low mileage 5.3 needs 2 pistons/rings - Need proper ring installation tips
11-02-2012, 06:34 PM
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low mileage 5.3 needs 2 pistons/rings - Need proper ring installation tips My 36K mile 2005 5.3 cracked 2 ringlands on #3 and #5 pistons (turbo motor). I got 2 VERY low mileage (3K) take out pistons in great shape and 2 brand new GM 5.3 ring sets. Motor is all apart and I'm ready to get it back together. I need some of you who have experience to give me the correct way to properly install the new pistons and rings. Bores checked out at factory spec, so I should be good in that area.
My main concern is the rings. Do new GM rings need to be file fit to the bore, or should they be good to go? And does anyone know what the spec is supposed to be for the ring gap?
Also, I have heard a lot of conflicting info on whether a cylinder hone/deglazing is needed on a low mileage engine. Cross hatching is still perfectly visible, and apparently GM had a TSB that stated for techs to replace the rings without honing on vehicles that had excessive oil consumption. I would have no problem running a hone through, but the engine is still in the car and I have heard it's a bad idea for the debris it slings around. Just trying to get this done as "right" as I can with the engine still being in the car.
My main concern is the rings. Do new GM rings need to be file fit to the bore, or should they be good to go? And does anyone know what the spec is supposed to be for the ring gap?
Also, I have heard a lot of conflicting info on whether a cylinder hone/deglazing is needed on a low mileage engine. Cross hatching is still perfectly visible, and apparently GM had a TSB that stated for techs to replace the rings without honing on vehicles that had excessive oil consumption. I would have no problem running a hone through, but the engine is still in the car and I have heard it's a bad idea for the debris it slings around. Just trying to get this done as "right" as I can with the engine still being in the car.
11-02-2012, 07:43 PM
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Nightmare where did you get your ring sets? I need one myself.
Also if you arnt sure if they need to be file fit or not, place one into the bore and use a piston to push it down about the length of the piston, use a feeler gauge and find out what the gap is.. probably around .020 if its pre gapped, if the ends butt then you need to file fit them.
Im not plannin too hone mine, after reading the TSB. I can post a copy of the TSB if you like.
Also if you arnt sure if they need to be file fit or not, place one into the bore and use a piston to push it down about the length of the piston, use a feeler gauge and find out what the gap is.. probably around .020 if its pre gapped, if the ends butt then you need to file fit them.
Im not plannin too hone mine, after reading the TSB. I can post a copy of the TSB if you like.
11-02-2012, 08:27 PM
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Nightmare where did you get your ring sets? I need one myself.
Also if you arnt sure if they need to be file fit or not, place one into the bore and use a piston to push it down about the length of the piston, use a feeler gauge and find out what the gap is.. probably around .020 if its pre gapped, if the ends butt then you need to file fit them.
Im not plannin too hone mine, after reading the TSB. I can post a copy of the TSB if you like.
Also if you arnt sure if they need to be file fit or not, place one into the bore and use a piston to push it down about the length of the piston, use a feeler gauge and find out what the gap is.. probably around .020 if its pre gapped, if the ends butt then you need to file fit them.
Im not plannin too hone mine, after reading the TSB. I can post a copy of the TSB if you like.
And yes, please post a copy of the TSB if you could. Curious to read it!
Thanks for the replies so far!
11-02-2012, 10:18 PM
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Subject:
Higher Than Expected Oil Consumption
(Replace Rings and Engine Valley Cover)
Models:
1999-2001 Chevrolet Camaro
1999-2002 Chevrolet Corvette
1999-2001 Pontiac Firebird
with 5.7L Engine (VINs G, S - RPOs LS1, LS6)
This bulletin is being revised to add model years for the Corvette, information on the LS6 engine and parts information Please discard Corporate Bulletin Number 01-06-01-023 (Section 06 - Engine/Propulsion System).
Condition
Some owners may comment on higher than expected oil consumption. When checked, the oil consumption could be in the range of 400-600 miles per quart (700-1000 km/L).
On the LS6 engine only, the technician may find oil behind the engine throttle plate and in the intake manifold.
Cause
The cause for this condition may be an interaction between the piston rings and the cylinder bore in vehicles that are operated at higher RPMs - typically manual transmission vehicles driven in a manner where the engine is frequently or consistently operating at greater than 3200 RPM.
On the LS6 engine only, the engine has a unique aluminum valley cover that has composite oil separating baffles and PCV plumbing incorporated. In some cases, the PCV baffle may not be properly sealed to the valley cover, causing oil to enter the PCV system.
Correction
On the LS6 engine only, replace the engine valley cover if oil is found behind the throttle body or in the intake manifold before replacing the piston ring. Refer to Engine Valley Cover Replacement in the Engine Mechanical - 5.7L subsection of the Corvette Service Manual.
A new set of piston rings is currently available through GMSPO. The new rings are part of a complete piston ring kit. Install only the number 2 compression ring and the oil expander ring from the piston ring kit. All other rings in the piston ring kit should be discarded. The original number 1 compression ring and the oil ring rails should be re-used in their original positions on the piston. All pistons should be used in the same cylinder bore.
Important:
Do not dress or hone the cylinder bore. Nothing should be done to change the bore finish for this condition. Changing the bore finish may aggravate the condition.
Refer to the Unit Repair Manual for appropriate ring removal and replacement procedure.
The number 1 compression ring and the upper and lower oil expander rails are re-used because they are already broken in for the bore that they are in. The new number 2 compression ring is made with a very sharp edge that will break in quickly.
Changing only the piston rings noted, with no change in driving style, should change oil consumption to an acceptable level. Changes in driving style that reduce the amount of time spent at higher RPMs will also positively affect oil consumption.
