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Question for Al, and other saavy mechanics/engineers

212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
I see boosted diesel engines used constantly in marine applications- to get the ponies, a diesel dang near has to be boosted.. but it seems rare that there are boosted (s/c) gasoline engines.. is the reason for this reliability or reducing maintenance?  Is it production costs? Is it that there are inherit risks with proximity of h20?  I'm just wondering.. it seems odd that there aren't a lot more options when that one is so easy to do..

I've located a s/c for a 4.3l on the cheap, and have been toying with the idea of putting it on an playing with it for the rest of this engines life.. there are some things I will have to address as far as fuel delivery, too, but it seems pretty straight forward.. there seems to be plenty of head space under the engine cover to fit it.. It looks like a change to a throttle body injection will be demanded, and supported by a Whipple delivery/monitoring system..

we're not talking a lot of boost.. maybe dial it in to ~5#'s max at WOT, which on paper will push the 190hp rating to somewhere in the vicinity of 280~290.... 

the drive (Alpha) should handle that, right? 

the mechanical compression of the engine, as is, is 9:1- which could be reduced some more by using some new head gaskets and dropping it to 8.5ish:1.. Vortec heads, btw.. I don't know what the dynamic compression is- but can figure that out when I land a cam card on that engine, and/or simply break out the compression tool and calculator.. I'm thinking a dynamic compression ratio in the 7.5:1 range, with fresh gaskets and studs will make hitting 5psi a bit safer and more reliable..

I've located a 5.7Mag, (from same guy who has the s/c, fwiw), and was planning on swapping/re-powering with that one- which is maybe the long term solution and end game, but it seems to me- unless there is a huge something I'm missing, that this s/c could be slapped on this engine in a weekend or two's worth of work, and running down the channel NLT the third.. I like the idea of less weight, less fuel consumption at idle speeds, and the same or similar power (maybe a little more consumption) as the V8 above plane.. 

What I can't get past, though, is if it isn't such a huge deal to do this, why it isn't done more often?  What am I missing with the idea of supercharging a marine engine?
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    BoatAwayBoatAway Member Posts: 179 ✭✭✭

    that's too much HP for an alpha to handle and maintain reliability.

    superchargers are great for car gasoline engines that rev up and down. keeping a constant preasure increase as in a marine application (sitting at 3, or 4k rpm) again, is going to hurt your reliability.

    by reading your posts, i'm sure your familiar with metal fatigue. that's what you're gonna bump into.

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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    I was reading where the alpha can handle 300... there isn't any way I'm going to invest in this little project by adding an out drive, too.. it would be fun to play with so long as I could avoid that, but certainly not worth it if it requires a new one..

    I hear ya about the fatigue.. I wouldn't expect the thing to last very long- or as an end solution.. for that, I'll move toward the V8 (and I won't mind replacing a drive for an end game solution).. there isn't a market for a salt water used 4.3l around here, so I won't mind running it to death playing with the s/c.. Plus, the s/c is dang near free, except for gasket kits, a few lines, a throttle body kit, ect..
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    stupid question of the day, and one I should do a quick search on before asking:

    are there any drives interchangeable with the A1 that don't require transom work?
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    RinkerYan said:
    Drew, my Yanmars turn out 240 HP and 420 lbs of torque at 2400 RPM. I would be curious if you can find out what a B2 can really handle. Keep in mind that it says" Diesel Bravo 2" on the case if that makes any difference. Thanks!
    I'm betting it's the input shaft that differentiates it...
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    RinkerYan said:
    Dont all the Cigarette boats have super chargers?
    a lot of them do... racers, specifically.. but they tear those things down as often as they race them.. :-)
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    Dream_InnDream_Inn Member, Moderator Posts: 7,594 mod
    Yan, I have B2s and yes they can handle my 496s with no problem. 

    Dream 'Inn III -- 2008 400 Express

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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    edited September 2013
    Yan, you've got a whole lot of complexity ahead of you while blueprinting a move like that.. for instance:

    You can start at either end; the prop or the gearbox or the engine.. if you increased the tq of the engine significantly enough, I'm betting your tq would allow you to spin the prop at a higher ratio via the gear box of the drive, and you could adjust the prop to compensate, allowing you to reach the same performance range at a lower engine rpm and load.. that's a ton of work, but it could be done.. it would give you better economy for same performance expectations and allow you better performance at same economy you have now... Not to mention faster at wot..

