Anyone Had Experience With Honing A Bore?

[scorpa3]

One of my friends bought around a barrel (well the liner) from a 2000 Honda XR400 tonight to see what I thought.

The bike has been burning a lot of oil recently and he decided to change the valve guide seals and piston rings. However, upon checking the barrel there are some very minor marks. Certianly NOT scoring, more like 'water' marks for want of a better description.

I was wondering if it was worth having the barrel honed or if the new rings would possibly clean/polish out the very faint marks?

Any advice welcome.

[barrybaines]

If you do need any boring/honing give Steve at piston broke in Bristol a shout he is somewhat of a legend on all things like this and will do a good deal. For an example one of my bikes I creamed in he bored out and supplied all parts need for less than half the price I could of got from the dealers due to his infinate knowledge of workable strokes and sizes. The man can save the unsaveable

[scorpa3]

If you do need any boring/honing give Steve at piston broke in Bristol a shout he is somewhat of a legend on all things like this and will do a good deal. For an example one of my bikes I creamed in he bored out and supplied all parts need for less than half the price I could of got from the dealers due to his infinate knowledge of workable strokes and sizes. The man can save the unsaveable

Cheers Barry, do you have any contact details which you can pm me?

[betapete]

if you pay postage ill do it for free for you, im a 2 and 4 stroke engine builder by trade and have all equipment in my garage lol, only takes 10-15 mins

[copemech]

if you pay postage ill do it for free for you, im a 2 and 4 stroke engine builder by trade and have all equipment in my garage lol, only takes 10-15 mins

Pete, what do you use on the nikasil ? A ball hone or a straight one?

[scorpa3]

if you pay postage ill do it for free for you, im a 2 and 4 stroke engine builder by trade and have all equipment in my garage lol, only takes 10-15 mins

Thanks for the offer, I'll give you a shout if I can't get it done locally.

Will the standard size rings still fit ok after it has been honed?

[gjbiker]

Without trying to upset the engineers amongst us I'll tell you what I do at home. Remember, I'm not an expert and honing a bore properly is best left to the experts, especially when the bores are coated. Nikasil is pretty tough stuff and can withstand a quick honing (30 seconds) but if you're unsure then give the barrel to someone you can claim compensation from !!!

I use a triple stone straight flexible hone that can be bought relatively cheaply from most automotive tool shops. (Ensure the stones are of a suitable length to bridge the ports when doing 2 strokes). I believe either ball or straight hones can be used with Nikasil (Correct me if I'm wrong Cope).

I use WD40 as a lubricant ( there are many abrasives of differing grades when the pro's do it, I use the abrasive quality of the stones - fine grade, plenty lube).

Using a battery drill at a moderate speed and plenty WD40 I run the hone up and down the bore trying to create a 45 degree cross hatching pattern. (This pattern distributes the engines lubrication effectively)

10 seconds is normally more than adequate for a de-glaze and produces a nice bed for the new rings. If you have deep scores i.e more than a scuff mark then you need to get the experts to do it (aggressive honing or re-bore, oversize pistons etc).

The standard rings should be ok but if there's been a lot of oil burning or compression loss its always best to check the bore diameter with the manufacturers tolerances.

Anyhooz, like I said, this is what I do and I've got away with it so far. I'm just a grippy Scotsman who likes to do as much as I can myself. (That said, I have had some expert tuition over my 30+ years spannering) If your unsure, leave it to the pros.

GJ

[betapete]

Pete, what do you use on the nikasil ? A ball hone or a straight one?

specialy made ball hone for my delapena leaves lovely finish and doesnt knock the ****e out of my machine, although my best frond who has a plating business normally does them for me, i dont like honing after prolonged use of the cylinder as for blade hones in drils, forget it, and wd40 doesnt stop tearing, always try and use proper honing oil, or the oil the engine normally runs in, if using ball hone on drill. my delapena uses proper coolant

Edited January 26, 2008 by betapete

[copemech]

Without trying to upset the engineers amongst us I'll tell you what I do at home. Remember, I'm not an expert and honing a bore properly is best left to the experts, especially when the bores are coated. Nikasil is pretty tough stuff and can withstand a quick honing (30 seconds) but if you're unsure then give the barrel to someone you can claim compensation from !!!

