"Elie, Larry (L.D.)" wrote:
Hi Paul, I hope this e-mail address is still good, as I haven't mailed you in 5 years or so...
Do you know whose 3.1 L 120 deg. V-6 block Bombarder is using for the V-220 and V-300T av engines?
As casting plants are expensive, I doubt Bombarder is making their own. As you may have read, the
V-220 is certified at 220 hp @ 6,000 RPM & the V-300T (turbo of course) does 300 hp @ 6,000. Water
cooled, they have a 3:1 PRU, and the whole thing is electronically controlled. There are any number
of 3.1 L engines out there that they might have based this on. I just don't know which.
Larry Elie
Ford Research & Advanced
Hey Larry long time no hear from. How's it going?
I was not paying any attention but if it is at OshKosh I'll take a closer look.
It did not occur to me that it was based on an automotive block.
In any event if they certify it they will have trouble as the FAA has been
going around and around with Thelert(s) on their MB based diesel AC engine.
The FAA wants to see a paper trail from the mine to the air.
Bombarder is a big company. Maybe they own the die casting plant that
makes the block for the auto manufacture. If so it will never hold
up on aircraft duty cycles.
What the FAA said on the Thelert is you have to scrap it after 1200 hour
or ten years whichever comes first. No rebuilding. Also Thelert must disassemble
it and inspect all parts for material and dimensions. That makes it
unacceptably expensive.
BTW Remember I was having trouble with my 94 Mercury V8 OBD II? I finally figured
it out. The guy that wrote the OBD II software screwed up. "Bank one lean." does not
mean both banks are not lean :) Turned out to be speck of dust on the hot wire
MAF sensor. One would think it was one of the two bank O2 sensors.
One another subject while I have you on line here is something I am proposing
to Mazda on the RX8 engine. What do you think?
Paul Lamar
"Elie, Larry (L.D.)" wrote:
A casting plant starts at $200,000,000 US, not including land or utility/railroad hookup. That's
for a small plant. Bombarder would never get it back, ever. Read my paragraph; I didn't say it
was auto block based (although that's a very real possibility) as boat would do as well. FAA/CAA
want paper, and paper is cheaper than parts. That's how Toyota got the Lexus engine certified, and
how their Piper look-alike will be done. My guess is the block is made in the orient, and the
paper trail will be produced. Paul, this is the block, not the rotating parts; aircraft duty cycles
are relatively light; torques are pretty small. There have been a number of blocks that were transferred
to turbo-diesel without event. That's a tougher application. I know the people doing H2 conversions
(that one IS hard... H2 explodes, it doesn't burn) and it still uses standard block castings. The only
criteria I know of that would limit a block would be if the dimensions limited the bearing size; that does happen (or has) and limits the durability. An example would be a motorcycle engine, but we have made some
that couldn't grow either.
Mazda is still trying to make a buck. They did Miller cycle, and a Comprex, but people are more keen on
styling than on the guts. These things didn't make a dent. Pity.
Larry Elie
I don't agree on aircraft duty cycles. Cars need only 30 HP average.
No way would they use more HP and still get 25 to 30 MPG on the
highway cycle. Run the numbers. Use an extraordinary BSFC of .40 if
you wish. Most car piston engines are good for only 300 hours
using aircraft engine duty cycles.
Aircraft engines need 150 HP continuous and 200 HP for five minutes.
Toyota was awarded 800 hours TBO by the FAA as I recall after an expensive
total redesign while a real aircraft engines have 2000 hour TBOs. That is
why Toyota gave up on the V8 and went with Lycoming. No pilot in his right mind
would buy a half million dollar airplane and then have to rebuild the
engine after only 800 hours.
What I was suggesting is that Bombarder was making blocks for some auto
manufacturer. I happen to know that Wankel GmBh Korf Germany was part of
a larger die casting plant making die casting for MB. Bombarder is
a BIG company. 200 million is not out of the question.
As far as holding up... the block is only a small part of the problem.
What happens is the automotive block is made too short for aircraft service
not allowing enough radius in the crank journals hence not enough fatigue life
for the crankshaft at high continuos power. This was a main part of why Orenda
went belly up with the Chevy big block based V8 aircraft engine despite having spent
50 million on the project. They eventually solved the water jacket cooling problem by
redesigning the block and heads but they failed to add the necessary length
to the block as that would require yet another new crankshaft forging die.
Further more inline engines and V engines are trying to shove the crank
out the bottom of the block adding to the overall engine weight compared to
a horizontal opposed configuration. Orenda should have started with a clean
sheet of paper using the horizontal opposed configuration as Honda is now doing
with their joint project with Continental.
As far as the turbo compound RX8 engine 30 MPG in the RX8 EPA high way
driving cycle surely will make a dent.
I can't think of many 120 degree V6's out there. Most are 90 degree. Some are
less. VW comes to mind. I think Ferrari has a 120 degree V6 but I don't think it
is die cast. I could be wrong. Ferrari spends over 300 million each
year for their Formula One racing program.
We are REALLY REALLY lucky to have the Mazda rotary :)
Paul Lamar
Good answer Paul,
Chris Cosman
The Rotary Engine NewsLetter. Powered by Linux.
ACRE NL web site. http://home.earthlink.net/~rotaryeng/
Copyright 1998-2004 All world wide rights reserved.