Changing out a 912 80 HP in a model IV

[Wheels]

Im replacing my original 912 80HP with a new one.
Its going into my Model IV and so far the removal of the original engine has gone smoothly. The new engine is unpacked on the bench,
1. I switched the intake and carbs so that it will fit into the Model IV round cowl engine mount.
2. The CDI is in the way of the oil tank.
3. The spider is interfering with the tank.
4. The tank is too tall for the model IV so I had it shortened, the screen is still to tall and the oil intake tube inside the lid of the tank is too long. I'm really enjoying this, said no one ...ever.
I can't wait to start the Dynon EMS D10 install. So, anyone else done this? Pointers, Spoiler alerts ... anything, ... anyone?

[Av8r3400]

Why do you need to modify the oil tank? I've had two of these planes and both used the stock tank...

I modified the firewall side of the engine mount with a tab to accept the ignition systems. Link (http://www.teamkitfox.com/Forums/showthread.php?t=7119)

[mr bill]

I shortened my oil tank also, as did a guy in California. The firewall was made per the plans. I only removed the round portion on the bottom, so there were no changes to the pickup tube or the screen.

[Wheels]

The original tank was shorter by a couple inches to accommodate the round cowl. otherwise the oil door on the top won't close. The tank ends up crushing the electrical braid on the back of the engine. The new tube in the lid is going to have to be shortened as well, it goes the full length of the oil tank as does the screen.
I like the placement of your modules. Did you have to lengthen the plug wires or did you use what you had? I"ll check on it today and start the fabrication process. I am going to have some help here for a week so I think I can get er done when my buddy arrives. He's an airplane guy from Alaska and pretty much works for food when he's on my place. :)

I"ll send some pics as well.

[Dusty]

Are the early and late oil tanks a different length,also shifting the modules away from heat and vibration to the cabin side of the firewall can only be a good thing.

[kmach]

Why not use your old oil tank ?

[Wheels]

The old tanks and new tanks are all the same hight. The Model IV round cowl had the tank shortened due to the tight space of the cowl. It reduces the oil quantity a minuscule amount.
I want to use the new tank because it has an upgraded hose connection to A/N fittings and I like the fact that the inlet and outlet ports are on the lid. It makes identifying a crack or failure easy and and easier fix than pulling the tank.
It looks like I will need to get longer plug wires and sheaths to move the CDI but I agree, moving it is the only option for lifespan of the part. Here is a picture of the tank and you can see that I need to shorten the rest of the hardware associated with the tank.

[Slyfox]

when I changed out my engine, I sent the tank to John and he fixed it up to the right height for me. I also updated to the new motor mount and new muffler. once I had everything put together on the new motor mount and mounts I went to the airport and swapped out engines in about an hour. easy very easy.

[Wheels]

I finished the tank tonight. It took about an hour to trim the extra length from the intake tube and trim the screen. Then I cleaned everything to make sure there was no metal shavings or screen material where it shouldn't be. I'll re organize the spider tomorrow for a good position on top of the engine for the tank.

[Guy Buchanan]

2. I moved my CDI to the upper right motor mount. (See photos.)
3. I moved the expansion tank forward by rotating the head water outlets, replacing one of the expansion tank outlets with an elbow by brazing on a Rotax water pump elbow, and replacing all the tubing.
4. I did the normal tank mods.

In addition, you may find the new starter runs into your firewall. I machined off the lugs on the back of the starter and made a recess in my firewall. (See photo.)

[Slyfox]

I finished the tank tonight. It took about an hour to trim the extra length from the intake tube...

you never did say what engine you were putting in. uls has the bigger starter yes, you need to bang the firewall in a little or something. also take the cover off your old water pump and put it on the new motor, the hoses will work out better if you do. get that cdi yes on the motor mount, all things will work out for this, all wires and stuff.

[Slyfox]

now, just a heads up. I don't know if you have the newer mount or the old one that is 95 vintage. but the newer mounts have a thicker wall. the old mounts use to break all the time. I had one, I changed it over when I put in my new 912uls.

[Wheels]

The new engine is an 80 HP Rotax just like the old one. The mount is the new style. I think your right about the water pump cover. I'll look into it.

[Bud Davidson]

Steve,
You mentioned the older mounts breaking.. where did the breaks occur?
I am reasonably sure I have an older mount in spite of the later date of original licensing of the airframe my engine came from.
Bud

[Slyfox]

pretty close to the tank, if you have the model 4. I'm trying to place it. usually having a wedge welded in the area helped, but that even broke on mine. nice to have a new motor mount. sorry I just can't picture it. I'll look and see if I had a picture of the old mount in my stuff.

[Slyfox]

http://www.teamkitfox.com/Forums/album.php?albumid=484&pictureid=6028

this is where the crack is, see the pieces that are welded on. that's for support, it cracks there. right in front of the tank. there is two spots.

