repower options - 1969 Owens/Concorde 33 sport fisher

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CamaroMan

CamaroMan

Member
Joined
Oct 2, 2024
Messages
7
Location
San Pedro, CA
Hi all - thanks for having me aboard! We just took possession of our first sport fisher. it was free with no engines or transmissions. What are some repower options? On a budget and this will be a diy thing. I own a marine repar shop but im not super familiar with diesel recipes -

im thinking two 12v cummins 5.9 thru velvet 72c or 73c drives maybe around 200-250hp each. id "like" to cruise around 18-22kts if possible without pushing anything too hard.

What other combos might also work?

I have a 12v cummins at the shop rn and could prob source a second one and marinize them-

Thanks!
 

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There's a few of those out here in So Cal,that have done the repower to the 6cyl Cummins, these guy's are all marlin guy's, like myself, from what I understand, they cruise in the 18-19 knot range, and are very good on fuel at 8 knot trolling speed, about 6 GPH. I've heard that they are a bit limited on space for fuel tanks of any size, but I could be wrong, however, understand that,that can mean different things to different uses. When we fish, we are typically offshore for a few day's, trolling, so need the fuel capacity, I would think 300 gallons would be the right number. Stout heavy boats, that push water well, and accomodate 4 fisherman for multiple day's. If that's your use, this is a worthy project!
 
Welcome aboard. Tony Athens is the Cummins guru. He is in the SoCal area. His website sbmar.com has a ton of info on Cummins repowers and a lot of videos too.
 
CamaroMan said:
im thinking two 12v cummins 5.9 thru velvet 72c or 73c drives maybe around 200-250hp each. id "like" to cruise around 18-22kts if possible without pushing anything too hard.

What other combos might also work?

I have a 12v cummins at the shop rn and could prob source a second one and marinize them-
Click to expand...

Dock neighbors repowered their gas 35 Bertram with Cummins 6BTAs, worked well. But... it cost them about $100K to do it (including replacing a gas genset with diesel) and the boat's total value didn't really increase much at all, maybe $10K. Give that some thought...

And it might lead you to just use decent modern marine gas engines, at much lower cost. And those could probably be just fine, for that boat. That could depend on whether your cruising plans include long distances or not, etc.

I've read Cummins does remans at pretty good value. Most of the things that go south on marine diesels is about the bolt on -- and especially the marinization -- stuff, so I think you'd be better off sourcing marine diesels instead of cobbling together something...

And see ref to Tony Athens, sbmar.com.

-Chris
 
Mainship Pilot said:
There's a few of those out here in So Cal,that have done the repower to the 6cyl Cummins, these guy's are all marlin guy's, like myself, from what I understand, they cruise in the 18-19 knot range, and are very good on fuel at 8 knot trolling speed, about 6 GPH. I've heard that they are a bit limited on space for fuel tanks of any size, but I could be wrong, however, understand that,that can mean different things to different uses. When we fish, we are typically offshore for a few day's, trolling, so need the fuel capacity, I would think 300 gallons would be the right number. Stout heavy boats, that push water well, and accomodate 4 fisherman for multiple day's. If that's your use, this is a worthy project!
Click to expand...
Thanks yes I believe I found some great articles on that very website discussing this will follow up on him thanks. Would those be in the 200-230 HP range I assume? This would be a shirt Fisher for me and the wife yes and friends or two. There are three large takes under deck will take a look today and snap some pics.. not even sure what steering system this is .. have a hydraulic unit a customer have me and a bunch of nice marine goodies incl 300ft of chain too. We plan to do an entire project and refit.

Hull is good and has a new paint job which is great. Will get a closer look and report back. Wish we could find a wood version that's rotted out so we can scag the classic hardware and old wood trim etc will need going for the woods transom and top of rails
 
Thanks ranger yes agreed .. will be diesel purely for range and so forth. I work on gas marine engines all day long so familiar with those.. Alot simpler and cheaper but the consumption is too much imo. Two 12v cummins putting along would almost sip fuel in comparison plus the weight is another issue. I have one good Cummins motor and cab easily source another for 500 which leaves me good funds to get the marine side sorted ..

