FX3 with 80 or 83 inch prop

[hawgdrvr]

Hello,

Doing research on a FX3 build and looking for opinions on the prop size. 80 vs. 83 inch and then of course 26 vs. 29 tires as the 29 is the min tire for the 83. Flying will mainly be east coast (VA) grass strips, nothing extreme backcountry in the near future.

I've been advised 83 for resale but in researching this forum there is some discussion where 80 may be better for lower altitude environments such as east coast vs. western mountain areas. Western may be in my future, I don't know but currently I live in VA.

Looking forward to your opinions and any real data from those that may have flown both.

Thank you.

[hawgdrvr]

I think for my use the 8.50 x 6 tires and 80 inch prop would probably suffice here in the VA area and save a lot of money. The problem is will I get "two'foot'itis" and wish I had the bigger prop? What if I move to the northwest to enjoy more backcountry flying and wish I had the bigger prop at elevation and larger tires? Of course resale has to be considered as someone moving from 8.50 x 6 tires to 29 or larger and a 83" prop is going to get hit with about a $15-20K price tag.

Has anyone seen or flown a FX3 with stock 8.50 x 6 tires and an 80 inch prop and can share the experience? How was the performance? Obviously the bias of backcountry with bush tires has to be removed here, just looking for honest observations of the default FX3 config (8.50 x 6 and 80" prop).

[Tsquared]

Neal,

I have the 80” prop and 26” bush wheels on my FX3 that I picked up in June. For reference I’ve got 55 hrs in type but only 2 flights (2hrs total) on demo FX3 with the 83” prop and 29” wheels so my experience in both is limited. My previous tailwheel time was in a grossly underpowered Champ 7EC and a Decathlon 8KCAB

I’m told that the 83/29 combo climbs about 200fpm better but I can’t really notice any practical difference. My 80/26 climbs plenty hard on takeoff and outperforms any GA bird I’ve flown.

Like you I debated on the 80' or 83” prop. I had several discussions with Cubcrafter folks prior to the build and decided to stay with the 80” for now. I live in MN and don’t envision doing any hard back country flying or high altitude/high DA until I retire and move to AZ, TX or some other state that doesn’t have snow and subzero temps for 6 months of the year. Since I have the option of landing on lakes without needing floats, the 80” prop also give me the option of putting skis on it in the winter.

For now the benefit are a higher cruise speed or similar cruise to a 83’/29” but burning less gas. Normal relaxed cruise for me is 62% power at 24 squared which gets me IAS 103 burning 7.4gph. TAS was 109mph. Flying the plane home 70% power at 24 squared got me 119 IAS/128 TAS @ 10.5gph. a 25mph tail wind got me a ground speed of 152 for that flight home which was helpful.
A slow evening flight with the door and window open is 44% power at 17.0in/2380rpm which gets me 77mph IAS/82 TAS burning 5.3gph.

I”m told the 8.5” tire will cruise faster, but are “squirrelly” on the ground. Can’t speak to that but 26” bush wheels and ACME Black Op shocks make for a very easy to taxi and land bird.

By the time I’m ready to retire and move west, I’ll be close to overall on the engine/prop. I’ll reexamine my type of flying and will think about trading up to 83/29 then, but for now I have no regrets for going with the 80/26 combo.

Trent

[hawgdrvr]

Excellent info Trent - thank you.

[Springloaded]

Neal
‘I’ve owned (4) SS (1) FX (1) FX3 that were my personal everyday flyers. I still have a SS and a FX3. About 2500hrs in a SS and about 400 last year in FX3s. I’ve flown both 80-83. When I flew the 80” I couldn’t figure out what was different,but definitely noticeable. When I got back I found out it had a 80” prop. The SS is about 40’ shorter on takeoff with both equally loaded 1/2 fuel 1 person. Yes It’s a little heavier airplane. Good thing is you can pull it back to SS speeds be close to same fuel burn. Sometimes I’m burning just over 5 gals a hrs just goofing off. The nice part is when you want to go somewhere you can push it up to 125 and get there. There isn’t anywhere you can go in a SS I can’t go in a FX3 that you really have any business landing on. We regularly take 2 FX3s to lunch with 6-700’ of yard with having to clear a 40’ power line or trees at either end. Resale value is better, we are selling lot more FX3s then SS by far right now. The ailerons are night and day between them. Ive been running 35s on both SS & FX3 , 2 of my buddy’s runs 31s. There about 1-2 mph faster then me,not enough to worry about. I would highly recommend 83” prop,I always recommend 31s. There’s is quite a bit of difference between 29-31s when/if you land off airport. The fuel injection is really nice, very easy to start hot or cold,very balanced fuel to all cyl. I didn’t see any real difference in maintaining just finished having 2 annuals done and really wasn’t enough difference to talk about. After having my FX3 for a little while I Decided to put my SS back on floats and leave it there. I found there wasn’t anything that the FX3 kept me from doing so now I have a hot rod on floats and a Hot rod on wheels. If you really want to get pushed back in the seat get Chip to give you a demo in the new big engine XCUB. Rumor has it he’s gonna have one I his hanger in a couple weeks.
My 2 cents
Chuck

[turbopilot]

Ive been running 35s on both SS & FX3 , 2 of my buddy’s runs 31s.

