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re-power CC Roamer Offshore (38ft)

Discussion in 'Chris Craft Roamer Yacht' started by roamer offshore, Jun 25, 2011.

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  1. roamer offshore

    roamer offshore New Member

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    the only other idea

    is new Walter V-Drives mated to Yanmar Diesels.

    supposedly the steel hull can handle it with some additional bracing. what do you guys think ?

    the mechanic believes my Chris Craft fuel tanks with rubber baffles are fine for Diesel. i don't know where to go for more information on that.
  2. roamer offshore

    roamer offshore New Member

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    engine room questions

    i am still considering a re-power with Diesel's. one concern is how Roamer reinforced or braced the hull for twin diesels. does anyone have photo's or drawings of the engine room or anything else relevant to the diesel 38' Roamer Offshore ?
  3. Fireman431

    Fireman431 Senior Member

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    What is the weight difference between your gas engines and the diesel engines? Talk to a mechanical engineer and they should be able to help you with the bracing.

    I have to agree that your blown engine dilemma was simply more than "bad luck". That many blown engines in such a short time frame was either improper work on the mechanic's part, improper parts used, or improper operation on your part. I have friends with large boats built in the 80's with the original running gear stil lin them. No issues aside from maintenance and normal wear-n-tear on parts. Were your consistantly running WOT prior to proper break-in? Overrevving? High Temps? There has to be a reason, even if it lies with the mechanic.
  4. roamer offshore

    roamer offshore New Member

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    i don't think so.

    i never over-rev'd. it never overheated. we even double checked the engines with an IR temp gauge like HVAC guys use. Wally is a great mechanic. it is just one thing after another. at first it was a famous boatyard in Waukegan. then i found Wally. each of the engine builders was considered to be an excellent machine shop. this time the engines were fine. but the V-Drive blew up and caused a sudden cessation of rotation for that engine - which blew the entire starboard drivetrain.

    at this point i have considered repair, re-power with new or newer gas or diesel inboards, re-power with sterndrives, re-power with outboards, or the new idea of re-power with jet-drives.
  5. Fireman431

    Fireman431 Senior Member

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    have you considered repowering with a sail? :)
  6. roamer offshore

    roamer offshore New Member

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    too

    bulky..... and too noisy.

    :)
  7. dsharp

    dsharp Senior Member

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    It sounds like a detonation problem caused by too much prop or too much advanced timing. I would think a modern computer controlled engine would cure a lot of the problems. The only problem with diesels that I could see is too much weight aft and the length of an inline 6 cylinder. Diesels tend to have a larger flywheel and housing that may set your engine too high for the deck. Most manufacturers have installation blueprints that you can download with all of the dimensions you need.
  8. roamer offshore

    roamer offshore New Member

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    although the engines are 50 years old

    i updated them with fully electronic ignition, electric fuel pumps with automatic shut of if the oil pressure drops, and computerized knock detectors.

    the knock detector senses any form of banging in the drivetrain. you should have heard it yelling at me in those instants when the v-drive blew and took everything else with it.
  9. roamer offshore

    roamer offshore New Member

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    it turns out

    that it was the prop, not the v-drive. the current opinion is that the props were too much for the boat and ran the engine too hard. so i have this bulging on the side of the block where the connecting rod impacted. its lovely !
  10. K1W1

    K1W1 Senior Member

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    Hi,

    Try to find another boat the same with the same engines, find out what props they are running and start from there, if they are undersized at first this will be better than being oversized and repeating your present failure

    Another thought I have had is: If the cylinder block is damaged can you not get an automotive one and re use a lot of your parts in it? You might have to re bore it to match the pistons you have and replace the crank plus a piston/rod or two but should be better than starting from scratch once again.
  11. Laurence

    Laurence Senior Member

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    Offshore Props

    I am running 22x21 Three blade props on my Offshore with Chrysler big block V-8's.
  12. Fireman431

    Fireman431 Senior Member

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    My 37' Carver runs 23 x 23 4-bladed props and still spins to 4600 RPM. Might consider a bigger set of screws.
  13. roamer offshore

    roamer offshore New Member

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    the prop shop did their calculations and decided

    i should use Hytorq DQX, 4 blades, 22D x 23P. apparently they were wrong...
  14. Laurence

    Laurence Senior Member

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    Props

    Chris Craft quoted top speed of 29 mph for Roamer Offshore. I believe 22x21 3-blade is original factory size. Just a thought, were you pulling more than 29 mph with your big props and therefore exceeding powertrain limits?
  15. roamer offshore

    roamer offshore New Member

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    3,500 rpm

    21 mph.

    i've put so much money and time into my floating cabin.....
  16. K1W1

    K1W1 Senior Member

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    Hi,

    Was 3500 RPM as far as they would go or was that as far as you ran them?

    What max do others with comparable engines get in your type of boat?
  17. roamer offshore

    roamer offshore New Member

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    i have not spoken with any of the Roamer owners

    the engine shop broke the engines in on a dyno and felt they should be capable of 4,400. i never took the engines past 4,200.
  18. K1W1

    K1W1 Senior Member

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    Hi,

    I would be dubious about an engine shop that tells me they have run my engines in on a dyno.

    Would they never rev past 4200 in your application or you never tried revving them past that?
  19. roamer offshore

    roamer offshore New Member

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    no it's true. he can even get they dyno to go counter-rotatinon !


    i just never wanted to push the engines so i never went beyond 4200.
  20. Laurence

    Laurence Senior Member

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