Repower

stevewy · Post by **stevewy** » Tue Jul 20, 2010 3:45 pm

I have a 78 FBC and am thinking of re-powering over the winter. The first step is to install a new gas tank (I still have the fiberglass tank ---- although no problems). I'm looking at going with fuel injected 502s, 425 HP. I'm interested in any experience or advice others may have. Currently I have 454's. What are your thoughts on going with the 502? Transmission? Shaft length? Prop's? Anything I'm not thinking of?

Mike_Lenz · Post by **Mike_Lenz** » Tue Jul 20, 2010 4:30 pm

I have 8.1 Crusades in my B35 and I feel they have all the power I need. My boat will plain at 3,000 RPM at 3,200 RPM I'm running between 20 - 23 MPH depend on conditions and reading 26-28GPH on my Flow-scan after she is timed out. I have had them in since 2005 and have had zero problems. I did replace the fuel tank when the engines went in just to be safe regarding Ethanol issues. I fish 2-5 miles offshore and most of the time I'm trolling on one engine burning about 1 1/2 GPH. I didn't feel I would get the payback from diesels the way I use my boat. My cost was less than $40,000.00 which included: 8.1 Crusades Captain's choice 496 HP Fuel Injected engines and transmissions. New 4 bladed props Dripless shafts Upper and Lower helm gauges every gauge Stainless fuel lines And installation. The fuel tank was extra. Good luck with your choice, Mike.

Buy2ls · Post by **Buy2ls** » Tue Jul 20, 2010 5:37 pm

Have an 1986 33 SF with 2005 8.1 Mercruiser Horizon S 370 HP. The Ideal cruise is 3400rpm and that gives me 22.5-23.5 Knots at 30-33 gph depending on the sea conditions and currents. I would say that 40K is an accurate figure. However I think you can get factory reman Cummins 330s for about 16K more total. They give about the same speed but burn 20gph. I would say if want a canyon runner go with the diesels, they give you alot more range 14 hrs at cruise vs about 9hrs. FWIW

Post by **dougl33** » Tue Jul 20, 2010 6:50 pm

The Cummins remans will be around $20K a piece with gears. That's $40K just for the engines and gears. You won't have to change the fuel tank, but there will be other things that need to be done.

Hattitude · Post by **Hattitude** » Mon Jul 26, 2010 3:03 am

Just out of curiosity, what kind of performance were you getting prior to your repowers? I am approaching the repower issue on my 32' Hatteras which is similar in weight and performance. Mike "Hattitude"

franklyprice · Post by **franklyprice** » Mon Jul 26, 2010 4:14 am

With gas engines I was topping out at 26 knots or so, cruise was usually 17 or 18 knots at 24 GPH. 19 knots would be a little more fun at 30 GPH. In hind sight, pretty pathetic really.

IRGuy · Post by **IRGuy** » Mon Jul 26, 2010 5:18 am

Doug... The last price I heard for Cummins Reman 6Bs (375 HP) with gears was about $24K, 330 HP were only about $400 less.

Post by **dougl33** » Mon Jul 26, 2010 6:35 am

quote:Originally posted by franklyprice With gas engines I was topping out at 26 knots or so, cruise was usually 17 or 18 knots at 24 GPH. 19 knots would be a little more fun at 30 GPH. Ditto.

Hattitude · Post by **Hattitude** » Mon Jul 26, 2010 8:03 am

Wow. It sounds like an increase of about 6 knots w/ the new 8.1's. I curently get about 16 to 17 at 3200 rpms depending on load and bottom. I would be thrilled at 19 to 20 knots. I'm getting preliminary prices of 28k for a pair of the new 8.2's. I am waiting for the Cummins estimate. At 125 hours a year of cruising, I don't know if the diesels are worth the investment. I've had the boat for 12 years and have no desire to step up. I appreciate all your input. I cruise this site often and find it very helpful. You guys are a great source information. Thanks, Mike

Drop Shot · Post by **Drop Shot** » Thu Jul 29, 2010 10:32 am

I have 8.1 H.O. , 425 H.P. Crusaders with velvet drives and 3 plade props in my 1986 Bertram. Cruise is 22knots @ 3200 RPM. Tops out at 31 knots with a clean bottom & gear. Fuel consumption is pretty good at 26-28 gph. I am pleased with both the performance and fuel consumption. I did install a new fuel tank, SS fuel lines, Dual paralled Racor 10 micron pre filters/water seperators, and a 2 micron final filter for each engine. Fuel injection demands clean fuel. All in all, a pretty good setup. Cost - $40,000.

lwrenn · Post by **lwrenn** » Thu Jul 29, 2010 2:17 pm

Your a little low on the cummins engines with gears are more like 22000 to 25000 per engine for recons. Go diesel and you will be much happier in the long run!

Hattitude · Post by **Hattitude** » Tue Aug 17, 2010 1:34 pm

As far as the gas 8.1's , are most people repowering w/ the 370 hp's or the 425 hp's "captain's choice" ? There is a difference in price. Is there a large difference in performance and is it worth it? We are looking at a winter repower and will be selling a pair of 1993 454's with 1300 hours. Thanks, Hattitude

lobsta1 · Post by **lobsta1** » Tue Aug 17, 2010 2:05 pm

Go with the 370's. The 425's make the extra hp in the upper rpms. Al

captgene · Post by **captgene** » Wed Aug 18, 2010 5:11 am

I went with the Crusader 8.1 385 hp. The 425 is a waste of $ and fuel. Cruise is 22 kt. WOT is 31 kt. At 22 kts I burn 28-30gph depending on the sea conditions. I did mine in Apr. 2007 and the cost was about $40K. I put in new shafts, awlgripped the engine room, and a bunch or other stuff like sync-n-cruise control etc. Gene Dugan Boca Raton, Fl. "Nauti Marie" 1989 33 FBC 2007 8.1 Crusaders

ericmyers · Post by **ericmyers** » Wed Aug 25, 2010 10:19 am

Hi all, I have been looking at 28-33' Bertrams and have a 28' Flybridge that would need motors rebuilt or replaced. any recommendations for the smaller 28' boat, either: keeping the 228 Mercruisers or repowering w/diesels and, if so, what size? thanks - eric