Just after Thanksgiving, I decided I had enough of my leaking Continental O-300. My engine only has 1,000 since bottom overhaul when it was converted to a D model in the 80's. Knowing that these engines are notorious for going well beyond tbo, and the fact that I have four cylinders with 350 hours since overhaul and two cylinders with 50 hours since new, I decided to split the case and reseal it. I was confident that my engine was sound but it looked horrible with all the paint coming off the bottom and quite frankly, it's embarrassing putting rags over your nose tire and fork after giving someone a ride . After a lot of cleaning, everything was inspected and reassembled. Most of my leaks were coming from the pushrod tubes and accessory case so I decided to install the real gaskets pushrod tube stc. The installation was straight forward and a very high quality kit. With shipping and the spring compressor tool, the cost was about $500 from Spruce. I also had the engine mount powder coated and replaced the mount bushings. If anyone is curious, I discovered that Continentals were gray and black until the mid 60's, plus I hate gold.Today I did the test flight and am pleased to say that all went well. The only oil leaks were residual on the pushrod tube seal from oiling them to install them. I am sure excited to have a clean dry engine and know that it should be reliable for another thousand hours. Below are several pictures of the process:

Most of the guys on the 170 site that have done the push rod seal kit state that they are equally happy. I am not surprised that you had leaks with a 26 year old overhaul. Continental has a 12 year tbo in addition to a total hours., This I believe is one of the reasons. NOTE: like the hourly tbo the calendar limit does not apply to FAR 91 operations in the US.

Wow, nice work. Way to get after it. How we love these machines.

Jeredp wrote:Just after Thanksgiving, I decided I had enough of my leaking Continental O-300. My engine only has 1,000 since bottom overhaul when it was converted to a D model in the 80's. Knowing that these engines are notorious for going well beyond tbo, and the fact that I have four cylinders with 350 hours since overhaul and two cylinders with 50 hours since new, I decided to split the case and reseal it. I was confident that my engine was sound but it looked horrible with all the paint coming off the bottom and quite frankly, it's embarrassing putting rags over your nose tire and fork after giving someone a ride . After a lot of cleaning, everything was inspected and reassembled. Most of my leaks were coming from the pushrod tubes and accessory case so I decided to install the real gaskets pushrod tube stc. The installation was straight forward and a very high quality kit. With shipping and the spring compressor tool, the cost was about $500 from Spruce. I also had the engine mount powder coated and replaced the mount bushings. If anyone is curious, I discovered that Continentals were gray and black until the mid 60's, plus I hate gold.Today I did the test flight and am pleased to say that all went well. The only oil leaks were residual on the pushrod tube seal from oiling them to install them. I am sure excited to have a clean dry engine and know that it should be reliable for another thousand hours. Below are several pictures of the process:

As usual, fantastic work and an inspiration to aim for!


Rod Hilton
Kincardine, Ontario, Canada
C-FKJJ ??

Tapatalk Pro

Did a Real gasket pushrod tube instillation on a C 85 in a Cessna 140. Was a learning experience. The directions where good and do follow them exactly. The machining was easy and done with hand tools. Not having to mess with barrels was great. Took exhaust,intakes.baffles and EXC off. Changed intake tubing and plugs while I was there. The cutting of the stock pushrod tubes took some thought. The first set was a learning curve. After that went faster. The compression tool was absolutely necessary. All the cleaning and scrapping took some time. Will see if my 2 hrs per guart consumption is less when the weather changes.
One interesting observation. Did find an intake tube that was barely on and a real intake leak. Three annuals didn't find. Something to look at but hard to find. The symptoms where there but all inspection could not find.
The only real hiccup was that the exhaust nuts where very tight clearance. The head end I'd the pushrod tubes is some what larger and caused interference with the nut tool interface. Had to grind a socket. The a&p asked me why I didn't get the special smaller nuts instead of the brass nuts. Learned much.
ML

meachamlake wrote:Did a Real gasket pushrod tube instillation on a C 85 in a Cessna 140. Was a learning experience. The directions where good and do follow them exactly. The machining was easy and done with hand tools. Not having to mess with barrels was great. Took exhaust,intakes.baffles and EXC off. Changed intake tubing and plugs while I was there. The cutting of the stock pushrod tubes took some thought. The first set was a learning curve. After that went faster. The compression tool was absolutely necessary. All the cleaning and scrapping took some time. Will see if my 2 hrs per guart consumption is less when the weather changes.
One interesting observation. Did find an intake tube that was barely on and a real intake leak. Three annuals didn't find. Something to look at but hard to find. The symptoms where there but all inspection could not find.
The only real hiccup was that the exhaust nuts where very tight clearance. The head end I'd the pushrod tubes is some what larger and caused interference with the nut tool interface. Had to grind a socket. The a&p asked me why I didn't get the special smaller nuts instead of the brass nuts. Learned much.
ML

Most mechanics have a few ground down sockets for various applications

I seem to remember something about removing an intake casting on the cylinder head to access exhaust hardware on a couple cylinders on O-200s but it has been a while since I worked on one.

