Thread: EEK Motor Back From Machine Shop To Find This!!

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ok so few weeks ago i got my 350 back from machine shop it had bottem end assy bearings/crank/rods/pistons/ bored .030 & deck shaved. so i got it back in my shop and covered/ wrapped in plastic untill i got my other parts.

Yesterday I put the oil pump/tray/pan/cam/timing gear/chain/cover/ balancer i then oiled the cyls as i was putting flywheel on and when turning it over i noticed on #3 a vertical mark on the outer wall so immediately looked at it grabbed my new lint free rag wiped cyc clean and my finger nail can catch it can even feel with finger.
I then looked at all other cylinders and noticed they all have a similar line in that spot??? but none of the others i can feel with my fingernail. Heres some pics. 12660453_668723026603006_1493302321_n.jpg12660307_668526559955986_32329557_n.jpg12660489_668526526622656_362761737_n (1).jpg12659828_668526546622654_759360206_n.jpg12674610_668526516622657_1508783283_n.jpg

Did you call the machine shop yet? Just wondering if its where they drug the boring bar out, anyway I would definetly do some more checking with more knowledables but to me if you can hang a fingernail its unaccepatable.

First thing that came to mind was a burr on a ring. Regardless, I think I'd be hauling it back down to the machine shop and ask them to explain what you're seeing. Anything you can feel is too much, seems to me.

I called owner is gone till monday talked to worker i said there's vertical line he said from bore gauge but then explained i can catch nail on it he said o it'll clean up on break in.
I can see by eye ( cam dint pick it up) the slight marks from the bore gauge those are nothing this on the other hand is a no no hell this motor had 150k befor it went to shop and it didn't have no vertical marks on it.
The shop is 50 miles from me but ill bring it if he ask. He can either fix it at no charge or just give me my money back and ill deal with it myself. I shouldn't have to fix there mistake after paying $1338.75

That black mark almost looks like that could be from a rod guide tool? That is weird that you can feel the mark and not a good deal.

Mark goes all the way to top of bore-happened when piston assembly was put into the cylinder. most likely from overlapping/improperly spaced oil rings or if a stroker motor needing a oil ring spacer across the wrist pin hole could be that. bevel at top of bore looks good but cross hatch lines look like it was honed with a hand drill?????hone pattern looks sporatic in every pic.

Does this shop have a Sunnen CK10 type hone or what do they use for bore/hone operations--------also did they balance the assembly????

"It will clean up on break in" is a bs answer. Someone screwed up, and they should fix it or refund your money.

The fact that the mark is there is troubling; the fact that you can feel it is alarming. That machine shop needs to get things right with you - no more BS.

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I'm just worried if they say ok we'll fix it that they don't hone out mark then slap pistons and rings back in say hell with the piston play and call it a day. As i don't have a bore gauge to check it after wards

When I enlarged the picture the edges on the scraped mark appear to be jagged (cross hatch appears to go through and over) and not caused by assembly error, perhaps the boring was not enough to remove previous scoring. It may be time to have another machine shop look at this. And, perhaps Pat will chime in with his expertise on this.

i'm not an engine builder . far from it . but why are there so many vertical scratches still present .

JMHO, the light vertical marks (not scratches) are caused by the rings at assembly, these marks are not too concerning to me (cleaning up the file marks at the ring gap ends will usually lessen these marks) and usually the break-in process takes care of these marks.
However, the score type scratch in the first picture is not normal to me, and maybe too deep for break-in to clean up. As I stated above, my concern is the jagged edges that a scrape usually doesn't cause. IMHO, this looks like a previous score that the boring didn't clean up. Years ago I encountered a similar problem, turned out the shop miss gauged the cylinder wear, ordered the pistons before boring and assembled hoping I wouldn't notice. Another shop fixed it, small claims court got my money back.

I've never had rings gouge my cylinders in the dozen or so engines that I have built. If the cylinders were grooved before the engine was bored, and the grooves were still visible after (the oversize was insufficient to remove the grooves) then the machine shop should have contacted you before assembly.

Good luck getting them to admit fault and offer a truthful explanation. The only marks you should see in the cylinders are crosshatching from the hone. (Period)

I now have also magnified the pic of the gouge and it appears that it was definately there before the honing-

also as I said before about the quality of the hone job--sucks even more after viewing it many times amplified.

You need a different block machined to fit your parts done by a shop that knows how, has the proper equipment, and knowledge/care about assembly------

Its these kind of shops that make it reasonable to go the crate engine route.

See the thing is when i tore this motor down Which it was all original. never used any oil or running issues. I looked at every cyl and there were no scratches or gouges like this on them. And i also thought if they seen this they should of contacted me befor assy cause i would of returned piston & rings and went .040 I brought it to this shop as its really the one around me that has newer machines clean work space and a professional look. I'm holding my tongue on saying anything bad about the owner as this could of been one of the workers.
This is the shop
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