Thursday, December 17, 2015

Engine Reassembly Completed – Ready To Install

Yesterday, the Rotax 912 engine reassembly process began. The first step prior to reassembling all the parts that needed to bo removed to custom fit the FF-1207 air shroud is to lay down two beads of high temperature silicone along the marks made on the engine casing. Some care should be taken to only apply the silicone to the crankcase area and not apply it onto the cylinders. The FF-1207 air shroud will be seated in the beads of silicone which will serve as an air seal and also to help secure the air shroud.
Two beads of silicone applied to the crankcase and ready for the FF-1207 air shroud to be seated into it.
View from above … one can see how the air shroud is seated into the high temperature silicone.

From this point on, the reassembly is a reverse order of the steps taken to remove the parts from the engine. First the coolant expansion tank and the four water lines are temporarily installed and marks are to be made on the air shroud for a dollop of silicone between the air shroud and water lines. Once the high temp silicone is applied, the water ports are seated and the M6 Allen screws are torqued to 90 inch pounds. Next the ignition module bracket is returned to its original position and the M8 Allen screw receives Loctite and is torqued to 215 inch pounds (18 foot pounds). Lastly, the carburetors/ intake manifold assemblies are installed onto the engine and the M6 intake manifold screws are torqued to 90 inch pounds.
Screwing the right carburetor/intake manifold assembly onto the engine … once the screws are torqued, the engine will be ready for instillation onto the firewall.

Although not told to do so, I also tightened up the bolt and nut that secure the ignition modules. If this poses a problem, I will try to come back from the future and edit this post.  At this point the engine is ready for instillation. Although, at this point, the plans instruct the builder to remove the carburetors for the installation of drip trays. Unfortunately, I do not have the luxury of time and need to move onto hanging the engine because the gentleman I borrowed the engine hoist from needs it to install an engine in his RV-10 … and I don’t want to hold him up since he was kind enough to loan me his engine hoist. Feel removing the carburetors is a task that can be just as easily done with the engine mounted … possibly even easier so will move onto that next.