Honing a non-coated aluminum scored cylinder?

[dswensen]

I'm messing around with a scored cylinder Poulan p4018. It's just for something to play with. I know about the bad things honing a plated cylinder can do, but what about honing some marks out of a non-plated cheapo aluminum one? Doable?

 

[Big_Wood]

I would imagine your hone would remove material something fierce on something as soft as aluminum but I have never tried it. if you try it I would like to hear the results

 

[machinisttx]

I wouldn't do it. The grit and swarf from the stones will embed itself in the aluminum at about the same rate the aluminum loads up the stones. I don't think any amount of honing oil will prevent this.

 

[Chris-PA]

Here is my "hone":

It's a large dowel with some thin foam attached at the end. I wrap 400 grit paper around it, squirt it with some WD-40 and go at it. I've cleaned up several chromed cylinders and a non-chromed 42cc Poulan. Two of those chromed engines met unfortunate ends for other reasons so I can't say how they held up. The other chromed one I only sanded lightly and it is fine.

The bare aluminum Poulan I took a fair amount of material off to remove a scratch that was just at about the point where you could feel it. That engine is holding up really well. I have about 7 tanks on it now, and I keep peeking through the spark plug hole to see how it is doing, and it looks great. Runs well too.

Given how fast I was able to remove material on the bare bore I would not want to try a powered ball hone.

 

[Stihlofadeal64]

That's a funny looking hone :alien2:

 

[dswensen]

Here is my "hone":

It's a large dowel with some thin foam attached at the end. I wrap 400 grit paper around it, squirt it with some WD-40 and go at it. I've cleaned up several chromed cylinders and a non-chromed 42cc Poulan. Two of those chromed engines met unfortunate ends for other reasons so I can't say how they held up. The other chromed one I only sanded lightly and it is fine.

The bare aluminum Poulan I took a fair amount of material off to remove a scratch that was just at about the point where you could feel it. That engine is holding up really well. I have about 7 tanks on it now, and I keep peeking through the spark plug hole to see how it is doing, and it looks great. Runs well too.

Given how fast I was able to remove material on the bare bore I would not want to try a powered ball hone.

Thanks for the ideas. I have a three "paddle" brake cylinder hone that I will try that fits pretty well above the ports. I have heard a ball hone can tear up the ports - I beleive it. It will sound alot like the bare aluminum Poulan that you noted. I have a new piston and ring coming. It will be a $20 experiment (saw was free).

Thought to self: I wonder if I would/could remove enough material to over-bore it (making a standard piston/ring not work)? Hopefully the one scratch isn't that deep.

Yes, I'm pretty sure it's an uncoated/plated cylinder; I tried muratic acid on it and it bubbled everywhere.

 

[machinisttx]

Thanks for the ideas. I have a three "paddle" brake cylinder hone that I will try that fits pretty well above the ports. I have heard a ball hone can tear up the ports - I beleive it. It will sound alot like the bare aluminum Poulan that you noted. I have a new piston and ring coming. It will be a $20 experiment (saw was free).

Thought to self: I wonder if I would/could remove enough material to over-bore it (making a standard piston/ring not work)? Hopefully the one scratch isn't that deep.

Yes, I'm pretty sure it's an uncoated/plated cylinder; I tried muratic acid on it and it bubbled everywhere.

If you were to take .010" out with a hone, you'd be there for several hours at least, and the cylinder walls would no longer be straight. If you want it overbored, take it to a machine shop and have them do it.

 

[dswensen]

If you were to take .010" out with a hone, you'd be there for several hours at least, and the cylinder walls would no longer be straight. If you want it overbored, take it to a machine shop and have them do it.

OK, good to know, thanks. I don't want to over-bore it, I just don't want to "over-hone" too much in trying to get rid of the scratch such that the new piston/rings wouldn't work. Sounds like that's not an issue.

Right now (after some honing) the scratch (just one now) is just barely able to be felt with a fingernail. I think I will put in the new piston and ring to check to see if it will make compression. If not, I can hone further.