    Building out an engine for performance is also making its consumption better in most cases, but is lost in how folks use them after building them... There is also the question about economy timeline of return after investing into it... Which is the only reason I'm thinking about the s/c.. its almost free.. it would be an investment of around $4k otherwise, buying it new..
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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    300HP will twist an alpha 1 - sooner or later.  Bravo 1 no problem. Bravo 2 no problem, depending a bit on rpm (it's meant more for load than speed).MT
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    I'm still mobile, MT, do you know if there are interchangeable drives that don't warrant transom work?
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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    edited September 2013
    Drew, I changed out an alpha1 for a bravo 1 on a Rinker 190 to accomodate a 390 HP 383. I'll try to find some pics to post. There was a slight difference in the bolt pattern but no big deal other than that. As I'm sure you know it's not hard to pick-up a good used Bravo 1 for a good price. We put a wipplecharger on a 5.7 once and it was awesome until it twisted the guys alpha1. Put a used bravo 1 on it and it just screamed. As I am sure you know, your 4.3 is nicely balanced. I believe all 4.3s have a real good harmonic balancer. If this is the case and you wippled it and put on a bravo 1 you'd be smokin 350s. P.S. I'm having to reach way back in time here but I think we had to add a sea water water pump to be turned by the engine because the alpha had its water pump in the drive tower - but that was still no big deal.Good Luck. MT
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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    edited September 2013

    Hey Drew, I have to thank you for getting me to take a walk down memory lane. I wasn't sure I'd still have the pics of that mod it was a looong time ago! So here's what the pictures are: This is a 190 Rinker that came from the factory in 1994 with a 4.3 LX. A few years later I got permission from Randy and Kim Slocum to put a stroked 350 magnum in it. We ran the 383 up to 400HP on the dyno and then dialed it down to either 380 or 390 HP (I can't remember where we left it) We ended up with a Barry Grant Demon 850cfm carb on it and a set of Corsa Captain's Call through hulls on it. It was gps'd at 70 mph and I smoked every baja on the river (Got more beers that way). It was a real sleeper. In the pics you will note the Bravo 1. You will also see that the swap from an Alpha 1 to a Bravo 1 was clean.I think we spun a 22" pitch from Precision Propeller in Indiana and set the rev limiter at 5200. I used amzoil race. P.S. You'll note the drive shower. Even with the Bravo 1 on it I realized I would have to cool the drive down -after I came back from one run and heard the hissing of water off the drive upper tower. I changed the drive lube and put the shower on the next morning. BTW I took an off shore racing course in Florida in the 70's on final exam dayI drove a Cigarette with tripple 900HP Hawks no problem but that little Rinker scared the cr*p out of me a number of times. It was crazy fast, I could spin the prop at 50 mph! At one point someone took a picture of me on a pass. I swear there was only about 6" of the rear delta pad in the water.Good luck with your project I hope you keep us posted! GO RINKER! MT ...Just found out - if you bring up the two pictures then click on each picture you can get a better view.

     

    Post edited by Michael T on
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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    Drew, I know you know this but if you whipple that 4.3 you'll have to be careful with fuel management as lean gas kills engines faster than anything. We always used high performance fuel pumps and I usually used Gaffrig fuel pressure monitors with alarms. MT
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    Looking at a throttle body injection in the 900cc/min range..
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    MT, thanks for the comments and pics.. I'll see if there is a Bravo hanging out in this dudes (no kidding) PILE of parts and pieces... my only fear is that "American Pickers" shows up at this dudes locality before I can get back over there.. :-)

    Al, I may just do it.. the 5.7 he has on a stand is functional as is, and is likely my end game project for this boat- and what the CFO/CEO (aka wife) is wondering is 'why are you going to do this twice?'... she understands projects in linear form with end goal, and she certainly understands 'boat down time', both of which she has an aversion to, for reason I equally fail to understand..

    it's decision time, I reckon... I want to do the s/c because it sounds like a lot of fun toying with- which means I may have to invest in a good set of oars, too..

    thanks all!
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    Michael TMichael T Member Posts: 7,227 ✭✭✭✭✭
    edited September 2013
    Hey Drew, I like the way your CEO thinks and she's right. If you want to build a wicked sleeper get that 5.7 and a Bravo 1 and play with it. The end result will be a great toy to have fun with. BTW after having a few years of fun with that 190 I got a really great trade-in for it on a new Rinker - two guys were bidding on it at the dealer. I still see it out on the rivers from time to time. So, it would be fun and a good investment!  Hard to beat that. Good Luck and please let us see your project if you go forward. MT.
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    BoatAwayBoatAway Member Posts: 179 ✭✭✭

    MT, I bet you're sorry you didn't take more picutres of that custom setup. thanks for sharing.

