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Looking at an Overhaul...Got some questions

avrojockey

Well Known Member
Patron
Good news is my Challenger Oil filter did its job...bad news, two tappets have gone bad...good amount of pitting. Not sure how it transpired, I fly regularly, use Cam Guard, and a dehydrator. Could be from prior owner but can't imagine it would take over 300 hrs and 3 years to surface...and we pulled a cylinder during pre-buy. Oddly enough it's on two opposing lifter bodies and others seem unaffected. I did catch it pretty early I think, less than 1/16 tsp of very fine particles. The particular cam lobe looks and feels ok no spalling and can't see any pitting...we'll see what overhaul shop says.

Engines ~1550 hrs and 30 years SMOH and ~ 650 hrs and 16 years STOH. Time for another MOH me thinks. To help me log some time towards A&P but mostly for the fun of it, I'm planning on doing this under the guidance of others.

Questions:
  1. Recommended overhaul shops for steel parts and case. I know of Aircraft Specialties and Divco...any other recommendations? Based on a past leaky through bolt, I'm guess there's some fretting that needs to be worked out...Divco still the go-to place for this case work?
  2. Any special tools I should consider buying that will make things much easier or must haves? Engine stand?
  3. With the price of cylinders and backorders should just I have mine overhauled? I have ECIs not effected by AD and have ~650 since installed new. Compressions are all good 76-78. Recommendations on shop that will do it? Maybe in WI or Chicago area? Someone that will do a port and polish at the same time?

In the process of disassembly, bag-n-tag, and documentation right now.

Thankful for any input.
 
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Cylinders appear to be in good shape. Why fool with them?? IRAN or Overhaul the bottom end and maybe high time accessories. Divco has been the go to shop for case work for decades.
 
Given the hours and the fact that the whole bottom end is being torn down, I would have the cylinders re-worked by a shop and call it a full Major. The guides don't last forever. I suspect that port and polish work is pretty limited in aviation to a few shops, so that may limit your options significantly.
 
Good comment by Larry - -you might check Poplar Grove Aeromotive. You can fly there. All my, and other locals, dealings with them have been positive.
 
Engine

Penn Yann in NY claims to have overhauled 320 and 360 in stock for exchange or will overhaul your engine. They appear to have a good stock of new parts as opposed to most shops that do not. Penn Yann has been in business for more than 50 years.
 
work to be done / tools

Avrojockey,

I drove to Tulsa to pick up my case halves at DivCo and got a tour through their place. Most impressive facility and great people to work with. Make sure you package your case halves properly because I was told at DivCo that parts arrived and were damaged by the shipper and were rejected at their inspection station. They will also inspect and recondition accessory housings, engine mounts, sumps.

Tools: make sure you have the tool to break the case apart.

Good luck with the rebuild and take your time.

Jon
 
Just did the same thing

I just did the same thing for the exact same reason, cam failure. I used Divco for the case, Aircraft Specialist for the internal parts. They are across the street so I shipped most of my internal parts in the Divco case box to save a few bucks.

I had the cylinders IRAN’d by Don George in Orlando. They also checked my crank and said to put it back in, it was fine.

I spent a lot of time watching Hangaratz on YouTube.

I got a lot of advice and encouragement from this community, special thanks to Larry Ruth (LR172).

The parts cost was ~$12K plus a prop reseal $2200. I think I saved $15-20K and it was a thrill to learn so much.

PM if you need any details on my journey.
 
Great suggestions everyone...Thank you! Another question...

I may just do IRAN on cylinders since they're in good condition and I'm not all concerned about engine value and overhaul "labels." If I go with new jugs to do a full major is there a potential I need to rework the baffling? I have ECI steel non-AD cylinders currently without tapered fins on steel barrel, and it looks like Superior Millenniums are still reasonably priced and more available.
 
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Cam lobe pic

Here is a pic of the cam lobe and tappet body that failed.
 