[Bud Davidson]

Steve,
Thanks. I will be watching the mount closely and will watch that part of the mount specifically. Glad to have light gray paint since a crack should show as a black line.
These bits of information are a valuable resource, a clear benefit of this forum. Thanks to all who contribute. I have made many changes and decisions based on the discussions.
Bud
IV 1200
912UL

[Slyfox]

what happened to me was I went to a flyin, richland wa. I had the tube break right off right where those supports are. The people in the shop next to the fbo went and welded the motormount for me so I could get back home. That held up until years later when I put my new engine in, of course I went to the 912uls from the 912ul and I didn't want that bigger engine on the old mount so I had John M. send a new mount with my new engine. So Happy with the new engine and the engine mount. love my fox. :D

The new motor mount has a thicker wall on the tubing. well worth it.

[Slyfox]

The new engine is an 80 HP Rotax just like the old one. The mount is the new style. I think your right about the water pump cover. I'll look into it.

the water pump cover has the tubes on at least one outlet rotated so a hose will make it to the water thingy on top better. trust me, you want that water pump cover. you should be able to reuse the gasket on your new motor. that is if it's a brand new one with 0 hours.

[Wheels]

The tube cracking on the older engine mount might look like cracked paint, but a small magnifying glass will reveal metal flakes from the broken pieces chafing under vibration. Just put the new mount on if you experience that. Its a quick safe fix.

[Wheels]

Ok, the elbow was 180 degrees off what I needed, the fix was easy. those hex bolts are 90 inch lb torque and an easy R/R. I didn't replace the o ring in there as it was not flat anyplace and has never been used except for the test run at the factory.
today is water hose, reservoir move day.

[Wheels]

Well, I may pay for my smarminess sooner than later.
I said don't modify the 912 but that's all Im doing right now. The mods are to fit the engine into a model IV round cowl so its not like I'm really doing surgery to boost performance, but some of it is ... well. ... challenging. I need to move the coolant tank to satisfy the oil reservoir placement. The water coolant elbows on the heads don't line up, can I heat them up and separate them from their flange? re-clock them and put in new hoses to fit? can't find it in the heavy maint. manual

[jrevens]

I suspect those are threaded & sealed with retaining compound, so you could probably heat, take it apart, clean & reassemble with new compound, but I'm not certain. You might do like my friend Stan did - swap that one out with the one on your old engine.

[Wheels]

I may end up doing that, but honestly I hate to use old parts on this pretty little motor. Ah, the dilemma.

[kmach]

They are held in place by retaining compound loctite 648.
You can heat them to release the compound. You'll need to get them hot enough for the tube to easily turn out. The tube has very fine aluminum threads, if you force removing, the threads will gall. Also make sure the threads stay aligned when removing or they will get damaged. A wooden dowl in the tube is handy.
Use a pick to clean the threads on both pieces, use loctite 648 to install .
Careful to not tighten past where you need for positioning, its better to have it slightly loose than to try to force another turn.
The Loctite 648 does the holding, not the threads, and it holds and seals very well.

[Wheels]

Thanks Kmach. I'll order the 648 tonight and heat them with a heat gun. I'll use the dowl and a good welding glove to handle them. :)

[Wheels]

OOPs, looks like Rotax forgot to tell Kitfox what the engine mount dimensions are. Or the old engine and the new engine are NOT ... EXACTLY the same.
:eek:

[rv9ralph]

Old and new engines are not the same. The dimension for the hole in the gearbox is a little different... but you found that out.

Ralph

[Wheels]

I got the adapters Machined. They will get re powder coated tomorrow.
This photo is of the back of the engine.
I want to remove the bracket holding the braided bundle but I believe the pick up will be disturbed if I do. I don't want to start an electrical issue. Are the new pick ups fixed in such a way that I can just reinstall that screw holding the bracket?

[Av8r3400]

Yes. You'll be fine to do that.

[Wheels]

Thanks, I"m probably manufacturing a better lifting shackle today with a friend who has a machine shop. I"ll send pix if its a cool fit.
Jay AKA Wheels

[Wheels]

Sagas being what they are, ... this one continues.:p
This is a picture of the engine mount for the model IV on the engine. Is this water tube threaded like the one I heated up on the cylinder and can I orient it to effectively clear the offending member of the engine mount system?

[efwd]

Awe Man, that Stinks!

[jrevens]

... Is this water tube threaded like the one I heated up on the cylinder and can I orient it to effectively clear the offending member of the engine mount system?

Yes and yes. One of them has to be clocked at a different angle than they come from the factory at on the 7SS installation with a new ULS engine also. You need to carefully clean the threads and use the correct retaining compound when reinstalling it at the needed angle. You've probably already been through that and aware of how it's done, I guess.

[Wheels]

Thanks. I"ll just have to be careful in that area with heat I think. there is an oil seal under the water pump impellor. I"m searching the heavy manual for info on removal. P.S. your up late. Thanks for the quick reply. I"m tired.

