Engine installation

[Mountain Cat]

Well, I finally got the 503 shoehorned into the cowling last week. Snug fit to say the least. Working on getting the throttle and choke cables hooked up. Fuel lines installed and fitting the exhaust is next. Ordered a new PowerFin prop today. Should have it maybe next weekend. This winter after I get it running and dialed in, I'll add the second 5 gal wing tank. Still have a new 5 gal wing tank on the shelf never used that I may part with if someone would prefer a wing tank vs. a fuselage tank. It might help with the CG a bit. The wing tanks allow for a nice baggage sack behind the seat which is handy. So the Mountain Cat is getting closer to snarling.

[LA F2 Flyer]

Very nice. One step closer. Did you order a two blade or opt for more?

[Mountain Cat]

I ordered a 64" two blade. Two bladed props do better on climbout and 3 bladed do better on cruise. Since I am not going anywhere, STOL is more important to me and my situation.

[LA F2 Flyer]

Makes sense! Looking forward to seeing pics of the completed install with the new prop!

[Mountain Cat]

Not going to paint cowling till everything dialed in.

[LA F2 Flyer]

Definitely looks like a snug fit!

[Badland-F5 Pilot]

Definitely looks like a snug fit!

I really like that smooth cowl.

Todd

[Mountain Cat]

That cowl was about 70% homemade. I had a few pieces left from the Polini modified cowl so I made most of it. Still have a small amount left to do to it.

[Badland-F5 Pilot]

That cowl was about 70% homemade. I had a few pieces left from the Polini modified cowl so I made most of it. Still have a small amount left to do to it.

That's awesome. I've gone through many imaginary cowl builds in my head, all depending on which engine I finally go for. More consultation with Chris and Scott will be needed before I make my final choice for what will be under the cowl.

If I go with a two stroke, I'm leaning towards the Hirth F23. I've heard very little bad about it, and what I have heard has for the most part hints of user caused issues. I think you also have recommended the F23 several times from personal experience?

If I go four stroke, which is what I'm really leaning towards is the Thump Air Scott has built and he and Chris are testing. The 35hp version is available now but Scott has manufactured a billet head and other parts to bring the HP into the low to mid 40hp range. TBO is still at 300 hours but Scott mentioned (if I recall correctly, which is questionable with me....getting old and possible wishful thinking ) that the TBO is at 300 for safety only. TBO may go up as testing results provide more positive results.

I like both engines a lot. For know, designs in my head is all I can do until I have the real McCoy in front of me.

I'm not a fan of the bump design, so looking for other possibilities. You've got a real nice smooth design.

Todd

[Mountain Cat]

It's basically a Skuraider design, or it originally was. It will fit the Badlands with minor adjustments. The issue it that it is a long cowling and too long for the Thump air or polini. The F-23 will fit it. The F-23 is a great engine (expensive) but will probably not make Pt 103 without a chute and careful building. While you are building, think about going Light Sport. Then you could have a powerful engine and a monster bush plane. The Skyraider cowling can be found for sale quite often,

[Badland-F5 Pilot]

It's basically a Skuraider design, or it originally was. It will fit the Badlands with minor adjustments. The issue it that it is a long cowling and too long for the Thump air or polini. The F-23 will fit it. The F-23 is a great engine (expensive) but will probably not make Pt 103 without a chute and careful building. While you are building, think about going Light Sport. Then you could have a powerful engine and a monster bush plane. The Skyraider cowling can be found for sale quite often,

My intent with the Thump Air was to extend the mount by an inch as well as use a prop extension to push the prop out a little more. Of course those numbers also need to be calculated to stay within structure tolerable limits. I can work with Chris and Scott on that. Plus the CG shift will need to be recalculated.

Since Peer's F2 CG is back near the rear max, I think the CG shift won't be a problem. I think it'll slide forward nicely (famous last words?)

On that subject I'm also curious to see how far the 303 shifts Peer's CG now that it's mounted and running. By the way, he's thrilled with the engine and you gave him a heck of a deal and nice early Christmas present.