In addition to the standard size piston ring kit listed below, a 0.25 mm oversized piston ring kit is available. The oversized piston ring kit should only be used in those rare instances where the cylinder bore size has been machined larger to accommodate the 0.25 mm oversized piston rings.
Higher Than Expected Oil Consumption
(Replace Rings and Engine Valley Cover)
Models:
1999-2001 Chevrolet Camaro
1999-2002 Chevrolet Corvette
1999-2001 Pontiac Firebird
with 5.7L Engine (VINs G, S - RPOs LS1, LS6)
This bulletin is being revised to add model years for the Corvette, information on the LS6 engine and parts information Please discard Corporate Bulletin Number 01-06-01-023 (Section 06 - Engine/Propulsion System).
Condition
Some owners may comment on higher than expected oil consumption. When checked, the oil consumption could be in the range of 400-600 miles per quart (700-1000 km/L).
On the LS6 engine only, the technician may find oil behind the engine throttle plate and in the intake manifold.
Cause
The cause for this condition may be an interaction between the piston rings and the cylinder bore in vehicles that are operated at higher RPMs - typically manual transmission vehicles driven in a manner where the engine is frequently or consistently operating at greater than 3200 RPM.
On the LS6 engine only, the engine has a unique aluminum valley cover that has composite oil separating baffles and PCV plumbing incorporated. In some cases, the PCV baffle may not be properly sealed to the valley cover, causing oil to enter the PCV system.
Correction
On the LS6 engine only, replace the engine valley cover if oil is found behind the throttle body or in the intake manifold before replacing the piston ring. Refer to Engine Valley Cover Replacement in the Engine Mechanical - 5.7L subsection of the Corvette Service Manual.
A new set of piston rings is currently available through GMSPO. The new rings are part of a complete piston ring kit. Install only the number 2 compression ring and the oil expander ring from the piston ring kit. All other rings in the piston ring kit should be discarded. The original number 1 compression ring and the oil ring rails should be re-used in their original positions on the piston. All pistons should be used in the same cylinder bore.
Important:
Do not dress or hone the cylinder bore. Nothing should be done to change the bore finish for this condition. Changing the bore finish may aggravate the condition.
Refer to the Unit Repair Manual for appropriate ring removal and replacement procedure.
The number 1 compression ring and the upper and lower oil expander rails are re-used because they are already broken in for the bore that they are in. The new number 2 compression ring is made with a very sharp edge that will break in quickly.
Changing only the piston rings noted, with no change in driving style, should change oil consumption to an acceptable level. Changes in driving style that reduce the amount of time spent at higher RPMs will also positively affect oil consumption.
In addition to the standard size piston ring kit listed below, a 0.25 mm oversized piston ring kit is available. The oversized piston ring kit should only be used in those rare instances where the cylinder bore size has been machined larger to accommodate the 0.25 mm oversized piston rings.
11-02-2012, 10:24 PM
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Wow, im glad i came across this one, probably going to be useful for you as well!
Models
A new connecting rod bolt torque specification was introduced to the GEN III and GEN IV Vortec(TM) small block V8 engines. The connecting rod bolts should continue to be tightened using two passes. The second pass value has been increased from 75 degrees to 85 degrees.
Install the connecting rod bolts and tighten. Refer to Piston, Connecting Rod, and Bearing Installation in SI.
Tighten
Tighten the connecting rod bolts a first pass to 20 N.m (15 lb ft).
Tighten the connecting rod bolts a final pass to 85 degrees using the J 45059 Angle Meter.
Models
A new connecting rod bolt torque specification was introduced to the GEN III and GEN IV Vortec(TM) small block V8 engines. The connecting rod bolts should continue to be tightened using two passes. The second pass value has been increased from 75 degrees to 85 degrees.
Install the connecting rod bolts and tighten. Refer to Piston, Connecting Rod, and Bearing Installation in SI.
Tighten
Tighten the connecting rod bolts a first pass to 20 N.m (15 lb ft).
Tighten the connecting rod bolts a final pass to 85 degrees using the J 45059 Angle Meter.
11-03-2012, 02:05 AM
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Thanks a lot for posting that! As far as the rod bolt torque specs, I installed the pistons and rings in the motor tonight. Used a torque wrench and got them to 15 lbs ft first and then did the 85* after that. Motor spins over nice. Hopefully will have it ready to fire towards the end of this weekend. I can post back with the results of the fix.
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11-03-2012, 11:46 AM
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Well, as an update...got the rods, pistons, and rings into the block last night. My new GM rings DID NOT need to be gapped at all. Not sure if this will hold true for everybody, but they checked out to be exactly what the old ones were.
For anybody that wants to know the factory ring gaps, I got .015 thou for the stock upper compression ring, and .023 thou for the 2nd ring. Bit tight for a turbo motor, but I'm not changing the other 6 so it's staying at that.
I'll update more when I get it buttoned up a bit more.
For anybody that wants to know the factory ring gaps, I got .015 thou for the stock upper compression ring, and .023 thou for the 2nd ring. Bit tight for a turbo motor, but I'm not changing the other 6 so it's staying at that.
I'll update more when I get it buttoned up a bit more.
11-06-2012, 07:32 PM
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As a follow up, motor runs now! Put 2 take out 5.3 pistons in with new GM rings, checked the ring gap compared to stock, and got it all back together. Put in fresh oil and antifreeze and it fired right up. Let it get to temp while holding the RPM's at various levels, and then took it for a spin. Broke in the rings by running it up to 3500-4500 RPM in gear and then letting off the gas and having the motor come down on it's own without touching the brakes. Did this for a few miles at varying RPM's and then gave it a few rips. Runs perfect with no noise, smoke, or anything. Thanks to all the guys that replied and gave me tips on the job!! 