[jrevens]

Yep, up late... trying to get ready for a road trip up to Montana before Oshkosh. I believe you want to remove the housing that the tubes are connected to from the rest of the pump, before you have to apply heat and do the job. It should come off clean and allow reuse of the gasket

[Wheels]

Yup, more disassembly of a brand new engine. I'm really going to like flying it huh?:p

[Guy Buchanan]

I re-clocked many of my water fittings and replaced a few with other angles. As John said you just remove the offending parts to heat them. It doesn't take much heat at all. Here's 8000 words:

[Wheels]

THANKYOU. I just made it one word. Yup, Your pix are a book for me. Really helpful. Thank you.

[Wheels]

Ok Im back at it. I took some time off to handle my ranch and other sundry duties. Now I can concentrate on the engine install. I took off the water pump housing to remove and re-clock the water elbows that were pointing at the engine mount vibration isolators. I got one out, the other is stuck. I heated it to 200 degrees with a heat gun, it turned about 90 degrees and stopped. Any ideas, or is it a pretty sure bet that it is galled and unusable.

[Flybyjim]

If the engine is purchased from Kitfox do they not change this at the factory before shipping the engine? Does this have any effect on Rotax warranty?

[Ronin]

When I was at Europa aircraft we had to reclock two of the water pump hose barbs for any 912/914 engines sent out. I did them all with a heat gun and did not remove them completely. The locktite will reseal. We never had one leak later.

[Av8r3400]

I used a map torch on mine. They may have cooled while you were adjusting try heating again.

[kmach]

I agree, it probably cooled on you .

When they are hot enough the loctite releases, and you can turn them out with not much effort.

[Wheels]

I could use a torch. I just don’t want to damage the part. I’ll soak it in alcohol for 24 hrs to soften the loctite then I’ll heat it in an oven or heat gun. Can’t work on it until tomorrow

[AirFox]

Jay you could just send it to Kitfox to have it done. Good luck!

Scott

[PapuaPilot]

If it has red Locktite (or similar) you will need to heat it to over 400 degrees to liquify it. I can't tell what type metal the part is but it should be OK to use a torch or put it in a kitchen oven at 425-450 without damaging the metal.

[Dave S]

Wheels,

A few thoughts on this thread:

1)

When I was at Europa aircraft we had to reclock two of the water pump hose barbs for any 912/914 engines sent out. I did them all with a heat gun and did not remove them completely. The locktite will reseal. We never had one leak later.

Heating and reclocking the coolant elbows without completely taking them out, cleaning and resealing may work if you are lucky, or work for a while; however, consider where the water pump is located if the joint failed later. I have seen one of these things work for a few years then start to drip - but it didn't leak at first - and when it did start to drip - it unscrewed without any heat being applied.

You won't know for sure what's going on unless the joint is taken apart, cleaned up and resealed with the correct permatex product.

2) The elbow is a bit awkward to get a grip on, one tip is to sand down a dowel so it fits inside the elbow as far as possible to give a person a short handle. Also the wood will not drain the heat away from the joint when trying to unscrew it. Discretion as to the amount of torque used is important. If the dowel bursts into flame - it's too hot;)

3) How much heat has to be applied is hard to determine since we won't exactly have a thermometer sticking into the metal to figure that out; but, consider that most permatex products (including the one recommended for his application) have an upper service temperature limit of 300 degrees F. Larry's use of a MAP torch isn't a bad choice to get enough heat on it - trying to figure out how much heat is needed might best be determined by heating the joint while holding torque till it starts to unscrew - then take the heat source away. Propane torch works too. The threads alone don't seem to be much of an interference fit - not exactly like a tapered pipe thread. Once the threadlocker is heated enough, the joint should release. The threads go down maybe 1/2" into the casting so the heat has to penetrate that far too - and, the aluminum sucks away heat really fast. The point a person has to understand is not reefing on the joint when it isn't hot enough is important to prevent damaging the threads- when the right amount of heat is applied, it should come out with not that much effort.

4) I can't vouch for the temperature limits of the pump seal.

The first time a person does this - it seems like voodoo - the second time more like science.

[Flybyjim]

I received a call Friday that my engine is shipping Tuesday, yea, and after receiving it I am to return the water pump housing to have Kitfox re-clock the water pipes and there is no charge for this service, part of the purchase. I am happy to hear Kitfox is going to do this, I would guess they have done many of them and the re-sealing should not be a worry to me. Oh, and the firewall forward is shipping the same day, moving forward!

[Wheels]

Hmmmm, wonder who is lurking on my thread. ha ha.
I bought the engine from Kitfox, Never thought of asking them to help me do this. I"ll call them. Thanks for the tips. I"m out until after tuesday.

[Wheels]

I heated the water pump cover with a torch. It didn't matter much. The damage was done. I ordered new parts and Im having them clocked to my specs by guys who do it every day. Yup, it was pricey.

[Dave S]

Looks to me like it was cross threaded some time before you got it - rough deal on the $ :(, but it probably would not have worked out any different no matter who took it apart.

[Wheels]

Thanks for the boost. It's just one more opportunity for me to tell my friends, "Never feel sorry for a guy who has an airplane." No whining, just winning.