    Drew, you're a tinkerer and you can easily swap things out. I say do it and just don't mash down on the thortle a lot. it'd be cool.

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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    So back to superchargers for gasoline engines, ideally they are used just for short-term performance from engine idle (acceleration).  This way you get big engine performance in a small engine package.  Once the engine (in a car) is at cruise they are a HP thief unless you clutch it and offer no benefit since cruise hp requirements are a fraction of the engines rating / capability typically.  Remember a gas engine is 'air' controlled, where a diesel is 'fuel' controlled, thus why you can run a diesel with boost100% of the time and it cares less.  Turbos work on the high engine rpm side since you need exhaust gas velocity to spin the turbine.

    In a marine application, since you need/want the power at cruise and to accelerate, the boost would be on all the time and engine life would be minimal.

    Diesel trains use a combo super charger and turbo charger, the SC clutching out once the turbo is spooled up to speed.  There is development for this for automobile engines in the 0.8-1.0 L diesels.  It's complicated has heck and a lot of issues with running turbo air through the SC.


    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    edited September 2013
    the difference, as I understand it, is that an automobile using a s/c boost loads the engine during acceleration, which is eliminated for the better part once a performance level is achieved...

    using a vacuum gauge as an indicator, on a non-boosted engine:

    idle = vacuum signal of 17'
    accel to 3kRPM under load, signal drops and returns as load is eliminated (drops to 10~15") ..  through gears, signal indicates load on engine, and moves with each leverage adjustment (gear) is altered (+3~5" per shift, and -3~5" at bottom end of higher ratio).. once level of performance is achieved, and ~if~ the engine has the proper gearing:RPM (power band specific to that engines curve) in it's final gear and is now levering under different load circumstance (profusely decreased), the signal returns to 14~17"..

    boats (most) don't use gears other than a single drive gear... they rely on prop specifications to fine tune the gear ratio relationship between the engine and the drive ratio..

    which is a long way of saying, engine load doesn't drop... if you were to vacuum signal check an engine in a marine application, and you open to 3/4 throttle, and once you break plane, you could dang near use that vacuum signal as both a RPM gauge and a speedometer, as all else remains constant.. an s/c producing 5psi to an engine at 3500rpm's is going to continue supplying that 5psi no matter, and the engine will consume it because there is no drop in demand, where as an automobile will lessen the need for that consumption as it levers its power through gears, and lessens its load along the way..

    thoughts?

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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭

    That's about right: it would boost 100% of the time, and since gasoline engines are air regulated, boost means higher fuel consumption too.  So that goes back to Al's comment: just put in a bigger motor! The KISS method.

    I work with the guys at Eaton quite a bit, and the engineering on these is pretty intense for the unit itself and putting it on an engine and both surviving. 

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    I PLAN on putting a 350 in it, but the s/c is FREE, and that is pretty much the fun of doing it... Basically I would have been expediting the 4.3's departure and having fun in the mean time.. as it is, though, the s/c is angled, where I need perpendicular for my intake/manifold marriage, and a tab is broken (above cylinder 6) which would have to be weldd up.. on top of that I'd have to use a tbi to use the thing, which apparently marries strangely with the intake manifold, and implement a megasquirt system on it- which is tricky with the cam profile for some reason I can't wrap my brain around... If I went this route, I'd have about $600-$1k in the job, without a donor.. with a tbi donor, I could either use a heavier injector or up the fuel pressure supply and dial it.. turns out dialing is tricky, too, as getting a wideband in the exhaust stream is tricky and requires tapping the manifold, or inserting an adapter already tapped between the head and manifold.. neither of which is optimal to sniff o2, but still better than lower in the system..

    Final line: eff that, it's too much work for the mid game of killing the tiny powerplant, and about equal to dropping in the carb'd 350.

    The 350 available from same guy has a cam in it akin to a marine cam in profile, but has a slight overlap.. I don't know if its worth going in to fix it, unless I can simply increase ratio on the intake rockers while keeping the exhaust rockers at stock ratio,increasing the velocity of exhaust pulse and clearing the first few inches of the exhaust passage.. I've not read of anyone doing this either on land or water, but it looks promising on paper.. I'll try to grab the 5.7 if that works out, but I refuse to buy an engine intended for end game solutionthathat is a ticking time bomb.
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    It never occurred to me to ask if that engine is flat or roller.. huh.. I'll find out!!
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    Dream_InnDream_Inn Member, Moderator Posts: 7,594 mod
    Yan, I agree.  From the first time I saw those, I thought why did it take so long! :)>-

    Dream 'Inn III -- 2008 400 Express

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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    Sweet Baby James.... that thing looks like F.U.N.......

