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Fuel efficiency

Posted: May 12th, '08, 19:58
by wmachovina
Having done the overhaul of Sea Chele retaining the good but ultimately replaceable 454s. with diesels, and in light of the cost of diesel, I would like to start a link discussing which engines to get. In my case high speed is not an issue but I need to maintain speed (22-25 kts) in a following sea. My yard loves cummins,complaining about parts cost on yanmars. Steyrs are an option. How much hp do I need. 73 FBC. Thanks in advance, Bill

Posted: May 12th, '08, 20:30
by Tony Meola
Bill

I am putting 270 remans in my 31 FBC. 1975 model year. John Jackson has the same engines in I think a 65 FBC. I believe he usually get around 24 to 25 knot cruise and he has a hard top and is heavier than us. I would say a good 5000 lbs heavier.

The cummins dealer I am using says I should burn around 16 to 18 gals an hour and be somewhere around 25 knots on the cruise. I do not have a tower or hard top, just the standard bimini.

I think the steyr's that are available might get you around a 20 knot cruise. I would think about the same as the old 240 Yanmar. I don't know what the boat would do with the newer 260 Yanmar's. Maybe Bruce would have a better idea on that one.

The Cummins remans will also come in a bit cheaper than the Yanmars. You probably could get a pair of the 270's between 37 and 40,000 before transmissions. The Cummins gauges will also fit the dash so you can eliminate some glass work if you need to. When I priced the 315 Yanmars, they would have cost me about 50,000 without the dash work to fit their gauges. Big difference in pricing and something to think about.

I felt $10,000 would buy me a lot of diesel fuel or some new electronics.

Something to think about.

Good Luck.

Posted: May 12th, '08, 20:35
by In Memory of Vicroy
My view is a B31 needs 250-300 diesel hp a side to perform to its best. Anything over that is pretty much a waste. The Cummins are my favorite, I have the 6BTA 250s with no issues in 15 years and cruise at 24 kts with any load you can pile on her. The 210 Cummins are good too, just won't give you the speed you are looking for. The Yannies work well too, the 4 cyl. 240s run as good as my 250 Cummins, and the 6 cyl Yannies do real well, but some models had valve train issues that have mostly been resolved by Yanmar so they say (after a class action lawsuit).

The advantage to the 210/250/270 Cummins 6B engines is they use a fresh water cooled aftercooler (not the 210, no aftercooler) that is virtually maintaince free vs. the higher hp 6Bs that get some of the higher hp by using a raw water cooled aftercooler - cooler air means more hp, cooling with 70 degree raw water vs. 180 degrees on the fresh water side. The sea water cooled aftercoolers require a lot of attention to keep the cores from going to pot....I've had a lot of boats with a lot of engines over the years, and the Cummins 6Bs are the best by far.

UV

Posted: May 12th, '08, 21:05
by nic
We got the 315hp 6lpta Yanmars in 2006 and we are very happy with them....(max 32.7kn with 20x23 4-blades which is plenty+) they were old stock then but new out of the U.S. and available because they didn't pass the US EPA regs apparently...I have heard nothing but bad things about the new Yanmar/BMW models so I think you are heading for Cummins.

Nic

Posted: May 12th, '08, 22:09
by In Memory Walter K
There is a simplicity in the Cummins 6bt series that make them very user friendly. They seem to perform the same no matter what the load. Because the engine has so much use in trucks, many parts are available at truck supply places at lower costs. Most seem to cruise at 7-8 gph. I have a Sportsfisherman with 210's and cruise at about 22kts and get on average 1.5 mpg.
Given the cruise speed you'd like, the 250-270's are probably your best bet.
Good luck. Walter

Posted: May 13th, '08, 07:56
by Bruce
Oh God, not another Ford vs Chevy thread............

Posted: May 13th, '08, 17:23
by nic
and I don't know how much fuel we use except more than the re-seller said we would. Why do those guys all lie?

Bruce, you say that like it's a bad thing....?

Nic

Posted: May 13th, '08, 20:29
by wmachovina
geee I did'nt mean to start a ford chevy war, just tryin to pick a motor that takes advantage of the hull and uses it to its greatest efficiency Sorry

Posted: May 13th, '08, 20:36
by scot
Chevy.

Posted: May 13th, '08, 20:52
by Kevin
No way! Steyr!

Posted: May 13th, '08, 21:02
by Tony Meola
Bruce

I did not think my comments about Cummins would start a rocker stopper thread. Just trying to lay out some facts as I know them. Three years ago I said I was going to drop in the 315 Yanmars. Three years latter and what I have learned for me the Cummins became the engine of choice. Simple, bullet proof and will give a cruise 4 to 6 knots higher than I had with the big blocks and cut my fuel consumption.

After looking at the Yanmar, I felt the Cummins was easier maintence wise and wallet wise. So why not.

Besides, Ford always used to win the races back in the 60' when they were in the game.

Posted: May 13th, '08, 21:17
by In Memory Walter K
No need to apologize on this site. Dealer service, proximity and parts availability play a part in the decision, too. Walter

Posted: May 13th, '08, 21:32
by Tony Meola
Walter

Your right. Parts play a big role. Plus a good mechanic. The yard that I keep my boat in used to do a lot of Yanmar repowers. After the owner passed on and his wife took over that did not happen anymore. When I spoke with Mack Boring and told them what I wanted to do, they said they were sure the guys left in the yard could easily do the work but they warned me that if I took it to another distributor to pay close attention since they had an issue with a repower with him.

The Cummins dealer has a great reputation and that also helped me make my decision. So you are right.

As one of my friends said, John will look you straight in the eye and tell you the real deal. Thats all I wanted to hear.

Posted: May 14th, '08, 21:49
by nic
Filled her up yesterday....US$6.75 per US gallon...and that's from the fuel barge, ie a discount! Interesting times.

Nic

Posted: May 14th, '08, 21:56
by CaptPatrick
Interesting times.
Seems like that's one of the ancient Chinese curses: "May you be born of interesting times."