35" tires on an SS would be 88 lbs. That is 10% of the empty weight of the entire airplane. Clearly you don't need floats on that SS, just a bigger tail wheel.

[Springloaded]

35" tires on an SS would be 88 lbs. That is 10% of the empty weight of the entire airplane. Clearly you don't need floats on that SS, just a bigger tail wheel.

Hmmm didn’t think of that🤔.Karen suggested i have one on floats and one on wheels so I didn’t have to switch back and forth,of course I didn’t argue😀. These planes don’t seem to mind the weight under the front seat,you don’t really notice it. You’ll see with a pod.
Chuck

[kiwibob]

Doing research on a FX3 build and looking for opinions on the prop size. 80 vs. 83 inch and then of course 26 vs. 29 tires as the 29 is the min tire for the 83. Flying will mainly be east coast (VA) grass strips, nothing extreme backcountry in the near future.

I had the LSA Carbon Cub prior to the FX-3 and did about 500 hours on it with 8.5s and the fixed pitch Catto. There were definitely places that I was unwilling to land due to soft strip or sand. Interestingly when I sold it the first thing that the new owner did was put it on 29", mostly for the "look".

I bought the FX-3 with 83/29" on the basis that if I ever wanted them then at original purchase would be the cheapest time to get them. A new 83" Hartzell looks like it's going to be $13-15k plus freight and tax and plus fitting and paperwork. You get it now for $530 plus the tyres but you're going to want them - unless your home field is not grass in which case you might not.

As for performance I doubt that I'd notice unless it makes a very significant difference. What I do know is that there's very little time for reflection between pushing the noise lever and leaving the ground. It happens in a rush.

Finally I've done just over 100 hours in the FX-3 and I still just love the look and knowing that the limiting factor is not the airplane but my competance and competence.

As always YMMV.

[hawgdrvr]

Thanks Bob, great insight. I'm not sure about landing on the grass at my home field (KFCI) yet, but I'm also not sure this will remain my home field so a lot of things in play.

I know there is the debate on SS vs. FX3, someone just emailed me about this. I'd love to see a post from people such as yourself having flown both and get your factual opinions on the comparison of the two so people making a purchase decision can listen to the experiences from people like yourself. I'm set on the FX3 but I did have the time where I was being educated on both and that decision is one that needs to be considered. For another topic, but it's good to have people like you that have owned both to share your experiences should you care to share.

[kiwibob]

Thanks Bob, great insight. I'm not sure about landing on the grass at my home field (KFCI) yet, but I'm also not sure this will remain my home field so a lot of things in play.

I know there is the debate on SS vs. FX3, someone just emailed me about this. I'd love to see a post from people such as yourself having flown both and get your factual opinions on the comparison of the two so people making a purchase decision can listen to the experiences from people like yourself. I'm set on the FX3 but I did have the time where I was being educated on both and that decision is one that needs to be considered. For another topic, but it's good to have people like you that have owned both to share your experiences should you care to share.

You'll get some great info from Rick and Chip. You also might want to watch Flightchops on YouTube who does a back to back SS, EX and Xcub with Randy here.

I've got four points of difference that you would notice.

FX-3 has way more useful load. The SS may have two seats but one is for a child if you want to stay legal. No way can you have two adults, full fuel and gear in the SS unless said adults are pretty small. Otoh the FX-3 will swallow pretty much anything you want to put in it, two (kiwi size) adults, camping gear, full fuel and a gerry can to top up and it's still legal.

The FX-3 is heavier and uses much more fuel. Economy cruise at 23 squared LoP is 7.6ish gph. My SS running at 1800/1900rpm and leaned by the pull until it coughs method was about 4.5 gph. Makes the full tank range about the same as the SS.

If it goes quiet the FX-3 goes full fine and there is enormous drag from the prop. So much so I rarely need to side slip. The down side of this is if the engine quits you're going to land somewhere very close by.

Finally I just loved the build process. I'm never going to build a plane that I'd want to fly in but the builder assist program was a real treat. I learnt a whole lot and although it was pretty tiring it was well worth while in understanding about the aircraft and knowing that the team at CC would not let anything sub standard though.

Either way you're going to have a blast.