While cleaning up a few things on my current project I found a very small crack on the bottom ring land of one piston. This motor has the non coated skirts and pressed in wrist pins. I have some spares but they are the ones that are coated.

1. Do you think one oddball piston would result in a major imbalance? Has anybody ever done this successfully?

2. Does anybody have a spare non coated piston and rod? Thanks!

 

Any way to weigh them? I would think you could make them match if the odd one was heavier...I always balance my own stuff then send a sample of each piece, the damper and the flexplate/flywheel to the balancer.

 

I thought about that I just need to find a scale or a machine shop that can weigh them.

 

I borrowed an electronic paint scale, , (now years later, I own it). I made my own rod weighing fixture.

 

I just called my local machine shop and they are gonna weigh it for me....Stay tuned!

 

Is your replacement piston a pressed pin or floating? If its coated and pressed pin it will work. It also makes it a 1 year only 2004 piston to be coated and non floating. Wont work if its a floating pin 2005 newer because there is a .002 difference in wrist pin diameter. Stupid GM had to make the damn wirst pin diameter just a tad different and screw up interchangeability!

 

Well, for anybody following along that might find themselves in this boat, I just had the two assemblies weighed and it was a 45 gram difference. This was with piston, rod with no cap or bearings and no rings. Oh well back to the hunt for one stupid piston.

 

I will have to confirm but im pretty sure I have a complete set of pistons and rods from a 2000 lq4. Message me if ya need some. I was gonna hold on to a couple but might let 1 or 2 go.

 

What kind of RPM are you turning. I wouldn't' worry about it personally. I ran 2 random coated pistons with my 6 uncoated. Ran great for a year, though I did blow it up eventually after a ton of abuse and highboost. (it went 8's in the quarter) Not sure what failed but I doubt it was related. Jy motor is a JY motor. Keep the revs reasonable, toss that sucker in and run it.

I just ball honed mine and tossed in the new assy.

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Don't you just love these things?!?!

 

Did your pistons show up today? If not hopefully tomorrow. Let me know.

 

Yep!! I really appreciate it too! I'll send you that package today and will keep you posted once I get it back together. Thanks again!

 

cool,i was hoping it would get out there before the weekend. Hope they work out and hope u have a place for the stickers. lol. I have been looking at injection systems and our turbos since I talked to you so I will keep you in the loop on my progress also.

 

Please do and I will do likewise

 

Got that package from ya today. Thanks!

 

Thank you!! Sorry for the delay but I ran out of stamps...lol. I have the long block back together now so I will be posting pictures soon.