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piston cylinder wall scuff wear pattern

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Old 06-25-2007, 03:04 PM
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Car: 1991 S10 pickup 2700lbs
Engine: 4.3L Z TBI
Transmission: 700R4
Axle/Gears: 3.08 7.625"
piston cylinder wall scuff wear pattern

disassembled the 85 LG4 engine today down to a bare block, it has 196k miles on it

some of the cylinders have a pretty wide piston scuff wear pattern across the inside and outside of the bores(across-ways)

some of the piston pins are tight and some are not

worn pins would cause accelerated wall wear like this correct ?

just wondering

this engine is funny cuz damn it still has the factory steel shim head gaskets although pretty rotted,
and it has the original GM nylon teeth cam timing gear
and GM oil pump
and all the bearings are still silver but are GM stamped and some are really badly scratched/gouged)

surprised the hell out of me

i call that pretty damn good for an old tired LG4

it still ran but smoked a good amount of blue smoke

its all going to the machine shop tomorrow probably

one hell of a dirty tired carboned up engine

ive seen worse(mostly due to bearings still being silver) but not alot worse lol



thanks
Old 06-25-2007, 10:05 PM
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Car: 1982 Trans-Am
Engine: 355 w/ ported 416s
Transmission: T10, hurst shifter
Axle/Gears: 10 bolt, true-trac, 3.73
Re: piston cylinder wall scuff wear pattern

I imagine the loose pins are somewhat related to the bore pattern, i'm having a tough time visualizing how, but if they match up in your engine (ie bore with most wear has loosest pin) then...

Doesn't really matter now though eh?

I can't pass shame onto you about rebuilding a 305 (haha ) at least tell me you're not going to rebuild it with all stock type parts right?
Old 06-26-2007, 07:22 AM
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Re: piston cylinder wall scuff wear pattern

I wouldn't worry about it... it's all going in the trash anyway. Pistons & block especially. Since no one in his right mind would spend $2000 rebuilding a 305 when $50 more would get a 350, and NO DOUBT you're in you're right mind, none of the parts in question will ever see the light of day again; and so that 305's death mode at 200k miles hardly matters any more.
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