Rebuilding Lycoming O320-D3G

GAZ · #1 12-10-2010, 03:50 PM

Thinking of rebuilding my Lycoming 320D3G. I have rebuilt several auto engines including a Mazda rotary. And after checking into prices for engines.... ECI Lycoming etc. rebuilding my own is starting to look pretty good. I'm looking for comments,advice and suggestions. I have checked in to having Divco do my crankcase and Aircraft Specialties do all my steel parts. I would put all new cylinder assemblies on. My carb.and Mag have less than 100 hours on them and the rest of the accessories only have the 248 hours on them. Has any body out there rebuilt their own Lycoming engine? If so I would love to hear how it went. Thanks, Greg

carguy614 · #2 12-10-2010, 05:12 PM

I will qualify first by saying that I am a professional auto mechanic and machinist by trade, so things might look a little different from where I stand. That being said, as rebuilds go, Lycoming engines are very basic, and compared to a modern auto engine, they are very easy to work on. The clearances are actually less critical, and they require only a few special tools.
The important thing is to identify and comply with all of the AD's that have been issued along the way. Using Aircraft Specialties Services for your steel parts will assure that you have servicable crank and rods, and I suggest you send the crankcase halves and accesory case to the guys at CSI and let them have a look. They are great folks and will advise you what needs to be done to bring them up to snuff. A new top end will simplify the whole affair. One note, when you add it all up, you may find the investment closer to the price of a new engine than you had imagined.
All in all, I prefer this method, as I always feel more comfortable with engines that I have rebuilt or assembled. YMMV.
Bottom line, don't be put off with doing it yourself. You will learn a lot in the process, and might even save a buck or two!!

Regards,chris

LifeofReiley · #3 12-10-2010, 05:51 PM

Divco and Aircraft Specialities did all my work for case and steel. I had extensive cylinder work performed by Seth Record providing him with NEW cylinders... the engine went together in two days when I got everything back and inventoried and a quality checked over. Follow the assembly procedures and it's really a no brainer.

If you have any concerns, send everything off and when its all ready, ship it to Texas, come down and we'll build it together and you can drive it home.

RV8RIVETER · #4 12-10-2010, 06:17 PM

I rebuilt mine and it is pretty straight forward. A very good learning experience and allowed me to custom work some of the compents.

Just send the applicable parts out to reputable shops for inspection/overhaul. Print out all the apllicable AD's to do as required while you have it apart. Bought most of my overhaul parts from ECI and AERO. If it your first time, it is a good idea to have an experienced person assist you with the assembly, to learn the tricks not in the manual.

Have fun.

Fearless · #5 12-11-2010, 05:47 AM

I rebuilt my D3G core with an IA and A&P looking over my shoulder. My rods, cam and lifters I sent to Aircraft Specialties. My overhaul gasket set and bearings came from Aircraft Specialties. My ECI cylinders I purchased new from Dart. My original case core was rejected and I bought a serviced case from 92nd West Aviation. I had my carburetor rebuilt by Avstar. I bought a rebuilt fuel pump and new wiring harness from Aircraft Spruce. My magnetos were serviced by Dr Magneto. The crankshaft was still in tolerance so I had it magnefluxed. The crankshaft had the AD already performed on it and had the PID number on the flange. The IA inspected all the other internal metal parts and found them in good working order. The engine was reassembled using the appropriate Lycoming service manual. Its not hard but you have to pay attention to what the manual is telling you. I have about $13000 invested in my engine. The new cylinders and rebuilt case pushed the costs up. I wanted new cylinders because I didn't know the history on the ones that came off the core. Using the Lycoming D series parts manual was a big help to me identifying parts especially on the gasket kit when the engine went back together.

After reading recent posts I am going to purchased an G3 Ignition system to work with the magnetos to try to help the engine live longer on this rebuild.

Note that my engine hasn't been started yet. Hopefully sometime next year. I picked these vendors after reading posts on the VAF forum over the years.