I always enjoy engine work posts. Looks great, I'm not a fan of Continental gold either.

Question; When work like this is done are components dimensionally checked? I.e. Measuring the cylinder bores, pistons, crank journals, etc? Or do you just visually look stuff over and put it back together?

PilotPeat wrote:

meachamlake wrote:Did a Real gasket pushrod tube instillation on a C 85 in a Cessna 140. Was a learning experience. The directions where good and do follow them exactly. The machining was easy and done with hand tools. Not having to mess with barrels was great. Took exhaust,intakes.baffles and EXC off. Changed intake tubing and plugs while I was there. The cutting of the stock pushrod tubes took some thought. The first set was a learning curve. After that went faster. The compression tool was absolutely necessary. All the cleaning and scrapping took some time. Will see if my 2 hrs per guart consumption is less when the weather changes.
One interesting observation. Did find an intake tube that was barely on and a real intake leak. Three annuals didn't find. Something to look at but hard to find. The symptoms where there but all inspection could not find.
The only real hiccup was that the exhaust nuts where very tight clearance. The head end I'd the pushrod tubes is some what larger and caused interference with the nut tool interface. Had to grind a socket. The a&p asked me why I didn't get the special smaller nuts instead of the brass nuts. Learned much.
ML

Most mechanics have a few ground down sockets for various applications

I seem to remember something about removing an intake casting on the cylinder head to access exhaust hardware on a couple cylinders on O-200s but it has been a while since I worked on one.

Been there done that on the note about having to remove intake castings to get at certain 0-200 exhaust hardware. And yes, even though I'm just starting in aviation mechanics, I already have a few ground down tools. And lots from working on Ag and construction equipment.

Looks great Jered. Really like the paint you chose.

I have a soft spot for the O300, a great engine, very under stressed. Mine leaked incessantly from the push rod tubes and no one could fix it. Cylinders came off, heads were scratched, money was spent. the final solution was simply cleaning the crank case breather tube.

I know another that was fixed completely with exactly the same technique. it requires a wire pull through, similar to cleaning a rifle barrel! Great photos, thank you for sharing.

aussie bob wrote:I have a soft spot for the O300, a great engine, very under stressed. Mine leaked incessantly from the push rod tubes and no one could fix it. Cylinders came off, heads were scratched, money was spent. the final solution was simply cleaning the crank case breather tube.

I know another that was fixed completely with exactly the same technique. it requires a wire pull through, similar to cleaning a rifle barrel! Great photos, thank you for sharing.

Might try that, mine throws a little oil around:)

Very nice job, I should do the same. I have a spare engine mount painted and I am going to switch to a Skytec starter so will be taking the engine off this annual. Also some baffling tidy up.

When my engine was built, my engine builder asked me what color I wanted the engine to be (O-360 Lycoming). I asked him if he could match the red of the airplane. He could. I think I have one of the few red Lycomings in existence.

Cary

whee wrote:I always enjoy engine work posts. Looks great, I'm not a fan of Continental gold either.

Question; When work like this is done are components dimensionally checked? I.e. Measuring the cylinder bores, pistons, crank journals, etc? Or do you just visually look stuff over and put it back together?

I measuered almost everything in the bottom end. I didn't disassemble anything in the cylinders, so bores were not measured.

Jeredp wrote:

whee wrote:I always enjoy engine work posts. Looks great, I'm not a fan of Continental gold either.

Question; When work like this is done are components dimensionally checked? I.e. Measuring the cylinder bores, pistons, crank journals, etc? Or do you just visually look stuff over and put it back together?

I measuered almost everything in the bottom end. I didn't disassemble anything in the cylinders, so bores were not measured.

Jared, nice work! Looks awesome and I am sure it is nice to not have to worry about leaks. Thanks for posting this!

FYI- I fixed your pictures that were rotated 90 degrees.

When you copied and pasted the links they looked like this:
backcountrypilot.org/images/originalphotos/3386/5307/bec088e7f371f7097cade705.jpg

The trick is to just remove the "original" out of the link. Like this:
backcountrypilot.org/images/photos/3386/5307/bec088e7f371f7097cade705.jpg

Typically it is easier to just take it out of all the pics rather than try and find the specific ones that need fixed. Hope that helps.

Thanks Evan!

Jeredp wrote:

whee wrote:I always enjoy engine work posts. Looks great, I'm not a fan of Continental gold either.

Question; When work like this is done are components dimensionally checked? I.e. Measuring the cylinder bores, pistons, crank journals, etc? Or do you just visually look stuff over and put it back together?

I measuered almost everything in the bottom end. I didn't disassemble anything in the cylinders, so bores were not measured.

Cool, thanks.