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post #1 of (permalink) Old 03-04-2008, 06:52 AM Thread Starter
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cylinder cross hatch

I've got an engine (running 351W) i'm trying to determine the condition of. I know it's leaking past some of the valves and that will need to be addressed. the cylinder walls have a small ridge ( i think it's small... about the thickness of a paper ). I also noticed if I look real hard I can see some of the cross hatch. Is this a good sign or would even a badly worn cylinder show this. Does this really tell me anything about the condition of the cylinder and or rings?
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post #2 of (permalink) Old 03-04-2008, 07:13 AM
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I've seen cross hatch on engine with ove 150,000 miles on the engine... and the engine was shot. There's only one way to tell.... get out your instrumens and mic the cylinders for taper and wear. Then have them bored and honed to oversize spec. Once you do that... then start on the pistions and rings.
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post #3 of (permalink) Old 03-04-2008, 07:17 AM
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I don't think examination of the cylinder will give you any reliable information about the state of the rings, pistons and cylinders. You should have done a compression check, with and without oil added, before disassembling the engine.

My guess is that it's OK, since the wear you describe seems fairly light, but the only way to know for sure is to put is back together and run a compression check.

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post #4 of (permalink) Old 03-04-2008, 09:29 AM
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Compression test.... That will tell you the condition of the compression chamber

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post #5 of (permalink) Old 03-04-2008, 07:30 PM
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motor test

yes need compression test but remember unless the test shows the pressure to be real low the main thing is the difference between cyl in other words it is more important to not have a large difference in compression from one cyl to another than it is to have all of them a little low.. if one is more than 20 lbs low you could have a broken ring or something got loose in the motor and has done damage.... best thing to do if you dont wantto put it all back together is just to have a good shop do the rebore of the block and depending on how much they have to do.. go to oversized pistons have the crank checked all new bearings of course and a new cam/// from there it is up t o you
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post #6 of (permalink) Old 03-04-2008, 08:08 PM Thread Starter
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you've answered my question Leve

I did check compression. around 120 in all cyls. except one was around 90. with a cap full of oil to each cyl. they all jumped to around 145 and the lowest cyl.(90) ended up being the highest...around 150. either way you answered my question... a wore out cylinder can still have crosshatch showing.
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post #7 of (permalink) Old 03-04-2008, 11:15 PM
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Think about it - crosshatch is just scratches on the surface. That shows the walls hardly wore. If there aren't any patches where the original crosshatch was missing - then the walls are almost like they were when it was assembled last time.
But - that only happens when the rings weren't seated properly. If they were seated the scratches would be gone.

You said there's very little ridge - again showing minimal wear.

Look real close for places where the crosshatch is gone - there's the wear points. Measure the roundness and taper to make sure it's right.

You may be able to just glaze bust the cylinders with a hone and use cast iron rings - and save quite a bit of money.

The problem may have been someone used chrome rings but did not break them in right - a fairly common problem.
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