Quote:
Originally Posted by ryanheacox
This has always been a confusing issue to me because to my mind shouldn't the rebuilder or the machine shop make sure that all rotating masses in the engine are balanced and if not take the appropriate measures to balance them? I can't imagine why anyone would skip that step, seems like an important one to me. Just like matching pistons, pins, rods, etc.
Then again, I've had plenty of conversations with people at car shows that claim the engines were never balanced from the factory because the stock crank lacks counter weights. I just smile and nod now.
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Again, this is likely one of those things where Grandpa made an assumption about how things were done and that information has been passed down as gospel. I have spent many, many hours at the archives reading and collecting factory prints of engine components (-amongst other items.) and I can tell you what it says on most of the prints regarding matching or in the case of the crankshaft, it states the crankshaft must be balanced dynamically within .3 ounce inch at any point of reference. Connecting rods were specified to be 198 grams plus or minus 1 gram, and pistons were to be within 4 grams when finished machined. Even those were matched as a set within those four grams.
With regard to should the rebuilder or the machine shop make sure everything is balanced? Well, again this is one of those things that consumers typically get what they pay for. I have some people tell me I am more expensive than some of my competitors, ...and they are likely correct however there are steps I do that are considered standard by me that are optional by other shops. Even Ford's Model-A was advertised as cheaper than a Chevrolet, -and it was until the bumpers and the engine oil were added into the sale of the Model-A.