engine rebuild tolerances
11-03-2003 | 08:26 AM
#1
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From: Heber Springs, AR
engine rebuild tolerances
There was a thread a few months back on "Winter Projects". Mine was a spare engine rebuild for fun and learning. Anyway, I measured the pistons and cylinder walls the other day. The block is clean and here are the measurements (.000 inch - my calipers)
#1 cyl 3.913, piston 3.909
#2 cyl 3.921, piston 3.908
#3 cyl 3.931, piston 3.908
#4 cyl 3.915, piston 3.909
I'm a bit concerned about #3 cylinder,,any comments? I'm traveling and not around my manuals so I don't have the tolerances. Is #3 at the limit, bore and re-treat the block to 1st oversize(pistons high$$), sleeve and JE pistons - how much $$ for that using 86 rods? TIA
#1 cyl 3.913, piston 3.909
#2 cyl 3.921, piston 3.908
#3 cyl 3.931, piston 3.908
#4 cyl 3.915, piston 3.909
I'm a bit concerned about #3 cylinder,,any comments? I'm traveling and not around my manuals so I don't have the tolerances. Is #3 at the limit, bore and re-treat the block to 1st oversize(pistons high$$), sleeve and JE pistons - how much $$ for that using 86 rods? TIA
11-03-2003 | 09:34 AM
#2
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Joined: Jun 2001
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From: The old country
Hi Bret,
And I quote..........
Cylinder/piston clearance wear limit: 0.060mm
Piston ring end clearance wear limit: Groove 1: 0.8mm
Groove 2: 0.8mm
Groove 3: 1.2mm
Cylinder bore out of round wear limit: 0.020mm
Cylinder bore 100.000mm to max 100.020mm (nominal 100.010+/-0.005mm)
Measure 65mm from upper edge of cylinder bore, transverse to clinder block.
Hope that helps!
And I quote..........
Cylinder/piston clearance wear limit: 0.060mm
Piston ring end clearance wear limit: Groove 1: 0.8mm
Groove 2: 0.8mm
Groove 3: 1.2mm
Cylinder bore out of round wear limit: 0.020mm
Cylinder bore 100.000mm to max 100.020mm (nominal 100.010+/-0.005mm)
Measure 65mm from upper edge of cylinder bore, transverse to clinder block.
Hope that helps!
11-03-2003 | 11:51 AM
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From: Heber Springs, AR
They were a combination of 4 measurements(average), two at the top and two at the bottom, as I don't have a gauge to measure the middle bore. But with the tolerances list by pikey7, #3 JUST gets by a very thin margin, .002. Hmmm,,,for just a spare and learning experience but right, I'll send it to the machine shop(recommended by serveral rennlisters, tried out by a friend - good work!). All other cylinder/piston(s) are good to go. If #3 is out of round or a slight angle, I'll cross that bridge when I come to it.
Rings - I have a set of new factory ones,,has anyone used Total Seal? Worth the extra cost? I've heard pro and con on them. Like I stated, this is just a winter fun project but I want to do it right, for me or in case some rennlister is in a bind. New mains, rod bearings, all seals and gaskets, head by Memphis Motorwerks, new water pump, oil pump cleaned..etc, presently disassembled.
Rings - I have a set of new factory ones,,has anyone used Total Seal? Worth the extra cost? I've heard pro and con on them. Like I stated, this is just a winter fun project but I want to do it right, for me or in case some rennlister is in a bind. New mains, rod bearings, all seals and gaskets, head by Memphis Motorwerks, new water pump, oil pump cleaned..etc, presently disassembled.
