Dyno results with lean cylinders
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Dyno results with lean cylinders

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    Some guys never learn. bocco's Avatar
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    Default Dyno results with lean cylinders

    Just trying to get a little education to help out a friend with motor problems. He had upgrades done to a big block motor by a builder that does a standard upgrade kit. Website shows dyno sheet and horsepower and torque that this kit is supposed to deliver. Twice this motor has destroyed pistons within hours of being on the water. The builder has told my friend that he ran it on the dyno and all looked good. He is also claiming that the 3 bad pistons are the result of a lean condition. The ECM programing was done by the builder. My question is. If you expect a certain horsepower because you do this same build all of the time. And you run a motor that's that lean on a dyno wouldn't you see lower than expected horsepower? I'm wondering if this motor was ever on a dyno. Also would you guys expect a builder to take a look at the spark plugs after a dyno run?

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    mo balls than $cents$ IMPATIENT 1's Avatar
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    fuel systems are different dyno to boat i'd have your freind looking at his tanks and fuel delivery

    Dare to be different, if it turns out great you can claim you planned it that way.

    Jetboatperformance.com

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    Some guys never learn. bocco's Avatar
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    Quote Originally Posted by IMPATIENT 1 View Post
    fuel systems are different dyno to boat i'd have your freind looking at his tanks and fuel delivery
    That's what the builder is claiming. But wouldn't that lean out all cylinders equally?

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    mo balls than $cents$ IMPATIENT 1's Avatar
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    Quote Originally Posted by bocco View Post
    That's what the builder is claiming. But wouldn't that lean out all cylinders equally?
    you'd think, but no, some cylinders are further from the throttle body and will see less air than the others.

    Dare to be different, if it turns out great you can claim you planned it that way.

    Jetboatperformance.com

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    gn7
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    This is why builders that sell engines but don't actually install them in the boat are insane, stupid, crazy, nieve or all of the above. My bet is the problems lies in the installation



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    Some guys never learn. bocco's Avatar
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    So yes, one place is building the motor and another is doing the install. Is fuel pressure at the rail the first place to check after the next rebuild/install?

    As far as I know though. The builder has the complete engine package minus the drive so that should include the fuel pump and filter. Or basically everything but the gas tank and the fuel lines. So not much to check on the boat. Maybe the tank vent?

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    Senior Member wagspe208's Avatar
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    Quote Originally Posted by gn7 View Post
    This is why builders that sell engines but don't actually install them in the boat are insane, stupid, crazy, nieve or all of the above. My bet is the problems lies in the installation
    Maybe the guy buying the engine should know how to set up his fuel system properly (or ask for recommendations)
    Half the time it is a struggle to convince a guy he is not capable of putting it together himself...how you think the you can't install it coversation will go? LOL
    Wags

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    Senior Member ap67et10's Avatar
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    i have heard soo many horror stories about boats and efi. I can think of the top couple of names in marine efi applications that i have heard personally from people that have 10's of thousands of dollars wasted because there engines were set up on a dyno, put in a boat, then hauled off to the dump. My efi procharged bbc will be going in my boat first, programmed by me for both boost setups, then pulled out for fine tuning on the dyno (and to see what it will do). but its seems that in all cases the boats were never lake tested with the programmer. boats have completely different load characteristics and it seems that even the biggest name can't seem to get it right. I don't know...all i know is that, I know what i know and i trust what i know, so i'll be the only one to blame if something happens to my engine.

    i will say this, it is a tough aftermarket for efi, all the good systems have proprietary programming equiptment and your average guy cant get that stuff. its a shame to have heard so many bad stories and people that have been hung out to dry by certain companies that are suppose to be the efi companies. i'm sure there are many that have nothing but praise...it just seems we always hear the bad ones.

    This boat should be lake tested with the programmer. And thats it...simple.

    AP
    Last edited by ap67et10; 08-05-2009 at 06:50 PM.

