Diesel Place banner
41 - 50 of 50 Posts

·
Premium Member
1995 Chevrolet Silverado Z71 6.5 TD
Joined
·
517 Posts
Try using a ball/flex hone to do the honing pattern.Some guys use the three legged hone which is okay too.The ball hone does a pretty good job overall.I bought a couple different grits from eBay.
I like the ball flex cylinder hone myself also.
 
  • Like
Reactions: dieselolds

·
Just add Fuel
Joined
·
619 Posts

·
Registered
Joined
·
783 Posts
I remember reading that article several years ago. Yeah, interesting perspective. Here's my story: this spring I overhauled a LeRoi Dresser 2 stage air compressor I've had for about 30 yrs. The thing is about 60 yrs. old and had a rod bearing knocking. The overhaul kit had two new pistons, rings, etc. and all needed for an overhaul. There were never any oversize pistons made for these and if the cyl. was worn past limits, you had to replace it. The high press. cyl. (2 in. bore) was about 1 thou. past limits. The only new cyl. I could find on the internet was insanely expensive. I'm lucky to have a very good machine shop close to me and they bored and sleeved that worn cyl. to original bore size. The low press. cyl.(4 in. bore) was still well within limits on bore. I had no cyl. hone big enough for this 4 inch. low press cyl., so just put in the new piston and rings and no honing. High press. cyl. got the same and the sleeved original size bore. Put it all back together and this thing was taking way too long to get to cutoff press. 180 psi. Much longer than before I tore it down. There's a chart in the back of the maint. manual on the compressor that shows the different models and how long they should take to get to different cutoff pressures. Mine was out of whack according to the chart. I ordered a new ball hone big enough for the unhoned low press. cyl., took it back off, honed it and put the compressor back together. I'd already rebuilt all the suction and discharge valves. Nothing else was touched except to hone the low press. cylinder. Ran it up to cutoff press. and the first time I ran it, the compressor made it to cutoff press. much faster. And got there in a shorter time the more I ran it. There's only one thing that was changed. Honing of a cylinder. No, it's not a gas or diesel engine, but it's cast iron cylinder and aluminum pistons. I'm calling BS on that article.
 

·
Just add Fuel
Joined
·
619 Posts
I don’t have experience with rebuilding without honing. Every engine I’ve built has been bored. Which of course then requires honing.
I HAVE seen plenty of Isuzu piston/liner kits destroyed by a technician with a hone - thinking he had to “break the glaze” on a new, perfectly finished liner.
Isuzu liners have an extremely smooth finish. You have to hold them just right in the light to see ANY crosshatch.
 

·
Registered
Joined
·
783 Posts
The machine shop did a nice cross-hatch on the new sleeve in the high press. cyl. Don't know if it was a ball hone or not. After seeing the way this compressor pumps after I ball honed that low press. cyl., the issue is settled for me. That guy that wrote the article is just wrong on this.
 

·
Registered
Joined
·
14 Posts
Safest bet is always "what does your ring manufacturer say?". The biggest purpose of honing is to get the proper surface finish for the rings to seat properly. Too smooth, the rings don't seat, and you lose compression. Too rough, the rings get destroyed, and you lose compression.

Different rings require different surface finishes to accomplish this. Boring without honing almost always results in far too rough, new rings in an already ran engine will often be far too smooth.

Chances are not honing with new rings is going to result in tearing the motor back down again pretty quick.

The other big thing to remember is cylinder taper. Most engines with high miles will develop additional wear at the bottom of the cylinder compared to the top, so that you end up with a tapered bore, and usually in an oval shape. This too is going to affect ring seat, usually in a negative way.
 

·
Registered
Joined
·
783 Posts
I believe you've got the cylinder taper backwards? Isn't the wear on a high mileage engine at the top of the bore more compared to the bottom.
 

·
Ronald Reagan fan
Joined
·
4,680 Posts
I believe you've got the cylinder taper backwards? Isn't the wear on a high mileage engine at the top of the bore more compared to the bottom.
Your right.Cylinder wear occurs at the top section of the cylinder and eventually most cylinders will taper as the miles accumulate
 

·
Premium Member
1995 Chevrolet Silverado Z71 6.5 TD
Joined
·
517 Posts
I have always honed engine cylinders when installing new rings and will continue to do so.
 
  • Like
Reactions: dieselolds
41 - 50 of 50 Posts
Top