Thread: How to hone a cylinder?

Save your $70 and go to Bunnies.
You can buy a whole compressor for that sort of money.

Al

Hi Groggy, depends on the type of hone you bought I suppose. The kind we always used ran off a hand held drill. We would run it in both directions so the scrathes went both directions in the cylinder walls.

We used a honing oil during use--but I have no idea what it was. My uncle used motor oil cut with kerosene though.

Take care, Mike

Originally Posted by ozwinner

Save your $70 and go to Bunnies.
You can buy a whole compressor for that sort of money.

Al

When I was given the compressor it came with a complete rebuild kit, so I think I'll use it.

Tell me though Al, do you reckon the Bunnies job will see me out? I think the current one (rebuilt) will.

Originally Posted by MikeW

Hi Groggy, depends on the type of hone you bought I suppose. The kind we always used ran off a hand held drill. We would run it in both directions so the scrathes went both directions in the cylinder walls.

We used a honing oil during use--but I have no idea what it was. My uncle used motor oil cut with kerosene though.

Take care, Mike

It's one of these click here

Yep, thats the kind we used. A good electric hand drill works well. We ran it about half speed or so with a smooth mostly slow movement up and down the cylinder. Pay special attention at the top of the cylinder if there is a lot of wear--there will be a lip.

Take care, Mike

The drill press wont work, as you cant go up and down the full depth of the bore quickly enough. Most hone cross hatching that you see on a fresh bore is at an angle of 45 deg or so, giving 90 deg to each other, this isnt all that important, but you can see that for the speed of the drill, you will have to go up and down kinda quickly, thus a hand held drill is the go.

If there is a lip on the bore of any real size, you will have to remove it before you go honing it, as you won't hone the lip away without hurting the shape of the rest of the bore. You will also need to lubricate the bore as you go, something like kero is fine.

If you are looking to use a pebble or ball hone, your wasting your time, it will look nice when your done, but it wont be true, the hone will just follow any irregularities that are already there. You really need a parralell stone hone to see what sort of condition the bore is in.

$90 is ok for a couple of pots to be honed, but if your still keen to do it yourself, go for it, its not a big or hard job. If you are way keen and didnt want to spend any money at all, you can even take to it with some wet and dry by hand, we did it on an old Mazda ute before we had a hone of our own.

Thanks for the advice so far, I can manage all that.

The only remaining question I have is "do I need to extend the hone out of the bore as I spin it - say, 1/3 of the stone - or should I try to keep it contained within the limit of the pot?"

That lil bit out of the pot wont hurt or cause any trouble, the worst that can happen is that you get a lil carried away and it comes out the top and goes bezerk, not that i've done that

Try this for the cross hatch angle.

http://www.hastingsmfg.com/Service%2...efinishing.htm

Best of luck

Great link, thanks Mick.

Well the compressor is back together at last, and much quieter than she was before dismantling.

I had some major drama trying to remove the crankshaft bearing from the case, finally getting it removed by an 'expert' who applied the judicious use of screwdrivers and fumpin' persuaders. He was an electrical motor rebuider and he was very good at what he did. For my part, I had tried for two days to get it off, eventually learning I needed a split collett bearing puller, which removes blind bearings. It was going to cost around $300 so I went to the motor guy, figuring if it was ruined I'd be up for $300 for a new pump anyway. Anyway, he didn't even charge me a cent!

Then I went around to Get Woodworking in Williamstown and Roy graciously allowed me to use his 20 ton press to insert the new bearing.

Next I had to remove the reed valves and replace them, so I did the logical thing and snapped the heads off two bolts in the process. After drilling them out and replacing them I got onto the honing.

Honing was uneventful. I removed the lip with wet'n dry, applied some cutting oil I had then used the DeWalt cordless for 5 mins. I soon had a crosshatch with a good pattern of 45 deg so I cleaned it all up and put it back together. It purrs like a kitten and easily gets 150psi, just like it used to. Altogether the exercise cost around $100, including a new pressure dump valve, drain cock, some locktite and $70 for the hone itself.

I ran it up in 20psi increments, retightening as I went. Last night I filled it to capacity then backed it down to 105psi. This morning I still had 105psi in the tank so I'm a happy camper.

Thanks for the advice everyone!