Putting a VIKING Engine in an S7 Courier
2013/04/21
In addition to the original Viking
Engine group: http://groups.yahoo.com/group/Vikingaircraftengines/
A new one has started which is not
censored by Jan. Worth looking at: http://groups.yahoo.com/group/Viking_Aircraft_Engine/
The Viking/Honda looks like a
possible alternative to the 912S Engine. It is less than 20lbs heavier (maybe),
is fuel injected, uses a stock automotive block and really looks nice! Jan Eggenfellner says it is $10000 les than
the Rotax alternative but in the S-7 environment, at current prices from Rans
of $21,000 for a new 912S and firewall forward kit (17+4 as of 2012/09/20), it
looks like it is about $5000 less. For about $16000 Jan offers the engine, fuel
pumps (pre assembled package), wiring harness, header tank, motor mount and
cowl; these last two items are not yet in production for the Rans. For another $2800 Jan will do the whole
installation. It sounds very appealing.
I started discussions with
Jan and sent him some info my S7S. Below are the areas I thought he might need:
First, Weight and Bal measurements
One of the first
tasks I wanted to do was plug the Viking numbers into my S7 weight and balance
spread sheet. I thought Jan would also want to do this especially if I were to
hire him to do the installation so I sent him the following material:
_
____|__|_____|_______|_____________|________|_______|_________|________|
Firewall
P E
Datum G B1 B2 BY Short S + Long
-29.5 -17
0 34 81.5 110 140/142 208 230
Stations are: Prop,
Engine, Datum, Main gear, Forward/aft Baggage station
Engine CG is approximate
(engine and prop, without muffler was about level when hoisted at the lifting
pad).
The prop hub measurement of
-29.5 is from Rans but I see 29” on mine plus a 1” spacer putting the prop at
-30”
All models of the S7 (short tail, long tail
and S) have the same moments from firewall (D) to
CG range: 46 to 51
Typical empty Cg is 49”; Most
fwd (low fuel, 220 pilot) 45”
I also sent Jan measurements
for the S-7S firewall forward which I’d obtained from Rans.
My early S7S has a heavier
cowl (15.4lbs vs. 11 stock) larger oil cooler, thermostats and cabin heater and
empty CG is 47.9”
Oil canister is on firewall
(dry sump engine).
Spinner is 12”
Jan thought that he might
move the Viking back a few inches but could put in a 2” prop extension. He
never said where the CG of the Viking engine is however my rough estimates and
adding the header tank gave a minimal CG change. Jan didn’t seem too interested
in the actual weight and bal numbers just how builder’s models have worked out.
He said:
I am more interested in the general knowledge between builders, as
if the airplane tends to end up tail, or nose heavy. Or right where it needs to
be.
The throttle control quadrant
on the courier connects to dual bicycle cable/spring return at the carbs. Does Viking use a
push/pull control? Yes
Fuel system:
Fuel line routing on this and
earlier S7 models has tank exits at front and rear of each tank. These 2 lines
from each tank are Y’d together part way down B1 to get one line per tank and
Y’d again at base of B1 to one line going forward.
Later S models have the
forward tank outlet going down the forward door post to a block below the pilot
where front and rear are merged. Both then have the fuel shut off just ahead of
the pilot seat. Mine has no electric fuel pump just the engine driven pump;
later S models have a fuel pump and gascolator on the firewall.
The baggage compartment is
defined by a cloth sack. There may be room below at either baggage station for
the header tank.
The header tank holds 2.5
Rad:
That is the stock coolant rad
angled down ahead of the firewall. My cowl is a little deeper there than stock
and the rad covers most of the air outlet area so that most of the air coming in
the top nostrils and from the oil cooler exits through the rad. The later S
models have the rad horizontal and a little higher with no baffling to get most
of the incoming air to exit through the rad. Some folks have added some
baffling to encourage more air through the rad.
Jan’s package has the rad
forward below the engine which may result in a pudgier cowl. Possibly it could
be moved back closer to the firewall.
Current battery is an Odyssey
(680?) at -142. It could be moved back to the next station at -170:
and looking forward:
and aft:
Without doing any
calcs, Jan thought that the existing battery location was good.
Mount construction
The Viking stainless mounts
look exceptional but I wonder about one design aspect.
Paul Lamar is a guy in
http://www.rotaryeng.net/mm-instruct.html
Paul’s main point which, I
understand, is a legitimate engineering rule of thumb is that all members in
such a structure should be in tension or compression and NOT see a bending force.
