REFLECTOR: Deltahawk engine

Fri May 6 10:32:21 CDT 2005

----- Original Message ----- 
From: "Grigore Rosu" <grosu at cs.uiuc.edu>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Friday, May 06, 2005 1:42 AM
Subject: Re: REFLECTOR: Deltahawk engine

> Warm thanks to those who expressed their opinion on the DH engines: 
> (in chronological order of answering) Andy Millin, J.P. Brooks, Douglas 
> Holub, Al Gietzen, Tom Martino, Dean May.  It was a very pleasant first 
> day on the REFLECTOR discussion list.
> 
> Please let me tell you a bit more about my plans regarding my 
> Velocity-to-be.  Any piece of advice is more than welcome, 
> including/especially criticisms!
> 
> I intend to use a constant speed propeller, more precisely to order the DH 
> engine kit promissed by Velocity, Inc.
> 
> I have little knowledge of mechanics or engines (I'm a computer science 
> professor), so simplicity of engine matters to me.  The fact that DH has 
> fewer moving components, no carburator or fuel leaning, no sparks, etc., 
> sounds very attractive to me.

That is what attracted me to their engine also.  I used to own a C-152, and had to grind the valves at 500 hrs, because it was leased back to a flight school.  If you don't baby those old style engines, they self distruct.  No valves, no magnetos on a Delta Hawk.  

> 
> I'm interested in flying long trips with my family (2 adults plus 1 
> child).  Speed is NOT the most important factor; what I care is 
> reliability, endurance and efficiency.  I'd like to also fly at least one 
> trip USA-Europe per year.
> 
Are you thinking of flying the single engine Velocity over the North Atlantic?  I wouldn't recommend you do it, because no matter how reliable an engine is, it could fail at any time, and swimming in 32 degree water is not much fun.  Everytime we cross the atlantic in the big jets, we always have engine failure contingency plans in the event of an engine failure 

> Does anybody know which of the 160, 180 and 200 models can fly the longest 
> distance on a given amount of fuel, at its normal cruising speed?

The talk at the Delta Hawk factory is that the 180hp model will probably need to be intercooled also.  The tests on the 200hp intercooled engine done on their dyno showed that the engine needed less fuel flow to produce the same torque as the 160hp.  They have no hard facts to back this up yet, however.  Also, the engine ran much smoother and produced much less exaust smoke when intercooled.  I would highly recommend the intercooled model.  
> 
> I understand the the only "drawback", if we can call it so, of a 200 model 
> is the intercooler, which may slightly complicate the installation.  Can 
> anybody think of any drawback of the 180 model in contrast to the 160 one? 
> TBO? (let's ignore the price and assume a constant speed propeller)  I'm 
> not decided which of the DH engines to pick, so I'd like to understand all 
> the factors before choosing one.

The Delta Hawk engine, because it is turbocharged, is able to produce sea level power up to and above 18,000 feet.  At some point above 14,000 feet, the engine now outpowers a fixed pitch propeller, and you now have to reduce power to prevent overspeeding the engine.   A constant speed propeller, in the same situation, can change to a courser pitch, produce more thrust and keep the engine speed within limits at greater power.  Of course, how much time will you be spending above 14,000 feet?  

> Also, another important issue: insurance!  Everything else being equal, is 
> the insurance for a Velocity with a DH engine any higher than for one with 
> a Lycoming?  Also, it seems that Deltahawk will soon certify their engine. 
> My dumb guess is that they will first certify the 160 model, in which case 
> the insurance of a Velocity with DH160 may be lower ... Any thoughts on 
> that?

Delta Hawk plans to certify all models in the future.  The only difference between the 160 and the 180 or 200 is intercooling, and that shouldn't really be a problem in the certification process.  The cost of insurance on a uncertified engine installed in an airplane will be more.  

If you wish to, you could call the Delta Hawk factory and talk to them there.  They are always happy to discuss their project with prospective customers.  However, when people do talk to them, it does take their time away from building my engine.  

Dean May
STGRG

> 
> Anticipated thanks,
> Grigore
> 
> p.s. I hope I'm not asking too many questions for a new comer ...
> 
> 
> On Thu, 5 May 2005, Grigore Rosu wrote:
> 
>> I am perhaps the latest member of the list (just received the confirmation of 
>> my order for a Velocity SE/FG a few days ago), so please let me start with a 
>> warm hello to all the enthusiastic Velocity Builders!
>>
>> I am living and flying in Illinois (Champaign-Urbana area), but I am 
>> originally from Romania.  I intend to move back to Europe in a few years, so 
>> I am 99% decided to go for a Deltahawk engine (as you may all know, in Europe 
>> the price of AVGAS is prohibitive).  I am also very impressed with the latest 
>> comparison data between the DH160V4 engine and the Lycoming IO-360, so it 
>> looks like a DH engine may be a very good choice even for one flying one's 
>> Velocity all the time in the USA ... (see 
>> http://www.deltahawkengines.com/perfor00.shtml).
>>
>> Are there builders on this list who are seriously considering a DH engine?
>>
>> Can anybody comment a bit on the three possibile DH engines, namely the 
>> DH160V4, DH180V4, and DH200V4?  According to Deltahawk's data, a DH160V4 
>> sounds like just good enough for a Velocity SE/FG.  However, a DH180V4 also 
>> seems very attractive.  Also, what would the REAL difference between the 
>> three engines be in the case of a Velocity SE/FG (ignoring the price)?
>>
>> Thank you,
>> Grigore
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