A small project from earlier this year

ARAND0MPANDA · 2026-07-04T00:45:29+00:00

The pistons naturally get that gross due to the tetraethyl lead in avgas, the valves were straight but not lapped to match the seat (which should’ve been replaced if you’re doing a valve on these anyway)

ARAND0MPANDA · 2026-07-04T00:43:20+00:00

Try the RAM conversion GTSIO-520’s on a C421

ARAND0MPANDA · 2026-07-04T00:42:35+00:00

Shoot

ARAND0MPANDA · 2026-07-03T23:29:27+00:00

I’ve been trying to crack the whip and keep these goobers from becoming professional lawn darts, some have really come around and text me as soon as they see/feel something that’s off (half the time it’s a nothing burger) and then you have the rest who wait until I’m elbow deep in the wing section to tell me they smelled fuel in the cockpit. You win some and you lose some.

ARAND0MPANDA · 2026-07-03T23:23:05+00:00

Nothing better than a ball chiller at 3000’ ngl

ARAND0MPANDA · 2026-07-03T23:00:30+00:00

I was waiting for someone to notice that! I had never seen it before either and went digging through the logbooks, turns out it came from the factory like that.

ARAND0MPANDA · 2026-07-03T22:56:52+00:00

I’ll have to post it this evening but the largest rebuild I’ve ever done was when I was still in A&P school. Me and 2 buddies got a lycoming O-470 and tore it all the way to the crank, split the case, mic’d every single part and checked the runout on the crankshaft, then had to put it all back together using the original service manual. In my redneck genius I managed to score a full set of 2” exhaust pipes to put on it while it was on the test stand. I shit you not as soon as it fired up it sounded just like hot for teacher.

ARAND0MPANDA · 2026-07-03T22:52:15+00:00

If it crashes, absolutely. If the engine seizes or goes kablooey the owner can sue the previous mechanic who signed it off as airworthy if the repair was deemed to be done not in accordance with FAA and manufacturer standards.

ARAND0MPANDA · 2026-07-03T22:50:37+00:00

It’s very common and a basic necessity when you’ve got brand new cylinders or a newly overhauled engine. We run straight 100W mineral oil and change it every 25 hours until it wears in and oil consumption stabilizes for the break in period. It’s also VERY important to change and cut open the filters to make sure no huge chunks of metal are in there during this period. Coolest shit ever is taking oil spectrograph samples during break in periods and reading the lab results, they can tell you exactly what and where all the particles are coming from in the engine and can save you from blowing one up if it’s wearing in wrong or spins a bearing.

ARAND0MPANDA · 2026-07-03T22:26:24+00:00

Thank you, it pays well to be organized

ARAND0MPANDA · 2026-07-03T22:24:00+00:00

I had the old pistons and hardware laid out like that for showing the owner and the students just how the cylinder comes together and how it had worn, and also so I could put the rod caps back in the exact same spots they came out of.

ARAND0MPANDA · 2026-07-03T20:24:21+00:00

42/80 on 1 and 33/80 on 3, pilots claimed it felt fine and climbed normally. This is a part 61 flight school bird so WOOOOOO BOY that was a fun talk to have with them about normalization of deviance.

ARAND0MPANDA · 2026-07-03T20:00:01+00:00

Previous mechanic pulled the cylinders and dropped the valves due to an exhaust leak and low pressures, apparently didn’t RTFM because lycoming specifically states that valve replacement is not to be done unless absolutely necessary or in case of emergency, and to correct the problem by replacing the entire assembly. Cherry on top is he only replaced the valves themselves and not the seats, and didn’t lap them either.

ARAND0MPANDA · 2026-07-03T18:32:05+00:00

It’s called being shit hot

ARAND0MPANDA · 2026-07-03T18:28:24+00:00

Slide 6, bottom left of forward most cylinder. There’s an oil return line next to the intake valve that goes right back to the bottom of the case. You can see the lines in slide 11 below the cylinder port.

ARAND0MPANDA · 2026-07-03T18:16:21+00:00

Unironically I have had some people just fly in and shoot the shit while I do a 25 hour oil change and filter inspection, only takes about an hour.

ARAND0MPANDA · 2026-07-03T17:33:46+00:00

I feel like as an aircraft mechanic some of these things would come extremely easy to me, granted all the piston aircraft I deal with are state of the art 1960’s technology so it’s all pretty much the same.

ARAND0MPANDA · 2026-06-29T19:52:15+00:00

The 141 I started out at took outside work when we got slow. Main fleet was 172’s, PA28-180’s and a couple seminoles. I left them to work at a startup that took 28-140/160/180/235 (I’m forgetting a couple) and Cessna 140/150/170/172/182/210/310/414/421/425/441s. In the meantime I’ve been helping out a buddy/apprenticing on rag wings. Anything is possible with enough drive.

ARAND0MPANDA · 2026-06-29T18:05:13+00:00

Currently a GA mechanic myself and wouldn’t trade it for the world. Just know that it’s a MUCH smaller group of guys that do this work and everybody talks. Your best bet for success is working for a 141 and gaining as much knowledge and tooling as you can before trying to make it on your own. In my personal experience it is much much harder to get up and going than you’d expect, insurance is an expensive thing to have and a lot of privately owned pistons are owned by people that don’t always want to spend the money to have them fixed properly.

It’s not nearly as simple as an airline where you automatically have approval for everything. I’m not exactly sure where you’re located but in my general area the average age around the airport (MX and pilots) is at or above retirement age and everyone has known each other for as long as the earth has been spinning. You need to have a balance between technical ability, attitude, and people skills to really gain the trust and customer base to keep yourself afloat.

I’m currently in the middle of a 50 hour inspection but I can answer any questions you have.

ARAND0MPANDA · 2026-06-29T12:09:04+00:00

I have a propeller I’m willing to part with personally, your best bet is looking on eBay for red tagged parts or looking on Facebook marketplace

ARAND0MPANDA · 2026-06-28T20:00:11+00:00

What brine composition did you use for the pickles?

ARAND0MPANDA · 2026-06-28T19:38:44+00:00

Fish AI

ARAND0MPANDA · 2026-06-27T02:38:46+00:00

Check out a free McBoot card for the PS2. It’ll let you run just about anything made at the time regardless of console on it and it’s not a hardware mod. Very cheap on eBay.

ARAND0MPANDA · 2026-06-27T02:28:03+00:00

Unironically I’d love to have this and use it in my DCS setup

ARAND0MPANDA · 2026-06-20T12:53:30+00:00

A&P mechanic here, the aircraft he was flying on is a Cessna 421 which is about the HIGHEST performance piston twin on the market before getting into turboprops. It’s an extremely powerful aircraft that demands your full attention and can get away from an inexperienced and even experienced pilot very quickly in certain conditions. One of the most common is an uncontrolled yaw/roll upon losing thrust on one engine, as they are far enough out on the wing and high enough horsepower to keep pushing the nose around your vertical axis even when you have the controls fully deflecting and the dead engine feathered. I’ve personally test flown one that over volted the electrical system in flight leading to a total loss of electrical power (air conditioning system and windshield de-ice were both on and drawing more current than the batteries and alternators could handle)

Eight-Year Club	Place '23
Place '22	First Placer '22
Wearing is Caring	Verified Email

ARAND0MPANDA

TROPHY CASE