A 1984, 340 Sea Ray sedan bridge?? Tell me about it, thanks

[fighterpilot]

Considering a 1984 340 Sedan Bridge with twin 210HP Cummins diesels. Boat is 7 hour drive for us so would appreciate a little help from the experts. Understand from previous post boat is straight drive. Now the questions--With a 8kw Onan generator how much room is there regarding the accessibility to the engines and the generator. On that model boat are there a lot hatches one can open to get to them. Once down in, can one crawl around and service the engines? Is the generator aft of the engines where it gets wet or is it forward of the engines, or ????. Will 210hp Cummins cruise that boat at 18 knots when loaded for fishing. Full fuel, water, 6 people with their gear and the usual ice etc. Can it be driven from the lower helm on plane. Not worried about seeing logs in the water but would like to see buoys and over boats.

How about construction. Not to step on any toes, but Sea Ray's reputation with the cored hull problems is all I hear. It is my understanding this boat has a solid hull. Is that correct. Is there coring in the sidewalls and the decks?

Appreciate the help. Thanks

 

[Redhook98]

OK, here are my impressions and observations from owning a 1983 340 Sedan Bridge....... Mine is gas powered with the 340-HP 454's. Straight drives. Both engines are under the sole in the main cabin (living room area). They have large hatches that pull up for access. The gen is in the lazeret just outside the sliding doors. Not sure about what you mean by getting wet. Mine stays bone dry, even when it was stored outside.

The engine room leaves a bit to be desired as far as space goes. The fuel tanks are outboard of the motors so the motors are scrunched together. Keep in mind again that I have big blocks. A straight-6 Diesal may be a bit narrower.. ? I cannot stand between, in front, outside or aft of my motors. Everything on the big blocks must be done from above. Changing water pump impellors is a bear.

The access for the gen is better. No issues there, but you still must do most maintenance from above. You can get down next to it though if need be. Both mufflers are right there as well.

As for power while underway.. Not sure. Your limited with your prop size because they are in 3/4 tunnels. The max diameter prop you can run is 17-inches. (as far as I understand). Your shafts (from the factory) are 1.25 inch SS shafts. If you prop it way up to 17 x 25 or so to account for the torque in these Diesals, you may have shaft issues... Thats a lot of torque..... The original props are 17 x 17 with 1.5 reduction. If someone went through the problem of installing Diesals, then I hope they upgraded the shafts as well.

Not sure if it a cored hull or not. Anyone? I have not had any hull issues outside the typical small blisters here and there.

Hope this helps in some way. I have never seen, nor heard of a 340 Sedan Bridge with Diesals. That would be a good rig if set up correctly.

 

[Big Island Lifer]

If you have the VIN you can call Sea Ray to get a copy of the original build sheet as well as get any answers for your cored hull question. If you search this forum you will find plenty of cored hulls or lack there of. There was a problem with a few boats that Sea Ray took care of. For the most part those problems were pretty overblown. There is most likely wood below the water line. If the boat was repowered to diesels I would hope that any problems would have been taken care of if needed.

As stated by redhook the prop selection will probably be your biggest concern regarding performance.

 

[fwebster]

I believe the 340/345DB is a Merritt Island boat and has a solid hull construction. All Sea Ray decks are cored. I think the bigger concern is going to be cabin leaks. The 340DB was known for leaks in the side wall, from the bridge, in side windows and forward berth window areas.

My other worry with this boat is that the gas 340DB is stern heavy and takes a lot of power to get on the water. A diesel is going to be as bad or worse from a weight distribution standpoint. I also think 18 kts from this boat when loaded is wishful thinking.

All of this is, of course, without even seeing photos of the boat. The only way you will ever get your questions answered is to get in the car and go look at the boat. Don't even make an offer without a sea trial because I don't think the 210hp engines are going to give you what you want.

Also, you have previously posted about 1 or 2 390 sportfishermen you considered.........this isn't anywhere near the boat the 390 is.

 

[fighterpilot]

Thanks for the information. Point well made regarding the props. When run throught boatdiesel.com calculator the 210HP would like a 21 inch prop. Since I didn't know the allowable prob diameter I couldn't enter it, but at 17 inches it will probably ask for 24 pitch or more, since the 21 diameter required 21 pitch. I will have to explore that and conversion should have included an 1 and 1/2 inch shaft.

Regarding gen location glad to hear yours stay dry. Many of the boats with the generator aft of the engines seem to be rust magnet, associated with bilge water and rain water down thru the hatches. Thanks again.

 

[fighterpilot]

I think probably I will pass on the 34. We do our own maintenance to the extent we can and at my age it sounds pretty tight even with straight 6 cyl diesels. I also feel we would be pushing it to get the speed desired at loaded weight. I sea trialed a 35 foot Californian Convertible last week with twin 3208NA, suppose to do 18knots, top 21 knots--we couldn't get it over 16 knots at wot and this was with only 1/4 fuel load and spanking clean, freshly painted bottom. Granted the sea ray is a lighter boat by 6000 lbs out the door of the plant, but never the less I think I will pass.

Still looking for a 390, but need diesel and lower helm. Weren't many made to start with and diesels are even scarcer to find. Thanks for the information.