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Yep...two of my tappet faces look exactly like that. My cam looks ok though. Splitting case tomorrow and will have a better look.
 
Not a fan of Divco but I agree with Aircraft Specialties in Tulsa. Too bad Chuck Ney is gone, he did my case and installed his nozzles.
 
Yep...two of my tappet faces look exactly like that. My cam looks ok though. Splitting case tomorrow and will have a better look.

The metal you found in the filter is cam lobe. Once the hardened layer is compromised it will not survive. For less than $1K you can replace the cam.

You do not have to buy new cylinders to overhaul an engine. I had mine IRAN’d for about $800 each.
 
I feel your pain

Just finished putting my engine back together yesterday after the same problem. I used Poplar Grove Aermotive.
 
What's the lead time today on a new set of cylinders? Narrow deck 360 in my case.
 
The metal you found in the filter is cam lobe. Once the hardened layer is compromised it will not survive. For less than $1K you can replace the cam.

You do not have to buy new cylinders to overhaul an engine. I had mine IRAN’d for about $800 each.

You called it! That one lobe is FUBARed
 

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Central Cylinder in Omaha can completely rework a case; welding, line boring, the works. They have all the equipment, knowledge and over 50 years experience.

Ask for Dan or George. Tell'em George sent you.

George
Omaha, NE
 
DLC

Since you need to replace the tappets, may as well spring for them with a DLC (diamond like carbon) coating and you'll not have to worry about the spalling every happening again.
 
Great suggestions everyone...Thank you! Another question...

" If I go with new jugs to do a full major is there a potential I need to rework the baffling? I have ECI steel non-AD cylinders currently without tapered fins on steel barrel, and it looks like Superior Millenniums are still reasonably priced and more available.

Nothing wrong with overhauling the cylinders and will still be a major overhaul. Anything that wears will be replaced and cylinder wall finish and valve interface area will be "as new." At 1500 hours, the guides are likely nearing a need for replacement and a valve job will freshen things up. Cylinders are the main item that typically doen't make TBO, so sending them to a shop makes a lot of sense. Nothing wrong with IRAN, as that should cover the major wear items.
 
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Since you need to replace the tappets, may as well spring for them with a DLC (diamond like carbon) coating and you'll not have to worry about the spalling every happening again.

I put those on the 540 at O/H. Not that expensive in the grand scheme of things and money well spent IMHO.
 
What's the lead time today on a new set of cylinders? Narrow deck 360 in my case.

I'm in the middle of 'the experience' - it's two weeks. Then another two weeks. Then another two weeks. And so on...

I cannot yet say when the two weeks ends.
 
Since you need to replace the tappets, may as well spring for them with a DLC (diamond like carbon) coating and you'll not have to worry about the spalling every happening again.

Definitely going DLC! Just dropped off the cylinders at Poplar Grove. Will see what they say but they only have 650 hrs on them so I may get by with a hone and re-ring on a couple during IRANs
 
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Anyone have opinions on Superior vs Lys vs Continental (ECI) Cam?

The Superior cam is $400-500 cheaper than the others
 
Why not opt for a Cam from LyCon with a bit more pep in it? Send those cylinders to them and let their CNC machine work on the ports, add some 10:1 pistons. Be sure to add cooling nozzles to the case. If your going to build it, you might as well get some power out of her.
 
Why not opt for a Cam from LyCon with a bit more pep in it? Send those cylinders to them and let their CNC machine work on the ports, add some 10:1 pistons. Be sure to add cooling nozzles to the case. If your going to build it, you might as well get some power out of her.

Heck yea brother! Thought about it for like bit

It's an -e2d with the split front main bearings like the O-235. Originally designed at 150HP it's been upgraded to 8.5:1 for 160HP and that's about all I need out of her. I'm in WI where everything has been plowed flat and I normally use the ship to commute as efficiently as possible so it doesn't fit my mission.
 
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