This monster was 6ton empty on cranes yesterday! And it's only a 33. Plan to fish on this offshore
 
Greetings,
Welcome aboard. Something to consider is the added? size and weight of twin V-12 engines.
 
The suggestion of twin outboards is something to consider. It would be much cheaper and way simpler to do. You would have to reinforce the transom and add a bracket to mount them. Without the inboard engines you could easily add a fuel tank in the engine room to increase the range.
 
Looking at the pictures of the shaft and log I would guess that gasoline engines came out of the boat and the shaft, log and props are sized for higher rpm gas engines.
Make sure the motor beds and stringers are not rotted. There is a lot of wood, probably yellow pine or mahogany in that boat. You will never get your money back from conversion with diesel engines. Owens was not a high end builder.
For the difference between cost of diesel install complete with log change and motor bed re-enforcement vs. gasoline, you will never break even buying diesel vs gas fuel. My guess is the diesel setup will be more than 4 times as much as gasoline engines and you still have a free Owens.
Free boats are like free baby chickens at the feed store.
 
I saw a 250 hp outboard motor mounted on the back of a 42 Hatteras Sport Fish. The motor mount was stainless steel and done very well. The 8-71TI's were still in the boat and operable. The outboard was used to troll for salmon. The big motors would not troll slow enough or get too cold.
The boa in Presque Isle Michigan.
 
CamaroMan said:
Thanks yes I believe I found some great articles on that very website discussing this will follow up on him thanks. Would those be in the 200-230 HP range I assume? This would be a shirt Fisher for me and the wife yes and friends or two. There are three large takes under deck will take a look today and snap some pics.. not even sure what steering system this is .. have a hydraulic unit a customer have me and a bunch of nice marine goodies incl 300ft of chain too. We plan to do an entire project and refit.

Hull is good and has a new paint job which is great. Will get a closer look and report back. Wish we could find a wood version that's rotted out so we can scag the classic hardware and old wood trim etc will need going for the woods transom and top of rails
Click to expand...
I believe at least 3 of those Owen's are in King Harbor, not far from you. May be worth walking the docks and do some reconnaissance,
 
Measured shafts they are tiny at 1.25 so will be going 1.5 for sure. Might even consider two 4bts in there but there are so many 6s around.b

Sbmar interesting article here :

Converting 6BTA to Marine

I have an old Canadian Fish Tug, with a Perkins 6.354 N/A from the late 60's. I picked up a 12V 6BTA out of a School Bus that I'd like to marinize for this old metal boat. Here's my high … Read More
www.sbmar.com www.sbmar.com
 
Just so you know the 4BTs are not balanced so they run a bit rough at low RPMs. Not a deal breaker necessarily but something to consider.
 
Comodave said:
Just so you know the 4BTs are not balanced so they run a bit rough at low RPMs. Not a deal breaker necessarily but something to consider.
Click to expand...
Hummm, Thats an interesting comment. Something to consider if your trolling, and a good harmonic balance, especially when billfishing, is important! I hadn’t heard this one!
 
I was considering the 4BT for a repower for a previous boat. I talked to Tony Athens about it. He didn’t recommend it for pleasure boats. He said he put them in commercial fishing boats with no problems because they left the harbor and ran them well above idle all day so the vibrations weren’t a problem. Before we retired from the CG Aux one of the members had an old Navy double ender that had a 4 BT in it. It was rough at idle and since we did a lot of training on towing we were at idle most of the time. It was somewhat annoying but it wasn’t my boat so I didn’t complain.
 
Comodave said:
I was considering the 4BT for a repower for a previous boat. I talked to Tony Athens about it. He didn’t recommend it for pleasure boats. He said he put them in commercial fishing boats with no problems because they left the harbor and ran them well above idle all day so the vibrations weren’t a problem.
Click to expand...
That makes sense. I know a bunch of fishermen here with 6BTs that have nothing but praise.
 
Thanks dave - I emailed Tony today. Im sure hes tired of hearing the same question over and over - i get it, so will see what he says.

With some luck I can find some nice 72c drives laying around in the 2.9 ratio and find another 12v cummins and spend some $ on the rest-
 
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