Nothing going on with the S21 yet as still working on the Sav rebuild but its getting closer. Lots of work being done on the engine though. My out of time 2015 engine has been stripped and measured to see what bearings will be needed for the mains luckily the engine is excellent and no fretting of the cases also the bore for the crank is perfectly round. The gearbox has been overhauled the crank has been welded and the crank and flywheel have also been balanced. Looks like none of the Rotax engines are balanced which is a bit of a shock especially for what they cost. So with the main assembly done I expect a big difference. The camshaft has been reground and nitrided. Most of the parts are here, new valves and gaskets and seal kits, new oil pump gears. Danny has perfected a great sequence of sand blasting the cases but not with sand its pretty tricky stuff but boy does it do a fantastic job. So just waiting on bearings and through bolts etc and the engine can go back together.
Picture of my engines cases after Danny has worked his magic on them
My big bore will be 114hp as std and hope for a bit more with a better exhaust. Danny is working on a new prop design that should be a lot better as well. This video is of a just completed S21 with a Rotax 915 IS in it. There is no wind on this day it was filmed
The engine is now here at home..all rebuilt.....its a beautiful thing :) Some pics of its assembly. Getting the last wing together on the Sav now and just waiting for the new dash so I can get ready to start painting..then I can get Mabel down to the hangar for final assembly and I can start on the mistress
The video shows the lifters rotating as they are supposed to when the cam has been ground correctly. There are marks on the lifters at the 12 o'clock position and they turn counter clockwise as the engine rotates
In all of this we found that the Rotax engines are NOT balanced at all..I was quite frankly shocked by this. We tested 4 cranks and flywheels to prove this. My engine has had the crank welded to make it stronger due to the larger hp and also it is balanced also the flywheel is also balanced so the whole rotating assembly is balanced. My engine guy is super impressed with the big bore kit I have. Everything is well made and done the right way. Even the pistons are perfect they are all exactly 504 grams each
Finally got around to spraying the matt clear high temperature paint over the engine to stop that ugly corrosion that gets on the front and top of the engine over time. Got another engine stand and fitted the spare ring mount I have here to the engine so I could easily mount it on the engine stand. Now I can start fitting all the new rubber hoses and other parts to the engine. The Rans uses a bed mount for the engine so it hopefully should be easy to then fit the engine when I get that far. Once I have fitted all the bits to complete the engine then I will "season" it as it will be at least 12 months I would think until its ready to go onto the fuselage. Not too far off getting ready to paint Mabel then it will go to the hangar for assembly and final fit out. If The Girlfriend hasnt sold by then and I doubt it will due to this virus nightmare I will fly her up to the farm and leave it there to free up the hangar. Then I can work on the S-21 at home at night and Mabel during the daytimes at the hangar as there are no lights in the hangar.