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WTB Tools needed for IO360 Top Overhaul
- Thread starter tom paul
- Start date
I recently did a top overhaul on my C90. I bought a set of superior cylinder kits. It had everything.
I very carefully read the directions for gapping the cylinders and the special tooling required to grind the ring gap just right with both the proper gap and that gap end angle just right.
I called my local aircraft engine shop. They said $50 per cylinder to gap the rings and have the pistons in the cylinders, ready to install.
No brainer. Cheap insurance that that critical step is done right by guys who do it everyday.
I very carefully read the directions for gapping the cylinders and the special tooling required to grind the ring gap just right with both the proper gap and that gap end angle just right.
I called my local aircraft engine shop. They said $50 per cylinder to gap the rings and have the pistons in the cylinders, ready to install.
No brainer. Cheap insurance that that critical step is done right by guys who do it everyday.
I love this. A hybrid approach to fill in where I don't have the experience. Thanks much for the great thought.
rmartingt
Well Known Member
Ring compressor is about $20 on Amazon. And if you need to compress the valves a bit to remove the rockers, you can make a tool in about 20 minutes with $6 worth of stuff from the hardware store. A bit of all-thread, some nuts, PVC couplers you can notch out, and a crosspiece from some scrap angle.
When we built my engine I needed two beam torque wrenches for the through bolts (one person on each side). Those aren't terribly expensive either.
You may need to carefully grind the end of the cylinder base wrenches a bit to clear the radius on the cylinder.
That's about the list of "tools I needed but didn't already have", as best I remember.
When we built my engine I needed two beam torque wrenches for the through bolts (one person on each side). Those aren't terribly expensive either.
You may need to carefully grind the end of the cylinder base wrenches a bit to clear the radius on the cylinder.
That's about the list of "tools I needed but didn't already have", as best I remember.
worth reinforcing here. In most cases, you will need to bleed down the lifters to get the rocker shaft out. Do some research on how to do it. Not difficult, but going to say "why can't I push out the rocker shaft?" I have yet to get a new base wrench that didn't need grinding. It is CRITICAL that the wrench goes fully over the nut. Grind as much as necessary to insure this happens. Those large nuts are tight and if you don't get full contact, you can round over the nut. Check each nut as you go, as sometimes you have to grind a bit more for the next one. Also very easy to get the wrench offset. Be sure you get eyes on the engagement and everything is squared up before turning that wrench.
If your engine has many hours on it, there may be carbon build up on the piston, preventing you from pushing out the pin. Do your research and be prepared for this. Especially challenging if you are trying to keep the pistons/rings inside the cylinder while trying to deal with that. likely impossible to do by yourself without pulling the piston out of cylinder.
Also you will need to pull the plunger and clear the oil out before reinstallation so that it can compress. Again, more research here. Would be wise to confirm lash is in spec while in there. while everything is apart, this is a very good time to do the wobble test on exh valves, so a valve spring compressor (DIY options out there) would be nice. You can do this by hand without the tool. Not optimium, but at least will be able to tell if too tight and getting close to a problem.
DO NOT let the connecting rod fall and hit the case!! can create sealing problems later
Thanks Guys! This is all great advice. I am approaching this with humility and respect for the high stakes, so I will study up and be careful. The advice on this forum is invaluable. These are exactly the tips I am looking for and I will be creating a spreadsheet of them that I will reference. For the record, I have ECI/Titan nickel cylinders with 1200 hours, and I am currently burning a quart every 1.5 hours or so, even after an oil control ring flush. The engine still develops great power (1700 fpm climb solo with full fuel at sea level) and compressions are good, but the numbers on oil consumption (and blackening in the first hour) don't lie. I am first pulling number 4, because that is the one that has zero cross hatching on the borescope. I will pull the piston out so no worries about that. Regarding the valve checks, etc... expect that I will be installing a set of four new cylinder assemblies, so I suppose that is a non-issue. They seem to have gotten quite expensive though. It looks like $2-3k per for new Lycomings. What is the opinion about rebuilt cylinders as an option? I am leaning toward new. regarding brand, I have read many stories about defective Superior cylinders so I don't feel comfortable going with them. Question, what are the thoughts on using torque plates when a cylinder is removed? Is that SOP? https://ryanaircrafttools.com/products/1598
Decades ago, cylinder rebuilding was what everyone did - cylinder shops were everywhere, and nobody went with a new jug unless the head blew off. Then cylinder assembly prices plummeted and a new jug with valves, piston and rings could be had for $1K when a complete rebuild was $800….so everyone went with new jugs and the ma & pa cylinder shops folded up. Now prices on new jugs have skyrocketed and if I were asked to guess, I think cylinder rebuilding might be coming back….but will it be any good? It takes knowledge, experience, and attention to detail to do a cylinder that will last, and most of the old-timers that ran cylinder shops are dead. If you have a shop with a great track record, I would consider them - otherwise, the new cylinders from Lycoming are generally pretty good these days….
Got it. This makes a lot of sense. Thanks Paul.
while a special process is required, there used to be folks that would hone the Ni cylinders. I would consider that with a new set of rings instead of buying new cylinders. While manyt shops work mostly on exchange, there are still some that will work on your cylinders. This assumes you valves still look pretty good. If not, than a full overhaul or new is better.
