Peninsular engines longevity

Discussion in 'Powerboats' started by Nounours, Oct 21, 2003.

  1. Nounours
    Joined: Oct 2003
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    Nounours Junior Member

    Hola everybody,

    I'm looking information about the Peninsular Diesel engines, specially about their longevity in light commercial applications.:confused:
  2. badges65
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    badges65 Junior Member

    all engines have longetivity it is the user who restricts that.
  3. Nounours
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    Nounours Junior Member

    peninsular longevity

    Thanks for your message badges65 but it doesn't answer to my question that I shall reformulate:

    What's the longevity in Marine commercial light duty of the diesel engines based on the GM 6.5L V8 cylinders?

    I think about the peninsular, and the Sea Wolf by Power Marine.

    Has this engine major flaws?

    The GM 6.5L diesel is widely used in non marine applications. As I've seen, the major problems are about the electronic injection as always. (EFI are also big problems on gas engines) so by the MISS
    (Make It Simple and Stupid) engineer principle dictates that on boats carbs or mechanical injections are easier to maintain...

    This engine can be found at very good price, and would be easily marinised.
  4. badges65
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    badges65 Junior Member

    depends on who you talk to some people have had no problems others heaps there seems to be no rime or reason which is the better engines.
    the 6.5 is the later and better engine as most of the bugs of the 6.2 were modified in its production..
    would stick to mechanical pump rather than electronic though..
    I rebuild a GM6.2L and marinised it building my own manifolds and heatexchanger (see
    but got rid of all the electronic situation ..
    i finally ended up with a set of 24V ex military glow plugs(after burning out 2 sets of suposedly 12V genuine !!!) and use a 10 second count 2 to 3 times depending on the temp ..
  5. Nounours
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    Nounours Junior Member

    Web sites about GM 6.5

    Hi badges65,

    Thanks for your post.

    It seems that the "old version" 6.5L has also problems with the glows as everybody tries to fix the problem.
    Problems with crankaft's cap bearings are evoked also.

    As always the electronics are causing problems. In marine applications it's better to forget electronics, salt is not good for cheaply made and expensively sold electronics...

    So it's better to stay MISS: no electronics. On gas engines a good marine carb Edelbrock solves a lot of headaches for less thant 300 US bucks... very easy to maintain and tune.

    For general interest I give the internet addresses of people selling this engine in its different versions:
    who sells Peninsular and Marine Power based GM 6.5 engines. Peninsular and Marine Power have their own sites.
    has a marine version.
    is the corporation who is fabricating the
    GM 6.5. They have a marine engine.
    sell rebuilt engines.
  6. Carteret
    Joined: Jan 2004
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    Carteret Senior Member

    6.5 lessons learned


    I own a Marine Power 6.5 and I can tell you about some of the lessons I have learned. The most important is to use a mechanical fuel injection pump. The electronic will never stand up to the heat. The electronic glow module is not very reliable for marine application. I switched to a solenoid manual glow system with the 60g plugs (longer glow) and have had great results. And probably the most important is fuel quality. A racor fuel filter is a most and quality fuel with a good flashpoint and cetane is very important. These engines in marine application have a compression ration of 18.1 (Peninsular) and 17.1 ( Marine Power). I once had hard starting problems and took a sample of my fuel to be tested and it had a flashpoint of 172 degrees. Should have popped at 140.
  7. kapnD
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    kapnD Senior Member

    You may find yourself very alone with this engine, as it is not built as a marine engine. consequently you wont find a dealer network, and (marine) parts may be difficult to obtain. As you can see from the posts here, it doesnt exactly come set up. Yes, I've also been tempted by "good deals" on these motors, but prudence dictates that in the long run, I'm better off with a Cummins, Cat, Yanmar, Volvo, etc. Good luck!
  8. JMC

    JMC Guest

    I own two. I have about 1000 hours on them. They are 1997 vintage. I have treated them well and they treat me well.

