Hi!
It’s been a while since I last wrote anything here. All flights have been uneventful :-)
Now the SR22TN is in the shop for its annual and …. there is an issue
I have two cylinders on the IO550N that show low pressure (48 psi and 40 psi) and are supposed to be replaced. Replacement cylinders from Cirrus seem to be quite pricey so I thought maybe someone here can recommend another supplier. The repair shop is open to any and all suggestions.
Does anyone here have some ideas or recommendations? Thanks.
Low leak test pressure is not an indication for changing the cylinders. Has a borescope inspection been carried out? Is the leakage via the valves or the rings?
That’s a good point and thanks for pointing it out. I will ask.
Replacement cylinders from Cirrus
Did you really mean to write „Cirrus“? Or rather „Continental“? Why would you buy cylinders through Cirrus?
Which maintenance shop is involved here?
You will need the part number. For US pricing go to controller.com and see who has got them and send a request for quote to all the companies and wait for the prices. In Germany you can go to https://www.globalaviation24.com or call up Röder. Yu can also inquire about overhaulung the cylinders at Röder or Dachsel but it will depend if that makes sense from an economic point ov view.
boscomantico wrote:
Which maintenance shop is involved here?
They are reading this and if they want they can reply themselves :-)
The part number and detail is:
658595A2BP cyl valve assy loaded balanced
At https://www.globalaviation24.com it shows “on demand” but I see prices for similar items.
If you need to fit new cylinder (big IF) then I would recommend you have the new cylinders checked by a reputable engine shop that will re-install the valve guides and fit the valves properly if the cylinders are new from the factory. A valve check and alignment will cost a couple hundred per cylinder and very well pay for itself because most likely the premature cylinder problems with TCM cylinders won’t occur
Boroscope inspection was done and it seems the pressure loss is via the rings.
As I understand it’s the rings around the piston. It also appears that the internal shape of the cylinders has been altered and thus there is pressure loss.
I’m beginning to understand why it’s said that a turbo eats cylinders. Now I’m wondering whether going a bit slower (65% instead of 85% engine power) might prolong that wear and tear on rings and cylinder wall.
I would suspect baffling as a possible culprit. Uneven cooling around the circumference. I also fly a TN Bonanza but with the Liquidair baffles. After about 1000 hours all is fine.