TRX250R.ORG
Workshop => Engine and Bottom End => Topic started by: dem3500 on April 20, 2016, 01:08:32 PM
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want to get a hone just to deglaze/prep for new rings. im pretty sure a ball hone is what i want. i tried a flex/ spring hone and it kept getting caught on the ports. i was looking at mcmastercarr cause i have other things to order from there anyway. they have a multi purpose, soft materials, and stainless/hard materials one. im guessing i want the one for hard materials. right? what grit? my first thought would be 600.
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I would not use a ball hone on anything other than cleaning a sewer pipe. If you are going to use a hone, use a rigid or mandrel hone. A mandrel or rigid hone will only touch the high spots and will improve the roundness and straightness of your cylinder. Remember ANY honing operation always increases the piston to cylinder wall clearance.
You are better off using your hand and sandpaper than using a flex/hone, ball hole, or flapper wheel to deglaze a cylinder bore. These types of hones make the cylinder LOOK GREAT but follow the surface that it encounters, not correcting ripples, dips, taper or out of roundness. They also bulge into the ports and cut heavily as they come out of the port.
I know some of the OEM service manuals say to use a ball hone to deglaze a cylinder. There are some things that get lost when the USA divisions translate the original shop manuals and I think than this is one of those things.... or the tech writer took it upon himself to show his gross misunderstanding of the proper application of machine shop tools. I will guarantee you that the factory did not use a flex hone, or ball hone to finish the cylinder bores and put the cross hatch on the new cylinders.
Two stroke rings will seat on a freshly honed bore in 5 to 10 minutes minutes with the proper break-in procedure. The top ring on a two stroke will seat in less than 15 to 30 minutes when installing them in the old glazed bore. On a two stroke the top ring is the ring doing all of the sealing. The second ring on a two stroke is just there to take over when the top ring is worn out.
Four strokes need a honed surface to seat the oil rings, not the top compression ring. Remember, honing always increases the piston to cylinder wall clearance
Honing is a machine shop operation like that of a grinding operation. These two operations are used as the next step after a machining operation and will improve the precision and surface finish of the bore.
Shops using a ball hone to hone a cylinder are under equipped and are not providing the service they are charging for. A different mandrel is required for about every 3 mm increment in bore diameter. The mandrels are expensive ($600.00 to $1000.00 each) but provide the same precision and surface finish the manufactures use.
If your cylinder is scratched up to the point that it needs to be honed to remove the big scratches it probably needs to be bored to the next over size piston. If you hone it enough to remove the deep scratches, the clearance will usually be excessive, the crankcase will not pump properly and the piston is apt to break off the skirts.
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Ball hones were designed to break the glaze and provide a cross hatch to get quicker ring seal.....I agree with you Jerry that if a cylinder has scratches in it that the ball hone will not touch then you should use the other type of hones.....