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    If you try to run max HP dyno tune on a boat, your asking for trouble. Dyno max HP will be on the lean side, ok for a drag boat, but no way for an endurance application.
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    Senior Member s2k1's Avatar
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    Quote Originally Posted by ap67et10 View Post
    i have heard soo many horror stories about boats and efi. I can think of the top couple of names in marine efi applications that i have heard personally from people that have 10's of thousands of dollars wasted because there engines were set up on a dyno, put in a boat, then hauled off to the dump. My efi procharged bbc will be going in my boat first, programmed by me for both boost setups, then pulled out for fine tuning on the dyno (and to see what it will do). but its seems that in all cases the boats were never lake tested with the programmer. boats have completely different load characteristics and it seems that even the biggest name can't seem to get it right. I don't know...all i know is that, I know what i know and i trust what i know, so i'll be the only one to blame if something happens to my engine.

    i will say this, it is a tough aftermarket for efi, all the good systems have proprietary programming equiptment and your average guy cant get that stuff. its a shame to have heard so many bad stories and people that have been hung out to dry by certain companies that are suppose to be the efi companies. i'm sure there are many that have nothing but praise...it just seems we always hear the bad ones.

    This boat should be lake tested with the programmer. And thats it...simple.

    AP
    Must be using the wrong stuff then! Autronic and Motec (my 2 choices) both offer the software for free, just download it from their website. What you may be referring to is tuners that put a "lock code" in the ecu, which I do not do.
    Chris @ Benchmark Performance

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    Will work for Boat pronstar's Avatar
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    Quote Originally Posted by bocco View Post
    And you run a motor that's that lean on a dyno wouldn't you see lower than expected horsepower?
    Slightly lean makes power...but doesn't help with engine longevity (obviously).
    Last edited by pronstar; 08-05-2009 at 07:30 PM.

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    Senior Member VDRIVERACING's Avatar
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    Quote Originally Posted by bocco View Post
    Just trying to get a little education to help out a friend with motor problems. He had upgrades done to a big block motor by a builder that does a standard upgrade kit. Website shows dyno sheet and horsepower and torque that this kit is supposed to deliver. Twice this motor has destroyed pistons within hours of being on the water. The builder has told my friend that he ran it on the dyno and all looked good. He is also claiming that the 3 bad pistons are the result of a lean condition. The ECM programing was done by the builder. My question is. If you expect a certain horsepower because you do this same build all of the time. And you run a motor that's that lean on a dyno wouldn't you see lower than expected horsepower? I'm wondering if this motor was ever on a dyno. Also would you guys expect a builder to take a look at the spark plugs after a dyno run?
    It shouldn't burn that fast, but one can't be too careful. I presume the builder has been told where and how the engine will be used, and allows some cushion in the tune.

    I agree with the others that one has to make sure the fuel delivery in the boat is sufficient. Also, the boat owner should use some good judgment and do some testing before leaning on it. Most of the race guys who dyno will still back the timing down for initial trials and check plug readings in short intervals to make sure things are OK, before stepping the timing back up (in small increments).

    If your friend still trusts this builder enough to try him again, I suggest he do it on the condition that the builder goes out with him to monitor engine functions during trials.

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    Senior Member ap67et10's Avatar
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    Quote Originally Posted by s2k1 View Post
    Must be using the wrong stuff then! Autronic and Motec (my 2 choices) both offer the software for free, just download it from their website. What you may be referring to is tuners that put a "lock code" in the ecu, which I do not do.
    Im sorry, i should clarify what i meant. in many cases the software is in fact available for your average person. There are definitely many systems out there that are still only for dealers though. I don't know much about the Autronic or Motec setups, but what i do know is that both are considered some of the top products out there...no doubt. And both do have software available for free. But the issues that seem to be with these, is the lack of support for your average joe that wants to do it themselves. It seems that info and product support is given only to dealers, and i'm sure that the dealer would be there to help, but still, now i'm relying on the info from someone else. Im not saying that it will be bad info, but i'd rather learn everything about a system, from the people that designed it...but as a joe shmoe...i can't.

    these things may be changing. it appears that there are more and more average people that want to have the power and support to do their own stuff, but it still seems we are not there yet. that is all i'm saying.

    AP

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