Author Topic: Did Flint /' Tonawanda balance ALL engines prior to assembly, OR only HP engines  (Read 607 times)

69Z28-RS

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I'm having a discussion on another board regarding Chevrolet's 'balancing' procedures.   I'm nearly certain I've read that standard engine components were NOT balanced on an engine by engine basis in the factory; that only the high performance engines were balanced using the parts for that engine...  Did I read that here or was it somewhere else?  I'm looking for a reference and specific information...

Gary
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

bcmiller

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I would think that they would all be balanced, at least to a certain extent. But I donít know for sure...
Bryon / 1968 Camaro SS 396 coupe - now old school 468 big block
1967 RS/SS 396 coupe L35/M40 - 4 generation family project
Looking for 68 Camaro with body # NOR 181016

69Z28-RS

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What I remember is that when Chevy specified the parts (pistons, rods, etc), they specified the tolerances such that the basic (non high performance) engines could simply be assembled and know that they'd be OK with how the cars would be driven.   If you've disassembled a non-HP engine, you will generally not find any 'balance' marks, or numbers/stamps on the rod/piston assemblies (which generally indicates the engine assembly was balanced).   OTOH, if you have disassembled a factory high-perf or SHP engine, the rods/caps will be marked indicating the assemblies were balanced as a set for that engine.

I'm thinking that perhaps JOHNZ may have confirmed this at one time, but I'm not sure where I first received this information...  I USED to have a great memory but... something happened to it!  :)
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

Kelley W King

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I do not think they balanced any engines unless it was something special. All the parts were ordered with specified tolerances which in a sense is a balanced assembly to a certain criteria. I think rods came with the caps and when marked had more to do with the bore lining up than balance. I have assemble engines with crank kits, new rods, and pistons and checked nothing except clearances with a plastigauge. They ran but were not race engines.
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ZLP955

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Gary are you debating individual component balance (e.g. matching rod and piston mass) or balancing a rotating assembly?
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-Racer at Lions Dragstrip in Long Beach.

69Z28-RS

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The rods/pistons in my 69 302 engine were marked 1-8 from the factory; I also have a '70 model 350 LT1 engine which when torn down had the rods/pistons marked similarly (from the factory).    Std engines do not get that; they only get assembled.

Both of these are 'special high performance' SHP engines...
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan

ZLP955

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Have you read http://www.camaros.org/pdf/flint_engine.pdf and specifically the third page regarding the broadcasting of pistons to match each of the bore measurements, with the block stamped against each cylinder to suit? Note that article is for Flint assembly.
Tim in Australia.
1969 04A Van Nuys Z/28. Cortez Silver, Dark Blue interior, VE3 bumper, Z21, Z23, D55/U17, D80, flat hood.
Sold at Clippinger Chevrolet in Covina, CA. Ex-Racer at Lions Dragstrip in Long Beach.

69Z28-RS

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Thanks for that link TIm!   I had read it before awhile back, but just read it again looking for information relating to my question, but didn't find it.   John described a single process without any 'special balancing' but also he didn't distinguish between standard engines and HP/SHP engines.   If the process he described was true for ALL Flint engines, then wherever I got my prior information must have been incorrect as John didn't address 'balancing operations' at all, or as a distinction for HP/SHP.
Gary W / 09C 69Z28-RS, 72 B 720 cowl console rosewood tint
69 Corvette convertible, silver/black 350 hp,
60 Corvette white/red, 72 Corvette coupe, '70 Mach I 
90 ZR1 red/red #246, 90 ZR1 white/gray #2466
72 El Camino, '55-'56-'57 Nomads, '55-'57 B/A Sedan