    "... I'd rather burn out, than fade away..."

    the primary concern I would have is how long that thing holds up... metal fatigue and all that, plus the fact they have an all aluminum block shoved in a housing (which is super cool)... In theory the aluminum dissipates heat better than steel or iron, however, the number of heat cycles is much less than the iron counterpart.. If they are using a standard block the aluminum is cast dang near free of carbon (I can't recall the actual makeup, but it seems like it was close to 8040 aluminum IIRC)..

    that particular block is fantastic for being light and perfect for a car (which has an extremely controlled temperature range with multiple thermostats) but it isn't made (in cadddy form) to maintain those kinds of numbers for long durations... it's made to produce adequate numbers (almost if not n/a numbers) throughout the RPM range, but to have a MASSIVE amount of boost available for the short spurts such as hard launches and passing situations... coming out of turns.. ect... for that thing to spool up and maintain the boost (non-turbo boost, mind you) is exceedingly **** every moving part inside it, from pistons to cranks, all of the valve train (valves SLAM on the seats), to even the soft surfaces such as head gaskets and bearing surfaces (okay, soft'ish surfaces)....

    this goes back to what Mr. BoatAway was saying- and he is dead right... that is asking too much from an engine in a Marine application- high rev's held over a long period, I just don't think it will last.. The notion, in my mind, was a good one because I intend on swapping out that 4.3, and wouldn't mind killing it in the process- and that, only because there is no market for a 6banger with a saltwater resume...

    I certainly wouldn't buy a s/c engine like that as and end game solution- though that is one COOL dang engine, and woudl be a blast (so long as your not caught offshore all alone with it)... !!!
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    that thing is a Baaadmofro no doubt about it... that power-plant is impressive at every level.. it is a testament to what engineers can accomplish.. seriously..

    image

    image


    image
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    'they' would likely be better served answering that question in 'gallons per minute', no?

    'they' could also do something Ferrari is doing, which is flippin' brilliance- they are using a computer controlled motor to press the cam shaft either forward or backward, which evenly increases lift/duration of individual valves, or (catch this) ACTUATES other valves that are not in use until 'requested' by the user.. meaning, a true variable displacement engine- whole cylinders can be DE-activated during cruising, which would use considerably less fuel- like, half less.. but when you need to power, you press the throttle and an automated process 'senses' what you're asking of it- moving the camshaft forward and pushing the lifters up a smooth transitional 'inclined plane', furthering the lift/duration of the primary valves, but actually engaging others that lay dormant unless you 'request' them.. it's flippin' brilliance to be sure!!

    THAT technology is several years out from finding a home in Marine applications, but it seems perfectly at home in such, don't ya think?
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    BoatAwayBoatAway Member Posts: 179 ✭✭✭
    RinkerYan said:
    Guys, Google the new Seven Marine 557 HP outboard. 6.2 L Super charged V8.. Sweet. I wish Rinker would come out with a twin outboard design similar to the new SeaRay where the out board motors are under a big hood. You get more cabin space that way. 
    don't get Al started on that topic!!!
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    All day long.. they're all about fuel.. if its conservative to start with, just open up volume and duration of injection, and there ya go..
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    I'll dig around some and see what I can come up with...

    know this though, and I promise to keep it brief:

    diesels are ALL about fueling- not only how much fuel, but when.. and then keeping enough air in the cylinder not to create cutting torches out of injectors...

    your engine runs HEUI injectors, which use a tiny piston to create high pressures, and is measured/limited by the injectors cylinder... increasing the pressure to them does no good.. that makes the injector itself the limitation... you could find those yans can't fit any larger injectors than they have... increasing air to a compression fired engine w/o adding fuel is going to do you no good... the space available where your injectors reside may be a limiting factor you can't overcome.
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    Black_DiamondBlack_Diamond Member Posts: 5,439 ✭✭✭✭✭
    @RinkerYan: Every diesel manufacturer out there says 'don't mess with the engine or chip it'.  It's really about warranty, after that it is not their problem.  Just a matter of bigger injectors and a bigger fuel pump, then of course pushing all the air into it you can (turbo usually).  Just have to watch your exhaust gas temperature.  If you can get the parts, you could empty your fuel tanks in short order.

    Past owner of a 2003 342FV
    PC BYC, Holland, MI
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    212rowboat212rowboat Member Posts: 2,591 ✭✭✭✭✭
    uh.. check that.... no HEUI for you!!! that thing uses a central pump and mechanical valves per cylinder...

    link to check

    all this said, this engine would be hard to modify within a specific range... you'd be better served attacking it from the gear side.
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