Intake Cylinder Repair on Lycoming 0-320-D2J on Cessna 172M

Lou Peak asked the engineer to help us, so after removing the head and making sure there were no stock valves or bent pushrods, he cleared us to fly to janicot and after a few days we went down to look for things. ready, in terms of having a proper compression test and sorting out any issues, so we want to thank era club and Lou in particular for their quick arrival, they came within 24 hours of calling which is really important for our mission. um there's a lot of things behind a mission like this to keep it in the air and we thank you for helping us at a pretty important time.

Well, here we have the compression test going on on the left side, you can see the air is pumped in and it has about 75 HP. On the right side is what's in the

cylinder

and we find that it is at zero Zer, which shows, of course, that we have a big problem and that we needed to take the entire

cylinder

. and take a close look to try to determine the cause, so the first order of business is to remove it. The Rocker covers these black covers that you see here and that gives us access to the rockers and underneath that. the valves and pushrods and finally the cylinder itself here are the rocker arms now exposed those are the brass shaped elements you see in the photo here you now see the rocker arms removed the two holes above are the tubes that house the push rods leading to the valves and below you see the valve springs.

Now it's time to remove the cylinder so we start unscrewing the bolts so four bolts to undo that's the first one yeah there was one to four little ones yeah okay so that's the cylinder off and now you see the piston exposed and underneath is the connecting rod to the crankshaft, so I hope they have a homemade thing to take them out because they have a little ball valve. If you magti the ball, it is not a good idea. Let's say for the moment here we have a couple of photos of the cylinder now on the top of the bench.

Now it's time to remove the valve. springs and so, with a special tool, these come off much easier to do here than to do it on the engine, okay, yeah, there are those little circlips, yeah, clips, clips, okay, that's what you had, little Ben Ben helping you and trying to get them back in, yeah. This handy tool was made some time ago at the Royal Era Club, for removing valve springs. A really interesting team. This is a close-up photo of the valve spring. Seen here, the valve stem cap and the circular tips around it. It is the pliers that must be removed to remove the valve spring from the stem.

The problem was that the

intake

valve was not positioned correctly in the cylinder, hence the carbon deposit at the base. Lou, the engineer said it was working a little. lean but not enough to be a problem in our next image we will see that the left valve is the exhaust valve, it is much cleaner, it was seated correctly and you can see the contrast with the

intake

valve, which was a problem the right. which was not placed correctly in the cylinder, in this photo we are looking down towards the top of the cylinder where the springs were placed, on the left side is the intake valve area with the valve removed in hand right.

The side is the exhaust area where you have the valve um still in place at the top and at the bottom you will see smaller holes that are for the spark plugs, the bottom hole still has the spark plug in it now if you look around to the left area where the inlet is, You will see that it needed to be rectified, it is not clean and the valve was not placed correctly, that is where the lack of compression originated, so the first thing was to take the valve to the machine. Um, putting it at a 30° angle and just to bevel the edge, which is the area that would sit against the cylinder and create a better seal, so here's the intake valve nice and clean, ready to go back into the cylinder. .

It's time to go back to the cylinder and here is the intake area again. You can see that it needs to be sorted out, so start with a more abrasive stone to polish and prepare it. This will take you a couple of hours working on it gradually, working very carefully to make the area suitable for the valve, you can see here also in the center of the valve area, the round hole where the valve shaft goes up and to which Later we will attach a spring that we saw removed earlier, so here we have the grinding stone that we are going to start using on the cylinder to prepare the seat for the valve and our next image here shows that stone. inside the cylinder placed on Ready to place the drill, you see that cross bar in the center of the fixture there and then the drill is placed and we start working on the cylinder preparing it after the grindstone.

This cutter comes that instead of being used with the drill, it is operated manually. The next step is with this very fine paste which is like very fine sandpaper that is applied to the beveled edge of the valve and then attached. to a stick and then quickly turned to do a very fine sanding of the cylinder seat that will receive the valve and there is a well prepared cylinder ready to receive the valve and provide the seal. that we need, so the next step will be to take care of flushing both the cylinder and the valve to make sure that there are no impediments that could get in the way of creating a good seal, so here is the intake valve now.

Here you can see that it is beautifully sealed just as we expected to have it and in fact it has been tested for leaks and there were none and here is a picture of the top of the cylinder again on the left hand showing the valve intake and also the right is the exhaust valve, both in place, so we're really going to start putting the cylinder back together, the dishes, also the special dietary requirements and its free delivery, the station sponsor's phone number important 9378 253 is easy to do. on and junior team social calendar this could be the club for you all inquiries 9450 3410 do you suffer from the excruciating pain of trial neuralgia? trial neuralgia support group can provide information on medications and is loading pain here's a photo of Cinder again and you We'll see on it the red oil seal at the base of the cylinder so we go back to the plane and we're going to put the cylinder on the piston.

If you look to Lou's right, you'll see above the rag, the piston hanging from the engine in his hand. Lou has a special device to help slide the cylinder over the piston. In the video clip below, as Lou replaces the cylinder, you'll look at the base of the piston. and the connecting rod and also the crankshaft P nice and smoke us SL the TR says that the morning must be stopped people you will see tomorrow 11 wn2 r99 for you to make a donation or become a member and of course it's time to try everything and make sure everything is working the way it's supposed to, so the job is done and in Quebec, kilo has put the top back on and is ready to fly home.

An interesting flight. You can see that he is overcast and he did a standard instrument sortie and got some instrument weather flights. the way back to wongan Hills that day and here we are back at The Hanger in wongan Hills later that afternoon after a successful flight and the next day we took off for the Midwest to ride magnet and Q for about 6.3 hours of trip without problems. Flying was fantastic, it was great to see us back in the air and thank you to the Era Club and especially Lou Peak for allowing us to get back in the air for