[Wheels]

Ok, it's game time. My replacement parts arrived and the 4 elbows in it are loose so I can clock them to my specs. Problem is, look.
Is my only option to remove the #4 elbow and adjust it so that it doesn't align PERFECTLY with the rear of the engine mount?
Guy Buchanon has great pics of his mod and I will duplicate as much as I can if I can get some pipes bent, but was hoping to avoid the dreaded heat, remove, clean, reinstall scenario of the other elbows. The one that I hashed up in my first round cost me a lot of money and a lot of time. My objective is no contact with the hoses and airframe or exhaust, no stress from misaligned elbows. Those two things appear to be ... quite challenging.

[Guy Buchanan]

When I did mine I bought a handful of 90's, 45's, and whatever else they had and mixed and rotated until I got the alignment I wanted. I even used one of the water pump elbows welded to the upper reservoir to get its alignment correct. Once I had the water pump alignment I wanted I marked everything really well, disassembled counting turns, then used the Loktite and re-assembled, taking care to spin in the same number of turns and aligning correctly before the tube seized. (For me it happened quite rapidly. Too rapidly.) Do it one tube at a time.

[Wheels]

I need to get the engine vertical to work under the heads on the bench. Have any of you locally manufactured a stand for your engine? Pics?

[Av8r3400]

I put mine on a regular engine stand from Harbor Freight and turned it...

[kmach]

I had an old school desk, put a 3/4" piece of plywood on it and drilled holes for prop flange center and holes, bolted through. it was very stable.

[Wheels]

I like the desk! I did make some progress today and I needed that. I used silglyde to lube the hoses while I fit them to the various elbows under the heads. I changed out various water pump angle elbows and came up with the likely route for cylinders 2 and 4. the hoses are touching and they need anti chafe tape or firesleeve but there are no kinks and I will be able to observe their heath pretty readily. I'll do 1 and 3 tomorrow and post some pics. this has been the toughest part of the install for me because I have been so concerned about the hoses not having any stress other than their normal job. I had leaks from the coolant system on my old engine and just can't imagine having to do extra maintenance due to a poorly fit engine. I"ll clean the silglyde off with soap and water from the hoses when I have everything situated the way its going to be assembled.
Thanks for the heads up on harbor freight and the desk, I will probably go with the desk idea and modify it to my bench. I just need to get at some stuff and working under the engine while blocked up on my table is a pain. Yes, its on a hoist for security as well.

[Wheels]

Ok, I got at the bottom half of the water system tonight and did the only thing I could do. Any comments on better ideas are welcome but I just don't see any alternatives other than to try and mitigate chafing and crimping as best I can.
So, I"m figuring on watching very closely for chafing, crimping, leaking. time will tell. But its just dang tight, and I haven't fire sleeved it yet.

[Guy Buchanan]

Not sure what you mean by fire-sleeving. You don't generally fire-sleeve coolant lines. You might put on chafe protection, or you might cover with radiation shielding, to keep exhaust heat off, but I really don't think you need to fire sleeve the cooling system. As to line installation. I have some pictures here (https://b-and-n.smugmug.com/Flying/Kitfox/). (Did I already send you that link? Can't remember.) Otherwise I'd say you're doing a good job.

[Wheels]

Chapter 75-20-00 page 7 item 7 says, protection tube heat, I assumed it needed fire sleeve due to the heat in the engine compartment, exhaust proximity etc. I agree with radiation shielding. (Sounds Star Treky) I"ll anti, chafe and do what I can to keep them from getting hot, but you can see there is little room there. So I like the idea of padding it with some extra hose and inspecting, ... a lot.

[Wheels]

Guy Buchanan's pics are saving me a lot of guessing.
Thank you Guy.

[Esser]

The only heat proctection I did were lines that were within 4” of exhaust piping. None of my coolant lines have heat protection.

[Wheels]

That reference is in the IPC

[Wheels]

I installed the final torque and safety on the engine mount and I installed the lower hoses. Yes, they fit, no extra room, but they fit. The one point I was struggling with on the left side is that the angle of my fitting is to reduce stress on the the hose but it was such a high angle that the hose clamp BARELY fit between the ignition electronic pick up and the engine block. I ended up assembling the hose to the water pump cover and THEN installing said pump cover. I think I will be able to replace the hose without removing the water pump cover but it promises to be a real pain. In the words of Guy Buchanan, heres a few thousand words.

Question? instead of a zip tie to hold a piece of split tubing over a hose for abrasion protection, could I use high temp RTV or gasket maker as an adhesive?
Now when the zip tie gets hot and becomes brittle, it won't fall off, because, ... its not there in the first place.

[jiott]

What I did in a couple of places where a hose needed chafe protection, but there was not room for firesleeve or something similar, was to use several wraps of silicone, self-vulcanizing "Rescue tape" around the hose or around the chafing structural member. This stuff is tough and it doesn't come loose and is unaffected by heat. I also used it where I needed to put a zip tie around a structural member. I also carry some in my emergency tool kit, it can temporarily seal a coolant hose leak.

[efwd]

That is exactly what I have done. Even the part about helping with zip ties.

[Wheels]

I made some progress on the cooling system today. Got the top tubes cut and I clocked the elbows. this is the layout.

