Changing out a 912 80 HP in a model IV

[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.

E1854F96-D2F3-45BB-81A8-FC09D812DE77.jpg

[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
Gearbox.jpg


The old, damaged shaft
old shaft.jpg

[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?