Could anyone give me some guidance, I am about to re ring my two stroke engine,it has an iron bore and rings, most people say the bore should be de glazed but i found this article which suggests that its the worst thing you can do CLICK HERE

Edited January 9, 201115 yr by Andy.T

Hi

I would always hone a barrel first it shows me the high spot and whether I do a rebore. I use a Delapena hone and not one of those cheap glaze busters. As well as the high spots it will show how worn the barrel is at the top. If ther is a slight ridge it needs reboring. Hope this helps

Jack

Hi

I would always hone a barrel first it shows me the high spot and whether I do a rebore. I use a Delapena hone and not one of those cheap glaze busters. As well as the high spots it will show how worn the barrel is at the top. If ther is a slight ridge it needs reboring. Hope this helps

Jack

Thanks for that info, I will say the bore looks fine,It hasn't seen much use since it was rebuilt, I was just going to fit new rings as piece of mind and noticed as you would expect the bore is shiny where the rings have been.It was just that article which I found that suggests it was a bad thing to Hone and it got me thinking.

To cut a long story short, things have moved on a bit since the 1930's to 1980's when bores werent always round, rings were cast iron, pistons were softer and most importantly oils left significant deposits on bores and cylinder heads.

The one point that isnt considered in the SAE article is speed of break in in competition engines(achieving a good compression quickly). Its important for a trials bike to seal well at low RPM, so quickly matching the ring shape to the barrel is very important. The article is based on road based applications where longetivity of components / performance is the main consideration.

A hone will provide a surface that will initialy wear components faster but will provide the seal within a much shorter time. This is why many manufacturers reccomend non synthetic oils during the first ??? thousand miles as they actually provide some controlled initial wear to get the seal established.

However, i'm tempted to say that you are probably worrying unnecesarily (get it honed). There would be far more wear caused by too rich a mixture or by dirt getting past your air filter. Getting the basics right is more important.

Personaly i would be more concerned with the correct piston to bore clearance, port chamfering, ring gap and squish clearance.

Dom

Edited January 9, 201115 yr by dombush

good honing is essential, it creates cris-cross scores and where each line crosses oil collects and is a good thing

just be careful glaze busting as you can remove quite a bit if you do it too long, enough to create scores

just my 2p worth tony

give the barrel a clean with some emery cloth and oil , and it saves you paying someone to hone it.

Ive always used 2000 grit wet and dry paper with plenty of 3 in 1 oil to lubricate it.

Yep I did my 247 a few months ago with wet and dry and fine oil - just enough to take the shine off the barrel. It is still going very nicely.

The bloke that wrote that article has never seen a diesel running on light load.I'm going to carry on honing bores when I do a freshen up or re-ring.I could give loads of examples but I cant be bothered.I've also been given advice by learned people from the intstitute of welders about repairing aluminium cylinder heads - most of it was total crap.

I sometimes wonder if they feed us minions rubbish to trip us up ?

Interesting article.

One thing I know for sure is hat when I was building a lot of Harley engines (and LOTS of top ends) I was having to rough up the cylinders a little extra just to get the rings to seat...probably because oil is so good these days.

I had several top ends bounce because they wouldn't stop smoking.

A little extra rough with the ball hone and no assembly oil in the cylinder and the rings broke right in.