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- Cummins Marine Forum Topics
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Shooters fuel tank
This topic has 2 replies, has 2 voices, and was last updated by
November 19, 2024 at 11:16 am Was Shooters fuel tank made from coosa, then glassed in with vinyl ester resin? I am in the midst of refurbishing my 31 bertram, and I am debating redoing the fuel tank in it as well.
2 RepliesNovember 20, 2024 at 8:35 am Alright.Ā I was debating the use of coosa, then glassing the crap our of it. I am not a fan of aluminum in a marine environment.Ā I’ve pulled older aluminum tanks in saltwater boats that were in very poor shape within 20 years of age. I knew you built an integeral tank in Shooter, then refurbished shooter to now Legit II, and your tank has seemed to hold up well over the years. Do you have an opinion on the use of coosa?Last Post by:
posted: 1 month ago
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Qsb6.7 or Qsc 8.3
This topic has 4 replies, has 2 voices, and was last updated by
2 months ago November 14, 2024 at 7:26 pm Hi. Currently Ā have Cat 3208 355hp (1985) engines .ConsideringĀ Ā repowering worth Ā Qsb 6.7 Ā 473 or QSc 8.3 500 hp Often said that the 3208 Cat above 375 Ā have issues as putting out to much power from the block . Want to avoid those issues if I do repower and am concerned that 480 hp from the Qsb 6.7 may Ā put me in that position understand exhaust sizes ,fuel lines, gear boxes Ā and seawater intake Ā shaft etc different for the Qsc 8.3 so more expen…
4 RepliesNovember 16, 2024 at 8:25 am Daunted, Tony has the QSB550 in his boat.Ā He has it loaded properly for longevity and operates it in a prudent manner as you would expect.Ā That should tell you volumes about the QSB6.7 in the higher HP versions. Watch this video and pay particular attention to his explanation of his loading/fuel burn at cruise. Steve Lewis 2007 Kadey Krogen 44 WidebodyLast Post by:
posted: 2 months ago
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Tiller/hydraulic Ram bolt – 316 SS, Bumax88 SS or grade 8 steel?
This topic has 2 replies, has 2 voices, and was last updated by
4 months ago
September 19, 2024 at 9:35 am Hello all – would you give me advice on the correct bolt material to attach the hydraulic ram to the tiller?Ā I assume it needs to have high shear strength so I thought Bumax 88 stainless steel or a grade 8 steel bolt should be used. hole size for tiller and Ram ball insert: 3/8″ thank you, Steve
2 RepliesSeptember 20, 2024 at 4:48 am will do.Ā Ā thanks Tony!Last Post by:
posted: 4 months ago
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1982 Bertram 38 Convertible – Engine Raw Water Thru Hull Location
This topic has 4 replies, has 3 voices, and was last updated by
4 months ago
February 11, 2024 at 9:56 pm Hi Everyone, I am working on the cooling system for this boat’s 6BTAs and doing it the “seaboard” way.Ā Ā I’d like to make some space when you enter the engine room and attached is a pic showing the location of current 2.5″ strainers and also newer 2″ strainers further forward.Ā The third picture shows where the new 2″ thru hull might go.Ā I don’t have a picture showing axial position of the thru hu…
4 RepliesSeptember 10, 2024 at 3:08 pm Hi all, Just wanted to report back that everything worked fine.Ā Kept the same scoops facing forward and went to the 2″ thru-hulls.Ā Runs good, 4 hours on plane no issues.Last Post by:
posted: 4 months ago
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Re-Prop Mistake?