[Wheels]

I am making progress. I mocked up the engine and exhaust manifold and it all fits.
I am mocking up the fuel manifolds tomorrow and wondered how others have connected to the engine. My old set up comes thru the firewall in the center and divides via brass barbed fittings to get to gascolator, fuel pump, pressure gauge, auxpump, fuel return,carbs, fun factor. most of the fittings are on the firewall and inaccessible for maintenance with the engine mounted. Is everyone with a model IV doing that?

[Guy Buchanan]

I moved my firewall penetration to the right side, mostly to reduce heat load on the fuel, but also to make it easy to access. The primary fuel line runs forward along centerline to the base of the firewall, then right in front of the pedals, then up along the edge of the firewall, then penetrates the top of the footwell. It's then a super-easy route to the fuel pump. Thousands of words attached.

[Wheels]

Thanks Guy! My hard fuel line comes up to the right side of the Firewall and then crosses to the center where it penetrates. I think I can easily modify the penetration point to mimic yours. I"ll look in the other "words" you sent and see if I have some blueprints of the other connections I.E. gascolator, aux pump and the like to get an idea of routing. My current penetration on the firewall puts about 5 hose clamps at junctions near the stator assembly. Yikes!

[Wheels]

I see that there may be some fuel lines and push on fittings available in metric sizes as well as Banjo fitting. I think I can nearly duplicate the hose assembly that came with the engine and now it will reach my outboard facing carbs. (model IV needs to switch left and right carbs and manifolds)

I'm looking to source the silicone hose for fuel lines and not finding any. I could use Gates or other fuel hose, but I like the removal of the 5 year rubber replacement by using the silicone stuff. Anyone got any Ideas?

[jabkwab]

As I learned on this great forum you don't have to swap the carburetors for a model 4. Just swap the manifolds.

Keep the throttle & choke connections on the outboard sides for easy adjustment / synchronization.

Jan

[Wheels]

This is a pic of how the 912 UL comes from the factory. the Next pic is how its mounted to the aircraft. I couldn't figure out how to get a picture to a private message. Sorry. Anyway, the carbs have to be switched from the manifolds as well as the manifolds from the left and right side, or the throttle and choke are inboard.
Step 1. switch manifolds. (now the carbs are on the wrong side.)
Step 2. correct step one.

[Av8r3400]

Just looking at your pictures, Guy, I think I saw a spot you didn't polish... :eek:

Seriously, that is one gorgeous plane!

[aviator79]

I thought the same thing! You know he's dedicated to polish when the aluminum fuel lines have a mirror finish.

[Wheels]

Here is an Idea I am toying with. Any and all thoughts are welcome. It will have banjo fittings on the carbs but everything else that isn't on the fuel block/manifold will have a barbed hose fitting and a clamp. All will be firesleeved.

[Guy Buchanan]

You accidentally sent thumbnails instead of pictures.

[Guy Buchanan]

Oh and thanks for the kind words, you guys. You know how it is, if you polish just one thing, then everything has to be polished. Them's the rules.

[Wheels]

I don't know why the pics came through as thumbnails. I"ll send them again individually, maybe they were too big.

[Wheels]

Here is the top view

[cap01]

wondering what you all are doing for connecting the mag switches to the new 6 pin connectors ? appears to require some weird assed crimper

[Wheels]

I hired an A&P to come out and help me finish the plane. He is an experienced electronics and avionics guy so the Dynon is his part of the completion check list. I"ll post pix this week. Keeping fingers crossed for a June 27 start and test flight.

[AirFox]

Good luck Jay. We'll be up to fly with you this summer for sure.

Scott

[Wheels]

Looking forward to that.

[efwd]

Nice Wheels. Im glad I am not the only one not interested in the wiring. I hope that the fact that I have Garmin harness' coming means I can get through it relatively easy.
Eddie

[Wheels]

The Dynon install went well. Having some trouble with the oil pressure sensor but I think its because we didn't do an oil purge yet so there isn't really any pressure on the sender. But here are some pix. No didn't start it because of a minor yet annoying feature of buying a new engine. New engines don't fit older prop hubs. There is yet another change and yes, another part to buy and yes, another wait and yes more money to spend and yes, I"m b**ching. and yes, never feel sorry for a guy with an airplane project.
Can you find waldo or anything glaringly stupid in this pic. Be brutal you may save my insurance company from buying my wife a new mercedes.

[Dave S]

Wheels,


I think we can all relate to how one thing leads to another; and, but we always prevail.


A couple considerations, which you may already have plans for.


The EAA tech counselors pretty consistently recommended the use of cushion clamps rather than zip ties on the engine mount tubes. The rationale is that the nylon zip ties in combination with the normal amount of engine vibration can result in the nylon ties wearing through the finish (powder coat or paint) and instigating problems down the road (rust or cracks). Can't tell for sure from the photo but it looks like there may be a zip tie securing a fuel hose to the engine mount frame.


I don't see fire sleeves on the fuel and oil hoses. Maybe they are not installed yet; but, certainly a good idea. In addition to providing some additional time in the event of an under cowl fire, they also provide abrasion resistance.

