rocketbob
Well Known Member
With all the cylinders off is it possible to put in oil nozzles/squirters or any other mods like this?
No case has to be apart.
With all the cylinders off is it possible to put in oil nozzles/squirters or any other mods like this?
No case has to be apart.
Yeah, I'm not going to do that. I really want to avoid putting any side load on the big end bearing. They are designed to take thrust, not side loads.
I have ordered a piston pin puller from spruce. If that doesn't work, I will build a tool to use a threaded rod to press the pin out.
That is how it's done. Being an A&P, I've pulled 100's of cylinders and pistons for overhaul. If you heat up the piston the pin will loosen up. You use a 1/2" ratchet extension put the big end on the pin and tap it out with a hammer. You will not be reusing the pin again and you will not damage anything.
Adding the piston squirters will add about 20 degrees F to your oil, about the same it removes from the piston bases. You will see this on the oil temp gauge.
This is beyond my shade tree mechanic abilities
I'm good enough to do basic things and, hopefully, recognize when its beyond me.
I continue to be amazed by, and grateful for, not only the level of expertise on this site and in this community, but also the level of effort those individuals are willing to expend to share it with the rest of us.
I only hope that I can help expand the collective knowledge here, even if its by asking stupid questions that others can answer.
I'm ok with judicious application of heat. Its the "pounding out" bit I don't like
I'd much rather press out. Perhaps I'm being over cautious about side loads on the bearing?
Make certain that you re-torque all thru-studs before turning the prop; you don't want to rotate the journal bearings.
Lycoming suggests you remove and replace the cylinders one at a time on a used engine so that all the thru cylinder bolts aren't all loose at the same time, but there is no chance the bearings will spin. It's not possible, they are indexed.
When installing the new or overhauled cylinders you won't be using a ring compressor, the pistons should be installed in the cylinders, ready to go. You just slide the piston right to the pin opening, push the pin in the piston and rod, then push the piston back down the cylinder and screw on the nuts. Don't forget the O-ring!
Saw the following article a while back. There are asymmetric pistons available for Chevy LSx engines. http://www.enginelabs.com/engine-te...-je-pistons-asymmetrical-line-for-ls-engines/
I have to very strongly disagree. My factory new Lycoming cylinders came with the pistons in separate boxes, the rings packaged separately etc.Lycoming suggests you remove and replace the cylinders one at a time on a used engine so that all the thru cylinder bolts aren't all loose at the same time, but there is no chance the bearings will spin. It's not possible, they are indexed.
When installing the new or overhauled cylinders you won't be using a ring compressor, the pistons should be installed in the cylinders, ready to go. You just slide the piston right to the pin opening, push the pin in the piston and rod, then push the piston back down the cylinder and screw on the nuts. Don't forget the O-ring!
Home-made out of a piece of pipe, short piece of aluminum, and some allthread.
I have to very strongly disagree. My factory new Lycoming cylinders came with the pistons in separate boxes, the rings packaged separately etc.
I totally agree that it is impossible for the main bearings to rotate IF the case has been properly assembled.
I'm stumped.
It got hot. Why? Dunno but have the cylinder shop measure. Armed with this knowledge I would get all four cleaned up and a set of new ECI pistons and rings.
It got hot. Why? Dunno but have the cylinder shop measure. Armed with this knowledge I would get all four cleaned up and a set of new ECI pistons and rings.
No hard evidence
Hey Bob, I looked up piston/bore clearances and Superior seems to say .0045" to .0065" at the skirt. Is this typical for this engine, parallel, no turbo, no jets?
It got hot. Why? Dunno but have the cylinder shop measure. Armed with this knowledge I would get all four cleaned up and a set of new ECI pistons and rings.
Now you know what needs to be done.
Let's Roll!
Pine Bluff Clinic is in 3 weeks
Love this stuff.
Pull 2 and 4.
What I do is measure the piston and aim to hone 0.004" cylinder larger than that. Since I have a Sunnen portable hone it takes a LONG time and some sweat to get to the right bore dimension.
The evidence the pistons got hot is judging by the amount of oxidized (burned) oil residue stuck to them.
Oh-yes, I totally agree. I meant no hard evidence of what caused the pistons to be hot.
7 whys to problem solving.
1. I have low compression. Why - because the piston scuffed and fouled the rings.
2. why did the piston scuff? - the piston overheated - reduced oil film, material strength and resulted in metal transfer
3. Why did the piston overheat? ---here is where the hard evidence is needed
What I do is measure the piston and aim to hone 0.004" cylinder larger than that. Since I have a Sunnen portable hone it takes a LONG time and some sweat to get to the right bore dimension.
Thanks, that is what I was looking for.
...Do I take this opportunity to put in higher comp pistons? say 9:1 or 9.5:1? Is there any real benefit/drawbacks?...
That much aluminum off of all pistons should have been clearly visible in the filter. It shouldn't take oil analysis to see that there was something not good going on in the engine.
Unless of course you just missed it when examining a filter with dirty black oil. When I look at filters I cut them up into two pieces, wrap them in paper towels and squeeze the oil out of the filter media with a vise. Anything shiny is then really easy to see.
T
I'm really thinking there was an earlier event, possibly much earlier, that caused a lot of damage, and its just been slowly building to this since then.
Or piston slap due to excessive piston/bore clearance.