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1934 Packard 1100 Crank balancing and bobweights


Volk

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Pretty routine work for any good crankshaft shop, set the crank up in a vertical mill, mill out the weld caps and the bolt heads, then remove the weight and the remains of the bolt. Some shops make new bolts like the originals, others have substituted socket-head bolts but in any case you weld over the heads when reinstalling and of course rebalance the whole assembly.

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So, aren't there tricks of the trade that allow you to leave the counterweights on when rebuilding an engine? I believe the area not accessible because of the counterweight is where the shoulder of the bearing is, and could be adapted to fit. Or, in the case of inserts, put a narrower insert and build up side of rod....

Just asking....

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If you don't have a milling machine, you can slowly drill them out using graduated sizes. It will be obvious when you get far enough into the bolt. They are also staked from the side. The cap screws will work fine and can be welded in place. You will have to have the whole thing balanced after the journals are ground and the weights reinstalled.

The only way to properly do this without removing the weights is to use a now obsolete portable crankshaft grinder which will get to all parts of the journal. Finding someone who knows how to properly use one, assuming you can find one of these grinders, is not easy. We had a man who came to our shop years ago and he did this routinely with his portable machine shop - he actually did work for my grandfather at his Sinclair station back in the 40s and 50s. (He also repaired Sherman tank engines in WWII both in Europe and the Pacific.) Since he and most of the guys like him have gone to the machine shop in the great beyond, taking it to a good machine shop and having them do it it probably best.

Dave packard12s@hotmail.com

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Guest donald ellis

Yes, I took my 1101 engine to a a machine shop in 1955 to discover what you have discovered all these years later. We talked about removing the counter weights drilling out the bolts grinding the crank and balancing the whole thing. This will be blasphemy to many but at that time I wasn't sure of the machinist and had limited money. What they did was to grind the journals less that full width (to clear the counter weights) and step the bearing shells to match. Packard had so much bearing area that I got away with it and ran the car for a long time.

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