This topic has 4 replies, has 2 voices, and was last updated by
6 months ago June 29, 2024 at 8:59 pm Thank you in advance, sorry about all the info but want to give as much data as possible for the best results! Hi all I know this topic has been written about a bunch of times but I’m looking for some help to I can get this right after an expensive first (and failed) attempt at a repower and new “recommended” props. I have used a bunch of prop calculators but want to give actual data vs theoretical as I have already wasted $100…
4 RepliesJuly 7, 2024 at 7:13 am Photo-tach the engines to verify your tach gauges. Photo-tach your shafts to verify your gear ratios. Run some prop calculators using the engine output specs I posted and be 100% sure all of the data you input reflects YOUR boat as it sits today and loaded up for how you use it. Rob "Luck is the residue of good design."Last Post by:
posted: 6 months ago
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Repowering ’62 Connie from 427 gas to 6BTAs
This topic has 4 replies, has 2 voices, and was last updated by
1 year ago January 17, 2024 at 6:30 am Hi all! I’ve got a ’62 45′ Connie that I am repowering from 427 gas to 6BTAs (JWAC). I am spit-balling that the performance should be acceptable, as I don’t run her hard at all, and don’t plan on changing that. I would love to hear what the brain trust thinks. Current setup is (2) 1969 Chris Craft 427s with Paragon 44s, 2.5 to 1 gears. I am swinging 22 x 22 modern 4 bladed wheels. Her weight is listed at 28000 pound…
4 RepliesJanuary 17, 2024 at 5:42 pm “Aftercooler looked clean, so passed on thatā¦Ā What does that mean? You must have x-ray vision? 160F Hi-flow thermostat is a must for this engine to get the tempsĀ safe Mounting–front of the engine and the side on the transmission Seaboard Founder Go here for the latest stuff we put together and share for all to see:Last Post by:
posted: 1 year ago
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1973 Aluminum Houseboat Repower
This topic has 4 replies, has 2 voices, and was last updated by
1 year ago December 3, 2023 at 6:18 pm Hello All! I’ve been preparing this post for about 2 years now. I have a 50 foot 1973 Pluckebaum Houseboat. I am repowering from the current twin Marine Power 454s (Late 70’s) mated to Velvet Drive V-drives with 3.14 reduction. This specific vdrive model have been out of production for a long time. As you see from the photos of the boat, it is an all aluminum hull and superstructure. It is s single level and has decent head clearance…
4 RepliesDecember 4, 2023 at 5:03 pm Jamie, This is way too complicated to do this way—You definitely do not want 302IV’s——————–Lets try 15 minutes or so on the phone–Drop me a note at [email protected]–your time zone is? Seaboard Founder Go here for the latest stuff we put together and share for all to see:Last Post by:
posted: 1 year ago
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Single diesel displacement trawler repower
This topic has 2 replies, has 3 voices, and was last updated by
1 year ago September 7, 2023 at 10:08 am Hi folks, I’ve got a 42 ft, 36,000 lb trawler with a Cat 3208TA and a TD507 2.54:1 in her.Ā It’s a Sunnfjord 42, they mostly build commercial boats and fishing boats but ours was built as a yacht. It’s go an 8″ wet exhaust going into a shower can style riser. Injection point is 48″ above DWL so they got that right. The Cat has 9000 hours, we plan to keep the boat long term so want to repower now rather than after it…
2 RepliesSeptember 9, 2023 at 7:18 pm What RPM and vessel speed do travel at when going from Point A to Point B?Ā Ā That will be a start as to whetherĀ “much less engine” will be suitable. Your hull is probably a 6-8K easy to move WINE & CHEESEĀ cruiser.. Seaboard Founder Go here for the latest stuff we put together and share for all to see:Last Post by:
posted: 1 year ago
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Thanks Tony and the Seaboard Cummins Forum!
This topic has 3 replies, has 4 voices, and was last updated by
1 year ago
July 5, 2023 at 12:17 pm I just wanted to say thanks to Tony and participants of this forum. After 15 years in a giant shrink wrap tent, I splashed my 1969 Chris Craft Roamer 46 and had a pretty much incident-free 108 mile run to my new home port. As part of the refit, I repowered from Super SeaMaster twin turbo and intercooled gas engines to Cummins 6CTA M2 420hp engines that light off immediately. They ran great the whole way. I discovered some diesel in the bilge at …
3 RepliesJuly 8, 2023 at 7:02 pm Congratulations on the successful trials.Ā Followed this on another forum for years and it’s great to see it on the water. I can only imagine how satisfyingly that was.Last Post by:
posted: 1 year ago
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CUMMINS 6BTA REPOWER AUTOMOTIVE
This topic has 5 replies, has 3 voices, and was last updated by