I've also already done the calc for weight with the F23, and with an F1 through F4 you're exactly right on the difficulty of making Part 103 weight. Those models will most likely need a chute to squeeze in the added weight limit with a safety device. However, I'm getting the F5 and it is titanium. That's 28 to 30 Lbs lighter than the F1 through F4. That of course is great but comes at an additional $$$$$$ cost Some would say too much, but I have the funds, am retired, and this'll be my only plane, so I'm going for it. I also plan on having a chute anyway, so either way there shouldn't be a problem.

I've considered LS, but with my past heart issues, the cost (and requirements with the FAA procedures) would make it more than I wish to deal with. Plus there's the initial passing of the medical to get back into the air. Yes, no medical is needed....except if the individual knows of a health condition that would prevent them from getting a GA cert through the normal procedure and/or they held a GA cert at any time in the past. Since I held my GA medical back in 1999, and I know I would have to go through the expanded medical approval to get even an LS cert back, I'm not able to go the LS route with a driver's license alone. The FAA made sure to include this in the FAR's to prevent skirting known medical issues. Sucks.

Besides, I like the ability to do all of my own work on my plane without FAA certification or approvals. UL gives me that and I can still land at towered air fields with advance permission if needed. Every UL pilot that has done call in's to ATC that I know of has said that they almost always are approved.

Lastly, I'm all about promoting the UL sport, so building the baddest UL is part of that. I would love going LS experimental, for the added benefits (including an extra seat), but I'll be plenty happy with the F5. I think I'm going to be able to do some amazing things with it.

It should be a lot of fun.

[Mountain Cat]

I fully understand the LS issue. I've been a PP for 40+ years so a different mindset. Forget the money vs. aircraft thing. One will never make it logical. Go for all the gusto you can.

[Badland-F5 Pilot]

I fully understand the LS issue. I've been a PP for 40+ years so a different mindset. Forget the money vs. aircraft thing. One will never make it logical. Go for all the gusto you can.

Yes indeed! There will be many telling me I was foolish for spending so much on an ultralight. Since I can't take it with me (the money or plane), what difference does it really make? I have less time left on this earth than I have been alive, so when I finally check out I don't want people to say I never really enjoyed my life.

It's all about the fun at this point.

[Mountain Cat]

Getting ready to order a lithium battery for the SR1. At 6 lbs vs.18lbs for an AGM one it seems worth the price. Since it will be used for starting only (no electrical system) charging isn't an issue. It will be charged at home when it needs it.

[Badland-F5 Pilot]

Getting ready to order a lithium battery for the SR1. At 6 lbs vs.18lbs for an AGM one it seems worth the price. Since it will be used for starting only (no electrical system) charging isn't an issue. It will be charged at home when it needs it.

Yes, lithium batteries are much lighter than lead acids. I had eight lead acids 100Ah for my travel trailer, weighing in at 65Lbs each. I replaced those with seven lithiums 65 Ah at 35 Lbs each. You would think the lead acids have more capacity, but they don't. Since draining lead acids past 50% of capacity can and normally will damage them, I really only had 50 Ah's available for 400 Ah total usable. Lithiums can drop to 20% capacity with no issues. That gave me 364 Ah, less, but not by much and Lithiums continue to put out full voltage until the are dead where lead acids slowly drop in voltage, forcing more current output to the inverter to maintain 120v. Which means the 400 Ah was really even less. Weight savings, much better performance, all around worth the extra cost. Great weight savings for you.

[Mountain Cat]

When building airplanes, don't worry about the pounds, worry about the ounces, pounds will take care of themselves.

[Mountain Cat]

Just got my new PowerFin prop today. 64" long. Sure is a pretty thing. Only took 8 days to get it. Was expecting 6 weeks or more as it seems almost everything takes that long now days. I loved the 'E' prop but a grd adj prop is nicer to set the correct static RPM.

[Badland-F5 Pilot]

Just got my new PowerFin prop today. 64" long. Sure is a pretty thing. Only took 8 days to get it. Was expecting 6 weeks or more as it seems almost everything takes that long now days. I loved the 'E' prop but a grd adj prop is nicer to set the correct static RPM.

Nice props and yes, I love the idea of ground adjustable. Bookmarked for future reference.

Thanks!