Aviomania - Viking First Impressions

[Abid]

Abid, a rotax 912uls only has 107 hp on the rotax dyno ... not in realy life

No it actually only has 98 HP and 100 HP with their intake which no one uses really. 107 is the Suzuki G13BB with high compression pistons otherwise its also only 100 HP with fuel injection. (MPFI). But its heavier than Rotax but with the extra weight it performs pretty much the same as a 912ULS does on a similar machine and in Florida or near sea level for people of normal weight (170 to 190 pounds), 912ULS provides adequate power for a gyroplane. It when you start getting 220 pounds with 2 people and hot summer is when you start to see noticeable performance difference with 912ULS. Cheapest way to get good perfrmance and not use a 914UL is to lose some weight

 

[Vance]

i have only one thing to add, you can't get enough power from a 4 stroke running at 6000 rpm max without a turbo charger
and one can't install properly a turbocharger if one doesn't have both a true dyno with all the sensors including shock sensor and if one have not played for years with engines for years
as for the weigth ,

How much horsepower is enough?

A Lycoming IO-320 makes 160 horsepower at 2,700 rpm.

Years ago I turbocharged a 98 inch Datsun and it ran trouble free for 100,000 miles before I sold it with 160,000 miles on it. I did not have access to a dynamometer for that project, had no antiknock sensors.
I used an SU carburetor and tuned it by reading the spark plugs.

I used the pickup for towing my road racing side car and hauling a Moto Guzzi Lemans to the races. I wanted to be able to pass people going up the grapevine hauling 2,500 pounds of racing junk.

 

[Abid]

Happy new year Abid,
what you are saying is true
i have only one thing to add, you can't get enough power from a 4 stroke running at 6000 rpm max without a turbo charger
and one can't install properly a turbocharger if one doesn't have both a true dyno with all the sensors including shock sensor and if one have not played for years with engines for years
as for the weigth , you are perfectly true, my friends are using heavy engines, they have not more then 200 hours for the moment
what I meant is that it is working for them and i don't understand why joe's engine did not work

Joe's engine did not work simply because its not properly engineered nor properly tested for the application. Very simple.

 

[Abid]

107 hp is a good number, how much does it weigh ?

If I remember right with light 40 amp alternator and light exhaust and muffler with SPG-2 gearbox and lightened intake, the weight of the engine installation was about 187 pounds. About 37 pounds heavier than Rotax 912ULS equivalent. Some people have successfully used Hirth gearboxes and they are probably lighter by 5 to 6 pounds. I did 11 trikes with Suzuki that are still flying around after 12 years. Some have updated some FI computers etc. however.

 

[Abid]

Vance,
you know well that my english is so bad that it is difficult for me sometimes to write what I exactly think
in addition you may not have followed the discussion I was having with Abid from the begining
we were talking about 4 stroke 1.5 atmos car engines and I wanted to say that it takes a turbocharger to get 130 hp from this kind of car engines OK ?
this what I meant by "not enough"
as for the use of a dyno or not if you want to fit your datsun engine in your gyroplane without any dyno tunning , you are tottaly free to do wathever you want
regards
and happy new year

Your English is a lot better than our French sir. I speak a few different languages and I started learning French when I stayed there for a couple of months. Unfortunately didn't learn enough or use it enough. Some day.

 

[PW_Plack]

I personally have about 600 hours in a trike with converted Suzuki G13BB engine...The problem is by the time you buy a new Suzuki engine and everything else you only save $5-6k over a 912ULS. So is there a big advantage and market.

Abid, have you looked into the Aeromomentum conversions? They claim to be assembling engines from all new parts with their proprietary gearboxes, and offer a 13BB-based 100-HP version for $8k complete. That would be a substantial savings over any 912.

I'm watching the progress of a couple people locally who have that engine in two-place PPCs. The 1.3L, 100-HP package is the only one they have lots of hours on, and it seems pretty well sorted in airboats. I'm skeptical of the fuel efficiency claims, as it's based on the ECU map, and a Geo automobile would probably be running 1800 RPM to get those numbers at 55% power, something you couldn't do driving a prop.