[Wheels]

Dave S,
Thanks, you are right. I didn't think about the Zip ties and they are a problem. I'll get some cushion clamps, and re do that. The Firesleeve is a must and I can't tell you why it isn't installed. Except that the Mechanic did some work while I was at the parts supply, so when I returned, presto. Do you think I can just split the firesleeve and zip tie, / clamp it to the required fuel lines, or should I break the fuel line connection and sleeve the hose. (worried about barbed fittings) maybe I'll buy more fuel line and re-do the manifold. I"ll listen to you, my wife doesn't want the mercedes.

[jiott]

Its perfectly OK to use zip ties if you first wrap the steel tubing with a cushioning tape, like the silicone rescue tape. I think it makes a much neater installation (I realize I could have done a much neater job of applying the tape) than a bunch of adel clamps all over the place. Just a personal opinion.

I think by splitting the firesleeve and then zip tieing it closed would drastically reduce its effectiveness in cas of fire.

[jrevens]

Just my 2 cents opinion about zip-ties. I know that the prevailing wisdom among many aircraft mechanics and others is that they are a poor choice, at best, for use in the engine compartment. First of all, there are cheap, maybe not so good zip ties, and then there are very good ones. One of my favorites are those made by Thomas & Betts (T&B) that have a small stainless steel insert allowing a more infinite range of adjustment as well as a very strong & reliable grip. The black UV resistant ones are the only kind I use. It's interesting to note that Rotax, for example, uses a lot of wire ties on their new engines as sent out from the factory, and they are not nearly as nice as the T&B ones. These are not there for temporarily securing the hoses, ignition wires, etc., as far as I know. They are meant to remain and be used that way on the operating engine. Of course, when using them on engine mount tubing and other similar situations, it's good practice - mandatory in my opinion - to protect the tube with a couple of wraps of something like a urethane anti-abrasion tape - that's what I use. FWIW, I had T&B wire ties all over my engine compartment on my OSH award-winning T-18, and the vast majority of them were still the original ones installed about 28 years and over 1300 hours ago, when I recently sold the airplane. They are a lightweight, easily installed item that are fine to use, in my humble opinion, if they are of good quality and used properly. It seems that there are probably many who wouldn't agree with that. I do use a lot of Adel clamps also.

[DesertFox4]

I used the blue (also available in black) heat resistant cable ties from SteinAir in the engine compartment. Search cable ties on their site. Various lengths available. I chose blue so my DAR could see the difference easily from the plain black ones. I still have some temporary non-heat resistance ties to replace before the inspection.

16095

[Dusty]

Can a new engine be ordered with the early prop hub or a multi fit pattern.
I may have to replace my motor soon:(

[Av8r3400]

Interesting discussion on the prop flange issue. I recently replaced the prop shaft in my gearbox (long story) with a used one from a very late model (2015) 912ULS. The bolt patterns were exactly the same as my old shaft (1997). My Prince prop bolted up without issue. I never even gave it a thought that the bolt pattern may have changed...


New shaft in old gearbox
16096


The old, damaged shaft
16097

[rv9ralph]

RE: Prop Bolt Pattern Change.

My discussion with Daryl at Warp Drive revealed that the Prop Bolt Pattern changed with the introduction of the 912ULS 100hp. It became the standard on all Rotax 9xx series engines from that point on.

Ralph

[Wheels]

Jiott,
the pictures say a thousand words. Thanks, It looks like a doable and durable and economic fix. Thanks

[Wheels]

Ok, just to clarify, The bolt pattern on the hub has changed as well as the size of the studs in the flange.
So, new question, who makes the "prop" Spinner flange? Me? Do I order a flange blank from Aircraft Spruce, Sportys, KitFox and have it pre drilled? Will this plane EVER fly again? Only the gods know. Or do they?

[Wheels]

Just thinking, I won't know if I need a new spinner flange until I match the old one with the new bolt pattern/size. Maybe I"ll get lucky. Not likely, but maybe.

[Wheels]

Called the manufacturers today. ... did not get lucky.
I want an aluminum spinner. They don't crack. They are shiny. They look cool.
My spinner back plate won't fit the new engine. A quick look at Aircraft spruce shows nothing R/R capable. (remove and replace) Now what? Get a machinist to fabricate one to my specs? Is there a manufacturer who makes three blade prop spinner assemblies for a Rotax 912UL? Ideas? Comments?

[cap01]

i just went thru the same issues with the prop flange on the new engine. luckily i had access to a newer warp hub and flange inserts. the problem was with the spinner back plate. chucked the plate in a lath and cut out the center flange hole to the correct size . i had reamed the holes in the plate for the flange inserts nuts but the plate wouldn't fit. seems all the holes had to be stretched a little to get the plate to fit. enlarged center hole was pretty much dead nuts center so that wasn't the issue. all the holes had to be stretched in the same direction so it had to be some difference between the flanges. i did find the paper work that tells about the flange changes and has the engine s/n when they changed.
at least now i have a useless old style warp hub that will probably go away when i decide what i happening to the old engine.
good luck
chuck

[Wheels]

Hey Chuck,
Seems we have twin problems. I"ll take my old plate to a machine shop I know. I don't want to wallow out the holes on the plate and rely on the center hole for alignment. I want good alignment and perfect balance.


