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King of my Man-cave.
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Discussion Starter #1
Here's another heads up on aftermarket parts.

I just (10 minutes ago) checked a new Eagle cast steel 400 Chevy crank, literally out-of-the-box.

The #2 main had .0025" run-out, #3 had .002, and #4 had .004" run-out. Crank no good. The customer is sending it back. I told him that it's possible that the next one may be similar. He's willing to take the chance, but if it is, he'll have that one turned.

The moral of the story is, you have to check EVERYTHING. Be it heads, rods, or cranks, take it to a good shop and have them checked out. It will save you a LOT of headaches.

tom
 

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Race it, Don't rice it!
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Had a crank miced two weeks ago for a local racer and it shown similar result's. I here a few people complaining about poor quality in Scat and Eagle stuff. Especially the eagle rods being resized wrong.

Your bettin on a high stakes game if you assume!
 

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I am trying to picture this since I am not 100% sure of the term run out. Is the run out the amount off of the centerline of the crank that the journal was ground, or is it the amount of taper from one end of the journal to the other? If I am thinking right, you would spin the crank with a dial gauge on the journal to check the centerline of the journal with the centerline of the crank. Any variation would be run out.

If so, seems that the indexing on the rod journals could be bad too. That could make for some weird piston timing and actual stroke length.

Chris
 

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King of my Man-cave.
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Discussion Starter #4
The crank is placed in vee blocks on the end journals. The dial indicator is placed on the center main journal. The crank is turned slowly. The run-out is read on the indicator. This is repeated on the intermediate journals. Anything over .001-.0015" can be considered too much, although .002" is considered "acceptable".

And yep, the crank indexing is also a consideration.

This was a crank that I would sell for around 190 bucks (although this one was bought elsewhere). You get what you pay for.

tom
 

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"May the Schwartz be with you"
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This is good information...especially to newbies.

I have seen "balanced" rotating assemblies so far out of whack it was obcene.

Moral of the story is...ALWAYS check your parts. If you don't know how, take them to someone who does.
 

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Actually, run-out is BEST measured with #1,2,4, and 5 mains torqued to factory spec. Leave off the #3 main, and set up your dial indicator. At Hot Rod U (my school right now), we don't let the cranks over .002".

My personal choice would be a Callies Dragonslayer, if money wasn't a problem. I don't think you can ever go overkill on a good bottom end (depending on app).
 

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Matty Munchen said:
Actually, run-out is BEST measured with #1,2,4, and 5 mains torqued to factory spec. Leave off the #3 main, and set up your dial indicator. At Hot Rod U (my school right now), we don't let the cranks over .002".

My personal choice would be a Callies Dragonslayer, if money wasn't a problem. I don't think you can ever go overkill on a good bottom end (depending on app).
I think that the machinist will disagree with you. With your method it looks like you could miss big problems. Looks again at the #4 measurement in this post.

Chris
 

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Matty Munchen said:
Actually, run-out is BEST measured with #1,2,4, and 5 mains torqued to factory spec. Leave off the #3 main, and set up your dial indicator. At Hot Rod U (my school right now), we don't let the cranks over .002".

My personal choice would be a Callies Dragonslayer, if money wasn't a problem. I don't think you can ever go overkill on a good bottom end (depending on app).
Uhh, Tom's got a pretty good idea what he's doing... you know, having done this since before either of us existed...

K
 

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Chris,

THis was the way I was instructed by Hot Rod program instructors. Basically the the first three weeks of the class is blueprinting the small block, including the crankshaft. We took Diameter, Out of Round, Taper, Runout, and Endplay readings.

In our run-out handout, we were instructed to torque those caps, and then take our reading off of Main #3. I assumed the gentleman knew his stuff, being in the field for 35 years, and owning a 30-ft flat bottom with twin 496 Weiland 671 strokers.

If I've been misinformed, please PM me with the proper procedure. Thanks guys!
 

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King of my Man-cave.
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Discussion Starter #12
Matty Munchen said:
Actually, run-out is BEST measured with #1,2,4, and 5 mains torqued to factory spec. Leave off the #3 main, and set up your dial indicator. At Hot Rod U (my school right now), we don't let the cranks over .002".
If that's what they're teaching at Hot Rod U, they aren't teaching you very well. Using that method, the run-out on the #2 and #4 mains would have gone unnoticed. And the #3 main "only" had .002". According to your criteria, that crank would have been called "good". IF that crank would have even turned, which is unlikely, you and your teachers would be scratching your heads and wondering "why?".

Vee blocks are the best way to check a crank for run-out. Second best is to install the #1 and #5 mains in the block (block up-side down and just the upper halves installed) and an indicator checking 2,3,and 4 main journals.

tom
 

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current hot rod: CTS-V
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machine shop tom said:
Here's another heads up on aftermarket parts.

I just (10 minutes ago) checked a new Eagle cast steel 400 Chevy crank, literally out-of-the-box.

The #2 main had .0025" run-out, #3 had .002, and #4 had .004" run-out. Crank no good. The customer is sending it back. I told him that it's possible that the next one may be similar. He's willing to take the chance, but if it is, he'll have that one turned.

The moral of the story is, you have to check EVERYTHING. Be it heads, rods, or cranks, take it to a good shop and have them checked out. It will save you a LOT of headaches.

tom
Tom, in your opinion who makes the best aftermarket cranks?
 

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current hot rod: CTS-V
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No I want to know who he thinks is the best. The low budget cranks seem to all have the occasional quality control problems.
 

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I think that most would agree that Lunati or Callies would be at the top of the pile for quality. Eagle and scat have some QC issues, but if you check them they will replace them if you find a problem. It depends on your budget and your tolerance level.....

Chris
 

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And if the budget warrants an eagle or scat, just have it turned 10/10 at a reputable crank grinder.

Chris
 

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King of my Man-cave.
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Discussion Starter #19
Cstraub said:
And if the budget warrants an eagle or scat, just have it turned 10/10 at a reputable crank grinder.

Chris
Yup, good idea! And check it when it's done. I say that 'cause two of the three crank grinders in my area are having trouble with their machines right now. They both have done good work in the past for me, it's just recently they have been having problems with main run-out. They have identical machines so it will be interesting to see what the problem is. The third crank grinder in my area has problems with journal taper so I am now sending my cranks to a shop 130 miles away (their works checks out ok).

tom
 

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TurboS10 said:
I am trying to picture this since I am not 100% sure of the term run out. Is the run out the amount off of the centerline of the crank that the journal was ground, or is it the amount of taper from one end of the journal to the other? If I am thinking right, you would spin the crank with a dial gauge on the journal to check the centerline of the journal with the centerline of the crank. Any variation would be run out.

If so, seems that the indexing on the rod journals could be bad too. That could make for some weird piston timing and actual stroke length.

Chris

Hey Chris,
Didn't you say in your bearing pic post that you were using an Eagle crank? Even though there was a lot of main damage is there any chance of you finding two sets of main bearings that weren't totally mashed and spinning your crank and getting a runout reading from #3. Even though your clearances were good maybe the runout wasn't.

Bill
 
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