repower for 1995 39 express

[nor'easter]

I am considering a repower for my 1995 39 Hatt, and I wanted to see if anyone has experience with a 38 or 39 repower. I am running DDEC 6V92s and am considering an update to Cummins QSM 11, CAT 12, Volvo D9, or the 12L Yanmar. All are considerably smaller (from diagrams anyway) than my 6V92s, and lighter. Also, all have excellent service networks here in San Diego. I would prefer to increase hp and displacement a bit not so much for speed, but to load the engines less and get better longevity. I love the boat and want to spend years with it! Any thoughts/suggestions/experience?
Thanks
Paul

 

[Captcoop]

I repowered my 45C with the QSM11 Cummins and have been very pleased. The problem that I had was engine room. The Cat was longer than the Cummins and needed the compact version to fit the space. Basicly they move the heat exchanger to a remote location that added to the instillation cost. I think you would be happy with either choice of the two. I only priced the Volvo and didn't go any further with that option. Good Luck

 

[garyd]

Why not rebuild the 6v92's. I would take them out in one piece rebuild them and put back in one piece.

If not I would be interested in some of your ddec parts to make a second station on my 41 that has ddec's.

have fun boating garyd

 

[nor'easter]

I have considered a rebuild on the 6V92s, but there are a few reasons that I am leaning towards a repower. The express lay out makes this a very loud boat with no salon to buffer the DD's growl, and newer technology is smaller, lighter, and more fuel efficient. With a replacement value at around 750000 (Cabo 40....if a Cabo can really replace my boat in open water), I am considering a refit to include updating multiple systems/paint/and marlin tower. I know that I will never recover the cost of this work, but I love this boat and it is perfect for running/fishing shorthanded or alone. I likely won't start until 2006, but we can talk about the DDEC parts if you are interested.
Thanks
Paul

 

[Genesis]

Are you looking to pick up speed, or just get a quieter and more social ride? What horsepower are the DDECs set up for?

 

[nor'easter]

My 6V92s are set up for 565 hp with 2.55:1 gears and 32x47.5x5 blade props and I fast cruise rarely at 24-25K, mainly at 22K at 1850 rpm. I want to maintain or slightly increase cruise speed, but also add a marlin tower. The boat currently has a soft top only. I also would like to go with a larger displacement engine for longevity concerns of working a 8-9L engine hard for 550-650 hp.

 

[Genesis]

My 6V92s are set up for 565 hp with 2.55:1 gears and 32x47.5x5 blade props and I fast cruise rarely at 24-25K, mainly at 22K at 1850 rpm. I want to maintain or slightly increase cruise speed, but also add a marlin tower. The boat currently has a soft top only. I also would like to go with a larger displacement engine for longevity concerns of working a 8-9L engine hard for 550-650 hp.

Yep.

The marlin tower will cost you at least a half-knot, perhaps a bit more.

One thing to be aware of is service access - it doesn't do you any good to put big engines in there if you can't get around them to work, and they get neglected as a consequence.

 

[nor'easter]

Access is a big concern of mine as well. Based on the size dimensions published on my DDs, it appears even the 11 and 12 liter engines from Cummins and Yanmar will fit, with even a little bit to spare, based on the diagrams/dimensions on the web sites for those engines. The 12L Yanmar looks like it is quite a bit smaller, and could really improve my access, especially on the centerline.
I have not read any bad press on the Yanmar or Cummins, and they both seem to have their acts together with respect to the 2006 Tier 2 EPA requirements. Thoughts?
Paul

 

[Captcoop]

The Cummins in my 45C are quite a bit smaller than the 6V92's in the boat. I now have approx. 1 ft. from the floor to the top of the engines and about 8 in more room in the front. When they installed the engines they sit lower into the stringers and back to the stern about 4in based on the amount that they cut from the shafts. I can't say it is a pleasure to work on the back side but it is easier to access. Good Luck

 

[nor'easter]

Thanks Captcoop, that is good news. The worst spot for access to my current mains is on the centerline. I can reach there easily, but I am a big guy and there is little room between to move and get to the forward engine room bulhead. How are the QSMs performing? Any reliability issues?
Paul

 

[Captcoop]

I have had no problems to date. The engines have about 100 hrs as of this weekend. If you are looking for information on the QSM 11 check out the Cummins web site for HP @ rpm/fuel burn weight and dimensions. Good Luck