I've decided to scrap my plans for a big performance upgrade to my RV-4's IO-360A1B and just do a top overhaul. The engine is currently fitted with Lycoming 10:1 pistons (supposedly from a helicopter engine according to the builder). From a quick borescope inspection, it looked to me like the pistons may need replacement due to significant pitting. I'll know more after I remove the cylinders this weekend.
If I need to replace the pistons, I'm considering using Lycon's NFS brand of forged pistons. Has anyone here used them? Do you have any thoughts on the quality relative to stock Lycoming units? I spoke with Lycon but it's sometimes hard to separate sales pitch from reality.
Lycon is also offering "gap-less" piston rings. I wasn't able to get much info about them. It seems like they might significantly reduce blow-by and oil consumption. Anyone here know about using gap-less rings in a Lycoming?
One of the stranger recommendations from Lycon was that, if I go with gap-less rings, I should get my intake valve guide machined for elastomeric seals to reduce oil consumption. They said the increased suction caused by gap-less rings will cause the engine to draw excess oil through the intake guides without the extra seals. I've been racking my brain to try and understand this. It seems to me that the effects of the ring gap would be very small and would therefore have a small effect on intake guide oil leakage which is supposed to be very small to begin with. Is this something real or just another aviation superstition?
If I need to replace the pistons, I'm considering using Lycon's NFS brand of forged pistons. Has anyone here used them? Do you have any thoughts on the quality relative to stock Lycoming units? I spoke with Lycon but it's sometimes hard to separate sales pitch from reality.
Lycon is also offering "gap-less" piston rings. I wasn't able to get much info about them. It seems like they might significantly reduce blow-by and oil consumption. Anyone here know about using gap-less rings in a Lycoming?
One of the stranger recommendations from Lycon was that, if I go with gap-less rings, I should get my intake valve guide machined for elastomeric seals to reduce oil consumption. They said the increased suction caused by gap-less rings will cause the engine to draw excess oil through the intake guides without the extra seals. I've been racking my brain to try and understand this. It seems to me that the effects of the ring gap would be very small and would therefore have a small effect on intake guide oil leakage which is supposed to be very small to begin with. Is this something real or just another aviation superstition?