BRM's Flexible Honing, Surface Finishing, and Deburring Blog Blog

BRM's Flexible Honing, Surface Finishing, and Deburring Blog

BRM's Flexible Honing, Surface Finishing, and Deburring Blog is the place for conversation and discussion about how to solve difficult finishing problems. For over 50 years, Brush Research Manufacturing (BRM) has helped customers use brushing technology to clean, rebuild, and resurface components ranging from engine cylinders to brake rotors to flywheels to firearms. BRM's Blog on CR4 provides real-world examples of how flex hones and wire brushes work. It also evaluates related technologies and invites questions from the community.

Previous in Blog: Miniature Brushes and Small Parts Manufacturing   Next in Blog: Quieter Cadillacs: Flexible Honing for Brake Rotors
Close
Close
Close
6 comments

How to Prepare Cylinder Walls for New Piston Rings

Posted May 12, 2011 3:05 PM by BrushResearch

There's plenty of debate about the best way to deglaze cylinder walls to prepare them for new piston rings. There are also plenty of questions.

The most common one we're asked at Brush Research Manufacturing is this: "What abrasive and grit type do I need for my honing tool?" Flexible hones provide a fast and effective solution, of course, but answering this question isn't always so simple. In short, the answer is this: "It depends". The cylinder and material determine the tool specifications to select.

Choosing the Abrasive

Fortunately, picking the correct abrasive type for a Flex-Hone is straightforward. You'll want to use silicon carbide for all cast iron cylinders and liners. For a Nikail liner, or in any aluminum bore application, select an aluminum oxide abrasive instead.

Choosing the Grit

The most typical grits we see used for deglazing applications are 180 and 240 grit; however, the range used runs from 120 all the way up to 400. We've even seen some manufacturers of extreme-performance rings recommend 800 grits, or even Levigated abrasives!

Corrosion, rust, or oxidation mean that you'll probably want skew your grit selection a bit coarser. Use a finer grit if you're running a high-performance engine with multiple tear downs and surface finishes per year, or are using very thin rings.

Read the Whole Article

Reply

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
Hobbies - Fishing - New Member

Join Date: Jun 2008
Location: Raleigh, NC USA
Posts: 13529
Good Answers: 467
#1

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 7:15 AM

Unless you're talking really high perfomance, I don't think it matters much.

If there's not a big lip at the top, and the cylinders aren't out of round, any off the shelf cylinder hone will work fine. All you're doing is knocking the glaze off so the new rings can seat themselves in the pistons.

I've never worried about it, and never had any problems. If they're worn beyond a quick honing, get them rebored and get some oversized pistons and rings.

__________________
Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. Ben Franklin
Reply
Active Contributor

Join Date: Feb 2009
Location: Los Angeles, CA
Posts: 21
#5
In reply to #1

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 12:34 PM

Kramarat-

The important differences between a Flex-Hone and other hones, particularly "rigid" three prong hones is that the Flex-Hone will not damage the bore by making it out of round. It is much easier for someone to harm their cylinder with a rigid hone.

__________________
Innovators in Brush Technology
Reply
Guru
Hobbies - Fishing - New Member

Join Date: Jun 2008
Location: Raleigh, NC USA
Posts: 13529
Good Answers: 467
#6
In reply to #5

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 1:32 PM

You're right. I've always used the hones with the balls on them, on a drill motor, fairly slow to medium RPMs, and a nice easy, even stroke up and down..............it's worked every time. Thanks for the clarification. A rigid hone in the wrong hands could really do some damage.

If there is excessive wear, I spend the extra money and have them professionally rebored with new pistons to match.

__________________
Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety. Ben Franklin
Reply
Guru
Technical Fields - Technical Writing - New Member Engineering Fields - Piping Design Engineering - New Member

Join Date: May 2009
Location: Richland, WA, USA
Posts: 21011
Good Answers: 783
#2

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 7:57 AM

"Dingle ball" hones are great, but each fits only a tiny range of cylinder diameters, so you may need several. But there's a salesman nearby!

__________________
In vino veritas; in cervisia carmen; in aqua E. coli.
Reply
Guru
Hobbies - DIY Welding - New Member

Join Date: Sep 2007
Posts: 1601
Good Answers: 57
#3

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 9:36 AM

When a rotating hone is pushed through a cylinder it leaves a helical series of parallel scratches (like a barber pole). When the hone is retracted at the same rate it was inserted and continues to rotate at the same speed, the angle of the helical scratches is reversed. Studies have shown that piston rings seat in the shortest time when the angle between the two sets of crossing scratches is optimized. I think it's 120 degrees.

Reply
Power-User

Join Date: Mar 2011
Posts: 238
Good Answers: 14
#4
In reply to #3

Re: How to Prepare Cylinder Walls for New Piston Rings

05/13/2011 11:56 AM

I think that 120 degrees is not always optimal. Recalling rebuilding a fairly new Harley-davidson engine last year, I found some information about different angles for different engines but I can not recall all of the arguments. Just that 120 is not always optimal.

Reply
Reply to Blog Entry 6 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Copy to Clipboard

Users who posted comments:

BrushResearch (1); harley (1); kramarat (2); Tornado (1); welderman (1)

Previous in Blog: Miniature Brushes and Small Parts Manufacturing   Next in Blog: Quieter Cadillacs: Flexible Honing for Brake Rotors

Advertisement