GAZ · #6 12-12-2010, 10:33 AM

Quote:

Originally Posted by LifeofReiley

Divco and Aircraft Specialities did all my work for case and steel. I had extensive cylinder work performed by Seth Record providing him with NEW cylinders... the engine went together in two days when I got everything back and inventoried and a quality checked over. Follow the assembly procedures and it's really a no brainer.

If you have any concerns, send everything off and when its all ready, ship it to Texas, come down and we'll build it together and you can drive it home.

What kind of cylinder work on your new cylinders did you have done?...Port & Polish? Thanks for the offer. May take you up on it. I get down to Dallas a couple times a year for work.

GAZ · #7 12-12-2010, 10:35 AM

Quote:

Originally Posted by RV8RIVETER

I rebuilt mine and it is pretty straight forward. A very good learning experience and allowed me to custom work some of the compents.

Just send the applicable parts out to reputable shops for inspection/overhaul. Print out all the apllicable AD's to do as required while you have it apart. Bought most of my overhaul parts from ECI and AERO. If it your first time, it is a good idea to have an experienced person assist you with the assembly, to learn the tricks not in the manual.

Have fun.

Is there a web site for printing out the ADs? Or where do you get them from? Thanks for the info.

GAZ · #8 12-12-2010, 10:46 AM

Quote:

Originally Posted by Fearless

I rebuilt my D3G core with an IA and A&P looking over my shoulder. My rods, cam and lifters I sent to Aircraft Specialties. My overhaul gasket set and bearings came from Aircraft Specialties. My ECI cylinders I purchased new from Dart. My original case core was rejected and I bought a serviced case from 92nd West Aviation. I had my carburetor rebuilt by Avstar. I bought a rebuilt fuel pump and new wiring harness from Aircraft Spruce. My magnetos were serviced by Dr Magneto. The crankshaft was still in tolerance so I had it magnefluxed. The crankshaft had the AD already performed on it and had the PID number on the flange. The IA inspected all the other internal metal parts and found them in good working order. The engine was reassembled using the appropriate Lycoming service manual. Its not hard but you have to pay attention to what the manual is telling you. I have about $13000 invested in my engine. The new cylinders and rebuilt case pushed the costs up. I wanted new cylinders because I didn't know the history on the ones that came off the core. Using the Lycoming D series parts manual was a big help to me identifying parts especially on the gasket kit when the engine went back together.

After reading recent posts I am going to purchased an G3 Ignition system to work with the magnetos to try to help the engine live longer on this rebuild.

Note that my engine hasn't been started yet. Hopefully sometime next year. I picked these vendors after reading posts on the VAF forum over the years.

I'm going to go with the new cylinders also. I think a new cam also, the one in it now was reground at last overhaul and a new one with a core is about 400.00. I know I will have to either get my old tappet bodies reground or get new ones? What about the hydraulic plunger assembies? I don't know of the G3 system. I run a lightspeed electronic ignition on the left side and a Slick Impluse mag on the left side. Very smooth, no rpm drop when shutting down the mag. Thanks for the info.

RV8RIVETER · #9 12-12-2010, 02:57 PM

Quote:

Originally Posted by GAZ

Is there a web site for printing out the ADs? Or where do you get them from? Thanks for the info.

You can search AD's here.
http://rgl.faa.gov/Regulatory_and_Gu...e?OpenFrameSet

Lycoming SB's and to order document list for your engine.
http://www.lycoming.textron.com/supp...ins/index.html

If you decide to work with an experienced engine builder or AP/IA they should have subscriptions to all applicable info.

N941WR · #10 12-12-2010, 06:13 PM

A friend is rebuilding an O-320-?? for his RV project. He has found some problems, will likely replace his cylinders, pistons (upgrading to 160 hp), and few other key parts. It looks like by the time he is finished with sending all the parts out for inspection, cleaning, etc. that he would have about the same amount of money in it as if he had bought a new ECi kit engine.

For the same amount of money he would have had all new parts, a new engine, that he can rebuild in 2000 hours.