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How do you file edges of ports on barrels?

Posted: Sat Jul 22, 2017 12:55 pm
by sportston
Could anyone tell me how to file the edges of ports on freshly re-bored barrels please? I know it should be done to avoid premature ring wear but am wondering how to do it without damaging the bores. With what tools?

Re: How do you file edges of ports on barrels?

Posted: Sat Jul 22, 2017 2:43 pm
by Zunspec4
Hi sportston,

Me again, nearly everyone else must be on their holidays :lol: .

I use a set of needle files but I have also done it using 180 grade wet'an dry. You don't need to remove masses of material, simply gently round off the sharp edges of the port. Think very small radius and not much more.

Cheers Geoff

Re: How do you file edges of ports on barrels?

Posted: Sat Jul 22, 2017 3:41 pm
by sportston
Ok thanks again Geoff. Where would I be without you?!

Re: How do you file edges of ports on barrels?

Posted: Tue Jul 25, 2017 6:30 am
by Craig380
Coming late to this, but I would recommend using jeweller's polishing stones, which you can get from hobby shops or pound shops. All you want to do is take the sharp edge off the port, like Zunspec said. Don't forget to do the sides of the port as well as the top & bottom.

These are the type, just do it by hand using the least coarse stone. The 'cylinder' type works best as you can make a chamfer then smooth it round.

Image

Re: How do you file edges of ports on barrels?

Posted: Tue Jul 25, 2017 6:37 am
by Zunspec4
+1 on Craig380's advice. Although when he says "do it by hand" that is without putting it in the drill I believe.

Cheers Geoff

Re: How do you file edges of ports on barrels?

Posted: Tue Aug 01, 2017 12:06 pm
by kb75ts250
The correct chamfer sizes will be in your service manual. I always used a dremmel tool with little stones like above or better yet solid carbide 1/8" burs http://www.gesswein.com/p-3094-solid-ca ... shank.aspx. Are you sure the shop that did the bore job didn't chamfer the ports?

Re: How do you file edges of ports on barrels?

Posted: Wed Aug 02, 2017 12:39 pm
by sportston
I automatically thought that they would have, but on inspection....nope.

Re: How do you file edges of ports on barrels?

Posted: Wed Aug 02, 2017 2:54 pm
by kb75ts250
Good job checking that out before just putting it together. You saved yourself from a disaster. Pretty unimpressive workmanship by the shop.
If you cant find the details in your manual just chamfer them at a shallow angle (about 15 degrees) to a distance of about .020 - .040" up and down from the top and bottom of the port edges. The sides of the ports just need the sharp edges removed. Be sure you also check your ring end gap and clean and oil everything real good before re-assembly.

Re: How do you file edges of ports on barrels?

Posted: Thu Aug 03, 2017 2:34 am
by sportston
unfortunately didn't notice until after reassembly. So already got a couple of scratches on the teflon coating but at least I spotted it before I ran the engine. The minor scratches are not the end of the world. Have disassembled it again and will rebuild after getting crank back from Chris Applebee.
Thanks for the advice guys