Topic: Cylinder hone

[dlhoulton]

What are your thoughts on cylinder honing or general cylinder cleanup? I've used this tool on my last build, http://www.enginehones.com/fl2to2.html and it did a good job of cleaning and putting the cross hatch pattern on the cylinder walls. Or do you prefer the standard three stone type you can get at most auto parts stores?
What grit would be preferred for just cleaning the cylinder walls and restoring the cross hatch pattern?

[70CB750]

I used 320 grit flex hone on the F engine, it made nice crosshatch, did not finish it yet, can't tell if it worked or not.

The three stones, according to knowledge acquired here, would take too much from the cylinder wall.

[dlhoulton]

Thanks for the response. When I had some valve work done last year the guy at the shop let me borrow one but I didn't no what grit it was. But like I said I used there's last year on my build and everything seems to have gone well with that motor.
As for the three stone hone, I agree with your thinking. If you don't know how to use it, you just might get a little aggressive and take too much cylinder wall off!

[crazypj]

Flex Hone is all you need to cross hatch for new rings. 3 leg hones will work but they can easily remove too much material, plus, they follow contours of original bore so are not much use in many re-builds
A 'proper' engine hone to size cylinder is real expensive, ($3~600.00 for new) but, it will true up a worn cylinder to the next oversize very very accurately (easily to within 0.0002")
As 'next' oversize is usually 0.25mm - 0.010" and 0.002'~0.004" is left after boring, a cylinder 0.006" or more over size doesn't need to be bored just honed and cross hatched.
The only disadvantage is it follows original cylinder centering which could be an issue if racing and original factory machining wasn't corret (majority of boring bars do the same)

[flybox1]

My $15 flexhone worked well for a new(re-ring) cross hatch.  Working slow...1-2 min tops.

[70CB750]

My $15 flexhone worked well for a new(re-ring) cross hatch.  Working slow...1-2 min tops.

That is bloody beautiful!

[PeWe]

Flexhone really easy to use.
I bought 240 grit when 320 was out of stock. I have read somewhere about someone used 240 and happy with it. I used extra oil to compensate.
It will be fine. I'll run in the new pistons the harder way this time with hard accelerations followed by engine decelerations. Not drive as si..y 1000 km's as I did last time soon 30 years ago 

[dlhoulton]

Should I use "Aluminum Oxide" or "Silicon Carbide"?
Also what size for the 750?

[flybox1]

My $15 flexhone worked well for a new(re-ring) cross hatch.  Working slow...1-2 min tops.

That is bloody beautiful!

thanks    liberal WD40 during. acetone clean up. light coat of motor oil before it went on the shelf.
I used this one on its absolute lightest setting.
http://www.amazon.com/gp/product/B002ZKUPAS/ref=oh_details_o05_s00_i00?ie=UTF8&psc=1

[lucky]

Ball hones or "dingleberry" hones are perfect for cross hatching a cylinder that has been bored.

Just make sure the cylinder is measured first.
No point in honing a piece of junk.

Run the hone at slowest speed while moving up and down the cylinder. 5-6 times is enough.

[crazypj]

Silicon carbide is harder and will last longer, for a single bike the aluminum oxide grit is fine.
Lucky gives correct 'timing', 30 sec at 2~400 rpm is more than enough.
The picture of honed cylinder is slightly 'flat', need to move in and out of cylinder a little faster to get a steeper angle (I taught 'Machine Shop' at MMI for almost 4 yrs)



This is deliberately a bit 'flat' (closer to 30 deg) instead of the recommended 45 degree angle
Changing the angle changes the way oil is retained in the 'scratches'
BTW, flybox, why are liners sticking out of block?

[CB750R]

I used a three stone on my engine. I have over 8000 km on it since I rebuilt the motor and its the only bike I own that doesn't smoke right now. 

( rock took out rad on my ZRX, and I own a yz250! Hehe)

From all I read the flex hones are great, but I was having a hard time acquiring one in the tiny little town I lived in then. And wasn't sure which size to get.

[70CB750]

I got my flex hone on eebay - after scouting all 4 local car parts stores.  All I found was a huge diesel flex hone in bumper to bumper.

That is more and more the case, it is cheaper to shop online than hunt locally for specific parts and tools.

[flybox1]

Silicon carbide is harder and will last longer, for a single bike the aluminum oxide grit is fine.
Lucky gives correct 'timing', 30 sec at 2~400 rpm is more than enough.
The picture of honed cylinder is slightly 'flat', need to move in and out of cylinder a little faster to get a steeper angle (I taught 'Machine Shop' at MMI for almost 4 yrs)

This is deliberately a bit 'flat' (closer to 30 deg) instead of the recommended 45 degree angle
Changing the angle changes the way oil is retained in the 'scratches'
BTW, flybox, why are liners sticking out of block?

they're not, thats just a shot from underneath.
i'll run the hone through a few seconds more and 'steepen' the angle.
thanks

[dlhoulton]

Thanks for all the responses and feedback. Always know I can get some good info and learn a little bit.

[PeWe]

I bought this one for my 65mm cylinders (836)
http://www.enginehones.com/258240sc.html

[dlhoulton]

PeWe, that's the same place I posted a link of. Looks like they have some good prices! Was doing business with them good. I'm thinking a 64mm will be the right size for a stock 750.

[PeWe]

Yes, I bought from them when the price was good and the shipping cost to Sweden  too. Other wanted double for shipping. I think I bought from the eBay shop.

Bore size, grit is explained on their site. 64mm must be ok for 61mm bore after reading there.
http://www.enginehones.com/technical.html
What diameter size should I order?
A hone tool's diameter is determined by the nominal bore size in which the tool is to be operate. A cylinder hone is always produced and used in an oversize condition. The degree of oversize creates pressure and a soft cutting action on cylinder walls. For example a 1" Flex-Hone® tool is ordered if a 1" bore (I.D.) is to be finished, the built in oversize provides the proper cut. Remember that all tools are provided in over-sized, so do not add inches or mm's to the ID that you are machining.  If the bore size is between standard Flex-Hone® sizes, the next larger standard Flex-Hone should be selected.

EDIT: I measured my brush and found it to be 70mm... It went well anyway since I carefully checked the result after a few strokes, continued until the bore was even crosshatched. I promised to take it easy as usual

The explanation of bigger size of my tool recommended for 64-69mm bore found in description:
Tool is labeled as 2 5/8" diameter but is actually slightly larger to apply the required wall for for honing a 2 5/8" bore

[crazypj]

There is usually 6~10mm range, allows flex hone to be used all the way down to the nylon bristles
Even in daily use they can last for months, for most people they will never be worn out

There's probably a 'market' for used ones?