Using the bore gauges to take the measurement is not actually that accurate, purely becuase the act of tightening them influences the dimension you get. What I would recommend is use your micrometer to set the bore guage to a certain measurement, say 82.53mm to start. Lock the bore gauge and check the dimension again. Then drop the bore gauge into the bore at an angle and holding the long handle rock it about the vertical position. If the gauge can't rock because it is restricted by the diameter of teh bore, you know the bore is less than the set dimension. If the guage is not restricted during rocking your bore is bigger. If it 'just' scuffs a little, then you are bang on, but measure the bore guage once more when you remove it as you could have influenced the dimension. I found this a more accurate method. Hope it helps.
Oh, I got one of those cheap honing tools with the 3 stones, sprayed some WD40 in the bores and cleaned it our to get rid of any carbon build up at the top as this where you are likely to see the most wear. Mine was right on top limit as you'll read in the thread link above.
Yes, 10mm from top surface of block which will be about 5mm down from top ring mark. Measure in line with crank and at 90 degrees to crank. I measured at mid point and lowest point as well, but if your in spec at the top, then you are probably fine. Mine was all in spec at the points where we are advised to take the measurement, but yje top ring position was heavily worn to top spec. It would have probably been fine, but as I was spending a chunk of money, I elected to get a better block. Hope its ok for you as the re-bore is cheap, pistons are not!
These aren't the best tools for novices. A flexhone is a much better way to deglaze the bores and add in a crosshatch pattern. http://www.clubgti.com/showthread.p...-LSD&p=1710084&highlight=Flexhone#post1710084
I agree with above. The 3 stones version are rubbish for proper honing, but OK for a quick clean of the bore. I sent mine off to be honed properly once I'd finished messing about with it. A flex hone will set you back about 60 quid though. May as well just get it done professionally as I think I paid 40 quid. Make sure you take the oil squirters out first
I would think that block is fine Dan bore-wise as I spent a while checking it. Just scuff up the bores fit new rings and fit it. Brian,
Technically speaking if you really wanted to get serious the bore should be measured with a torque plate attached to get the most accurate results but honestly, I think the block is fine, as said, rough up the bores and run with it. Ive been over it with the gauges and you can hardly feel the lip at top either with a finger nail - dare I say there is no lip. Brian,
Looking at those results, I'd assume you are probably reading about 0.02-0.03mm undersize as std bores are 82.51mm. Still looks really good to me based on my recent experiences. What concerned me with my block was the section between 5mm and 10mm from top of block at 90 degrees to crank. Mine was 82.59mm ish at 5mm, but well in spec at the 10mm point. Most people agreed it would be fine and I was about to build it, but a replacement fell into my lap at the right moment. 4 thou, or 0.08mm wear is VW limit, but this will be a conservative manufacturers limit. In real life it will work beyond this spec, but how far beyond is unknown. I'm sure Brian is spot on with the check of the block and I would have no reason to doubt him. However, if i were about to spend a bunch of cash building an engine, i'd want a few other opinions too. This is not distrust of Brian, just dubz finding his feet with something he hasn't done before. Every days a 'school day'! If it's not, what's the point?
lol, mine had a lip at the top that you could feel with your fingernail, ive seen worse be rebuilt and have been fine so i just took it to my local shop for a honing, after the honing you could still see a small area at the top of the bore where the honing had missed just below the lip. i rebuilt this block with stock internals, new rings and bearings, there was a small amount of movement in the pistons at TDC but again, ive seen a lot worse. this engine is now in my car, i barely gave it a chance to run in, it has had 7000 miles of absolute abuse now and is still going very strong and uses minimal amount of oil considering how hard it gets driven. we will see how its running as its going on garage streamlines dyno next month. by the sound of it, your block is better than mine was...
here we are read post 29 and 32, its not really saying theyre no good but there is some advice in there http://www.clubgti.com/showthread.php?216851-ABF-stripped-need-technical-advice-with-pics/page2&highlight=abf+pistons
Really hard to tell from the pics, but as you are buying new bearings, may as well get -.25mm ones and give the crank a regrind.
