Cleaning those pistons is interesting. I always assumed you would simply replace those as the cylinders are replaced. Do pistons tend to have a longer more useful life than their cylinder counterparts?

Pistons and cylinders are not being replaced. We are putting new rings and used it as an opportunity to clean up the pistons. The cylinders are in great shape and only have less than 700hrs. We are putting new valves though.

Short day at the shop. I have a new found respect for what it takes to make the final project look factory finished.

The prep work necessary to have a paint look good is time consuming. I inspected all the media blasted parts before prepping the paint. I found a small crack in the balance tube bracket. Luckily for me an amazing welder is about 1/4 mile down the road at the next private airstrip. 10 mins and $10 later I had a fixed part.



Each part was cleaned, blasted, wiped down with Acetone and blown off with compressed air.



All the parts hanging on the paint booth.



Valve covers ready for paint.

Since Sean has to work, I figured I can update a bit...

Cylinder assembly time...



I have already bead blasted the heads and checked for cracking... All good on that front... Also, intake and exhaust guides are good...



My cylinder clamp is such a handy tool... Rotate the cylinder to grind the valve seats..



We are installing new valves... Old ones have quite a bit of wear for only 680 hours...



Intakes are ground at 30 degree angle..



Stone in place over the arbor...



Seat grinder motor ready..



Solvent is used as a coolant for the stone..



Turn the stone over for a 20 degree relief cut..



Remove the arbor to prepare for lapping..



Lapping compound on the valve...



The ole suction cup hand lapped stuck on the valve..



What the compound looks like after hand lapping the valve in...



Valve lapped in... Dark grey line is where the valve seats into the valve seat... This is what you want to see for a good seal..



The seat after lapping...



Exhaust valve after doing all of the above but at 45 degrees..



Compound cleaned up, both valves in their seats and my tool set up with the valve holder in place..



Rotate the assembly to install the springs..



Steal spring seats and intake valve seal set in place...



Valve springs are directional on this engine... Not that the right side of the spring has tighter spacing between the coils than the left side... This side of the spring must be on the bottom (closest to the cylinder head) of the valve...



Springs set in place with top plates.. Note the exhaust plate is a rotating type...



Spring compressor in place..



Compressing the spring to install the new valve keepers



Keepers installed



Both valves are installed



Assembly rotated 90 degrees for the hone..



Done... Nice crosshatch..



5 done...

At the end of my day I got all 6 done... Next is the paint all the individual parts...

Brian

Great pics... Thx for sharing!

I edited my above post... Accidentally posted it before I was done..

Nice pictures, cool to see the clean up and reassembly of the cylinders.

Please put some new pistons in those cylinders They cheap-

Great thread!

great pics. Handy spring compressor.

Awesome Brian! Can't wait to get her back in the air!

SixTwoLeemer wrote:Please put some new pistons in those cylinders They cheap-

Great thread!

I would if we were doing an overhaul... This is a repair on a 680 hour since major engine... These pistons will last until TBO

Speaking of pistons...



Checking ring gap and pre installing Pistons in the cylinders..



Double check those part numbers... Note the TOP written on the ring...



Insert the ring and push it in toward the top with a piston



Here is the ring in a good location to check the gap..



Overhaul manual has the ring gap limits listed... Note on the 520 cylinders each ring has a different tolerance ...



Top ring gap is min .033.... I do not have a .033 gauge so I am using a .025 and .008 stacked...



Gap was too tight so I had to file it just a bit...



Check, file, check and file until it is right... Repeat for the rest of the rings...



Install the rings on the piston.. First the oil control ring.. It is a 2 piece with this spiral spring put on first...



Then the ring on top.. Note text is facing up toward the top of the piston...



Install compression rings.. On the 520 cylinder there are different part numbers for the 1st and 2nd ring grooves so you have to make sure you get them in the right location... Make sure the ring gaps are staggered..



Oil the crap out of everything.. Cylinder walls, piston, piston pin.... Don't be stingy...



Using a ring compression band, compress the rings and install the piston in the barrel... I could not get a picture with the band on due to oily hands.. It is laying on the table though.. Note also that the oil scrapper ring is not installed at this time... I will be installing those when I install the assembly to the rest of the engine...



For now I just pushed the piston into the cylinder so I can set the assembly to the side upright on some cardboard...



Three cylinders done.. Note that the oil scrapper ring is set on top of the cylinder... I will keep the scraper ring with that cylinder since it has been gap checked to it...

That's all for now..

Brian

Great thread!

Thanks for taking the time to detail all the work Brian. Very interesting!

Fascinating thread.

Do keep it coming - this is very interesting stuff.

Make sure you don't use those sorry pinkish valve cover gaskets that shrink. I just replaced 3 more. I have some older cylinders sitting around that I replaced and noticed the blackish gaskets that were put in back in the mid 1990's are still perfect.

Brian-StevesAircraft wrote:..... Note also that the oil scrapper ring is not installed at this time... I will be installing those when I install the assembly to the rest of the engine...

Why don' you install the scraper ring now? Does it tend to "de-oil" the oily cylinder walls & cause rust?

hotrod180 wrote:

Brian-StevesAircraft wrote:..... Note also that the oil scrapper ring is not installed at this time... I will be installing those when I install the assembly to the rest of the engine...

Why don' you install the scraper ring now? Does it tend to "de-oil" the oily cylinder walls & cause rust?

When I install the cylinders I have to pull the Pistons back out enough to pull the pin and install onto the rod... Since the scraper ring is on the bottom of the piston, it is easier to install it later so I am not compressing it twice with the ring compressor...

Today's progress...



Installing the rods to the crankshaft...



Rods are stamped, 1 through 6.... Both the cap and rod...



