Forward Progress Resumes!

Upgraded parts arrived from the factory in very short order, thanks Jan.


First task was to reinstall the upgraded flywheel and the PSRU.  First shot below is the backside of the PSRU with the newly pressed on spider gear onto the splined shaft.  Also seen below is the new aluminum bushing that replaces the pilot bearing.

The next shot illustrates the first of 2 elbows that begin installation in the former location of the site glass of the PSRU.  These fittings will connect to the oil tank return line.

About to press in, or in my case, tap in the pilot bushing.

Another shot of the thickness of the bushing.

Home sweet home for the foreseeable future.

The upgraded flywheel and the rubber doughnuts.  Note the unthreaded studs on the flywheel upon which the rubbers will mount.  No more bolts and nuts needed to secure them to the drivetrain.

Doughnuts mounted to the flywheel, awaiting installation on the crank pulley.

 Finger tightening the 6 flywheel bolts after a generous coating of blue loctite.

Torque wrench and requisite elbow grease liberally applied.

Rubber doughnuts hung in place in the correct orientation as designated by the hand drawn image (from the factory) on the flywheel.  It will be hard to screw this up.

Now carefully begin the alignment process of the splined driveshaft into the pilot bushing and the 4 aluminum standoffs/bolts into their respective holes on the engine.

It actually fit quite easily and there was no real force required to set it into place.  Another liberal dose of elbow grease and the torque wrench finished off this important task.

Now, I wanted to continue to plumb the PSRU for its engine oil circulation, so the first of 2 flared steel fittings was threaded into place with sealant.  This was the original location of the gearbox temperature sender, so I removed it and relocated it the adjacent hole.  The flexible steel oil circulation line was pretty short and I needed every bit of help to span the distance from the oil galley port on the engine to the PSRU.  You can just see the terminating end of the flexible steel oil line on the left side of the picture.

In order to obtain good access to the oil galley port, it was necessary to remove the intake manifold which requires a ball hex driver as shown below by the extreme angled approach to the allen bolt.

Once the manifold was removed, the target was much easier to locate and a trial fit of the flared fitting with the other end of the oil line.  Again, the flared fitting was tightened into the galley port with a liberal amount of thread sealer.

Next, the manifold was reinstalled paying careful attention to the clearance of the steel oil line.  There could not have been any less clearance between one of the pipes of the intake and the terminus of the oil line - literally 1 or 2 millimeters.

 Another view of the oil galley end of the line as it runs to the PSRU.  That is the starter that the oil line is passing over enroute to the PSRU.

And finally, a complete shot of the oil line running from the engine's galley to the PSRU.  Note the adele clamp securing the line from interference with the ring gear of the flywheel.

Upgraded oil tank installation is next up.  After applying a thin coat of the Right Stuff to the top of the oil tank, where it mounts to the block, it was necessary to get a long allen driver with extensions to reach the mounting holes.  I believe there were 12 M6 metric bolts that had to be installed and torqued to 35 inch-pounds torque.  Lots of overhead reaching with delicate positioning - not too much fun....but got her done.

This shot shows the bottom of the oil tank and looking up into the lid, where the bolts are securing the assembly to the block.

The blue return line from the PSRU had to be connected to its bung, threaded with a barbed fitting.  Also seen in the background is the silver steel teflon oil supply line which runs from the block to the top of the oil tank.

Last task for this installment involved glassing up another oil cooler duct.  I used a couple of tin cans, taped end to end for my mold.  Covered them with duct tape and then slathered them with car wax.  Three or four layers of glass cloth should do the trick.  Shown below is the beginning of the mold removal process, which involves carefully destroying the tin cans.  It was not as difficult as it might look.  After some initial crumpling, it was easy enough to work a thin bladed screwdriver around the edge and bend the can inward, so it could be removed.

The prize!

Going Backwards?!

In the interest of maintaining a Viking engine with all of the up-to-date enhancements and upgrades, I found it necessary to get on the list for a new oil tank and flywheel.  Early adopters, like myself, to a relatively new alternative aircraft engine are subject to such things.  So here's what we've got:

1. An upgraded oil tank that is now a welded unit, as opposed to the original that is bolted and siliconed together.  On top of the inherent strength and tighter fit, the new unit features an improved filler neck and dipstick tube.  But the real draw for me is the bung that is now welded in place to receive the engine oil line and fitting that returns oil from the PSRU!  The Viking engine has another port that ties into an oil galley on the block from which high pressure oil is routed to the PSRU.  Instead of a small quantity of 90 weight gear oil (about 3 ounces), the PSRU will be supplied with a constant supply of circulating engine oil.

2. A new, slightly heavier flywheel made out of steel, replaces the second generation aluminum model that has been prone to the development of cracks.

