REFLECTOR: engine size & CS prop

Mon Feb 4 16:01:01 CST 2008

Greg,

How dificult/expensive would it be to transit from a fixed pitch to a CS
propeller?  In other words, suppose that in order to get quickly in the
air, one chooses a fixed pitch propeller (assuming they are easier to get,
though I'm not sure about that; they are obviously cheper though).  Then in
2-3 years, suppose that one realizes that one would really like to have a CS
prop.  Is it difficult/expensive to switch?  My question is probably very
silly; I really have never installed a prop.  I'm just looking for options.

Best,
Grigore

On Feb 4, 2008 3:28 PM, Greg Poole <greg at pooledresources.com.au> wrote:

>  For the same reasons I gave for going with the bigger engine, I would –
> if the budget allows it – then go with a constant speed prop. I believe it
> is generally acknowledged that a  correctly set up CS prop will enable you a
> much wider performance envelope than what is possible going fixed pitch and
> will consequently get you up to flying speed much faster than most fixed
> pitches which tend to compromise  one end or the other (usually both!).
>
>
>
> While the factory has favoured MT props to date, they are not universally
> popular amongst Velocity drivers due to high service and purchase cost and
> very soft blades which have proven easily damaged…as a consequence, many of
> us await reports on other brands such as Vesta (how's it going Dave Dent?)
> and the one Milt is promoting….
>
>
>
> *Greg in Sydney*
>
>  greg at pooledresources.com.au
>
>
>
>
>
> From Grigore Rosu
>
>  The recent messages on this list (for which I warmly thank you) made me
> switch my vague opinion to a Lyc 200HP engine.  Would an MT propeller work
> fine with it?  I'd like to keep things simple and safe for this airplane,
> and I saw lots of complaints on propellers on this list.  I wouldn't mind
> picking a fixed pitch propeller either (to be honest, in our club we only
> have fixed pitch propellers, so I have close to no experience with variable
> pitch ones).
>
>
>
> Grigore
>
>
>
>
>
> On Feb 4, 2008 11:33 AM, Lawrence J. Epstein, MD <ljepstein at hotmail.com>
> wrote:
>
> It all depends on your time frame. If you are a year out from engine
> install, then you have more options.
>
> Soon after delivery of the 1st production run, DH will have a "Firewall
> forward (back)" kit available for the Velocity, which according to Doug (who
> I spent about an Hour on the phone with a few months ago), should be very
> complete. Therefore, I wouldn't expect it to be a whole lot more
> "experimental" than the Lycosaurus.
>
> The first production run (awaiting delivery) includes many velocity
> builders (not to mention all the prototype work to date), so there should be
> good experience by the time your engine would be delivered.
>
> If you need an engine in the next 12-18 months, then I would go with the
> Lyco.
>
>
>
> Larry Epstein
>
>
>
> -----Original Message-----
> *From:* reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] *On
> Behalf Of *Grigore Rosu
>
> *Sent:* Monday, February 04, 2008 10:59 AM
> *To:* Velocity Aircraft Owners and Builders list
>
> *Subject:* Re: REFLECTOR: tools, tools, and tools again
>
>
>
> Dear Larry,
>
>
>
> I was and still am a strong supporter of DH engines.  When I ordered my
> kit, I was 100% sure that I'd install a DH engine in my airplane.  In the
> meanwhile though, after realizing how much time everything takes, I changed
> my mind and decided to go for a standard and well-tested configuration.
> There are many much more experienced builders than me who would be happy to
> go for an inovation like that, because they have a much beter big-picture
> than I do.
>
> My hidden (from wife) plan is to finish this SEFG and then, while flying
> it, to start building a new Velocity airplane, "the airplne of my drams",
> that time as an "experienced" builder.  That will definitely have a diesel
> engine (also, I intend to eventually move back to Europe, where diesel is a
> lot cheaper).
>
>
>
> Grigore
>
>
>
>
> On Feb 4, 2008 8:16 AM, Lawrence J. Epstein, MD <ljepstein at hotmail.com>
> wrote:
>
> Since you the have the luxury of some time before you make an engine
> choice (I lead a very luxurious life, I started my project 12 ½ years ago),
> you should at least take a close look at the Deltahawk diesel. With any
> luck, the production engines will be delivered and flying by the time you
> are ready. I won't go in to the advantages here (many pages of discussion in
> the archives as well as their web page), but it has been engineered & tested
> primarily on a Velocity and as Avgas gets more problematic, a diesel looks
> more & more advantageous.
>
>
>
> Larry Epstein
>
> 173 FGE
>
>
>
> -----Original Message-----
> *From:* reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] *On
> Behalf Of *Grigore Rosu
> *Sent:* Monday, February 04, 2008 8:59 AM
> *To:* Velocity Aircraft Owners and Builders list
> *Subject:* REFLECTOR: tools, tools, and tools again
>
>
>
> Dear Reflectorists,
>
>
>
> Thank you everybody for the valuable input on tools and the engine.
> Following your advise, I'll most likely go with the Lycoming 200HP, when the
> time comes.  My original 160HP choice was based exclusively on range, but I
> see the points you made, so probably in this case less range is OK for the
> increase in power.  I would still be grateful for an answer on the prop arc
> diameter ... or is the general advice to use a little cap chain and not
> worry about positioning?
>
>
>
> Regarding tools, I have just made another order with Aircraft Spruce;
> another $200.  I think I spent close to $2,000 so far on tools; I had almost
> no tools when I started my project.
>
>
>
> For those who are just starting their project, please do not
> underestimate:
>
>
>
> 1) the number and cost of tools that you will need for your airplane;
> better be realistic than  have surprizes.  Of course, if you can borrow
> tools from a friend or another Velocity builder that is great; but I am
> totally isolated in a university city (Urbana-Champaign) and my friends only
> know how to write computer programs and solve mathematical equations; never
> heard of something called "pipe flaring" :-)
>
>
>
> 2) the amount of extra-, initially unexpected time you'll need to spend
> scratching your head or waiting for tools/materials.  Give each subproject a
> generous estimate, then triple that.  I started fitting the pilot side lower
> strake on January 18 and I was convinced that I would close the top strake
> by the end of January if I give it all my time/energy.  There were the
> "unexpected" fuel senders, which slowed me down a few good days:
> "unexpected" because they were not even mentioned in the manual, and slowed
> me down because I had to order and wait for them, then learn how to install,
> ask, etc.  Well, now is Feb 4 and I still have to wait for the "unexpected"
> finger strainers, the AN fittings needed for the change in plans, etc.
> Assuming I receive these by Thursday and did not forget to order some
> important little thing which will delay me one more week, then I may have a
> chance to close the strake by the end of the week, say Feb 10.  Applying the
> reasoning above, that probably means Feb 18 or so, making it about 1 month
> of work for one strake only.  There is this Jeffco thing, though, which I
> have never worked with and which has no proper webpage with detailed
> explanations on how to use; I can only optimistically hope that there will
> be no other "unexpected" issues with it ... though there always were ...
>
>
>
> Grigore
>
>
>
>
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