Close up view of where you will find the stamped number... This is rod #1... The numbers have to be next to each other when installed.. If you do not see both then the rod cap is on backwards...



Assemble the rods to the crankshaft with lots of oil applied to the bearings...



Here is Rod number 2 on the crankshaft...



All the rods must be installed so that the numbers face the top of the case... In this picture, rod number 1 is the top Rod and number 2 is the lower Rod.... When on the stand looking down at what would be the top of the engine the number 1 Rod points to the left and 2 Rod to the right...Rear of the engine is upward to the top.... Note the numbers on the rods are both facing the camera...



Rod nuts are torqued with oil on the threads..



All the rods on with the nuts finger tight ready for torque..



Rod nut torque values... These are 7/16-28 nuts so the values are low 39.6 ft. lbs. to high 43.8 ft. lbs. Tighten to the lower value first..



After the first torque, check to see if any of the key holes line up... If not, then slowly tighten to the higher torque value... If key holes still do not line up... Take off the nut and swap it with a different one and try again... Repeat until it is all are torqued and then install the keys...



Getting the case ready... Installed pipe plugs for the oil galleys and set all the main bearings in place... Will install a new needle bearing for the accessory gear and then lay in the thread seal tomorrow... Hopefully will have cylinders on by the afternoon...

Brian

Great thread & photos, Brian-- I don't usually get to see an engine until it is at least mostly assembled. Cool to see what the innards look like as it goes together.

More progress today...




There are 4 of these oil galley plugs.. One on each end of each case half...



This needle bearing...



Is installed here... It is for the starter gear shaft...



Organize all the bolts and nuts by size... Makes it easier when assembling the engine... All lock washers are replaced with new ones...



Make sure your prop governor drive is installed into its case half.. The governor gear is driven by a gear on the camshaft...



Set one case half up on a barrel to prepare for the crankshaft...



Crankshaft assembly is removed from the stand... Time to install the nose seal..



Nose seal is 3 pieces...



The spring is a PITA to put on... You have to unwind the ends, then wind them back on the crank...



Spring and backer ring on the crank...



Now the hard part... Getting this one piece seal stretched over the crankshaft flange..



Put the seal in a water bath..



Heat it up...



And I mean really get it hot....



Remove it from the bath and set it on the edge of the flange... I had dad put it on so I could get a couple of pictures of it going on... Dad adds a little oil around the flange to help the seal slip over it..



Using a couple of long bars... Stretch the seal around the flange...



Like this...



Once it is one.. Let it cool and then assemble the spring and backer to the seal..



Oil the bearings, camshaft saddles... Everything that needs it put oil on it...



Two people.. Hold up the opposite rods and drop the shaft in place... Set the timing marks up near the camshaft..



Set the cam timing marks into the gear and the roll the shaft down into position... Double check the timing by rotating the assembly and verify alignment..



Oil up and insert the thrust bearings..



There are four of these... And they can only go in one way..



Apply a liberal amount of camshaft lube onto all of the lobes...



Apply permatex sealer to the case half.. Only need to do one case half, leave the other half without...



Set the mag drive gear and shaft in place...



Thread seal... I use the double thread method with the thread going on both sides of the flange holes...



More thread seal..



Get your buddy.. Hold up the opposite rods and set the case in place... Make sure the thrust bearings do not get out of place when setting the opposite half down onto the assembly... I use white lube on the thrust bearings to sort of glue them in place...



Insert the flange bolts... Finger tight the nuts...



Through bolts... Also finger tight the nuts on the lower bolts..



The cylinder through bolts have a pair of o-rings that go on the center of the bolt... The o-rings have to be stretched on and slid down to the grooves...



After all the through bolts and case bolts are installed.. Set the assembly back onto the stand...



Getting the cylinders ready.. Make sure the rocker pins are set in place and don't forget the base o-ring...



Put the o-ring on, pull the piston out just enough to get the pin out and install the scraper ring... Make sure the ring is on the right direction...



Slide on the cylinder... I compress the scraper ring by hand using the ring band compressor...



Two down...



Ready to torque...

Brian

Getting there....



These are cylinder base wrenches...



This is how you use them to torque the cylinders...



Torque sequence...



Torque numbers... Follow the list top to bottom using the drawing above for the sequence... Torque once at lower torque and then torque again at the higher value...



Torque on the idler gear shaft...



Cut off all the excess thread seal that is exposed....



Getting the starter drive, oil pump housing, mag drive covers and other items ready to install...



Using the gaskets, mark the outlines on the case with a pencil...



Brush on permatex...



Gasket..



Apply sealant of the part and oil up the gear..



Set in place, install and torque the nuts and bolts..



Mark, apply sealant and set the gaskets for the oil pump and fuel pump block off plate..



Fuel pump block off plate installed and nuts torqued..



Oil pump housing set in place... Sometimes you have to use a little persuasion..



Oil up the pump gears... The driven gear sets into the camshaft..



Looking at the cam gear, make sure the oil pump gear is lined up...



Oil pump idler gear, I just dip this one in my oil bucket and set it in the housing...



Wipe away excess oil from the mating surface of the housing...



Apply sealant...



The oil pump is thread sealed... This is the diagram for how to apply the thread...



Thread set in place...



For some reason Continental had the bright idea of designing the housing with this one nut that has to be installed at the same time as the housing is put in place... If you forget, you will say words not fit for children to hear...



Torque all the nuts...



Install the tack drive and cap... Keep in mind, this cap has reverse threads... So instead of righty tighty lefty loosey it is lefty tighty righty loosey...



Sean's 182 has an electric tachometer so the tack drive gets this sealed cap installed...



Oil pickup tube installed and bolts torqued...



The pickup tube bolts are safety wired...



Oil pan cleaned up... Seal installed and bolts torqued...

Next... Clean up, mask off and paint gold..

Brian