09-18-2021, 01:41 PM | #1 |
Drives: 2010 Turbo LS3 Join Date: Dec 2009
Location: Palm Bay, FL
Posts: 2,734
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Do These Scratches Look Bad Enough to Kill Compression
When I was running at NCM the banjo bolt for the boost reference on the wastegate came loose and then I noticed I was getting blow by out of the oil filler cap/filter. I made sure the catch can was working and then did a compression check. 5&7 were at 120 while the rest were 180 to 200.
I pulled the head today and took some picks. I generally let the machine shop do the internals so I don't know if these scratches look bad enough to be the problem or if they are fairly normal. I can't feel them, but I guess if I could that would mean I needed to bore the cylinders. I'm hoping to have these honed and new rings put in.
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2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes.
2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes. |
09-18-2021, 04:16 PM | #2 |
Drives: 2011ss/rs camaro Join Date: Sep 2011
Location: florida
Posts: 1,261
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Are the scratches worse in the cylinders with lower compression?
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09-18-2021, 04:32 PM | #3 |
Drives: 2010 Turbo LS3 Join Date: Dec 2009
Location: Palm Bay, FL
Posts: 2,734
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The pics are of the cylinders with the worst compression.
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2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes.
2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes. |
09-18-2021, 06:18 PM | #4 |
Drives: 2010 Camaro SS LS3 Join Date: Dec 2007
Location: Manitoba,Canada
Posts: 47
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Probably cracked ring lands is your problem... need to pop those 2 pistons to verify.
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2010/2SS/LSA Conversion/ Stock Pulley/ ZL1 Fuel Pump and FPCM settings/ Tuned by ME!
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09-18-2021, 10:24 PM | #5 |
Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012
Location: Vance Alabama
Posts: 8,018
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Nope. Send it.
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Retired wanna be cylinder head porter
2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X |
09-19-2021, 03:47 AM | #6 |
Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020
Location: Austin, TX
Posts: 2,100
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I don't know how many miles you have on it but it looks like a lot. I did my cam at 153k and all my cylinders still had the crosshatches in them. By looking at yours I would think that your about ready for a rebuild. You might get away with a hone job yourself but I don't think a machine shop will do it for you because I think that they will want to bore it
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Build Thread https://www.camaro5.com/forums/showthread.php?t=609817 Last edited by morepowerjoe; 09-19-2021 at 04:12 AM. |
09-19-2021, 04:24 AM | #7 |
Drives: 2015 Summit White 2SS 1LE Join Date: Feb 2012
Location: Vance Alabama
Posts: 8,018
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One of my cylinders in my previous build after honing. I went full send on it. Ran great.
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Retired wanna be cylinder head porter
2015 2SS 1LE Clutch reservoir, Vararam DRX, ported TB, TSP 2" headers, MGW shifter Totalled: 2010 1SS Wilkes Performance/Eagle 416 shortblock, TSP custom valvetrain, PRC 260 heads, Edelbrock Pro Flo 102, th400 swap, 8" PTC 5500 stall= 535/435 at the wheels tuned Gen 3 Performance and Dyno 10.97 @ 124 full weight in 3100 DA CamaroFest X |
09-19-2021, 07:37 AM | #8 |
Drives: 2010 Turbo LS3 Join Date: Dec 2009
Location: Palm Bay, FL
Posts: 2,734
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Thanks everyone. The engine only has 28k and maybe 8k since forged piston and rod installation. It still sounded great before I pulled the head, but I felt like power was down a bit and puffs of smoke from the valve cover filter was something new, but no smoke out the exhaust.
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2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes.
2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes. |
09-20-2021, 10:06 AM | #9 |
Drives: 2010 Camaro SS2,L99, LSA SC Join Date: Aug 2017
Location: Huntsville, AL
Posts: 2,147
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Any signs of damage to the head gasket?
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09-20-2021, 12:03 PM | #10 |
Drives: 2010 Turbo LS3 Join Date: Dec 2009
Location: Palm Bay, FL
Posts: 2,734
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Nothing obvious. I was looking at the pictures I took and there appears to be a small black line between the cylinders. I'll have to go back out later today and confirm that is real.
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2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes.
2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes. |
09-20-2021, 05:17 PM | #11 |
Drives: 2014 Camaro SS 1Le Join Date: Feb 2016
Location: IL
Posts: 1,587
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09-20-2021, 05:55 PM | #12 |
Drives: 2014 Camaro 2SS Join Date: Feb 2015
Location: Metro Detroit
Posts: 492
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Looks to me the pistons are expanding too much from heat in the bore. Which causes the skirts to scuff the cylinder walls. The deeper looking, long one is either debris or a ring end gap starting to butt, or a folded over oil ring. Piston cooling jets would help if you dont have any.
Last edited by G8One2; 09-20-2021 at 06:38 PM. |
09-20-2021, 08:51 PM | #13 |
SomeguyK
Drives: 2010 Black 2SS/RS Join Date: Nov 2014
Location: FL
Posts: 1,947
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Full send.
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09-21-2021, 08:31 AM | #14 |
Drives: 2010 Turbo LS3 Join Date: Dec 2009
Location: Palm Bay, FL
Posts: 2,734
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The boost reference came off, so the waste gate did not open all day. Luckily, I had just switched to a copper T4 turbo gasket, which was attempting it's best to exit the heat at the turbo. I'm thinking that exhaust leak and the open boost line were the only things that kept boost from going off the charts. I have no idea how much boost it saw, but I'm thinking it faired pretty well.
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2010 SS - On3 kit with downpipe cutout, CTR 78/80, CompCam 239/251 620/632 122+4, E85, Z28 suspension and ZL1 diff with Outlaw axles. Gen6 ZL1/1LE brakes.
2011 Vert - 416/w 230/236 .612/.602 115lsa, 1LE suspension w/32mm rear bar. Z28 diff. ZL1 brakes. |
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