DD engines

[Trojan]

Will the 8-71N last as long as the 6-71N In comparable boats? Boats like the 43 verses the 53? Will you get the same amount of hours with each? What type of cruise and speed can I expect with a 53 with 8-71N. I ask this because I have a lead on a early 70/53MY with 8-71Ns. I want to get a live aboard, but I don't want to give up a perfect 43DC either. I don't want to get something that is going to disappoint me. I'm not after speed. I just want something I can live on full time and be able to go different places with the admiral when I want to without being crowded. I'm not ready to buy at this moment espessialy with the market falling. But I could be if the price got right. So I want to be prepared.


BILL

 

[SKYCHENEY]

I think typically the straight 6 will last a little longer than the v-8, all other things being equal. But, both naturally aspirated engines should give great service life if well maintained. I think your cruise will be much less on the 53 with n's than the 43 with n's. Our 43DC would cruise 15 knots but a 53 with n's will not plane. Realistically, it's a 10 knot boat or push a wall of water at 13 knots and burn twice as much fuel especially for a live-aboard with all of your extra "stuff".

 

[Boss Lady]

The market is right to buy right now. Nothing is selling. With insurance increases in certain parts of the country, and fuel prices have been high. It is a buyers market. I have seen several nice looking 53s well under $200K, which is a give-away price in my opinion. This was probably Hatteras' most popular model and the 53C is one of my favorites. I almost bought one, but could not find a real project boat, so I bought a 48 YF. The biggest thing that impacted the demand for the 53s was the demand for more speed, which the 53 cannot deliver, it had a real long life in the model lineup for both the MY and the convertible. They did not deliver modern speeds even with the most powerful engines installed in the last of the breed. Hatteras moved on to other models with more power and speed to meet the demands of the market. If you can live with a 10 knot boat, there are none finer. Ample room, and quality. You will need about 1500 hp or more to make one cruise above 20 knots, they are heavy boats. Now that fuel is coming back down towards $2.00 a gallon I think that the market will start going back up around spring, and most of the panic sales will be gone. You have to remember that most of the people who own older boats are not the super wealthy. With all the tax hikes and insurance increases even the well to do are feeling the pinch. Those who were stretching things a bit don't have the extra and we are seeing a lot of boats at distressed prices. Buy low/sell high.

 

[Trojan]

Was there a lighter version of the 53 made in later years? Will the ti's plane? Is the fuel rate the same on the 53 as on the 43 at 10 knots cruise?

BILL

 

[yachtsmanbill]

Hey TB ! FYI-- On our trip from Mobile to Iuka, Miss. on average, we would run 100 miles per day,at 1500 rpm @ 11 mph and burn about 100-130 gallons of fuel. I think some of the variables were wind, current and waiting for a few locks. GPH is such an erroneous figure that I prefer to calculate MPGs.
This is on the 58 w/ cockpit extension and 12-71Ns w/2:1s.
New 50A 220 shore cord solved a myriad of problems !! Everything is up and running. ws

 

[jim rosenthal]

I don't think there's any difference, practically speaking, between the life of 8-71s and 6-71s, both naturals. Either engine will last a very long time if properly maintained; they ae pretty low-stress units. Yes, they are noisy, and they leak oil, and are not especially economical, but for what it would cost to replace them you can buy a lot of diesel fuel. The noise you can learn to live with, the oil leaking can be at least partly resolved by paying attention to the various drains and rerouting crankcase pressure using CCVs instead of AirSeps.

The 43 MY will be faster; they weigh less and the power/weight ratio is better. If you don't mind going slow, on a 53 with N series Detroits you'll be able to go slow for a long time. I think the 53s with 92 series engines were able to go somewhat faster, but none of these boats are speedy and if you want to get places fast you should get a different boat. Even cramming bigger engines in (totally impractical) wouldn't really get you much of a performance dividend. You'd pay dearly for your knots. In fuel and upkeep, if you ask me.

53MYs offer nice interior accommodations, a classic look, good build quality, a good ride and weather capabilities. I think they are a narrow boat by modern standards and this and the decor are probably what date them more than anything else, according to my broker friends. They are complex boats with a lot of ships' systems and, compared to boats built now, probably too many electrical systems, but at the time they were made, they were very much up to date and they were strongly put together. If you can find a nice one which has had its maintenance and upgrades, is solid and looks the way you want, there is no reason not to buy it. Live within its capabilities and you'll be a very happy boater for a long time.

 

[MikeP]

Yes a 53MY w/ 8V71TIs will plane. Top speed on ours fully loaded with all our stuff is in the mid 17K range on calm water. Just before winterizing she managed 17.8K with 3/4 fuel and full water. However, we mostly run at around 10K with a fuel burn of around 10-11 GPH. At 17+ the burn is around 45GPH. I was never good at math but...

All of Jim's comments are right-on re the boat in general.

 

[Genesis]

IMHO the 53s, whether MYs or Cs, are "underpowered" by today's standards.

Then again so are the 45Cs! 18kts doesn't cut it for cruise in the ideas of most people these days, and that's a big part of what makes these boats affordable (to both buy AND operate) compared to today's iron.

If you want to make 'em go fast, you can. It just requires gobs of money both originally (for the engines) and on a continuing basis (for the fuel.)

IMHO, its a mistake to do that though, especially for the MYs. I understand the desire with the convertables and those folks who want to go fish (and get there and back fast) but I fail to understand the argument in a motor yacht.

IMHO there is real value in a "tank" of a boat, especially when the seas kick up and things get nasty. And while some people would argue that the electrical systems are "too complex", I put forth the other side of that argument - flexability is always good, especially if you actually intend to travel with your boat.

 

[Trojan]

Very good info. It is kind of on the line of what I was thinking from listing to the past comments. I think I will pursue this a little more. Thanks guys. The boat is a fresh water boat. So I get a break there. But I don't think the guy is ready to deal yet. But it won't hurt to check it out. I like the MY version the best. The trouble I have here is I must negotiate not only with the boat owner, but with my admiral. She has this idea that we should purchase a new home first. I say the boat IS the new home. She finds something wrong with this picture. Go figure. I need a good plan.

BILL

 

[Will]

There was a problem with water jackets in earlier 8-71s. I think it had to do with them not extending far enough down the cylinder bore. This caused piston seizure. I don't know if it was corrected by the early '70s or not.
Will

 

[Boss Lady]

Just remember you can't cruise in a house! there is so much to do if you have a boat, boats make memories. A new house is just a place to put you stuff and watch tv! LOL

 

[REBrueckner]

Engine lives and NMPG should be about the same. You can compare HP/CUBE and see both are about 0.6 or 0.7, way under the threshold of concern at 1 HP/cube.

What's far more important is what speed they are normally cruised: 2100 will wear a 71 a lot faster than expected; at 1600 RPM one might last forever.

Past threads suggest that 43 and 53 Hatts at displacement speeds, say 8 to 10 knots, have about the same efficiency ..about 1NMPG. Apparently the theoretically greater efficiency of a longer (LWL) boat is offset by greater weight and beam.

Another thread, "Turbo vs NA efficiency" may also be of interest.

Remember fresh water boats are more prone to underwater mositure absorption (blisters) and possible delamination...