Good morning,

I am interested in feedback/thoughts regarding a 350is 130hp engine as a suitable choice for a Cruzer 750 LSA build, flying in 6000+ MSL locations, at gross weight 1320 lbs?  I am in Colorado with my normal airport takeoffs from 5000 to 7000' MSL.  I'm a Front Range flyer, and don't really intend to do 12K+ mountain flying.  

My scouring of the Cruzer and 750 STOL specific forums have lots of good information about UL engines, but not very much on actual performance of anyone flying a 350is in these higher altitudes. 

The turbo 914 is of course an obvious choice, but out of my budget at this time. 

Thanks for any feedback.

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Mike,

I am based at 4500' in Idaho with a 350i. Lack of power has not been an issue. My Cruzer leaps off the ground. Climb rate is 750' per minute or higher with two people on board at this elevation. At much lower elevation I had 20 gallons fuel, one 200 pound pilot, and a passenger who claimed to only weigh 250 yet could barely squeeze into the seat and the plane still climbed out at a solid 750' rate with prop set in the middle, general performance, setting. At this max 1440 lb. weight it did have a more solid ride and stalled and landed a little faster...Over all I have been very pleased with the UL Power engine. The 350is might have an edge on performance over the 350i, but enough to justify burning higher octane fuel? The only other engine I have seen in use and also like is the Rotax 912 with a big jug kit installed. Several Rands S6 and S7's boys have made this conversion at my local airport with no complaints.

If you ever come over to southeast Idaho you are welcome to go for a ride in my Cruzer. It has 40 hours at this elevation and 60 hours at near sea level. Been having a great time.

Ralph       208 680-2561

N750RP

Ralph, thanks for your note and apologies for my delayed reply. Your feedback is good, glad to hear it performs well at your altitude. And thanks for the visit offer. 

The 350is performance chart ( http://ulpower.com/en/engines/ul350/ul350is#2-performance ) still shows about 90 HP at 10000' MSL.  I would guess that this amount of HP power would be pretty functional at a fully loaded (either 1320 or 1440) Cruzer at my normal altitudes. Not a rocket but serviceable.

Just not that many Cruzers flying up here yet.

What kind of fuel do you use?

How has your maintenance of the 350i been?  Easy, difficult, are parts obtainable?  Support by Mfg?

Thanks for your feedback,

Mike

Attachments:

Words to live by “Read Service Bulletins.” I lost the altenator fan shroud near Kingman on a long distance flight because of my failure to practice literacy. Very loud clanging noises from engine compartment cause extreme pilot stress. Thirty dollar repair and maxed out heart rate. Only other maintenance has been oil changes and setting valve clearances. Wick’s supports UL with the basic routine items. Fuel has been ethonol free Mogas. Would use regular premium gas except I used too many hard to reach rubber fuel lines.The 350is calls for better octane then Mogas.  100LL? Valve cover O rings are special heat resistant compound. $10 each special order at local bearing shop. Keep a couple of spares as they will occasionally stick and break when accessing the valves. Do not use regular car oil. The flat tappets require different oil additive package. I only have 115 hours and am still learning. No idea about major repair type support. At 6000’ ft and 2700 RPM I Cruzed around 105-110 on recent long trip. Today it was 120 mph ground speed, with tailwind, class brazo airspace.

Ralph N750RP

Ralph,

Message receiv ed 'Read Service Bulletins'!  

1. Fuel: I understand the issues of ethanol in fuel, and how it can eat away rubber or fiberglass parts. I rebuilt the fuel system on an ELSA trike specifically because 'normal' fuel with ethanol ate holes in the fiberglass fuel tank. What a PITA. These days the problem seems to be well understood and fuel lines and related parts can be built with parts that work just fine with ethanol. I don't know for a fact but I suspect the Zenith FWF kits would come with this (where a FWF engine is capable of running on gas/ethanol mix).

2. Fuel types: I am not finding 93 octane fuel in my area (Colorado), and in fact there is just not much of it to be found out here in the west. There is no Mogas at airports around here that I know of. I have read other Zenith user posts where they use 91/92 with our without ethanol in the 350is, without problems. As long as they stay away from the top RPM values. 91 octane is easily found, though most in my area contains ethanol.

>>Conor: 308 hrs on a 350iS. I've only flown the last 40. Running 91/92, w/or w/o ethanol.

3. 100LL - while this is the most expensive it seems to be the most findable, locally or during an any XC flight.