1 year ago April 24, 2023 at 7:43 pm I have a 1937 retired Canadian Fish Tug.Ā Currently powered by a Perkins 6.354 N/A.Ā The tug is keel cooled with dry exhaust.Ā I’ve purchased a 1993 Cummins 6BTA CPA 1579, with low miles/hours that I’m looking to repower with.Ā For the most part this conversion should be straight forward with already having dry exhaust and the keel cooler.Ā Where I’m hung up, is on the aftercooler.Ā Is the aftercooler required if I’m plum…
5 RepliesApril 27, 2023 at 7:26 pm Original aftercooler on the engine was air to air or coolant cooled?Ā Some good pics on the engine would answer that for me.. Original engine rating was? (HP & RPM?)Ā Ā What are you expecting to gain over the Perkins you have now?Ā Ā Any good 6BT 5.9 with a good working turbo,Ā set up right can makeĀ up to about 150HP in the 2400 RPM range without an aftercooler at cruise,Ā using about 8 GPH of you want to run that hard…Ā Seaboard Foun…Last Post by:
posted: 1 year ago
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Shaft/Engine Re-Alignment
This topic has 6 replies, has 4 voices, and was last updated by
1 year ago
April 19, 2023 at 7:47 pm 25 Years ago I had SS strust made by my prop shop and they have done well. When the 6BTA’s were installed they were remove and reset as part of the engine install.Ā That was back in early 2019.Ā All has been well. However, I took my extended family out to see the 4th of July fireworks back last summer (’22).Ā I anchored up with dozens of other boats just out of the intracostal and watch the show.Ā Ā However, when heading back to the c…
6 RepliesApril 27, 2023 at 5:12 am Yes I have, and yes, I followed your directions.Ā I only really have one spot on the shaft to measure with a dial gauge and that is 4″ behind the coupler (v-drive boat).Ā My question is where the high & low spots are, and by how much, give you any guidance as to what adjustments in the motor mounts need to be made?Last Post by:
posted: 1 year ago
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Searay 330 EC Re-Power Yanmar
This topic has 3 replies, has 3 voices, and was last updated by
1 year ago April 24, 2023 at 2:14 pm I have a 1997 Sea Ray 330EC repowered with twinĀ rebuilt 2002 Yanmar 6LPA-STP 315HP. 2;1 gear and 18″x21 pitch 4 blades with cup. Listed below are the current specs: No load RPM 4200, loaded RPM’s 3600, top speed 24knts, boost is at 18 psi and I’m told on these engines 20 is tops. My issue is that the performance of my boat is far less than the performance of the sister boat set up with all the same drive gear. One variable I&#…
3 RepliesApril 25, 2023 at 11:16 am 5 year difference in boat model year can change things, weight being a big one.Ā Have both boats been weighed on the same lift? The sistership has more prop diameter and more pitch and is turning more rpm’s than you? Have the tach’s on both boats been verified ? Your boat is overpropped and/or has a low power issue… Rob "Luck is the residue of good design."Last Post by:
posted: 1 year ago
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Is 1 1/4 Raw water pick up enough for 6BTA 370’s?
This topic has 3 replies, has 3 voices, and was last updated by
1 year ago
March 20, 2023 at 6:08 pm I’m sure this will be the first of many questions as I go down the road of repowering my 1974 35 Bertram convertible. Basic overview is the boat originally came withĀ big blocks. then at some point she was repowered with Cat 3208 NAs with aftermarket M&W turbos…. IĀ run the boat forĀ charter fishing…but it has come to the point whereĀ Ā I need a little upgrade in speed, fuel economy and Technology. I am repowering Her with t…
3 RepliesMarch 21, 2023 at 9:14 am Thank You Guys.. nice to confirm what i was thinking…..ĀLast Post by:
posted: 1 year ago
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Repower cruisers yachts 360
This topic has 8 replies, has 4 voices, and was last updated by
1 year ago January 15, 2023 at 11:32 am Hello i have a 2009 cruisers yachts 360 express currently equipped with mercury 8.1s with zf63iv ratio 2.5 and 1.5inch shaft i am repowering with twin diesel yanmar 6lpa stp2 and keeping same gearbox. The boat came from factory as an option with the following setup: yanmar 6lpa with zf63iv ratio 2.5 and 1.75inch shaft my question is : should i upgrade my shaft from 1.5 to 1.75 or i will be safe keeping my old shafts? Ā
8 RepliesJanuary 31, 2023 at 3:42 pm When I re-powered with 6BTA’s at 355 HP each from 200 HP Detroit 8.2L engines and went from 3 blade to 4 blade Nibrals (22X20)I kept my 1.5 inch Aq19 shafts after getting different suggestions.Ā My 38 ft boat is likely heavier than yours and carries 300 gallons of fuel and 80 gallons of water – about 24,000+ lbs. Transmission is 1:1.75 so shaft RPM’s may be similar but also consider mine are diesel and yours are gas.Ā Not sure …Last Post by:
posted: 1 year ago
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Repower Cruisers Yachts
This topic has 1 reply, has 2 voices, and was last updated by
2 years ago November 3, 2022 at 12:32 am Hello, I am the owner of a 2009 Cruisers yachts 360 express powered by twin Gaz engines mercury 8.1 with ZF63IV (ratio 2.5) I am in the process of repowering my boat with twin diesel engines. I have contacted cruisers yachts and found that this boat model was powered with diesel engines from the factory with either Yanmar 6lpa-stp2 and zf63iv (ratio 2.5) or Volvo Penta D6-350 and ZF85IV (ratio 2) I am confused between repowering with brand new Y…
