Lycoming Camshaft Inspection

[keltro]

Is there any way short of complete engine disassembly to inspect a Lycoming camshaft and lifters for corrosion........I have an HI0-360-A1A converted to an Experimental I0-360-A1A
several years ago after a complete overhaul..........It was flown less than 20 hours and has not ran or had any long term storage methods done to it.........After hearing the fact that
Lycoming camshafts tend to rust during long periods of nonuse I would like to inspect the cam lobes and the lifters without a complete disassembly if possible...........Help !!

[vaflier]

Remove. A front cylinder and you can take a look.

[WLIU]

Actually, you need to remove both a front and a rear cylinder to see the entire cam. No other way to get to it.

There is a Lyco SB that describes removing the valve covers, pulling the pushrods out, collapsing the hydraulic valve lifters and measuring the cam lift with a dial gauge.

No easy answers.

Best of luck,

Wes
N78PS

[keltro]

Thanks Guys...........That is better than a complete disassembly..........I presume that a cylinder can be pulled without pulling the piston all the way out........Just enough to remove the piston pin ??

keltro

[WLIU]

What you are going to do is turn the engine until your piston is at top dead center, then remove the cylinder so as to slide it right off the piston and gently lower the piston and connection rod until it rests on the case. You can then set the cylinder aside and take a good look at the camshaft lobes. You will need a ring compressor tool on the piston to slide the cylinder back onto it. While you have the cylinder off, you should install a new cylinder base O-ring, unless you know that the one that is there is almost new.

If you yourself are going to do this, just in case you have not done this much, I should mention that when you take the valve rockers out and want to remove the push rods, you want to be carefull not to pull the hydraulic lifters out and/or lose track of them.

Best of luck,

Wes
N78PS

[vaflier]

You do not need to remove the piston from the cylinder. Simply pull it out far enough to remove the buttons and the pin. A helper makes this easy to do. A new o ring is definitely a good idea. Done this way you will not need a ring compressor.

[Wsquare]

There is a Lyco SB that describes removing the valve covers, pulling the pushrods out, collapsing the hydraulic valve lifters and measuring the cam lift with a dial gauge.

Wes
N78PS

Do you happen to have the Lycoming Service Bulletin number, that describes process for checking cam using cam lift measurements? How about a web link to the service bulletin?

Also, about how long does this procedure take if being done for the first time?

About how long should the procedure take, assuming one has done it a few times already?

Thanks, Wayne

[WLIU]

First, some of how Lyco suggests that the valve tappet assemblies should be handled is described here - http://www.lycoming.com/Portals/0/te...0Lifter....pdf

The procedure that you are interested in is mostly described here - http://11hc.44rf.com/manuals/engine-prop/lycoming/aerosportspower-library/360_series_ops_manual/sec_5-maintenance.pdf

How long will it take? If you budget a half hour per cylinder you are unlikely to be disappointed. Someone who has done it a few times can likely do it much faster, but I think that a half hour is a safe guess.

Best of luck,

Wes
N78PS

[Wsquare]

Thanks. I probably should have mentioned that I have a Lycoming 0-235. I am not sure if it has hydraulic lifters. I think it has solid lifters. If solid lifters, then using a dial gauge to "map" the lift on each cam lobe should be fairly easy, unless I am missing something. Is anyone aware of Lycoming data sheets that specify the allowable limits on the cam lobe lift profiles? Is there more to this than I am thinking?

if the 0-235 has hydraulic lifters, then I need the procedure on how to deal with the lifters, so the hydraulics don't impact the dial gauge when mapping each cam lobe. I can't find this procedure in the referenced materials. Any additional ideas, references?

thanks, Wayne

[kedens]

Is there any way short of complete engine disassembly to inspect a Lycoming camshaft and lifters for corrosion........I have an HI0-360-A1A converted to an Experimental I0-360-A1A
several years ago after a complete overhaul..........It was flown less than 20 hours and has not ran or had any long term storage methods done to it.........After hearing the fact that
Lycoming camshafts tend to rust during long periods of nonuse I would like to inspect the cam lobes and the lifters without a complete disassembly if possible...........Help !!

If it was me I would pull the cylinders off the pistons and inspect the cylinder bores. If they are steel cylinders they may have rust pitting. I have done this several times and reused the same rings with no problems.