I just don't want to change the spinner type to the crappy fiberglass style and watch it crack, flake and chip as I have seen on so many. The aerodynamic consideration is that a small spinner offers no real advantage to the flat nosed drag problem. I flew the plane without its spinner to do a prop pitch test and was amazed at the sink rate after pulling power for landing. The spinner does a great deal to enhance airflow.

My old engine is on the bench. I will sell it but haven't decided how to do that yet either. the pickup for the stator was the problem and It needs to be adjusted. The old wiring harness is just to aged to be safe in my opinion. So the core of the engine with its accessories is what I have. I"ll see who wants to play with Electrical and they will have a motor.

[cap01]

i kinda wish that i didn't have a new style hub, i had been considering getting a whirlwind for the new engine. this engine change has drug on for sooo long , i really wanted to get back to flying. i did have balance concerns for the spinner and will check it closer for center. i have ran it a couple of times and about to balance carbs and realized i have a problem with the new macfarland throttle. i have a couple of people that have shown interest in the old engine but i haven't given much thought how to deal with that . i seem to have a nagging concern about liability.
did you hook up the soft start on yours? it really works nice.
hope you sort out the spinner plate. i never realized there was a problem until i
i went to change over the insert nuts on the flange, was a big surprise.
cp

[Geowitz]

If you end up needing a new spinner that will have to be drilled anyways check out B&B Sport Aviation in Maryland. They are the KievProp dealer and sell an 8.75 Inch carbon/fiberglass spinner. Great quality and durability. No cracking or crappy gelcoat to deal with. Comes in 3 blade version, but when I switched to 2 blade they were able to sell me a dome that had not been cut and I fitted it myself. Not sure what diameter you need, but figured I'd give them a plug. I think it's about $250. Sorry, don't have a better pic right now.

https://www.bbsportaviation.com/

[Guy Buchanan]

A tip for your new spinner:


Before you put on the spinner backing plate, install #10 nutplates at about 8 or 9 locations on the vertical face near the edge, but far enough away to accomodate #10 fender washers. Set the nutplates so you can screw into them from behind the spinner and thereby attach weights (washers). This makes dynamic prop balancing much easier. You can then add weights at each nutplate without removing the prop or spinner. Super-easy.

[cap01]

good tip, thanks

[avidflyer]

Wheels, I sent you a PM. JImChuk

[jrevens]

A tip for your new spinner:


Before you put on the spinner backing plate, install #10 nutplates at about 8 or 9 locations on the vertical face near the edge, but far enough away to accomodate #10 fender washers. Set the nutplates so you can screw into them from behind the spinner and thereby attach weights (washers). This makes dynamic prop balancing much easier. You can then add weights at each nutplate without removing the prop or spinner. Super-easy.

That’s a great idea, Guy! If you started at the center line of a blade and installed a nutplate exactly every 30 deg. (12 total) it would be ideal.

[PapuaPilot]

I made 12 holes in my backplate without the nutplates. When I balanced my prop I just put the final weight in the appropriate hole.

[Wheels]

I appreciate the help. You are all awesome. I called Warp Drive and those guys have my loyalty hands down on service. Daryl spent some time on the phone with me this week and I did buy a carbon fiber spinner and back plate assembly from him. He said it was unlikely that I will need to balance the unit I am buying as it is a well designed and tested spinner. The color will match my plane and I can install and fly rather than continue the game of drilling balancing, hoping, testing, etc. Tell me no one saw this problem coming and just ignored it. Pretty much the way I feel about the last 17 minor adjustments for fitting the engine. I have not enjoyed the ride and I will NEVER build a plane. Hoping for successful engine start on Friday of next week, but I have been saying that for quite some time now. Cheers

[cap01]

i found the service information released by kodiak research dated november 1994.
the very short story is that from september 1994 on the 912 ul starting with sn
4153100 will have version 2 propshaft with 13mm collar nuts

[Wheels]

Super, I don't know why I didn't look for that

[cap01]

heres a link to bolt pattern standardization service info
https://legacy.rotaxowner.com/si_tb_info/serviceinfo/4kul94.pdf

[Wheels]

The engine first start went according to plan. Dead battery had to be charged. After three attempts had to be charged again, new battery has been purchased. Start went off with good results but the Dynon DS 10 has many configurable screens. After replacing the supplied oil pressure sender with a Kavlico sender, the problem of oil pressure sender communication was partially solved.
The Dynon must be configured for your engine and the individual screens for RPM and pressure have been manually input. I think I may fly tomorrow.
Of course the nose cone didn't fit. That would have been too easy. Im looking for something that will fit a rotax powered round cowl. Not as easy as I thought.

The mech stuck around for the engine run and signed off the plane. The pneumatic balance and blade pitch are on me.
Not a problem. If things continue as they have been, there should be a major weather system or an earthquake that destroys my runway. I cant wait.