1 ReplyNovember 4, 2022 at 3:08 pm IMO, prop your D6 350’s to 3600 RPM minimum with the vessel loaded for bear, and you’ll be just fine using ZF63IV’s that are in perfect shape or “as new” …Ā Ā Seaboard Founder Go here for the latest stuff we put together and share for all to see:Last Post by:
posted: 2 years ago
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Bertram 28 new power prop sizing
This topic has 1 reply, has 1 voices, and was last updated by
2 years ago October 24, 2022 at 8:17 pm Hi, a friend of mine is needing popellers size Ā recommendations for Bertram 28 1972 withĀ Cummins 4bta 250hpRpm 600 to 3000Shaft 1-3/8 Wating on trans ratio Ā any one with similar set up? Ā Ā
1 ReplyOctober 25, 2022 at 5:11 am Ratio is 1.56:1Last Post by:
posted: 2 years ago
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Yanmar 4lha-stp, lack of power
This topic has 1 reply, has 2 voices, and was last updated by
2 years ago August 15, 2022 at 9:14 pm Iāll keep it short and to the point. I did a motor swap from a Volvo d3 to a yanmar 4lha-stp. Iām running a Volvo dps-m Outdrive with 195 gearing boat is 21ā and about 5500 loaded.Ā problems- No power going up the trailer(rpm no higher then 1600). Lope between 900-1100 rpm, boat only gets 24knts wide open at 3500 plus. Put bigger props and lope is at idle(real bad) and 1k rpm going up trailer.Ā motor info. Injector pump rebuilt, injectors re-set,…
1 ReplyAugust 17, 2022 at 5:27 pm What the past history of the motor?Ā Didn’t you run it before the install? Why did it need a injection pump rebuild?.. Certified shop?Ā The loping could be a bumper spring issue .. Get a 0-30 PSI accurate boost gauge on the engine, and get your tach accuracy verified at a steady 3000 RPM in neutral Seaboard Founder Go here for the latest stuff we put together and share for all to see:Last Post by:
posted: 2 years ago
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What am I missing?
This topic has 7 replies, has 3 voices, and was last updated by
2 years ago February 1, 2022 at 3:47 pm I have a 37 foot 11.5 beam 20,000 pound Roughwater that is currently powered by twin 250 HP Detroit 8.2s. After a fire in a nearby marina I was able to purchase the motors from a 2007 Meridian that had external damage from the fire, it was not the boat that burned but moored next to it. ( check your shore power connections in winter!) I got two low hour, very well maintained 330 HP, 6bta s with ZF 80 A – 2 gears at 1.5:1, the mixing elbow,…
7 RepliesAugust 9, 2022 at 9:56 am Here is an overlayed picture of the Detroit 8.2L (Red) with 502 Trans with a Cummins 6BTA with ZF 220A (Black).Ā By superimposing the scaled diagrams in Photoshop and lining up the Faceplates of the transmission output flange you can see how they stack up.Ā Same degree of down angle.Ā Detroits are wider and the Cummins are a couple of inches longer.Ā The Cummins/ZF packages save about 1500 lbs on the install. Only other somewhat issue was the Cu…Last Post by:
posted: 2 years ago
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Repower Considerations
This topic has 4 replies, has 3 voices, and was last updated by
2 years ago December 8, 2021 at 2:41 pm We have a 37 foot, 16,000 pound 1987 Roughwater 37′ that is currently powered by twin Detroit 8.2 350 hp engines with TD 506 gears. We love the boat and want to repower. It has newer fuel tanks, 1.5 shafts, new logs, cutlasses and struts. The steering system is also updated. The bottom was just compleatly stripped and re done. Currently with the 8.2s, we cruise at 8-9 knots at 1750 RPM 14-16 at 2,200 and exceeed 20 knots WOT. We are not ri…
4 RepliesAugust 9, 2022 at 9:33 am Are you sure they are 350 HP engines.Ā These look just like mine – standard Detroit/Allison Turbocharged which were rated at 205 HP..Only J&T and a couple of others made Aftercooled or twin Turbo and Aftercooled engines with the 350 HP.Ā I don’t see any of that hardware in your pictures. What is your fuel burn at 16 kts and at 20 kts? My 38 ft Chris Craft with the DD 8.2L weighs more and at 18 kts it burned 18-19 GPH.Ā I repowere…Last Post by:
posted: 2 years ago
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Genset exhaust routing
This topic has 6 replies, has 3 voices, and was last updated by
2 years ago
July 15, 2022 at 6:19 pm I realized a while ago that the port side of my project boat is getting heavily loaded compared to the starboard side. To balance the boat better, my best option is to relocate the Fischer Panda 12k genset from the port main engine stringers to the main stringers on the starboard side. This is a 1969 Chris Craft Roamer 46, and the genset exhaust thru-hull is welded to the hull. The Awlgrip paint job is done, so I’m not willing to make new …
6 RepliesatLast Post by:
posted: 2 years ago
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Shooters fuel tank
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