Lionclaw

Lionclaw

Well Known Member
Today I began the teardown of the 320-h2ad I recently purchased. I thought I'd post pictures on Picasa and share them here. Those thinking of buying a run out engine and overhauling it themselves may find this interesting. I'm certainly not an aircraft mechanic, and aside from some experience with automotive engines, all of my knowledge is coming from the overhaul manual and parts catalog. As you can see the corner workspace in my single-car garage is less than ideal.

http://picasaweb.google.com/pilotandy/RV9AEngine

I began by removing primer lines. Strangely they only go to 3 cylinders. Maybe this is normal?

Next I removed heating elements, intake pipes, oil return tubes, spark plugs, valve covers, rockers, fulcrums, pushrods, and pushrod shrouds. Several shrouds have small dents (like someone tried to remove the plugs with a wrench!!?!). One shroud is completely destroyed and one pushrod is missing.

With the shrouds gone I was able to remove the lifters. I've got them all in labeled bags now to make sure they can go back where they came from. The lifters all look perfect. No spalling or uneven wear. The tops are perfectly flat. I can't feel any scratches, wear, or uneven surfaces. I inspected a few of the cam lobes and so far they look nice.

I then removed the nuts at the cylinder bases (really a pain!), removed the cylinders (taking care not to let pistons/rods damage case), pulled the piston plugs, knocked out the pins, and removed the pistons.

My guess is the pistons will need to be replaced. They all have scuff marks and gouges around the tops. The cylinders have a lot of lead buildup at the tops, but I'm hoping they're all serviceable. I don't see any scoring or damage to the barrels.

Anyway, if anyone has any advice/input I'd love to hear it. I plan to remove the sump and split the case tomorrow. More pics to come...
 
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Andy,

I recently rebuilt a O-320 E2G engine, Went thru the same gymnastics you are doing. I have a word of advice for you, DON'T rely on what you see as a good or bad part.

Don't be concerned with keeping the parts seperate for each cylinder unless you plan to reassemble with out sending the parts out for inspection.

Here is my recommendation, remove all the steel parts, EG Cam, Crank, Gears, Thru studs, Connecting rods, Rockers , hydraulic units (DON"T disassemble these puppies), Tappetts and anything else you can. Box them all up and ship the whole package to Aircraft Specialties ( http://www.aircraft-specialties.com/ ) .These guys do a great job are fair priced and an excellent source for any other parts you might need.

Depending on the condition of the crank you may need over-size bearings, they will tell you this. As for the case dont mess with it box it up as well and ship to Divco for overhaul and inspection, ( http://www.divcoinc.com/ ).

Make darn sure you have the proper manuals and parts list for the engine, you will find many errors as I did for the E2G.

The approxmate cost for my rebuild was moderate I think,

Case repair $850.00 + Shipping
Engine parts Inspection and regring of crank $1200.00 + Shipping
Other parts, bearings, reconditioned hydraulic
units, reconditioned tappetts, ETC. $ 800.00 + Shipping
4 reconditioned cylinders, new pistons, rings, gasket set $ 2200.00

New fuel pump, MAG overhaul and a new MAG
(Found the pump and MAG on Ebay) $ 600.00

Exchanged the sump, E2G wont work in a RV-9 N/C

One more item if you have a buddy at a FBO or you have a AP that you know real well pick his brain for hints and ideas, and ask lots of questions.

Good luck

John H
 
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Andy,

Just looked at you pictures. Save your self a lot of grief, buy, beg or steal an engine stand. There is no way you can do a decent job with out one to reassemble the engine.

John H
 
Fellow H2AD disassembler

Here are my thoughts as I read your post and look at your pics:

Three lines to the primer because the 4th is where usually manifold pressure is picked up. My H2 from a 172 had 2 primer, one MP, one to a standby vac system. Van's primer system uses two, but that's a guideline, not a rule.

I'd choose Crankcase Services out of Tulsa, OK rather than Divco. I did, could not be happier, $700 flat fee, and the work was outstanding, timely. Aircraft Specialties is a first class outfit. Call them in advance, they will ship you a special crankshaft box. You want this. Ship them everything steel. They will keep you in the loop as stuff moves though the process, if you want.

If you're going to OH the cylinders, pitch the pistons. Any reputable shop will send you new pistons and pins with the OH barrels as part of the package. Although - be advised - with new valves, new guides, reused springs, new locks, the good shops were looking at $900 per barrel for OH. I've found Lycoming new cyl complete for $1250. I'm buying new. I don't like the second-run cylinder head cracking odds. If you want my first run cores, let me know.

Lifters are a 'replace at TBO no matter what they look like' for an H2, per lycoming. Doesn't matter what they look like. Cam you can get lyc new, for $800. My cam was bad, but it didn't matter - I was going new no matter what it looked like.

I built a good stand. YOU CANNOT LIVE WITHOUT IT. Buying one would have been easier, but once the engine is done, I'll have a bomb-proof table!

Rick 90432
 
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Cool project

Love the pictures, agree that you'll need an engine stand. I have several manuals in .pdf that I found are good referance for looking at parts and assembly, they don't replace your manual and table of limits but still help. Send me an email if you'd like some copies. I can also help you out if you get stuck on something. Have fun.
 
I appreciate the feedback. An engine stand would definitely make things easier, and I certainly plan to get one for assembly. My bach aches like nothing else from hunching over that thing.

I went ahead and pulled the sump this morning. After that came the oil pump and oil filter attach assembly.

With that done, I removed all of the hardware holding the crankcase together. I thought splitting the case would be a simple matter, but I couldn't get it more than 0.125" apart. I finally realized that the rubber crank oil gasket at the front of the case was stuck to both case halves. I peeled it back and the whole thing popped apart.

I went ahead and updated the Picasa album with my latest progress.

Thanks again for the responses. I'm going to start checking into overhaul places this week and see what this will run me. The plan is to make common sense decisions that will result in a safe "experimental" engine at a price that won't break the bank.
 
Superior cam

Andy, may I suggest that you investigate Superior's camshaft if you need a new one. I read on one website (can't recall where at the moment) where a friend with a racing camshaft profiler ran a check on a Lycoming stock cam, and was shocked that find that it slammed the valves open and closed harder than any other cam he had ever seen. Turns out that Superior's new cams are much friendly to the valve train. Just something to think about.

Joel
 
Lyc's have very low spring pressures and operate at low rpm's, so a high lift cam profile isn't a problem, in fact is a good thing. This has the effect of leaving the valves open longer during the combustion cycle.

Contrary to popular belief the H2AD is one of the best engines Lycoming produced, in my experience. I know of one that went 3700 hours before it was exchanged for a factory reman.
 
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keep it up Andy

Andy - this is great info... please keep up the picture taking density all through the rebuild process. This will encourage some of us to "go for it" and rebuild our own engines (with appropriate documentation and A&P help).

This will be a great resource! I hope you can keep posting those photos.
 
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