Cylinders

[rkittine]

Hi,

Just started my annual on my 7CCM and one of my cylinders on the C-90-8 is soft. 50/80 with leak down appearing to come through the crankcase, so assume this is a ring problem. I am going to pull the jug and send it to Gidson in Oklahoma for rebuild, but am considering keeping it as a spare due to the time on my engine. Anyone have a recommendation on which new cylinder might be the best to purchase:

Millinium
Titan
TCM

Also, does anyone know if an 0-200 cylinder is really an OK alternative as two distributors have told me that do not have the C-90 part number cylinders in stock, but that I can substitute a 0-200 cylinder which one told me the only difference is 3 valve springs in stead of 2 and one told me that plus the C-90 has a "Rotator" on the exhaust??????

I understand if I was to change all 4 to a Titan or Millinium, that I could change the timing and actually get a little more HP out of the engine. I am not very knowledgeable about this.

Thanks for your help.

Regards, Robert

[joea]

Robert,

I have been told by several people that the only difference is as you said, valve springs or the like.

One thing that I would really recommend is to do the "pushrod tube STC upgrade" on whatever cylinder you put back on the plane. This upgrades the pushrod tubes on that cylinder to the new style that DO NOT leak oil. While you have it off its worth it. I hear the cost is under $200 for the upgrade but well worth it.

Joe A

[rkittine]

Thanks Joe, I will see if Gibson will do that. Probably will keep this one as a spare, but I am not sure yet. My local friend, who is a mechanic and helping me, says we should put the rebuilt one back on and then when overhaul time comes, replace all for with new ones. That makes sense too. - Ciao - Robert

[Roger Anderson]

I had some disappointing work done by Gibson about a year or so ago. Their turn around time was great, packing great, and price good. However, having had 4 cylinders overhauled by them (A65s), two had to be done again within 50 hrs or so, both having practically no compression. They did one again. The other I sent locally. That shop said it looked liked it had 2000 hrs on it and much of it was beyond wear specs. Additionally, Gibson returned one with one of the two pushrod tubes stuffed into the cylinder backwards, the flared end at the wrong end....sitting along side the other pushrod tube looking totally opposite in appearance. Made me wonder about quality control, inspections, ...or who in the hell was doing the work. My A&P wouldn't touch it and had me send that one back also. I sent them an email about all these issues and got no response. They use to have a good reputation......but........

[rkittine]

Thanks Roger - That is scary. I share a hanger with a guy who had a good experience. Might want to rethink this now. - Ciao - Robert

[rkittine]

Can anyone recommend a better place of the Cylinder Overhaul? I haven't shipped it yet. - Thanks - Robert

[Paul Agaliotis]

Robert,
I have heard good things about Corona Cylinder, but haven't used them. It's best to find someone local if possible.

My choice for new cylinders would be TCM followed by ECI and last Superior.

All of the small Continental cylinders are interchangeable, to a degree. Check out Service Bulletin M92-8, it gives you all of the information. The GO-300 stuff is kind of particular.

Paul

[rkittine]

Thanks Paul - I talked to TCM they are not overhauling these, but my concern for a new one was the AD on the 0-200 / C-90 cylinders that require a different timing, because of separation. I think it is 24 degrees BTDC instead of 28 and I was told, though I am not very knowledeable about this, that it costs you about 4-5 HP. If I put on the Tital or Millenium and then later change the other 3 I can change the timing back, as I understand it. The rebuild was because I hope to overhaul next winter and 4 new cylinders will go on then, so this is a short term fix. - Caio - Robert

[Paul Agaliotis]

Robert,
The AD is for specific part number cylinders. Not all are subject to the AD.
Paul

[rkittine]

George, Thanks for clarifying that. - Funny thing is that I keep getting conflicting stories about whether an 0-200 Cylinder is a direct replacement cylinder for a C-90 Cylinder or not. The 2 verses 3 Spring issue does not seem to be a big deal, but then I was told about an Exhaust Value Rotator on the C-90 Cylinder that maybe is not on an 0-200. What ever that is? - Thanks Again - Robert

[rkittine]

Sorry meant Paul. Called TCM, ECI (Titan) and Superior (Millinium) and none of them have a C-90 Cylinder In Stock.

[DC Krog]

I have heard bad stuff about Gibson as well. I recommend Harrison Cylinder in Indiana.

DC Krog

It's not just about price it's also quality and reliabilty with one engine on board!

[GWestphal]

Robert, I was building up an 0-200 for my champ originally so I ordered a set of 0-200 cylinder assemblies from Superior and they came completely assembled with paperwork calling out the assembly number etched on the cylinder mounting flange at the case. Later I bought a C-90-12 and wanted to used the cylinder assemblies on the 90 but those cylinders can only be used on a 0200 if your AI knows to check the paper work. Superior C-90's use a different part number so are etched with that number. I finally put them on the 0200 and ordered a set of ECI's for the C-90. Superior told me the FAA wanted different assembly numbers so they could track them to a particular type of engine for compliance to any future AD's. When you put new jugs on your C-90 you may want to check out whether they are the correct cylinder assembly for that engine - especially Superior. I didn't check with ECI if their numbers were the same or not as I ordered only C-90 assemblies...................Gordy in Mn

[rkittine]

Thanks Gordy,

Superior confirmed that there was a different part number, for model tracking, but that otherwise the cylinder assemblies are identical. Since they did not have C-90 ones in stock, they just ground out the old number and etched in the new one on a 0-200 Cylinder. Its on and tomorrow will test run.

Ciao - Robert

[Paul Agaliotis]

Robert,
The C90 had a few different cylinders. If you look at Service Bulletin M92-8 it will show you the applications.

On the Superior cylinders, I have a set of A65 cylinders and inquired about +.015 O/S of the cylinders. The oversize is allowed but they don't make rings for the application, does anyone know if the cylinders require a special ring? They weren't too helpful in finding the correct ring material.
Paul