He concludes with:
If these rules are
violated the motor mount might still work but it is nearly impossible to
predict the stresses and deflections without FEA and therefore these kinds of
mounts are extremely dangerous. They may crack without warning.
It appears that many of the Viking mounts
disagree with his approach in that they do not have multiple tubes converging
at a point and frequently have cross braces meeting another tube not at a
cluster. This is one example:
Paul would disagree with this
design. Is he wrong? Jan’s response:
Yes, wrong.
The cross bar does not contribute to holding the engine.
It only allows for the 2 top rubber dampers to share the load equally.
We will not build Viking engine mounts to anyone else's
specifications.
Jan
Sounds like a load which is
applied mid span which others feel is a no, no. Also it looks like that tube
that does hold the engine has no other support.
So, finally, before firing off
my $8000, 50% down payment, I took a look around the net to learn more about
Egenfellner and his previous products.
I did some searches to see
what all was out there on Eggenfellner engines. Turns out there are unsatisfied
customers from his Subaru days and the reduction drives he designed for them.
There have been accidents and at least one fatality with one of his
engine/redrive/prop combos where Jan played an active role in the installation
and testing of the engine. There are claims of paid for but unshipped items.
OK, but this was years ago and with a different product so I was still willing
to consider the Viking but maybe not as an outright purchaser.
As a result of this info, I
sent Jan this note:
Hello Jan.
What I've decided is that getting a Rans S7S flying with one of your engines would be of as much benefit to you as it would be to me. Further, there is no doubt that with so few hours on the engine in any airframe, I am taking some risk in setting aside my proven 912 and going Viking.
I would still be willing to make one of my S7 airframes available for a Viking and aggressively put time on it but not with me footing all the cost.
If you would like to participate in a cost sharing arrangement, let me know.
Peter
Jan replied:
Not interested.
Thank you
Jan
I then sent a note outlining
these thoughts to the Rans Flyers and S7 yahoo groups. One person then
forwarded my note to the Viking group. Jan actually posted it for a couple of hours
and did reply to the financial part of it but then removed it from his group.
It was message number 2443 and did include my questions on the mount design and
a suggestion that there are dissatisfied customers from his other product
offerings. You can see his response in message 2444.
Since first airing this,
several people have pointed out info on the net about Jan’s level of success
with his previous Subaru ventures and some of the accident reports related to
Eggenfellner powered aircraft.
Apparently Jan does not feel
the need to talk to these issues now nor to deal with any subject matter that
may have a negative reflection on his product.
Nevertheless, many of us hope
that Jan has resolved the issues that were a problem in the past and that the Viking
thrives.
2012/10/01
Issue number 103 of Contact
magazine has some comments on Jan’s creative history and an evaluation of some
design flaws in his earlier drives which may still exist in his current
offering (granted listed by a competitor, now deceased, Bud Warren); these
include: type of gears, bearings, lubrication.
The title of the article is: “Eggenfellner Gearbox Problems? Meet the
Alternative”.
A couple of days ago Jan put
out three youtube videos in which he tells his life story focusing on his
involvement with auto conversions. He is candid enough to mention that not all
of his offerings were successful, attributing some problems to trying to go for
higher horsepower engines. I sent a note to the Viking group congratulating him
on his openness in the videos but went on to suggest that maybe he could add to
his credibility by getting some expert engineering evaluation of his drives,
couplings and electrical system.
He did not let the message
get posted nor did he reply.
Next I sent him this note and
also got no reply:
From: Peter Cowan
To: Jan Eggenfellner
Sent:
Subject: Just a suggestion
Hello Jan.
You are proving the claims that you do not want to talk about any issues you feel are critical of your efforts and that is certainly your option.
What is curious though is that you then go and publicly admit on Youtube that you have produced products that were not successful. Why would you do that without then going on to concretely show how you have addressed and fixed those problems? This defies logic.
Take a look at what Bud Warren said about your drives in Contact magazine issue 103 (issues are ball bearings, spiral gears and poor lubrication)
and make the effort to demonstrate technically how you have fixed this; or, alternatively, stick your head back in the sand and say nothing about past failures. Unfortunately, with the web, what you have said and done will always haunt you, forever.
Just a suggestion
Peter
You can read the Contact article here: http://issuu.com/panzera/docs/issue_103-teaser and go to page 4 and 5.
This is a video of Jan presenting at
Near the end of October, I received
a request from Samantha to pay my 50%. I explained what had happened and
suggested she encourage Jan to deal with these issues.
She did reply that Jan agreed
to reduce the price for my S7 installation by $1000. I told her that now, money
was not the issue but rather getting some technical info was more important.