Measuring crankshaft runout, Wondering how you guys measure crankshaft runout Options

[Langing]

BGB says the first thing you do when you are checking whether your crankshaft is within specs is to measure the runout. The illustration in BGB shows the crank suspended at each end main journal using a pair of special V-blocks and a dial indicator measuring the runout at the center journal. Looked simple, and pretty easy to do. I have a dial indicator and just needed V-blocks. So, I began a search for a pair of V-blocks.

So, ok, who has been through this agony and can help me do this otherwise 'simple' job? I called a local dealership and they told me they charge $115/hour (or it might have been $150/hr, I wasn't listening so good after I heard the first hundred). Honestly, I would like to do it myself, but I cannot find suitable V-blocks. Could I just make a wood fixture support each end, made so that they have a circular place on them so the crank is level and let it rotate on wood?

[enderswift]

Nope, you'll never be able to make anything from wood precise enough, particularly for total run-out. Better off removing all but the end bearings from the block and spinning the crank on just two mains

In any case, as someone who has blue printed a 3s prior to full rebuild, I can just about guarantee that your crank is fine. Toyota induction hardened the journals for petes sake...talk about overkill

S

[Langing]

Thanks Enderswift, may I pose a follow-up question?

I finally decided to order a single longer V block, and when it comes in I will cut it such that there is one V block that is able to fit the short main journal just before the lumpy thing that connects to the flywheel (0.8"), leaving a longer V block to support the main on the other end of the crankshaft.

I have been worrying about the metal to metal interface where the journals will be rolling on the V blocks while I take the measurement. Thinking I might use the old bearings between the journal and the metal of the V block to prevent scratching. So, I am waiting on the mail for the V block and a 2" to 3" micrometer necessary to take the set of readings required for the journals so I can get the correct bearings.

In the meantime I believe I have located a shop in Raleigh that will clean the block ($45), magnaflux ($50), polish journals on crank ($35), and balance the crankshaft, pistons, and rods ($125). Those prices did not seem unreasonable to me. Before taking it I plan on knocking the old expansion plugs out, so the cleaning operation can work better on the water jacket. Bought brass replacements that I will install when it is back.

Can you think of anything I might have missed, or something that is just a waste of money? For example, I am not so sure the journals need polishing, and wonder if magnafluxing is really necessary. I have convinced myself that the balancing is essential, since it can be done to much greater precision than at the factory.

[Bitter]

Dude, plastigauge that thing and just be done.

[enderswift]

Dude, plastigauge that thing and just be done.

agreed. your crank is not bent, you don't need to check runout.

everything else sounds about right price wise

read this:

http://www.6gc.net/forums/index.php?showto...0487&st=100