They also compare "dry weight," which makes the Suzuki look better against the Rotax. I believe the 13BB uses greater quantities of oil and coolant.

A friend who just ordered one says the package is very quiet and smooth, an advantage I'd expect using an inline vs. flat configuration.

 

[Abid]

it is just fantastic to see that your trikes are still flying after 12 years !, 185 pound is not so heavy in my opinion,16 kilos more then a rotax is just a very good result , very good, it is really easy for 2 people to loose 8 kilos each in esterns countries like us !

Haha. Absolutely I will soon one day visit Pascal, but I think I will have to speak some English if I want to learn French . Its gotten to the point that my dreams of playing Squash as a teenager are even in English. I was at Blois in 2011 last I was in France and I flew around the French country side a little. On the way back from Blois, I even landed in a farmer's field when we encountered a wall of bad weather. The farmer unfortunately thought we crashed and called the police. Thankfully the police officer had been to Tampa and loved our beaches so they just let it be. Whew!!! I had no French ULM license and the aircraft was not even properly registered in France. I was flying with EU microlight champion who was French and that helped and my passenger was a cute French American girl and that definitely helped. LOL.

Yes 185 to 187 pounds is not a bad weight but that's after taking a lot of precautions for weight. Its easy to come out at 200 pounds with that engine as well.

 

[Abid]

Abid, have you looked into the Aeromomentum conversions? They claim to be assembling engines from all new parts with their proprietary gearboxes, and offer a 13BB-based 100-HP version for $8k complete. That would be a substantial savings over any 912.

I'm watching the progress of a couple people locally who have that engine in two-place PPCs. The 1.3L, 100-HP package is the only one they have lots of hours on, and it seems pretty well sorted in airboats. I'm skeptical of the fuel efficiency claims, as it's based on the ECU map, and a Geo automobile would probably be running 1800 RPM to get those numbers at 55% power, something you couldn't do driving a prop.

They also compare "dry weight," which makes the Suzuki look better against the Rotax. I believe the 13BB uses greater quantities of oil and coolant.

A friend who just ordered one says the package is very quiet and smooth, an advantage I'd expect using an inline vs. flat configuration.

Yes. They are right here in Florida. They are no lighter than what I was able to do myself. The problem with them is when it takes many months to get an engine after ordering, its basically a non-starter. The G13BB Suzuki engine is the one that is 100 HP stock and can be increased slightly. The problem with all these companies including Viking is standing behind their product after sale. None of them have a good record of doing that well. Rotax asks you to pay at first and send them defective components back but they determine warranty and do pay the customer back once they have the original defective parts back. They also pay labor at a predetermined rate if its a warranty issue.

If I was inclined to do it, I would simply hook a SPG-2 or a Hirth gearbox on and stand behind the engine myself instead of relying on Viking or Aero-momentum. I do not trust them to treat people right. Unfortunately and sadly my fears are proven right like the story of this very thread and this isn't the first one I know about. How these companies expect OEMs like us to entertain their products when they behave like this is beyond me.

G13BB is going to be 35 to 40 pounds heavier installed compared to 912ULS. There are just no two ways about it. Trust me I tried to make that conversion as light as possible without cutting down reliability. There is no further magic. Yes the engine runs very smooth and is also better fuel consumption compared to 912ULS a little. I used inline configuration always

 

[PW_Plack]

how can they get 130 hp at 66% rpm out off a 1.5l honda engine without any turbocharger ?

The normally-aspirated (atmo) Honda S2000 was SAE rated at 120 HP per liter, so it's not impossible. But that car had a much higher redline. Honda rates the 1.5L engine in the fit at 130 HP at 6000 RPM, with a redline of 6800 RPM. Working the math backward from the Viking website, the graph shows 130 HP at 2350 prop RPM; that's 5475 engine RPM, which is 80% of the engine manufacturer's published redline.

