Scored Cylinder O320 E2D

I asked my mechanic to scope no. 1 since the compression was 60, expecting to find a valve issue. Instead he saw lots of scoring on the cylinder wall. Deep grooves. He said the cylinder wall looked shinier than it should and that it must be chromed. He also saw hone-marks and speculated that someone might have run a hone through a chromed cylinder-not good. He thinks the scoring is from bits of chrome that have come off. #3 had scoring too.

The engine has no documentation other than it was built up "from components by the builder" of the aircraft (RV-6A). The engine and airframe have about 420 hours. Compression dropped from the 70's to 60 on number 1 at about 300 hours. I have not checked the oil screen but that is next.

I am new to the experimental world. Questions:

-Can I install new jugs myself? I am not the builder of the aircraft.
-Are there certificated jugs vs. experimental? Difference in price?
-Recommend a good source?

Thanks,
Dave
RV-6A

Dave,

Welcome to VAF. I will leave it up to others to answer your questions but you came to the right place. Lots of engine guys on the forums.

Dave H. said:

...I am new to the experimental world. Questions:

-Can I install new jugs myself? I am not the builder of the aircraft.
-Are there certificated jugs vs. experimental? Difference in price?
-Recommend a good source?

Thanks,
Dave
RV-6A

Click to expand...

Yes, you can do the work yourself. However, it sounds like you should get some help, if you are asking this question. (Not to worry, replacing cylinders is very easy. Assuming you don't need a major overhaul.)

Yes, there are both certified and experimental jugs and you can use either. ECI has experimental jugs for the O-360 but I don't know about the O-320. Either way, they are interchangeable.

Check out ECI or Superior. They both make good cylinders. With ECI it can be cost effective to buy a complete cylinder (Piston, rings, jug, and valves.). You will probably have to figure out the proper length of the push rods for the valves.

When you take it apart, label everything so you know what cylinder and which rod you have.

You will see hone scratches thru the chrome if it was done right. Scoring is not unusual but its not desired. Depends on where it is. If its where the rings form a step on the cylinder walls then its not unusual to see.

Thanks

Thanks for the advice, gentlemen.
A look at the oil pick-up screen showed some carbon particles but only a couple of thin, shiny, ferrous particles, which my mechanic says are probably from the cam.
Interestingly, there are carbon particles in the oil filter pleats that are larger than the holes in the pick-up screen. How did they get there? Is it possible for the screen to not fit perfectly and allow some particles to sneek through a gap somewhere?

Thanks again,
Dave
RV-6A