cylinder honing

[narx]

How important is to hone a cylinder before installing new piston rings?
Cylinder is in a good condition and honing marks are still visible but surface is glazed as expected to be.
I am having trouble finding a machine workshop competent enough to give them a cylinder without to be worried weather they will ruin it or not.

Is there any way to do it by hand, maybe give it a few passes with a fine sand paper, could it be any good?

 

[EkBlAd.]

If the cylinder issn´t damiaged you dont need to "hone" it?

 

[Areomyst]

Do a search on Google for "Flex Hone" or "Flex-Hone". Ball hones are not very expensive, and can be operated easily with an electric drill while running at very slow speeds.

I will usually hone a cylinder if installing new rings, especially if it's a higher mileage engine. It helps the rings to seat and "break in" better if you run it in correctly after the rebuild.

It's really up to you though, if the engine is smooth and not damaged (just a little glaze) then you don't really have anything to worry about if you choose not to hone the cylinder.

 

[tiba_karotsu]

same here, i rehone the cilinders (cast-iron) when swapping in new rings or piston kit, it only takes 4passes to deglaze the bore.

 

[xzburnoutzx]

Stupid question, but what does this glaze mean, as I understand the shiny layer covering the bore.

 

[narx]

I've googled flex hones and found out everything about it, I've heard for it before but never used it.
I'll try to find a shop that sells those here. I see they are sold in different grits, which one to use for a plated cylinder?

But I am still tempted to do it with a sand paper in a spiral motion like real honing is done, hmm.

xz - You are right, glazed means very smooth, shiny.

 

[ruud.]

let you cilindre hone by professionals with a diamant hone machine. This will garantue a round cilindre and with a good operator you will have a good piston clearence!

 

[yamaha getund]

but its always something

 

[adas]

Aloha, on a cast iron cylinder, I use a cheap brake cylinder 3 finger hone and use a slow speed drill action and move the hone in and out VERY FAST for 4-5 seconds to get a nice cross-hatch. For Niksal cylinders I use a green pad and fingers to remove a very little bit of the shine. (it probably does not remove the shine or help, but it makes me feel better. )

Frank

 

[narx]

Aloha, on a cast iron cylinder, I use a cheap brake cylinder 3 finger hone and use a slow speed drill action and move the hone in and out VERY FAST for 4-5 seconds to get a nice cross-hatch. For Niksal cylinders I use a green pad and fingers to remove a very little bit of the shine. (it probably does not remove the shine or help, but it makes me feel better. )

Frank

I don't understand what do you mean by using gren pad and fingers. Is it some kind of abrasive?

 

[tiba_karotsu]

I don't understand what do you mean by using gren pad and fingers. Is it some kind of abrasive?

it's called 3M Scotchbrite.

 

[narx]

it's called 3M Scotchbrite.

OK, he should've said so

Then probably a 600 grit sand paper would do the job even better. Like you said adas, it helps just to make you feel better.

 

[tiba_karotsu]

600 grit sandpaper is too fine try a 280 to 320 grit sandpaper.

 

[Areomyst]

Many sources warn against using the 3 fingered brake hone, because they can snag the ports. They are excellent to use with 4 stroke cylinders, but not reccomended for 2 strokes. The Flex Hone would be the better choice.

Having said that, I have used the 3 finger brake hones before I got my Flex Hone, and diddn't have any trouble, but it's not a something that I will do again since I have the proper tool.

 

[tiba_karotsu]

i have the 4 finger model plus it has very long honing stones.

 

[ruud.]

OK, he should've said so

Then probably a 600 grit sand paper would do the job even better. Like you said adas, it helps just to make you feel better.

with a 600 grit you fuck up your cilinder! hone stripes let the lubrication hang so you have less friction with your piston and a better cooling! if i do it by hand i use a 120 grit! or even less!

 

[ex-racer#2]

I've googled flex hones and found out everything about it, I've heard for it before but never used it.
I'll try to find a shop that sells those here. I see they are sold in different grits, which one to use for a plated cylinder?

But I am still tempted to do it with a sand paper in a spiral motion like real honing is done, hmm.

xz - You are right, glazed means very smooth, shiny.

125 GP bikes with Nikisil plating use 600 grit sandpaper just like you described between piston changes. I always used WD40 and 600 grit and it worked perfect. The key is the motion so that you turn the right amount for the amount you stick you hand into the bore. On a 125 your hand fits but on a 50 or 70cc it might be tough to get a full "stroke".

 

[narx]

125 GP bikes with Nikisil plating use 600 grit sandpaper just like you described between piston changes. I always used WD40 and 600 grit and it worked perfect. The key is the motion so that you turn the right amount for the amount you stick you hand into the bore. On a 125 your hand fits but on a 50 or 70cc it might be tough to get a full "stroke".

Thanks, nice piece of information, I also thought that 600 could be too fine like others said.
My cylinder has 65,6 mm bore so it wouldn't be a problem to stick my hand in it.

Thanks for the comments everyone.

 

[ruud.]

125 GP bikes with Nikisil plating use 600 grit sandpaper just like you described between piston changes. I always used WD40 and 600 grit and it worked perfect. The key is the motion so that you turn the right amount for the amount you stick you hand into the bore. On a 125 your hand fits but on a 50 or 70cc it might be tough to get a full "stroke".

so why do they do that?

 

[MONZAV8]

so why do they do that?

you want a slightly rough surface for the rings to "seat" into. The roughness also holds lube too.