He is apparently uprating redline to 8300 RPM.

 

[PW_Plack]

I won't believe them until I see the engine on a dyno...have a look again honda says 130 hp @ 6600 rpm, not 6000.

Sorry, I was working from memory. Thank you for the correction. The discrepancy in percentage of redline is unchanged, however.

I will be mildly surprised if we ever see this engine on a dyno.

 

[Vance]

No Title

It is my observation that most engine suppliers exaggerate the horsepower.

I have spent a lot of time operating engine dynameters and getting consistent readings is not a simple thing.

I once had an 89 horsepower Harley Davidson Sporster that in a magazine article they decided it was making 112 horsepower because it was so fast??? I told them it was a certified dynamometer and they still just made it up.

My 140 horsepower unfaired Fuel Sporster supposedly needed 200 horsepower to set the 199.9 mile per hour record it set. Again it was a certified dynamometer. They were just so used to bar talk numbers that reality seemed unrealistic.

If I was marketing an engine I don't know what I would do.

In my opinion horsepower is just bar talk and the reality is in how it performs. Horsepower has been so distorted and exaggerated that advertised horsepower is no longer a useful metric.

If you can get an engine to breathe more rpm makes more power and less rpm makes less power.

More compression or a better combustion chamber may make a small difference.

A useful way to estimate potential horsepower for a normally aspirated engine on gasoline is one foot pound of torque per cubic inch times the RPM divided by 5252. If it is supposed to make a lot more it is likely a fantasy.

Example: 1.5 liter engine is 91.5 cubic inches times 6,000rpm=549,000 divided by 5,252=104.5 horsepower.

My Lycoming 320 cubic inches times 2,700rpm=864,000 divided by 5,252=164 horsepower.

For the Sporster 89 cubic inches times 5,500rpm divided by 5,252=90 horsepower.

 

[dinoa]

Even worse is the weight game even though it only takes a scale to measure.

 

[PW_Plack]

In my opinion horsepower is just bar talk and the reality is in how it performs.

The SAE standards used by auto manufacturers in the US for stating HP are of some value in achieving apples-to-apples comparisons, but in road vehicles with stepped-ratio transmissions, a wide torque band may improve real-world acceleration numbers. In an aircraft, if the prop and gear ratio are optimized, HP should accurately predict thrust potential, and torque at RPMs below full power shouldn't make much difference beyond improving response.

Up until the late 1960s, auto HP was a simple calculation based on displacement (or marketing department fantasy) which was of little real-world value. For a while in the 1970s, some horsepower was radically understated in the face of escalating insurance company surcharges. Auto manufacturers now quote SAE net, installed HP, which is supposed to be measured with engine-driven accessories such as power steering in operation. It might be possible to improve peak HP in an auto conversion beyond the manufacturer's SAE claims through optimization of intake and exhaust systems, elimination of accessories not needed in an aircraft, and without the impediments of emissions and MPG constraints.

But I would not expect Eggenfellner or any other low-volume converter to have better intake/exhaust or camshaft science than Honda when tuning Honda engines. I'm also skeptical of the claims of aftermarket engine accessory manufacturers.

I have more faith in dyno numbers if the salesman isn't the one running the dyno and reporting the results..

The best yardstick we can likely have in aviation is the advice of the prop manufacturers. They know what thrust should be generated by various combinations of length, pitch and RPM, and should be in a good position to debunk bogus HP claims.

 

[Resasi]

Joe, good to hear that after two sad events you seem to have sorted the problem. Congratulations for that and carrying on.

 

[Joe Pires]

Joe, good to hear that after two sad events you seem to have sorted the problem. Congratulations for that and carrying on.

Thank you. Things continue to progess well. Just returned from Zephyrhills where I visited with Greg Spicola, and half a dozen other gyro guys. 182 mile roundtrip. New Years eve I flew to Wauchula and back a 200 mile round trip.
​​​
While cross country flying is not my primary goal it's good to get the experience and develop the confidence.

