handful of barnacles on a prop will do!

 

[Sparky1]

I'm trying to figure out what RPM is appropriate for cruise? I sorta figure there are 2 cruise speeds...most fuel efficient (which would be somewhere around 9 knots?) and the manufactuerers "suggested" cruise rpm? Ive got 871TIs.

So, what RPM do you cruise at, what engines do you have, and what's your burn rate?

Dave,

I've posted this on more than one occasion, and it's always good for discussion. Maybe it will help. It's a Boating magazine test you can find on the brochures archive on this site.

http://www.hatterasowners.com/Brochures/53ED/53EDA-0083.htm

 

[TopHattandTails]

Dave,
I've got a 1980, MY Classic, running 8V71 TI's, Allison's. I've got a Tank Tender to monitor fuel levels, and do the calculation based on a top off of the fuel tanks. To the best of my calculations, I burn ~36 gph (both engines and genny running) at 1850 rpm (that includes time puttzin' around the docks and such at idle). I've got a little water soaked into the keel (that a few heated indoor winter storages might tackle for me), but the max engine rpm I am achieving right now is 2,200. I might take a little cup out of the props to see if I can't get her to spin more in the 2,300 - 2,350 range.
The real test is for you to run at WOT and see what your max rpm's are. I would then say your "cruise" should be 90% of that. Then go top off your tanks, take a real long cruise, then top off again. Try to minimize your idle time - the longer the cruise the better. This will get you pretty close to what your burn rate is. I'm sure there are easier methods - but what the heck - run the boat!

 

[SKYCHENEY]

How do you get 15+ knots at 2,000rpm? Sounds like you are on plane at 2,000? Im not and just pushing a LOT of water and going about 12knots. Do you open her up wide to get her up on plane than back off? How low acn you drop the RPMs and stay on plane?

With full tanks it gets a little harder to stay on plane. Once the first 200gals are off, she runs really well at 2050. Remember, these boats were first designed with about 500gals of tankage and were later increased to 700gal. I do also store in heated storage for 6 months out of each year so my hull is probably quite dry.

I do usually go up to WOT and then back off. I ended up taking my props down from 28x31 to 28x28.5 to be able to acheive 2350rpm at WOT loaded. Even though it runs nice at 15-16kts, I still usually cruise at 1300rpm. It is quieter, uses less fuel, and with the stabilizers is still very comfortable in all but the worst sea states.

As was stated, you should experiment a little. If you top off the tanks before each cruise, you will get a good idea of what she burns. Just don't make the mistake of trying to get that exta knot above hull speed. If you are going to do that, you might as well put her up on plane.

 

[MikeP]

Our 53 will not get up on plane unless we go to WOT. It will fall off plane at 1900-2000 RPM. WOT produces 17.8K with a clean bottom;shafts/props though neither eng will spin much over 2200 RPM.

DO NOT make the mistake I did when we bought the boat 5 years ago and the next day sailed it down the Deleware river, through Cape May and up the coast to Long Island. We cruised at 1700 RPM and spent the entire trip pushing a HUGE wall of water and burning an incredible amount of fuel. I later found, thanks to folks here, that I could not have picked a WORSE rpm to operate at. So either run it around hull speed or on plane.

Normally we cruise at around 9.5K but I must admit the boat is much more solid-feeling and exhibits considerably less roll on plane. That shouldn´t be a surprise since it was designed to do that, NOT to be a displacement cruiser.

 

[ThirdHatt]

I have to push the throttles to full before my boat gets on plane as well (8V71ti's/58YF). They spin about 2300rpm for a bit until the bow stops rising and begins to drop a bit. Then I put the trim tabs down to help level the boat and stay on plane as I throttle back to ~1950-2000rpm depending on load, etc. 1900rpm or less and she'll fall back in the hole even with full tabs.

That article on the 53ED is really great for a reference of what these boats did when brand new. The only caveat to keep in mind is that a brand new boat with brand new engines and zero owner furnishings or provisions on board is going to perform and respond differently than once these boats are older and have all the owner's stuff and cruising provisions aboard. This is why you must factor in actual experiences by real cruising boats like the ones posted above. These reports should give you a more accurate representation (on average) of what your boat should do today.