F

Finley Atherton

Well Known Member
I have an 0-320 with 9:1 pistons and ECI Titan Nickel Carbide cylinders and would like to change to the standard 8.5:1 pistons so I can have the ability to run Mogas. All looked relatively cheap (piston/ring set about $100 per cylinder) and straight forward until I found out that the cylinders will require a somewhat complex two stage honing process using the required ECI Nickel Bore Rejuvenation Kit.

I would have it done by my local licensed aircraft engine shop but they have not honed a nickel carbide cylinder before. I would be interested to hear from anyone who has had this done and how it turned out.

My engine has about 420 hours and has excellent compression and low oil consumption.

Fin
9A
Australia
 
I wouldn't touch it. It should run fine on mogas with 9:1 compression. I know guys that run mogas with H2AD engines and those are 9:1.

The rejuvenation kit that ECI sells is nothing more than a cheap Lisle cylinder hone with diamond stones. Its not really honing, but scuffing. Honing will make the cylinder perfectly round which that tool is incapable of doing.
 
Bob is far more an expert on these things than I am, so all I can add is that when I went to look into honing and re-ringing my ECI Nickel Cylinders a month and a half ago, I basically got a "nope, we can't do that!" answer form the engine/cylinder shops I talked with. ECI would have done it for me in San Antonio, but since I had 1500 hours on the jugs, they said I'd probably need some valve and guide work as well, and they consider the "Category A" cylinders junk at 2,000 hours anyway, so it was just throwing good money after bad.

If you can run them "as is", the way Bob suggested, I'd do it - if you do decide to hone and re-ring, I've got a set of new rings designed specifically for the nickel cylinders that I bought, and now won't be using.

Paul
 
I thought it was the category A cylinder heads that are junk after 2000 hrs, so long as they last that long. What makes the cylinders junk?
 
Rivethead said:
I thought it was the category A cylinder heads that are junk after 2000 hrs, so long as they last that long. What makes the cylinders junk?
Click to expand...

As I understand it (and I can always be wrong), it is not cost effective to replace just the cylinder heads on a jug - you can buy a whole new stud assembly from Lycoming for $1100 these days.
 
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Ironflight said:
As I understand it (and I can alwasy be wrong), it is not cost effective to replace just the cylinder heads on a jug - you can buy a whole new stud assembly from Lycoming for $1100 these days.
Click to expand...

Nothing rong about being wrong..............:eek:
 
Thanks for the replies. Looks like I will be leaving them at 9:1.

Bob, I don't suppose you would know if those guys using Mogas in the H2AD engines are using mags or EI and if they have retarded the timing by 5 degrees from the standard 25 degrees.

Fin
9a
 
Stock mags, don't think they changed timing. I have 9:1 pistons for my Rocket and its going to be set up to run mogas. No worries.
 
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