Planning a repower

[captcrunch]

I think I have a set of motors lined up for my 1988 38c this winter to upgrade over the 671 Detroit’s. A repower is a good opportunity to clean up old wiring, replace items that are difficult to get to such as battery charger and a/c condensing units while engines are out, Any suggestions of things I should be planning to do or do while the engines are out.

 

[madhatter1]

A lot more will become apparent once the old engines are out. While we’re at it kind of thing. All good and even with extra costs there will be no regrets. We pulled the engines out of our 34 just to do a lot of other clean up, maintenance, and upgrades.

 

[Captain Ralph]

Sound absorbing mat. New engine strainers, New Racor filter system. New fuel lines and management valves. Priming and polishing fuel pumps. New AC hoses. Blowers. Mufflers. Lighting. Real H V Bilge pumps. Sumps for grey water and AC condensate. New battery boxes. New battery cables. Improved engine trays.
Battery management for house, thruster, inverter and electronics. New gen-set(s). Stabilizer install.
Then, Fire bottles. Auto fire shut down on all equipment. High gloss paint.

I'm just getting started spending your money,, any left for the new engines??

 

[captcrunch]

Captain Ralph, a very through list. Improving in the battery system in my 38 is something I’d like as gen starts off starboard engine battery now and would prefer separate starting battery. Updating halon system also a no brainer. If only I had room and money for a seakeeper….

 

[Pascal]

I think the most important things are what directly affects the engines. This is what I did when I repowered my 53

Battery system: dedicated start bank for each engine and gen isolated from house bank. New charger, relocated if necessary. I installed new Promariners outside of the ER to keep them out of the heat. New battery cables and battery switch as well

Fuel system: new hoses and racors, unless the existing racors are in really good shape. Priming pumps too

Shaft and wheels: pull them and have them checked. On the 53 with 20’ long shafts I went to single piece shafts. New cutlass bearings and dripless seals

Check the exhaust system. Different engines mean new exhaust risers, but check the hoses. Mines were in really bad shape and had to be redone, again about 20’ of them per side.

If your aircons are working fine, you may want to leave them alone. The older units seems to last a long longer than the new ones… before the repower I had converted the boat to chillers, best comfort upgrade I ever did.

It took a few days of cleaning the gunk in the bilges and then paint with bilgekoat.

 

[Captain Ralph]

Just remembered a project that would have done better with the engines out;
Check, clean up or improve those limber holes and tunnels that helps water drain in-between frames and stringers.
Some bilges just don't drain away all the water.

This may also include an engine tray plug to help it drain just water.

 

[jim rosenthal]

When my Hatteras was repowered, one of the 'while you're in there's was to replace the copper hydraulic lines to the Hynautic steering. They were not leaking (yet) but they were pretty beat up and I figured it was a matter of time. So they ran all new nylon high-pressure tubing. This was easy to do with no engines in the boat. It would have been MUCH harder after the engines were in.

Also, if not already mentioned, if you want a built-in oil change system for your engines and generator set, at least run the lines to the three oil pans now- you can install the manifold and pumps etc later on, but it will be much more difficult to put all the plumbing in later on. Especially with the oil pans all full.
Apologies if already mentioned.

 

[captcrunch]

Good call on the limber holes and the steering lines!

 

[cww]

What’s wrong with the Detroits? I went through this decision and wound up rebuilding mine. My boat didn’t have a lot of wear and tear on anything though, my engines were trashed by a bad mechanic not from use. You may be in a different situation, but I couldn’t make it make sense to repower. Would have been 3-4 times the cost. The only attractive part of it was I could have got more power, engines have shrunk with time you could get 600hp in those engine rooms now instead of 462. I didn’t think it was worth it, more power means more fuel. Curious what you’re going with and why you’re changing?

 

[captcrunch]

Cww, starboard motor took a hit from exhaust leaks, I found a deal on a pair of 6.7L fpt 550hp engines, so essentially for the cost of an overhaul on both motors I can repower with the fpt’s, have more speed better fuel efficiency and longer range. The 507a twin discs will bolt up to them and no need to change shafts. I included in my budget new battery charger, new a/c condensing units. Generator is newer with under 1k hours so no need to replace.

 

[cww]

Cww, starboard motor took a hit from exhaust leaks, I found a deal on a pair of 6.7L fpt 550hp engines, so essentially for the cost of an overhaul on both motors I can repower with the fpt’s, have more speed better fuel efficiency and longer range. The 507a twin discs will bolt up to them and no need to change shafts. I included in my budget new battery charger, new a/c condensing units. Generator is newer with under 1k hours so no need to replace.

Got it, sounds like it makes sense for you for sure. I have a MY so getting engine blocks in and out of there was a major expense vs. inframes that could be done inside the engine rooms with the boat sitting in its normal slip. I'm always jealous of convertibles for the ease of repowering. On the a/c condensers, anything wrong with them? If they're the old blue cruisair units, those last forever, the new ones don't. I'd clean and repaint them before I'd replaced them.

 

[Pascal]

On the classic galley down 53s as well as other MY with engine hatches in the salon, pulling the engines for a repower is no big deal. In my case three guys with A frames and rails and about 4 hours is all it took to get the engines on the aft deck for a crane to pick them up. Dropping the 6CTAs was even easier

In my case with naturals it made little sense to do an inframe especially since an inframe doesn’t address the gear, and a few other things like main seals, oil pump etc.

It s amazing what a couple of guys can do with minimal equipment.


https://youtu.be/nvjsv4KzCb8

 

[jim rosenthal]

If the gears will bolt right up to the new engines and you don't need to change the gear ratio or the shaft size, you are ahead of the game. Even better, if the gears will bolt to the new engines, and the rear mounts are on the gears, you may be fortunate enough to only have to build new front mounts.

Another thing you may need to do (apologies if A&A) is relocate the sea water intakes if they are not in the right area for the new engines. The time to do this is when everything is out. And fit new sea valves etc.

 

[cww]

On the classic galley down 53s as well as other MY with engine hatches in the salon, pulling the engines for a repower is no big deal. In my case three guys with A frames and rails and about 4 hours is all it took to get the engines on the aft deck for a crane to pick them up. Dropping the 6CTAs was even easier In my case with naturals it made little sense to do an inframe especially since an inframe doesn’t address the gear, and a few other things like main seals, oil pump etc. It s amazing what a couple of guys can do with minimal equipment.https://youtu.be/nvjsv4KzCb8

I watched all your repower videos, I follow your channel on YouTube. Love everything you’ve done to your boat, and especially love the running angle you’ve got with the new tabs. That is definitely on my list.

 

[Boatsb]

Most modern engines will require a down angle transmission in these old boats. Look at the running angle and the engines incline before you commit.