LAMPSguy

LAMPSguy

Well Known Member
I have tried to find more info both here and on inter web, have some time. Not many of us will have a -14 built too soon, and will not have the engine to overhaul, but I was wondering if anyone has enough time on these engines to know: I have been told that the cylinders cannot be overhauled, already too big (not sure if it is cylinder wall thickness or piston/ring size) but I was told you would need to replace the cylinder (or pistons) at overhaul. This seems like an expensive proposal. Sure, OH will hopefully be some years off, but at my age (hope to have it flying by 40) I would prefer an engine that can definitely be OH'd w/o replacing.

Maybe I am not remembering correctly, maybe I am not understanding the process. looking for understanding.
 
I would not worry about it as a cost issue. I think the majority of overhauls on 360's now use new cylinders. The cost of new ones has dropped so much in the last 10 years that in most cases it does not seem cost effective to go the overhaul route.

George
 
jetdriven said:
New ones are almost 4 grand from Airpower. EACH.
Click to expand...

My.l, I don't have that much in my overhauled angle valve...including the core. Admittedly, I got a deal...but 16k in cylinders alone? Ouch.
 
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I thought the angle valve cylinders were more like 2300.00 from airpower...are the cyclinders for the IO 390 different than say the IO 360 A1A?
 
390 cylinders are larger in bore, and a heck of a lot more expensive than the already-expensive IO-360 cylinders.

Best bang for the buck is the IO-370/IO-375, as far as new engines go.
 
What about the XP-400 cylinder?

I know it has a larger bore than an IO-360, but it is less than an IO-390. Displacement is made up in stroke.

So, I'm pretty sure my cylinders start as stock Millennium IO-360 cylinders, just bored a little. Would be worth considering the 400 over the 390 for this reason and the initial cost investment.
 
Exactly

I understand from a mechanical side how and why we do overhauls, but this is the stuff I was asking about, the logistics of it. Like I said, I am at least 2 years from an engine, but I want to consider all that in my decision.

-14 calls for a 390, and it looks like it would be an easier solution, especially if Vans ends up with precut baffles, etc. My concern is just as stated above...just looking for the availability/expense of all parts required for an overhaul.

All costs being equal up front, I will probably plan a different engine (more work to install?) if the overhaul costs a lot less.
 
Too early to gauge overhaul costs...

I spoke with Jeff from Thunderbolt about overhaul issues and costs... he said that they had not really thought about it yet since none of the engines had been out long enough,but they would need to start to think about it. I suspect that the cylinder prices listed are based on preserving their competitive position as a new engine supplier. Without any actual need for replacement cylinders a reduced price would only benefit other engine builders assembling their own version of a -390. Reportedly, Lycoming pushed the price of major engine specific parts up considerably around 4-5 years ago and the other notable builders stopped marketing the -390.
 
IO-390 vs XP-400

The Superior XP-400 will fit anywhere the IO-390 will, including all baffles, induction, mounts, etc.
 
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