Hone 2nd stage for new rings ?

[ti325v]

I have an older bauer/poseidon 200lpm, 200 hours regular synthetic oil changes, and it has quit a case of blow by..around 40 to 50 lpm.
3rd stage is nice, 1st stage rings have not even seated yet.
I have a spare set of 2nd stage rings handy, metal, coating with something black.
The 2nd stage bore is beautiful, piston is good, it will take 2 hours to swap the rings...think it is worth it ? If so, do I have to hone the bore ?
I have read about dozens of ring replacements but no mention of honing the cylinder bore.
Thanks !
Cross posted on TDS.

 

[CraigAClark]

I would hone the cylinder. Then I would take a new ring and place it in the cylinder at about an inch down the bore. Make sure it is even all around. Then check the ring gap. If the gap is outside acceptable tolerence, the cylinder is worn out. Unfortunately, they do not make over sized rings to compensate. I do not recall what the max gap allowence is for that stage, but I'll try and find it since it is the same for Bauer.

 

[ti325v]

Hi Craig.
Thanks very much...
Looks like I gotta take the jug on a plane trip to Saigon as there is no cylinder hone on the entire island !
I can find no other reason for the blow by, new valves.....clean cooling pipes, low hours, though the thing that lead me to this was....one of my staff members took the line that goes from the crankcase to the first stage head off, why i do not know....and although the oil should be removed by inter stage separator, I am concerned that running the pump for 50 plus hours without that injection of oil may have damaged the second stage rings, though the cylinder looks beautiful. not a scratch or polished spot in the bore.
Do you think the first stage oil blowby oil is critical to the second stage ring's ? Or should I be looking elsewhere..always open to suggestions.

 

[rcontrera]

That line between the first stage and the sump is the first stage lubrication. Check the condition of the first stage rings as long as you have it apart.

 

[ti325v]

Hey Ray:
Waiting for my valves to arrive here in Vietnam from you.. (Not your fault they are not here !)
Thanks for cluing me in on the purpose of the breather...
I would have thought the first stage got its lube from below...but then again with fresh air coming in with no residual oil I can see how the head may be very dry.
Okay with that in mind, as i mentioned in the first post..the first stage rings look great, not even fully seated..., second stage rings are fully seated, (Baked on coating worn off all the way down all of the rings....
The question remains...Hone the bore ? It looks beautiful, Craig is a smart guy and experienced guy , but your opinion counts too !
I have never read about honing a compressor bore when replacing rings and with no hone on the island it is something to be prepared for !!!
Thanks
Larry

 

[rcontrera]

I haven't serviced a Bauer in a LONG time so if Craig says to hone it ... hone it!

The Coltri parts are so cost effective that is is easier and cheaper for us to just change them out ... including cylinders.

 

[ti325v]

okey dokey, thanks !

 

[OkByMe]

Never heard of NOT honing a cylinder to seat the rings, whether it is a compressor, internal combustion or hydraulic motor. This "cross hatch honing" is always necessary. Micrometer the cylinder before honing, check the maximum ring gap for the ring. If it is too close to the max, you may have to bore the cylinder and replace the piston. Since by the time you hone and the rings wear in the max gap will be exceeded and you will be right back where you started. In this case, it would be cheaper the replace the cylinder if the piston is still good.