    Most "marine engines" are car engines that have been marinized. Mercury uses GM products in its gas engines and has a partnership with Cummins for its diesel products.
  9. gonzo
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    gonzo Senior Member

    Electronics do not cause that many problems. Engines with EFI have less mainteinance and longer life than carburated ones. The myth about old technology being better is no more than that. Changing parts does not solve a problem if the cause of the failure is not fixed first. For example, a loose battery connection will damage a ECU.
  10. Corpus Skipper
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    Corpus Skipper Hopeless Boataholic

    Lord knows you'll never have a loose battery connection in a boat! :D Those #@**! wing nuts on marine batteries should be outlawed! I converted mine over to clamp-type lugs (brass, no lead!) because I got tired of cleaning and tightening them every time I tried to start the engines! I'd definitely do this if you have EFI.
  11. gonzo
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    gonzo Senior Member

    Both Mercruiser and Volvo Penta issued bulletins eight years ago about wingnuts. They specify nylock nuts on the battery. A failure of any electronic component is not covered under warranty if the battery has wingnuts. Many boat manufacturers continue to deliver boats with wingnuts :confused:
  12. Ilan Voyager
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    Ilan Voyager Senior Member

    Conclusion about GM 6.5L based engines

    I was the "nounours" who began this thread, and I'll give the result of my search about these engines:
    These engines are not able to withstand the marine work unless being severely derated, for example the 170 HP has to be worked at 110 HP. With the turbos versions it's worse.
    In Europe these engines have very bad reports (simply considered as totally unreliable) as have written to me some ex colleagues from the DCN (Direction des Constructions Navales of the French Navy). So the final choice has been Yanmar 4LH with very good results, they cost finally just a bit more.
    It seems that GM is unable to make good diesels...the european Ford diesels have made good marine engines since a long time.

    An interesting new the Mazda designed Duratec (based on the english Zetec) Ford 4 cylinders specially the 2.3L used on the Ford Ranger is a very good candidate for a small gas marine engine with no internal modifications and with the usual security mods about alternator etc. It weights about 120 kg....

    The antique V6 and V8 american engines are now technically outdated and reliability is now close to zero, as I see everyday with the Mercruiser escapes for example, or the EFI failures.

    Last thought; raw water cooling is a technical nonsense in small engines. A part the fact I dislike the use of a highly corrosive cooling medium (sea water...), a modern small engine needs absolutely to run hot at about 85-95 celsius degrees as it is designed in that way. Try to run this engine cooler (45 to 50 celsius degrees) and the problems will begin.

    A fresh water (I would say better a doped ethyglycol) cooling system is far simpler and cheaper than internal mods of the engine. No corrosion problems, no salt deposits, no escapes detroyed in one year...what a relief!
  13. gonzo
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    gonzo Senior Member

    That American V8 and V6 engines have zero reliability is not true. Where do you get statistics from? EFI's last a long time and have a great trouble free record. Do you consider the 8.1 outdated and if so why?
  14. 65ldiesel
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    65ldiesel New Member

    Max power performance marine inc


    Lightweight, compact, powerful, efficient, dependable and surprisingly affordable, the International diesel 6.5 Diesels bring traditional diesel reliability with extraordinarily low fuel consumption to pleasure and work boats in the 25 to 35 ft. class.

    Available As:

    Naturally Aspirated - 200 HP @ 3400 RPM
    Turbocharged - 260 HP @ 3600 RPM
    Turbo Aftercooled - 300 HP @ 3600

    Size And Weight

    6.5 Diesel V-8 configuration is extremely compact. There is no comparison for space with the inline competition. Typically, the Marine Power Diesel fits the same space provided for a 454 CID gas block. Lightweight, at less than 1,000 lbs., Size H 35, W 29, L 40,the International diesel 6.5 /6.2 Diesel provides an optimum power to weight ratio.ratio.


    When it comes to repowering from gas to diesel, the 6.5/6.2 has no match. A repower installation with the competitor's lower RPM diesel engines requires a complete change of shafts, shafts logs, struts, etc.

    The International diesel 6.5/6.2 Diesel can literally replace a big block gas engine using existing equipment. The savings can reduce the total cost of repower installation from 30 to 40%.

    718-694-0999 EX 11
    718-694-2275 FAX

    Joined: Oct 2002
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    Location: Conn in summers , Ortona FL in winter , with big d

    FAST FRED Senior Member

    If you just need a cheap fine diesel , get an International DT 466.

    These smooth running engines have been produced for over 20 years and at 100 to 150hp are as reliable as a DD 6-71 that weighs doubble.

    Easy to find in any truck junk yard , and life expectancy is in the Thousands of comercial hours , not hundreds.
    Std SAE bell housing , so find a used Twin Disc of the right ratio & have at it!

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