[OMC-Boats] Guy with modded v6 Sportsman for sale

On the subject of four-barrels, what do you listmembers think of the job this guy did on a v6?:

http://lansing.craigslist.org/for/1509082087.html

There's not much left original except the block. The Sportsman hull and interior looks to be in bad shape, but the engine might be worth something. Just wondering if any of these mods would change the "Sportsman 155 experience."

-Doug Julien

--- On Thu, 12/17/09, Scott Veazie <scottveazie@...> wrote:

> From: Scott Veazie <scottveazie@...>
> Subject: Re: [OMC-Boats] Fuel Injection
> To: bchowk@..., omc-boats@...
> Date: Thursday, December 17, 2009, 4:28 PM
>
>
>
>
>
>
> Having had a Rochester Quadrajet 4bbl on the '74
> 22' Glastron I had with 225hp 307V8, I'd highly
> recommend a true quadrajet. Small secondaries for
> "good" fuel economy, large "toilet bowl"
> secondaries to really throw the hammer down.
>
>
>
> ~Scott
>
>
> Date: Thu, 17 Dec 2009 15:52:36 -0600
> From: bchowk@...
> To: omc-boats@...
> Subject: Re: [OMC-Boats] Fuel Injection
>
>
> Well there you go....You guys Rock! Like ya'll I
> thought about it briefly and stopped at the expense. Like
> ya'll I think it would be "cool" but in the
> end not neccesary. Really appreciate your insites guys,
> interesting!
>
> Sounds like you made a wise choice John.....In the
> cool but not neccessary category, have you ever thought
> about a 4bbl for your V8?
>
> Cheers,
> B.C.
>
> Dec 16, 2009 02:52:27 PM, omc-boats@...
> wrote:
>
> On Wed, 16 Dec 2009, Lee K. Shuster \(lks\)
> wrote:
> > I think you made a good choice. You should be able to
> "dial-in" a Rochester
> > 2G-series fairly accurately with a little care and
> understanding:
> >
> http://www.oldcarmanualproject.com/manuals/Carbs/Rochester/2-Jet/1964Manual/pages/64Rochester2Gmanual_0002_jpg.htm
> > Moving to just about any type of fuel injection (TBI
> or MPFI) system on an
> > old boat would be financial folly, IMHO. 1) You would
> spend more than the
> > boat is worth, 2) It would no longer be original and
> 3) the "improvements" in
> > turn-key reliability, serviceability, performance and
> fuel econonmy would be
> > barely noticeable.
> > Not only would you potentially be looking at major
> changes to electrical
> > wiring, fuel delivery, distrubutor, possibly intake
> and exhaust manifolding,
> > and ECM programming, but to what means? Most likely
> you'd run the ECM in
> > "open-loop" mode, without an O2 sensor,
> which negates the ability to have the
> > ECM adjust Air/Fuel ratios based on 02 feedback.
> > I've given this subject a lot of thought for my
> own boat, as there are many
> > alternatives out there for my small block Chevy V8.
> I've decided that the
> > stock marine Rochester carb is pretty hard to beat,
> when it's properly dialed
> > in.
>
> I'd agree with Lee here. Having implemented electronic
> fuel injection on a
> variety of engines that didn't originally have it
> (mainly motorcycle
> engines used in snowmobiles applications), I would say
> it's not worth it,
> *unless* you are doing it for curiosity and entertainment.
>
> These engines generally aren't run over a wide range of
> conditions
> (temperature, altitude (excluding Lee)) and don't have
> exhaust
> aftertreatment (catalytic converters) that is sensitive to
> precise mixture
> control Carburetors can work very well for steady-state
> applications,
> especially when you care more about performance than
> emissions or fuel
> consumption.
>
> I've never adjusted the fueling on my engine, but I
> would guess it is tuned
> to run 5-10% rich - an air/fuel ratio that leads to maximum
> power output
> and lower exhaust-gas temperatures. This is a range where
> small variations
> in fueling don't really make a huge difference in any
> aspect of
> performance.
>
> The reason fuel injection systems exist is primarily
> because modern
> emissions controls system require that the air-fuel ratio
> be maintained
> within 1% or less of stoichometric over a wide range of
> operating
> conditions. Three-way catalytic converters used in gasoline
> engines
> require that the air-to-fuel ratio rapidly switches from
> lean to rich
> around this range - if it were to stay slightly lean or
> slightly rich for
> any length of time, emissions might be 10 times higher, and
> you might end
> up burning valves if it were to be a bit too lean on a
> high-performance
> engine. When engines are run "a little rich",
> there's a lot more tolerance
> for errors.
>
> Electronic engine control systems also have advantages for
> easy starting
> and warm-up, but I've never had problems with that on
> my engine - even at
> below-freezing temperatures it usually starts within a few
> seconds of
> cranking, will idle right away with the throttle slightly
> advanced, and is
> ready to idle with the throttle fully closed within a
> minute or so.
>
> Another advantage to electronic control systems is that
> "tune-ups" might no
> longer be required - the systems (with O2 feedback) are
> self-tuning and
> adapt for variations in fuel and other factors. However,
> the amount of
> time you'd put into the initial setup of the system and
> tweaking it
> (because you can!) would be far more than the time
> you'd spend on decades
> of tune-ups.
>
> It really wouldn't be hugely complicated to do (add an
> crank encoder on the
> flywheel or distributor, drill ports in the intake runners
> for injectors,
> cobble together a fuel rail, mount up some coil drivers,
> add a TPS and MAP
> sensor, and come up with timing and volumetric efficiency
> map for various
> RPM and throttle positions), but the but benefits would be
> fairly small.
>
> I'm guessing you'd get perhaps a 5-10% improvement
> in fuel consumption over
> a well-tuned carbureted engine, significant improvements in
> emissions (100x
> or more, though you'd never know without hooking it up
> to an emissions
> bench), a lower idle during warm-up, and improved starting
> (probably on the
> first or second revolution).
>
> Really, I'd love to add forced induction, electronic
> throttle control,
> electronically-controlled shifting, and closed-loop fueling
> control based
> on feedback from a wide-band O2 sensor, but what's the
> point? I'd also
> like to get out on the lake and enjoy my boat, regardless
> of whether it is
> working as well as it good be! Carbs really are awesome, as
> long as having
> fueling within 5% or so is "close enough" and you
> don't mind having to
> adjust them once in a while. Feel free to add fuel
> injection if you are so
> inclined (and definitely tell us about it - I think
> it'd be awesome), but
> it's definitely not necessary!
>
> Ethan
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Received on Thursday, 17 December 2009