In order for all this to come to pass, it was necessary to remove the old flywheel/ring gear assembly and the PSRU and return them to the factory.  The ring gear gets reused, but the old flywheel goes away.  The PSRU has a sleeve pressed onto the drive shaft.  Yet another issue to be resolved was the removal of the pilot bearing from the crankshaft....more about that later.  In its place will be a brass ring.

First in the process was the draining of the engine oil and then the coolant from the radiator and hoses.  Radiator is now detached, with only the rear bracket remaining.  Cross over tube was completely removed as well.

 And there she lies, draining the last drops of the Evans NPG coolant into my oil change pan.

Up next was the oil tank removal.  The unit is bolted together with a long bolt that runs from the top to the bottom of the tank.  Even after removal of the bolt, the work is just beginning.  Breaking the seal of the Right Stuff silicone was a huge chore.  I was in disbelief at the strength of that stuff and its ability to hold aluminum parts together.  In the end, it was the use of a pry bar (no less) that was required to carefully separate the tank bottom from the body.  After removal of all but one of the 16 M8 allen bolts holding the tank top to the bottom of the engine, it was time to pry again.  This time the old oil recirculation bung was used with the pry bar and the block of the engine to break the tank body from the tank top.

The shot below is looking from the ground up and shows the bung on the tank body that was pryed against for removal.  Once you had the pry bar in place, (between the bung and the engine block) the silicone was relatively easy to break...but when you realize the leveraged force required to do so, it leaves me with a great respect for the strength of that silicone product.

 With the radiator and oil tank removed, it was time to turn my attention to the removal of the PSRU.  Unfortunately, I did not get any shots of the removal process.  Below is a picture of the tapered 2x4 that I carefully used to pry the PSRU away from the engine block after the 4 large bolts were removed.  It was really quite easy to slide it off the engine with just a slight bit of encouragement.

With the PSRU gone, the rubbers or vibration dampening doughnuts and spider gear are clearly visible on the flywheel.

Six nuts removed and the spider gear/doughnut assembly comes away nicely, leaving the final 6 flywheel bolts.

Close ups of the spider gear and rubber doughnuts are shown below.

To get the necessary torque on the flywheel bolts, a simple locking mechanism was employed to restrict crankshaft rotation.

Bolts are out...

...and off comes the generation 2 flywheel and ring gear.

And there is the next target - the smallish blue ring: the pilot bearing.

I have to say that pulling that bearing was fun!  No kidding.  I googled up a few youtube videos about guys using everything from axle grease to a piece of bread to strips of water-soaked paper to use hydraulic pressure to remove bearings.  So that's what I did.  The water/paper trick looked to be the neatest and simplest, so that is what I tried.

 Start with some paper soaked in some water and then start stuffing them into the bore of the bearing as shown in the first two photos below.

 Next up, begin "plunging" a shaft (in my case, a 7/16 nut driver, whose OD just matched the ID of the bearing) with the aid of a hammer or mallet and compressing the soaked paper shreds.  As you penetrate deeper with the shaft, remove it and replace with more soaked paper shreds.  Rinse and repeat.

Before too long, you end up with the bearing slowly peaking out from and then entirely protruding from the bore!  Works like magic!

Lastly, pry out the soaked paper and you are done.  Unbelievable - but I'm easily impressed.

Before I close this tome, I'll make mention of another implication of the upgraded oil tank....and it is not a minor one.  The new oil tank will require me to relocate the oil cooler to a location lower on the firewall to insure clearance for the PSRU oil return line.  That consideration, combined with the fact that the new tank changed the location of the filler neck and dipstick tube and there are wholesale changes that have to be made to my upper and lower fiberglass cowls!!!!!!!!!

Specifically, the oil cooler duct will be relocated to the lower cowl.  The first 2 shots below, show the amputated oil cooler duct and the foam filler patch, awaiting its new glass cloth and resin.

Inside view of former location of oil cooler duct.

Sanded, cleaned, glassed and peel ply'ed and it will be ready for finish sanding/filling to make it seem like a distant memory.

Next the lower cowl has been cut to facilitate the new lower position of the oil cooler duct.

Front view of the cooler duct's new location.

 The upper cowl not only lost the oil cooler duct, but the oil access hatch door will have to be relocated too.  First shot below shows the inside with the foam patch awaiting shaping to the original shape of the cowl.

Outside view of same.

And the saga continues....

Finally, both of the patches are glassed from the inside as well, to insure structural integrity of the cowl.

Next installment will begin the reversal of this "going backwards" process as the upgraded parts are due in tomorrow, so stay tuned.  There will be plenty of perils on the way toward achieving the engine oiling of the PSRU....not to mention the new oil cooler duct in the lower cowl and the relocated oil access door on the upper cowl.