[Shotimes] (OT) Marauder

[David P]

Don,

    I never inferred that anyone has perfected 4V design. I've inferred that
4V is superior to 2V, and it is from a physics standpoint. 4V will replace
2V as a standard if we get to that point before push-valves are usurped by
newer technologies.

So, you are saying that Ford is delinquent for having to put a blower on a
4.6L motor to make power similar to a 5.7L motor?

If this is old, and people won't change their minds, why do you bother
joining the conversation? I usually filters those out. No need to get
negative about the conversation. It's not like we are talking about ways to
make a million dollars by only opening envelopes or something.


David P

95MTX



~
----- Original Message -----
From: "Donald Mallinson" <dmall@mwonline.net>
To: <shotimes-admin@autox.team.net>; <shotimes@autox.team.net>
Sent: Monday, November 04, 2002 10:29
Subject: Re: [Shotimes] (OT) Marauder


> Well, a 4V design has more to do with high rpm breathing
> than emissions.  IT is easy to get plenty of swirl in a 2
> valve design, and has been proven, there is no real
> emissions bonus between the two designs.  Several
> manufacturers have plenty of OHV designs that meet or exceed
> emissions for the forseeable future.
>
> Many people forget that OHC or 4Valve designs are not
> anything new, they are just the "thing" at the moment.
> There are also several examples of 4V pushrod single cam
> motors!  The OHC design came along at almost the exact same
> time as the ion-block pushrod did, I can't say exactly why
> the pushrod won out many years ago and became the dominant
> design,(probably because of cost,but when it comes to the
> world of todays motors, not much is new other than computer
> control, pretty much everything else was thought of and
> tried in the first half of the 20th century.  Chevy made a
> V8 OHC motor many years ago, long before the small block,
> about the same time as the flathead Ford.  It was dropped.
>
> What WILL be dropped in the near future will be ALL cams,
> OHV or OHC. I won't be upset at that moment, and I hope you
> won't be either when those to cams per head become junk heap
> fodder.  Individual control of each valve lift/duration/open
> and closing velocity is the next big thing.  Already
> happening in F1, it will happen in big diesel engines next
> because they run slower and a beginning design for an
> actuator will work.  Higher reving gas motors will come
> later, but it will come.
>
> The hydraulic VS solid lifter is a non issue for this
> discussion since it can be done either way no matter what
> design, I never talked about maintenance since the 60k is
> really not needed till 100k, that is what experience has
> taught us.  I don't see a real difference on maintenance,
> but experience has taught us that 4V motors are MUCH more
> expensive to re-build.  Twice the valves and machine/parts
> time on the heads is the main difference, and one cam versus
> four.
>
> As far as what wins on power?  4V motors sure don't have an
> edge there.  Ford is resorting to blowers to come close to
> the small block that is running more power, more torque and
> the same if not better mileage or emissions.  End game on
> that discussion.  If the 4V motor had such a big advantage
> as you imply, then there would be big HP motors out there
> without power adders.  Check out any fast import racer,
> virtually ALL of them rely on power adders to get numbers.
>    They don't have the low end torque to get good et's so
> they rely on top end power for MPH and help on ET.
>
> I admire and love the 4V motor in my SHO's.  I also admire
> and have owned and enjoyed the pushrod motors.  My 66 Grand
> Prix has a smooth power that can't be duplicated in a 4V
> motor, or at least it hasn't been yet.  My SHO has a top end
> rush that isn't present in OHV cars other than extreme race
> cars.  I like both designs because they BOTH have their
> postive and negative points.
>
> I have spent this much time on this discussion, just because
> you claim such a huge advantage for the OHC 4V design.  Yes
> it does have some breathing advantages if you want to run
> high rpm applications.  For 99.9% of the driving that
> Americans do, the OHV 2V design, that is just as old as the
> 4V OHC designs, is a BETTER application, this just can't be
> disputed.  More torque down low, same basic economy/emissions.
>
> This is getting old, and has the makings of an argument
> between two people that won't change their minds.  I choose
> to go with the evidence that we know about and experience
> that teaches us that while one design is "considered" newer,
> it isn't, and there are uses for each.
>
> People will be hot rodding small block Chevy's till cars are
> finally outlawed and we all use Star Trek transporters.  AND
> people will probably be making fast 4V OHC designs too.  But
> the OHV 2V people will have more money in their pockets and
> easier speed on the drag strip!
>
> Beam me up Scotty!
>
> Don Mallinson
>
> David P wrote:
>
> > Since all OHV motors are two-valvers, and four valves allow more
efficient
> > combustions, then pushrods DO have a bit to do with emissions, at least
> > until they figure out a way to cram 4V onto a single cam. Sure, injector
> > placement, intake flow, etc play a large part, but when considering
solely
> > 2V vs. 4V, 4V is going to win on emissions and power. You think maybe
there
> > is another reason why the Corvette runs a 2.73 final?
> >
> > As for OHC being high maintenance, I think you are forgetting that the
SHO
> > does not have a hydraulic tappet. Remove the hydraulic tappet from any
OHV
> > motor and it becomes just as maintenance intense. Not as expensive to
build,
> > but just as expensive to maintain. If Yamaha had inserted hydraulic
tappets
> > into their design, we would not be sitting here exclaiming the need to
do
> > the 60k on time.
> >
> > Sure, the small block (or more specifically, the OHV design) will be
around
> > for some time, but eventually it will be dropped in lieu of more
efficient
> > designs in our nation's quest for emissions reduction. Don't get upset
about
> > it though, as OHC's days are numbered as well. There are much better
> > air/fuel injections systems on the boards and in testing that don't have
> > valves as we conceive them that will see fruition in the last half of
this
> > century, leaving OHV as the predominant valve design of the 19th, 20th
and
> > 21st centuries. Not too bad a run, but definitely a technology that has
> > outlived it's usefulness.
> >
> >
> > David P
> >
> > 95MTX
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