Cylinder Hone - Stone or Flex-Ball Type and Grit

[oliver2-44 9,761]

I'm gradually getting tools together to do some engine overhauls.  Some engine will need to be bored, but some that will just be show tractors could be honed and re-ringed.  I have a stone type hone with 120 grit stone that I recently used on one engine. That engine bore was still in spec, but had some rust in it from sitting a long time.  I haven't run it yet, but the 120 grit seemed a little course. 

So, what type hone do you use for a re-ring job? 

What grit do you recommend?

Any tips to achieve the 23 deg hone marks that is recommended? 

 

The ball hones are sold in many sized.  What range can a ball hone cover. i.e can a 3-1/2" hone be used on a 3-1/4 bore? and on a 3" bore?  

 

Thanks in advance.

Edited July 3, 2019 by oliver2-44

[WHX?? 48,828]

Dan's @Achtopretty good at getting the cross hatches in Ollie... he'll chime in. Pretty sure he uses a ball in 220.

[adsm08 2,069]

Stone and berry bush hones serve different purposes and do different jobs, both are needed for a proper hone and re-ring job.

 

As a cylinder wears it doesn't become bigger along it's whole length, it gets eg shaped like () with a lip at the top, because the rings don't pass to the bottom of the cylinder, or to the very top. This leaves you with more wear in the middle and very little if any at the bottom, and the lip at the top is a spot with no wear. The stones are to take the lip off and straighten the walls by taking it over-bore, and/or clean rust off the cylinder walls.

 

The berry bush is to put the cross-hatching back on the cylinder walls. This cross-hatch is needed to give the oil a path to run down slowly, and help the rings seal. Without a proper cross-hatch on a newly bored cylinder you may find you have no compression.

 

A ball hone should be sized as closely to the cylinder it is going to be used on as you can get, I'm not sure what the range is.

 

Getting the cross-hatch angle is a product of how fast you spin the hone vs how fast you move it up and down in the cylinder. It can take some practice.

Edited July 3, 2019 by adsm08

[stevasaurus 22,764]

Jim, there are some great videos on You-Tube for this process.  I would go with the balls if the cylinder is with in specs and all you need is the cross hatch.  check out the vids. 

[squonk 41,155]

To get the top ridge off you need a ridge reamer. Stone hones are for sizing. Ball hones for de-glazing. To get the cross hatch, Slow the drill way down and move the hone up and down very quickly.

[adsm08 2,069]

1 hour ago, squonk said:

To get the top ridge off you need a ridge reamer. 

 

Ideally yes, however in a pinch I have removed a small ridge with a stone hone. You do have to be very careful to do it slowly and use as much of the length of the stones as you can to not wear a groove in them.

 

I've also used 80 grit instead of a ball hone, again, in a pinch.

[Tractorhead 9,064]

Before hone a Cylinder, few advices.

you must measure the cylinder in round, and it is in tolerance on different heights.

Hone doesn‘t round a Cylinder, it‘s just for the Finish after Bore.

if the Bore isn‘t round, more like an oval you have to bore it before to next oversize and need an oversize piston.

 

If the cylinder is round or in tolerances and just have slight scratches, you can try to polish them out with stones.

but you need a lot of oil, to spill the shavings out and don‘t overheat the hone self.

WD40 does this job good.

 

The Hone Balls, here known as Flexhone, what was the Brand name are available in different sizes.

Here we have the same rules, use much Oil or WD40 to clean the Surface and washout the shavings

and even cool the Hone and the Surface. First time it sounds complicated, but if you did it first time,

Do it carefully and you will see, it was not that witchwork.

 

I used Flexhone on several Engine Restores in different sizes, a lot of older Monkey engines,

my KTM Racing Engines even on my Mercedes 608 Engine 4 cyl. 4,8 Litres.

 

My seller, who was also an Racing motor professional advices me, even if they tell something about 45deg. Ignore it,

give the Engine cylinder a 72 deg hone result for best Quality, he tolds me and he was right.

 

I used a Wooden board where i make some 72 deg. Crossing Lines to have an visual support for the result.

using few times also my Makita accudrill in low gear just tapped a bit the trigger to move it slow enough.

it runs about 80-90rpm to bring the 72 deg. a Speed controlled drill is for the beginning mostly much easier to use for

also in low gear and speed complete restricted.

 

have a look at a flexhone video.

 

 

If you have a drillmount, that makes it a lot easier to handle.

Another solution, if you not have a Drillmount was, make 2 marks (i used tape for)

on the upper and lower shaft of the flexhone to take care you dont push to deep or pull it out while using.

 

I was excited about the result and swear on the Flexhone.

all Engines i reworked with them are still running and have less Oilconsum if new Pistonrings used after.

 

To get an idea about my used speed and how to get 72 deg. Here another vid.

 

 

[Achto 27,609]

7 hours ago, WHX24 said:

Dan's @Achtopretty good at getting the cross hatches in Ollie... he'll chime in. Pretty sure he uses a ball in 220.

Not much for me to add here, it seems I came to the party a little late.