 

[Abid]

Thank you. Things continue to progess well. Just returned from Zephyrhills where I visited with Greg Spicola, and half a dozen other gyro guys. 182 mile roundtrip. New Years eve I flew to Wauchula and back a 200 mile round trip.
​​​
While cross country flying is not my primary goal it's good to get the experience and develop the confidence.

Ah I missed that. I was at our shop right behind the airport from 1 to 6 pm working on latch lock design for the AR-1 canopy. Next time

 

[RMM]

@Resasi...thanks for bringing this thread back on topic. Very good news from Joe indeed. Wish him hundreds hours more of happy flight. Joe, please keep us up to date from time to time on your Aviomania. What a gorgeous machine. Congratulations.

 

[Joe Pires]

No Title

Just got back from a one hour flight with Laura. This is the longest flight with a passenger to date. I was curious to do a fuel burn test. We flew conservatively with rpm between 5200 and 5400. We were doing about 65 or so and we burned 6.5 gph on that trip. Ed is welding up an additional spun aluminum tank that we will add to the machine for another 2.49 gallons which will give us a usable 13 gallons and really give us the range we want. So far my 100 ish mile trips have been between 1 hr and 16 minutes to 1 hour and 24 minutes so the additional tank will give us confidence in trips of that length even if we push the speed a little.

I now have taken passengers up to 200 pounds off my grass strip and at current temps performance is not an issue. Today's take off with Laura had me air-born in about the same distance I normally get off with my single place.

I have decreased my prop pitch and now occasionally see 6200 rpm. There is a bit left still but I am not likely to change till I see the results of thinner summer air.

There was questions on how I solved the overheating issue. Originally Jan had only a bottom vent that went into a reservoir. The problem we kept experiencing was the air had to push out the oil in order to vent. He finally added an upper vent but unfortunately he vented it into the same reservoir. The problem was the lower vent which he relied on for the oil to return did not allow the oil to return. its location behind a gear stopped the return. The fix was fairly simple. I plugged the lower vent. Then to make sure the upper vent actually vented we put the finger of a rubber glove over the vent hose and we could see it inflate. It also however vented oil. I moved the reservoir high on the mast so that the oil would develop some back pressure as it came out and flow quickly back in. Before the change, after a 30 minute flight I had 9 of the 12 oz of gear oil in the reservoir. Also the gear oil actually took days to run back into the gear box. Now I have about 2.9 ounces leaving the gearbox and it drains back in within 10 minutes. It is possible that the 2.9 ounces is just a result of having 2.9 ounces more than the gear box wants, but I am not going to fret that. I have reached stable gearbox oil temps that run between 185 and 195 degrees on average. I have done 4 gearbox oil changes during this process and do not seem to be making any metal.

The least favorite part of the Aviomania is the cramped pod. You can see by the one of the attached photos the legs of a tall pilot. Even I find the pod restrictive. The pod I have is not the current production pod. I have not seen the new one but Nicolas says its bigger. He has also offered to send me a new one for the cost of freight. I plan to take him up on that offer.

I continue to be very happy with the wide-chord blades from Ernie. Laura has flown in every two place gyro that will take her up. Shes a bit of a gyro tramp but I love her. She says its the smoothest of any gyro she has flown in. Here are some pics.

 

[All_In]

Hi Joe
Glad to hear you got the overheating problem solved and are enjoying her now.

The new pods are larger than your production prototype and I'd take him up on the offer. Not sure how he affords it?

Nicolas is a generous man as it costs him to upgrade for free.

When he upgraded the G1sa gas tanks from 8 gals to 10 he sent ALL the US owners new tanks for free.
He also sent a 2nd new enlarged pod to a two place customer who ordered, paid for and received the old style pod for free.
He sent me all new body parts to upgrade from the G1sa to make it a modern G1sb all for FREE just because he did not want me to flying the old style either.

 

[CLS447]

That's great news, Joe ! You need to update your avatar. Have fun !