Insight in diesel Luhrs 28 re-power

Discussion in 'Diesel Engines' started by Luh28, Jul 27, 2021.

  1. Luh28
    Joined: Jul 2021
    Posts: 6
    Likes: 0, Points: 1
    Location: Michigan

    Luh28 Junior Member

    MIA thanks for the info! Yes, I'm not going to change the shaft log but will put in a new shaft because I have no idea of the alloy of the old one and at 1-1/4" it will have to be the newest 22 grade to be able to apply 300 hp to it. The old engine stringers were 4x6's covered in roving, bolted to the 2x6 hull stringers (also glassed) they ran the length of the engine bay also providing a base (with wedges) for the V-drive. I'll do the same as they are at what seems to be a universal spacing apart for engine mounts, the height I'll probably work out with mockups just to be sure once I commit to an engine. Same with the shaft as I'll mock that up and then have it machined. The 17" four blade prop that was stock had only about 1.75" clearance to hull, a bit tight. So that's were that RPM variable fits in as higher cruising RPM allows smaller wheel. Ultimately, seems shaft dia. and shaft log angle are really driving engine choice. If I start over with a new log and strut It would allow much more options but not interested in opening up that can of worms.
    7228Sedan, yes, it's weird I found some old Luhrs promo material that mentions in the early 70's you could get the boat in traditional wood topside construction or all fiberglass, guess it was a cost option. I love this boats low wide and simple design, (and the 3GPH I got, albeit at tugboat speeds) but if I knew how much rot I had when I started this project I would of hauled it to the dump. But hey, I have learned a lot and found it's a really juicy rationalization to buy more tools! I'm lucky that it's parked in front of my shop so basically the biggest cost so far has been time, and I've got that. In the end, I'm replacing almost everything and it will be way stronger and more durable than the original. The original Honduran mahogany T&G cabin sides are now 1" thick laminated marine ply w/4 coats of laminating epoxy and 4 of LPE on the interior mahogany finish 4 coats 2part epoxy/ LPE on the exterior. The sides where challenging as they are 14' long, requiring me to do some 8:1 scarfs on the 1" thick laminated 4'x8' sheets. Lots of time to build the bench and jigs to support it all. I'm keeping all the original cabin lines and it's been a challenge seeing as all the decks are curved and the cabin sides angled, lot's of mockups! Always interesting tearing into old carpentry and finding all sorts of boo boo's - Friday afternoon rushed construction details. I'm replacing all the wiring (which was non marine grade) plumbing and tanks. Tore out what is probably several owners worth of sub grade hack jobs. Thank god the hull is built like a tank! The Mercury Diesel options are a 2.0L four and a 3.0L V six that are VW TDI diesels and a 6.7L inline six (480-550hp) that is made by FPT, a Fiat subsidiary that my local diesel Cummins/Yanmar supply now carries and has good things to say about, he can get me a new FPT 280hp one for @30K. Funny thing with the Mercury line is that the dealers seem to know less than I do when it comes to the diesel line. And the price quotes I've been getting range wildly 28-50K for the 3.0L Some are also kinda leery about Mercery diesel as apparently they have changed suppliers a lot (Navistar was one) causing local mechanical support/training issues. Thanks for all your input! One of these days I'll sit down and organize an online site with all the photo's I've shot documenting the whole process.
     
  2. 7228sedan
    Joined: Nov 2009
    Posts: 343
    Likes: 11, Points: 18, Legacy Rep: 60
    Location: New Jersey USA

    7228sedan Senior Member

    I'm excited to follow along, I miss mine a lot... it no longer suited the family's need as I am looking to do some extended cruising/offshore fishing. Plus, I couldn't safely get my disabled son up the ladder to the bridge. Aside from the future dreams, she was perfect. A very efficient, stable ride. MIA, I'll be lurking in the depths, not going anywhere anytime soon :) Cheers all.
     
  3. Luh28
    Joined: Jul 2021
    Posts: 6
    Likes: 0, Points: 1
    Location: Michigan

    Luh28 Junior Member

    She's a beauty, I like the dark blue hull, is that original? If you don't mind, curious what you got for her. It is in the back of my head deciding on the re-power. I paid 25K 30 years ago for my diesel version. I don't expect to get back my labor cost for the cabin/decks rebuild, but would like to recoup the engine cost. Thanks!
     

  4. 7228sedan
    Joined: Nov 2009
    Posts: 343
    Likes: 11, Points: 18, Legacy Rep: 60
    Location: New Jersey USA

    7228sedan Senior Member

    Thank you, definitely a labor of love as you are well aware of :). Originally she was same as yours with off white and powder blue stripe. I painted the hull, deck, and fly bridge myself using Interlux Perfection. Hull side is Mauritius Blue. Deck, bridge were bright white. I put down Interdeck in white in the cockpit. Here's some more pics from my listing when I let her go. I think I got around $7,500-$8000. With all of the sweat equity, and fresh motor, transmission, prop, shaft, electronic upgrades, rewiring, updated shore power AC/DC systems etc I certainly didn't make any money that's for sure. But that's not what this was about. I had her for 10 years, and turned her form a decrepit old scow into something relatively respectable. I learned a ton, and discovered all of these fine folks in this forum along the way. There are multiple lifetimes of experience from around the world in here. All of which came into the picture at one point or another. Please shoot me a message at any time if you'd like to chat. Sorry, didn't mean to hijack your thread ;-)
     

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    Last edited: Nov 18, 2021
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