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G'day all, Hope that everyone is enjoying the Festive Season. I have removed sump and No 1R piston and rod to replace worn gudgeon bush, caused by lack of oil from blocked oil supply. Have replaced bush and am wanting to re-install piston. Have rod connected but have found that a standard ring compressor does not fit square to the block, due to unique shape of the Packard block and piston. Would much appreciate advice on installation. Shop manual mentions nothing about it. Is one supposed to compress rings individually at each land?
Please advise. Peter Toet.

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Hello all, advice from a learned friend revealed that one needs to grind ring compressor to Packard profile to enable safe piston entry. shall send pic. Merry Xmas everyone.
Peter Toet

Peter,

Was that advice from our friend up North?

There is an illustration of the Twelve piston ring compressor (S.T. 872) in the January 1935 Special Tools and Shop Equipment Catalog, page 15 of the Motor Section.

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wow ! there is an old car/Packard expert in northern Australia ? Do tell us more !

Sorry, not northern Australia, just North from our situations.

The guy concerned has restored a number of Packards over many years including a teens Twin Six, early '30's Super Eight, a 120, a '51 Convertible and more. However his most recent restoration, a few years ago, was a '38 Twelve Club Sedan. The Twelve when bought had purportedly been rebuilt, but wasn't, necessitating a complete rebuild of the engine. The rebuild was done by the guys engine rebuilder in the northern New South Wales town where he lives. They both learned a lot about Twelve engine rebuilding through that very expensive process. Because of that experience I'd PM'd Peter suggesting he contact our friend or his engine rebuilder.

An aside, because of this guys '38 Twelve Club Sedan, another Packard guy who lived still further North(but again not northern Australia!) became enarmoured with Twelves and purchased one for himself. A benefit that came from the ownership of that Twelve was the new owner facilitated the manufacture of reproduction Twelve distributor caps(by Bosch!)! These caps were being advertised in the CNB but I don't see them now in the Sept '17 issue, which is the only one I have to hand.

Thanks for the info and pic David, The tool did not show up in the Packard Special Tools catalogue which I have. It showed a ring compressor which was for the Six, 120, eight, Super Eight but excluded the 12. I was wondering if you also know the connecting nut torque setting and also the main bearing cap torque settings. I have been unable to locate either of these settings in the Shop manual, Service letters and other general motoring Maintenance manuals of the era. I have the connecting rod bolted together but I have yet to set the torque. I am also curious as to whether I should use the Packard setting or the setting for the Caddy bearings which are fitted. Please advise your view on whether this is relevant or should the crush be about the same anyway. I'm guessing that 55-60 ft/lbs should be sufficient for the connecting rod torque setting, comparing bore/stroke/rpm with the 3.5 inch bore Six and 3.5 inch bore 356 Super Eight motors.
Peter Toet.

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Really no surprise you didn't find torque specifications in Packard's service literature, though the concept of a torque-measuring wrench goes back to the late 20s, it really wasn't until just a year or two before WW II that the wrenches became commercially available in quantity and manufacturers began to issue specifications. Motor's Manual, a very highly respected independent auto service manual, lists 65-70 lb-ft. for the main bearing bolts. It does not make a recommendation for the rod bearings.

If one wished to guesstimate a torque value for the rod bearing retaining nuts, rather than using bore and stroke of another Packard engine as a basis for extrapolation, I'd think using bearing journal diameter and bolt diameter and thread count would be more appropriate.

Thanks David, I missed seeing it in the Motors Manual that I have but it certainly is there. Yes, you are also correct about using the journal diameter, bolt diameter and thread count. I shall have a look at those. The replacement bearings are also much reduced in width to the original Packard rod bearings. I shall ponder this for a while before I do anything which may be unwise. Thanks for your advice. 4 hour later update. Have set torque at 65-70 ft/lbs, mostly at around 70 ft/lbs to get split pin in. Have started engine sans exhaust. no pin rattle. shall re-torque and fill with conditioned water tomorrow. Noted quite a bit of corrosion on some block entry points of the aluminium head. Once restarted, I shall re-attach front suspension and other ancilliaries. Water Wetter for anti corrosion appears very necessary. Noted some radiator tubes with gunk in the inlets. May need Toet backflush with modern exhaust system.
Peter Toet