Regarding 100LL in the UL engine, can you explain more what you meant by your comment here? :

>> Valve cover O rings are special heat resistant compound. $10 each special order at local bearing shop. Keep a couple of spares as they will occasionally stick and break when accessing the valves. Do not use regular car oil. The flat tappets require different oil additive package. 

I am flying in a Remos GX with a 912ULS engine and all they put in it is 100LL. I think the maintenance cycle includes an oil change every 50 hours and a full check every 100 hours. This GX is used at a flying school so it gets lots of hours.  No issues with 100LL in it from what I've heard.

And this website is a wealth of information about UL engines, and frightening regarding 100LL in a 350 series engine:

http://www.myulpower.com/p/why-not-avgas.html

One of my, and I'm sure lots of folks goals, is to fly their Cruzer XC. This 100LL use appears to be a real problem doing that. 

Thanks again for your comments. Thought they call Light Sport 'simple' aircraft, they are anything but.....

Mike

Just sitting at 320 hrs on my 750 STOL 350iS; I've only owned/operated it since 265.  

*Last 35 hours has been on Amsoil Dominator 15-50.  Just added 0.3 qts.  Don't expect to put more in before my annual in late May.  Replacing the FWF kit oil/air separator with antisplat in a couple weeks.  It can't hurt.

*Using 92 octane (mostly ethanol-free).  The first few tanks I added an octane booster.  After my research, and understanding the way I'm working my machine I've determined that 92 octane is fine.  More to follow when I encounter issues, or see more on inspections.  I am trying to not use 100LL any more, but will if needed.  Planning to carry a couple 5 gallon collapsible fuel bladders.  But so far I've been able to land a private strips, and use loaner cars/fuel cans to get go juice. 

*I definitely suggest reading the posts in the www.myulpower.com site.  30 minutes, and you can probably read all the posts.  Some will be pertinent to you, some not.
*Have fun, fly often. We've got to have confidence in our structure, powerplant, and fuel system or the flying isn't fun, we'll fly less, we don't expand our capabilities, and therefore are not as safe (or enjoyable).  
-If in the northwest look me up, and come fly my machine.

Thanks Connor,

Your experience sounds very promising with regards to 92 octane fuel. The idea of carrying collapsible bladders is very doable. I did that when flying a trike XC as it was a smaller Rotax and could not use 100LL. It worked, a bit of a pain, but doable. People at airports are some of the nicest, most helpful around. 

>>We've got to have confidence in our structure, powerplant, and fuel system or the flying isn't fun, we'll fly less, we don't expand our capabilities, and therefore are not as safe (or enjoyable). 

Well put. A friend of mine who flies said 'I finally figured out the airplane was not trying to kill me, and then it got a lot more fun'.  Maybe a bit extreme but also true.

Thanks again for the feedback on the UL engine, this along with the other posts is really useful information.

Mike

Friends,

I am flying a 650 that I built and completed 2 years ago.

I have the UL350i engine so my comments are not completly germane to this thread.

I was able to climb to 11,500 at gross weight on a hot summer day searching for cooler smoother air on an AirVenture practice flight coming home from Oshkosh in June.

Was still bumpy, but less and 82 degrees into a 30 mph headwind. a long ride home to NE.

I would think the 350is would be great power for the 750, but as others have pointed out, the octane requirement is why I chose the i instead. Yes, if you can make it work till that 100LL alternative hits the pumps, your in great shape.

I have also made every effort to not use 100LL. The only I have used was 25 gallons of a 25/75 percent mix of 100LL / 87 nonalcohol that the airport said would work for 91 octane. This was a stop in northern Iowa on the way to and back from AirVenture.

My engine has 250 hours and is performing flawlessly with compression numbers holding exactly and not any oil added between changes at 50 hours.

I have great confidence in this engine and will welcome the day when I am not trying to plan flights by looking at Flymogas or whatever.

I would love to find a couple collapsible fuel bags as well, but did not find anything on the internet I trusted to purchase or felt I could afford. Any suggestions to look at from fellow flyers?

Fly safe.

Jerry

Five gallon hard plastic gas jug got me across Utah last week. Buddy has what appeared to be bomb proof collapsible 5 gallon bag. Salesman for firm that sold him his was happy to sell me one for $100 until Mogas was mentioned. He warned me that his bag worked great for Avgas or jet fuel, mogas not so good. Mogas appears to act as solvent on seams and extracted the dye out of the fabric. Sounded like more then ethanol was possible culprit. Good honest man who works at doing right by his customers. Lesson learned, ask questions and buy from fellow fliers who know their product.

Ralph

N750RP

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