[mr bill]

We know the feeling

[Wheels]

I walked into the hangar and looked at my project sitting in the dim light of overhead flood lighting. There were tools and empty oil bottles around her feet. She sat there without her cowlings and two empty mouse traps on sentry.
The extra parts, the ill fitting nose cone, and the little drip of oil below the left corner of the heat blanket was just the icing on the cake. I shut off the lights, started up my tractor and started moving dirt. The little plane will have to wait until I feel like it. Im pretty tired of the process. Not one single aspect has gone according to plan. I"m too close to quit and I'm too Peeved to continue. I have 300 acres of hay to get in, and frankly, I would rather do that right now.

Dynon called back with an answer to the tachometer problem. The set up screen in the installation manual calls for several options. Deciding which one will require an optical tachometer to satisfy me that I'm seeing what is being reported.
190.00 sound reasonable for an answer? Welcome to aviation 101.

[Wheels]

Victory is never sweeter than when it is hard won.
tonight I fueled up the the fox and completed a final run up with the new Dynon settings from Steve at the company. Voila! beautiful readable believable vibrations of engine RPM!
All in the green, I took off in the evening light and flew for a few minutes to get the feel of it back. She makes 95mph at 5400 rpm. Probably a result of a slightly flat pitch and the lack of a nose cone. The ambient temps were in the 90s and the engine temps were relatively cool. I did a couple circuits and tested out my landing skills. My wife cried a little when I landed, she was afraid I was about to quit. and truth be told, I was. Its been a long road. I think the end of the ridiculous maintenance may be upon us. We should be able to fly, just ... fly.
I'll keep you posted.

[Wheels]

What is the right nose cone for a new 912ul in a Model IV round cowl. the 9 inch carbon fiber option is not it.

[aviator79]

Victory is never sweeter than when it is hard won.

Way to stick with it. Congratulations.

[efwd]

Great Job Wheels! I know what you mean. Wiring is staring me in the face. Just finished summer vacation on the Green River UT with my boys and my brother. Now I need to start installing wiring harness'.

[DesertFox4]

Happy news Wheels. Safe Kitfoxing.

[cap01]

i know the feeling also when the bliss returns

[Slyfox]

Victory is never sweeter than when it is hard won...
that is so fantastic. If you want to meet up sometime, I would love to fly with you. It was a very long road for you to get what you wanted, now go fly and enjoy. soon you will forget about what troubles you had and have nothing but fun memories of flying your fox. again, enjoy.

[Wheels]

I Balanced the carbs with a carb mate today and after an hour I gave in and used a dual gauge from a Twin engine plane. I got it pretty close but not as happy as I would like. Seems like the idle immediately following start was pretty rough for about 5 minutes. Then all was fine. I put a larger diameter balance tube on it and Im sure that is a good Idea. other than that its performance stock.

I"m still showing 5860 at take off climb showing 60 mph with VY. I"ll take a half degree out tomorrow and test again.
I think It was straight and level ish, at 105 showing 5800. So Im thinking that adding a nose cone and just dusting off the plane will net me another 5mph.

Thank you all for the encouragement and just for biting your own tongues while I ranted or moaned. I owe you a debt actually. I'll try to be the guy who pays forward the right way.
OK, tomorrow is full tanks early A.M. and start the real shake down.
cheers.

[Wheels]

I pitched the prop a little steeper. I"m seeing 120 mph at 5760 RPM! I think I"ll back it down a little tomorrow but I like going fast. I'm wondering how to really take care of the engine for the long term. Do you all really fly your Rotax engines at 5500 all the time?
Will it live long doing that?
What if you don't get 5500 static?
It was 5300 static today (90 degrees outside) and once I was straight and level I was cruising at VNE at 5460. Is that ok?
I took it to 9k feet to cool off and check performance, it just got better and better. I have about 4 hours on it now.

[DesertFox4]

Made to run 5,500 revs all day long. I got better cooling when running between 5,350 and 5,500 rpms in the Arizona heat. Moving more water throught the system is my impression. My 912 ul with fixed cruise prop would ground run up to 5,150 to 5,200 rpms. Once airborn it could go to maybe 5,650 full throttle.
Flew mine 3 years and put 1,100 hours on it. After selling it I tried to keep track of it and see what kind of hours built up. Last report it was nearing 2,000 hours and running strong.

[Wheels]

Thanks Desert Fox. I misprinted my tach reading. I am seeing 120 mph indicated at 5460. I"ll do a an airspeed check this morning before the wind comes up and report what it looks like in the cool air.
Thanks again.

[Slyfox]

I have an adjustable prop and keep it at about 5400 all the time. Rotax at osh told me that if you can do that your gear case will last longer.

[Wheels]

Im closing this thread. The Engine is in and working well. I have about 10 hours on it and I'm happy with it's performance and the Dynon DS10 as well. the minor adjustments that are coming are just ... minor adjustments.
Thank you all for real help and real advice. there is no where but here to get answers. You are the duty experts and you are the voice of reason. Thanks again.