bikecarbfred
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posted on 25/3/17 at 02:33 PM |
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CYlinder Wall Scratch
Abit cheesed off lads. I was honing the cylinders , all going really well and on the third cylinder I was unbalanced and slipped finger off the drill
trigger and ended up pulling the hone out right at the end when it was not turning.
Caused a very feint vertical scratch 1 inch. I honed 30 seconds more and smoothed it abit but you can just feel it with the nail.
When you run the palm of the finger you cannot feel it.
Only a small setup 1.4 litre, around 150bhp. I can't be overboring it as I have purchased the new rods n pistons.
The cross cross pattern is now etched pretty good on the cylinders.
I didn't fancing honing it abit more because it's a engine rebuild and the tollarences were quite tight although acceptable for a rebuild.
p.s I am not 100% sure if the scratch was there in the first place.
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snapper
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posted on 25/3/17 at 03:32 PM |
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Give it a good clean to remove all hone grit and look again
Take a photo and post
I honed/de-glazed at home a bore that had vertical groove, turned out ok compression was good when built up
In a sense if you can't rebore, your stuck with either taking a chance or going further with the hone.
If you build it up now and find you need to hone more it's just a set of rings
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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bikecarbfred
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posted on 25/3/17 at 03:53 PM |
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quote: Originally posted by snapper
Give it a good clean to remove all hone grit and look again
Take a photo and post
I honed/de-glazed at home a bore that had vertical groove, turned out ok compression was good when built up
In a sense if you can't rebore, your stuck with either taking a chance or going further with the hone.
If you build it up now and find you need to hone more it's just a set of rings
Hi snapper. Pictures here.
That's what I was thinking @ chancer & a new set of rings.
Light sand with some sandpaper???
[Edited on 25/3/17 by bikecarbfred]
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gremlin1234
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posted on 25/3/17 at 05:06 PM |
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the main scratch looks too straight to me to be caused by removing a tool by hand. I also noticed some other minor scratches parallel.
what was the reason for rebuilding then engine?
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bikecarbfred
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posted on 25/3/17 at 05:22 PM |
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quote: Originally posted by gremlin1234
the main scratch looks too straight to me to be caused by removing a tool by hand. I also noticed some other minor scratches parallel.
what was the reason for rebuilding then engine?
Yeah that's what I thought. Because the flexi-hone tool did come out easy enough and doubt it could have caused that. It could have been there
before.
I'm not actually rebuilding my own. I am building another from this engine that I bought from salvage company and the tolerances were pretty
good.
I can't see it effecting compression one bit but I am no expert in engine building. I wonder if I should just pick up some sand paper and smooth
it off. Must be 0.01 to 0.03mm. Or is worth just put the flexi-hone back in for 2-3 minutes or so and apply more pressure to the side of the scratch.?
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gremlin1234
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posted on 25/3/17 at 06:06 PM |
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can you run the honing tool 'anticlockwise' ?
also for sanding, what paper would you use? I am sure I have seen something saying don't use emery, unless the block is going to be washed
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bikecarbfred
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posted on 25/3/17 at 06:11 PM |
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quote: Originally posted by gremlin1234
can you run the honing tool 'anticlockwise' ?
also for sanding, what paper would you use? I am sure I have seen something saying don't use emery, unless the block is going to be washed
Anticlockwise yeah I can, why what would that do mate?
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rusty nuts
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posted on 25/3/17 at 06:51 PM |
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Many years ago , at least 45 I did a head gasket on a Fiat 600 . On removing the head I found all four cylinders had what looked like a vertical
groove machined in the bores , further investigation found all of the Pistons were missing one circlip and the gudgeon pin had scored a deep groove.
Other than the overheating caused by the head gasket failure the engine ran like a sewing machine so new circlip song, rings and big end bearings were
replaced with no ill effects. That scratch, although not ideal is unlikely to cause any problems. It may well have been cause by a broken ring?
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gremlin1234
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posted on 25/3/17 at 07:25 PM |
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quote: Anticlockwise yeah I can, why what would that do mate?
difficult to describe, but I shall try: it would reverse the leading and
trailing edges of the grove, so the edges would wear differently as it is honed.
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bikecarbfred
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posted on 25/3/17 at 07:54 PM |
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quote: Originally posted by gremlin1234
quote: Anticlockwise yeah I can, why what would that do mate?
difficult to describe, but I shall try: it would reverse the leading and
trailing edges of the grove, so the edges would wear differently as it is honed.
I think I know what you mean. It would like try and "smudge" it.
Also have you guys seen my honing lines. There are more like 25 degrees ish. I can't get 45. I was quick enough going up and down. Medium speed
on drill setting. But yeah I was purposly speeding the up and down cycle to get a more angle.
This block does not have any oil gallery for cylinder wall so is it better less angle in the pattern so it holds just that bit more oil for a longer
time.?
p.s the honing tool I use is the patent beaded flexi-hone from usa. Think around 220 grit but will have to check that.
Pretty good tool as it is not harsh.
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snapper
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posted on 25/3/17 at 08:30 PM |
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Perhaps drill rotation too quick, I used a variable speed drill on slow.
Scratch looks very mild, I would not worry.
Here is my at home cleaning tip...
Wash out with thinners and rags until rags do not show signs of dark stone and metal grains then use a cloths lint roller, you will be surprised how
much it will pick up, you will use several sheets per bore, I used two complete rolls for four bores.
You will get to a stage when the lint roller sheet is almost clean but persivere until the lint roller sheet sticks to the bore, remove it and give a
further wash with thinners.
Job done
I eat to survive
I drink to forget
I breath to pi55 my ex wife off (and now my ex partner)
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02GF74
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posted on 26/3/17 at 09:10 PM |
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that scratch is not going to make any noticeable difference.
honing is not correct - try running at much lower speed and move tool up and down; aim to get diamond type marks like here:
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bikecarbfred
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posted on 27/3/17 at 07:55 AM |
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I wonder if it's the WD40 because compared to my picture yours looks deeper scratch pattern. Mines super smooth.
Wonder if there should be less lubrication to get a deeper scratch. I'll try it at a lower speed.
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bikecarbfred
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posted on 1/4/17 at 12:31 PM |
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I managed to get a deeper angle lads. Thanks for the help. I reduced the speed on drill.
I put quite abit of WD40 so it looks alot smoother than the picture above which looks like a more abrasive scratches.
I don't feel like having a another go at it. lol
[Edited on 1/4/17 by bikecarbfred]
[Edited on 1/4/17 by bikecarbfred]
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bikecarbfred
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posted on 1/10/17 at 09:03 PM |
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Does the honing scratches have to be deepish i.e feel the scratch,
I used the 240 grit flexhone and have put the pattern in but they don't seem deep when compare d to some of the images on google where the
scratches seem so bright when you get a light on them.
I went up and down for about a 30 seconds or was it a minute lol on each one
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