I use a triple stone straight flexible hone that can be bought relatively cheaply from most automotive tool shops. (Ensure the stones are of a suitable length to bridge the ports when doing 2 strokes). I believe either ball or straight hones can be used with Nikasil (Correct me if I'm wrong Cope).

I use WD40 as a lubricant ( there are many abrasives of differing grades when the pro's do it, I use the abrasive quality of the stones - fine grade, plenty lube).

Using a battery drill at a moderate speed and plenty WD40 I run the hone up and down the bore trying to create a 45 degree cross hatching pattern. (This pattern distributes the engines lubrication effectively)

10 seconds is normally more than adequate for a de-glaze and produces a nice bed for the new rings. If you have deep scores i.e more than a scuff mark then you need to get the experts to do it (aggressive honing or re-bore, oversize pistons etc).

The standard rings should be ok but if there's been a lot of oil burning or compression loss its always best to check the bore diameter with the manufacturers tolerances.

Anyhooz, like I said, this is what I do and I've got away with it so far. I'm just a grippy Scotsman who likes to do as much as I can myself. (That said, I have had some expert tuition over my 30+ years spannering) If your unsure, leave it to the pros.

GJ

You see there, it takes a diploma and balls ! Simple!

[betapete]

You see there, it takes a diploma and balls ! Simple!

[gjbiker]

Mmmmmmm

[betapete]

Mmmmmmm

[gjbiker]

No offence taken Pete. Like I said, broad shoulders

As for the difference between honing and glaze busting I'm fully aware of the difference, it's purely the fact the tool used for said glaze busting is called a hone. Perhaps I took Scorpa3 out of context but by the way he described the condition of the bore. My apologies if he meant honing to a degree of an oversize (after a re-bore obviously), I just assumed he wanted to get rid of some faint marking which is easily achieved using a

[copemech]

No p*** taking intended GJ, think that was more of a "oh REALLY!" comment towards Pete.

You see, it is a very specilized process for those in the trade. Untill you have examined some of this stuff under an electron microscope, you may not quite realize exactly wot hoes on here, thd the pro's do not want to be the ones paying for the damages if something does not work out!

Several decades ago, I too was in the motorcycle trade, and we had an old Itialian boreing bar in the shop. As there were no digital instruments at that time, no less CNC gear, a proper rebore of a steel 2T hole could be a bit of a challenge and depended much upon how good you are at measure and fit! We would cut the hole, finish fit with the straight hone, then put the cross hatch in with the balls, chamfer the ports by hand. All takes a bit of skill, but that was how it was done, down to .01 mm or so.

I have no idea what you can do with the nikasil and the newer bikes, but with fitted pistons you should likely be able to make some things work.

As I am nothing better than a builder anylonger, I let the machinists do their thing and I do mine. If it does not work out, I send the bits back and they pay the labor!

A 4T can be a different animal as far as oil control goes. I can tell you horror stories with re-chromed bores used in aircraft engines. God, I hate them things, would prefer to see a oversized steel cylender any day, even with a ****ty hone job! But I just stick with the cars by trade nowdays. These things can really screw with you as well. And much of this you cannot actually see with the naked eye!

So yes, I can get by with murder on my own little experiment! It could well cost me if I did it for hire! If your's is screwed up, you are likely to get a new one! Botch your own, or it might just work? Best thing I can tell the novices is to remove aluminum transfre with muratic acid diluted about 50/50 with water, and polish score marks a bit using 320 grit crocus cloth and oil following the natural crosshatch. If your problem is bigger than that, you should consider sending it off to a specialist!

Hope that helps!

[scorpa3]

Thanks everyone for the advice. It just goes to show what difference there is between mechanics and engine builders.

I too served a full apprenticeship as a mechanic and worked for almost 20 years in that trade and still work in an engineering environment but never as an engine builder. I would go 12 months or more and not see a crank shaft, it's often not economical to carrry out more than top end overhauls. That's the throw away culture we now live in. "Mains gone? Change the engine!"

You are quite right, upon inspection, sadly deglazing or even honing won't help unless it is taken out to the next size up and replated, so a cheap fix isn't on the cards.

Looks like he will have to bite the bulet and get a 440 big bore kit.

Thanks again everyone.