28 Knot Cruise

billb · Post by **billb** » Wed Apr 27, 2005 6:58 am

Question for the group....How much horsepower would it take to cruise at 28 or so knots with a 33???and what brand of engines would the majority chose??? Bill

franklyprice · Post by **franklyprice** » Wed Apr 27, 2005 7:11 am

370 cummins or 440 yanmars Frank Price

Rick · Post by **Rick** » Wed Apr 27, 2005 7:29 am

Bill, You've got to go with Frank on that. My Merc's are 310 each at the prop and I cruise at 20 knots. I could push it a little higher but not much. The 440 Yanmars if you want to be sure.

Post by **dougl33** » Wed Apr 27, 2005 7:43 am

I'll bet you'll need more than 350 horsepower from diesels. As was previously stated, maybe the Cummins 370's and most probably the 440hp yannies. The real question should be how often would you be able to cruise at that speed. More than likely you'd only be able to do that 30-40% of the time. These are, after all, 33 foot boats and not 60+ foot battlewagons. Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA

franklyprice · Post by **franklyprice** » Wed Apr 27, 2005 8:01 am

My question is, at what point do you start to push the bow down from the stern lifting ,caused by the propshaft angle.These things were made to cruise a little over 20 knots and top out about 30, if you're lucky. The fact that they plane off at about 20 knots would tell you that they're designed for some speed but at some point you've got that shaft angle to contend with. My guess is that at speeds much over 30 knots you'd start to see real handling issues , like bow steering and chine walking, though it would be fun to try to see how fast one would go , on someone elses nickel of course. Doug? Let's make yours into a hot rod, what do you think? Frank Price

Post by **dougl33** » Wed Apr 27, 2005 8:13 am

Not me. I'm too busy living vicariously through Tim right now. He was kind enough to be our test subject for the 8.1's. Who'll volunteer to drop in the 440hp Yannies? My pockets certainly aren't deep enough for that (over $30K per engine!!). Also, as I've stated before, once you start talking about $60K-$70K I'd sell the boat and get something that already has diesels (i.e. 37 Bert or 36 B'Fin). Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA

billb · Post by **billb** » Wed Apr 27, 2005 8:24 am

Yes, I agree not much time you could run 28 knots offshore, but man, sometimes when you're 70 miles offshore, like we do here in Texas, it sure would be nice to run say an easy 26, 27 knots coming in....what a dream....what about 420 hp 3126 Cats???anyone like those???or 375 hp 3208's????..I do love the 3208's but just a little slow....20 knots cruise and 25 WOT....but very dependable so far.... Bill

franklyprice · Post by **franklyprice** » Wed Apr 27, 2005 8:36 am

I don't think the 3126's would fit and from what I hear the 375hp 3208's need enough big add-ons like the intercooler, that you may have a problem with that fitting also. After hearing of sean's engine access problems , I think I'd stick with an inline 6, those 3208's do look like a really tight fit. Frank Price

Post by **dougl33** » Wed Apr 27, 2005 8:44 am

I guess this answers the question about the 28 knot cruise and the 3126's. http://www.yachtworld.com/core/listing/ ... =1387&url= If this boat could be had for $145K I think it would be a good deal. Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA

billb · Post by **billb** » Wed Apr 27, 2005 8:46 am

Frank: I think Sean's boat is a new model with tight access to the motors, mine is a 1983 sportfish so the motor are out in the open, except for my tackle centers, which are mounted over the engine boxes.... will the 370 yannies fit???but I heard Yanmars are so much higher... Bill

photo finish · Post by **photo finish** » Wed Apr 27, 2005 10:21 am

doug, i bet those numbers on that boat are mph not knots i looked at a 41 egg down the street that has 450hp 3208s i did not know the 3208s came that high.... once i load my crusaders to 4400 and they are broken in and i strip my bottom i bet i will be at 33knots crusader also told me today my cruise should be around 3600rpm so with some tweaking i should cruise at 24 knots. Tim Stamm Photo Finish 1981 33' Bertram FBC

billb · Post by **billb** » Wed Apr 27, 2005 11:04 am

Tim: so your'r getting 31 KNOTS with a dirty bottom???? thats fast! Bill

Post by **dougl33** » Wed Apr 27, 2005 11:21 am

Maybe not. There are guys on this site who are cruising at 27 knots with the 370 cummins. Its not inconceivable that 420hp could do 30 knots. At the very least, now we know that the 3126's will fit. Anyone have any idea what the 3126's way? Any updates on the new props? Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA

billb · Post by **billb** » Wed Apr 27, 2005 11:27 am

Doug: they are Caterpillar, come in 300,350,385,420,and I think 450... but the 450 are the electronic pumps, so I have heard they are little troublesome.....they put those in the trucks we sell, but they are only 210 horse, what a shame.... Bill

Post by **dougl33** » Wed Apr 27, 2005 11:35 am

Sorry I should have said does anyone know what the 3126's weigh? I know their Cats, but I didn't know how much more or less they weighed than the 3208's. Regards, Doug L. 1986 33 Bertram FBC Queen Elizabeth Marblehead, MA