[DeTomaso] what crankshaft to get?

[Chance Dorsey]

Mike is absolutely correct on the matter of Chinese materials vs Chinese machining.  I found out the hard way that when it comes to building your motor, rule number one is to assume that none of your parts fit until you verify that they do.  In other words.....trust no one.  Not the machinist, not the company that sold you the crank.  No one!

I'm sure any veteran engine builder learned this lesson a long time ago, but the 393C I just finished was the 2nd motor I've ever built.  I'm not even sure I can count the first motor as a real build since it started out as a long block.  So this was the first motor where I built it starting with a bare block.

I was so certain that I had done the right thing when I ordered my 393 rotating assembly from Probe that I marched right over to the machine shop with all my new parts and had him balance everything right off the bat.  Bad idea, because on the day that I decided to drop that crank into the block was the day that I realized that the crankshaft endplay was around .0175.  If I had checked the crank measurements before having the crank balanced I could have just sent everything back to Coast High.  Ouch.......lesson learned!!!  Long story short, I ended up spending the money I should have spent on a properly machined crank on having the crank welded and ground .010 under and thrust width brought into spec.  The gentleman who did the work for me to bring the crank back into spec is Buddy Strobeck down in San Antonio.  He came highly recommended.  However, he mentioned that he thought the forging and nitriding on the crank was high quality.  Its just that the machining was just way off.

However, I later realized that the specification differences between a Cleveland crank and Windsor crank might also be to blame.  Most Cleveland cranks are just turned down Windsor cranks right.  The only difference being the size of the mains and the width of the crank thrust surfaces.  On a Windsor the thrust surfaces are .015 wider which puts the crank I had right in the ball park of a Windsor crank.  So basically the crank I received had Cleveland sized mains and Windsor sized everything else which is normal with the exception of the thrust width surfaces which should have been machined to Cleveland specs.

The moral of the story you ask........I would completely feel comfortable with the Chinese forgings, just make sure everything fits perfect BEFORE altering anything in hopes of still being able to send it back to the manufacturer if its not right.

Thanks,

Chance Dorsey
Austin, TX

On May 24, 2012, at 8:24 AM, MikeLDrew at aol.com wrote:

> 
> In a message dated 5/24/12 6 04 22, rtaspl at aol.com writes:
> 
> 
>> 1 Eagle - 4340 good price
>> 2 Scat   A bit more money
>> 3 Callies  more money but do I need it
>> 
> 
> I think the cost/quality curves cross at Scat.   When I was doing my 
> research for my stroker motor (99% of my research was "Ask Dan" it seemed, but I 
> did actually do some independent research too), I got turned off from Eagle 
> cranks.   They are a 100% Chinese deal, from what I understand.   Dan flew to 
> LA and we toured the Scat factory together.   Their raw material starts off 
> in China but all the final machine work and quality control takes place at 
> their facility in California.   If you buy a "Ford Racing" crank from Ford, 
> it's simply a rebranded Scat crank--we saw them loading cranks into Ford 
> boxes.
> 
> Yes, you can spend $7000 on a crankshaft, but for road-going Gomers like 
> us, that's way overkill.   If you were running a pro-stock car at 9000 rpm, 
> fine.   But for hard street use and occasional open track work, I think Scat 
> represents the best overall value.   And given that their forged cranks are 
> only about $200-300 more than their cast cranks, I can't see the reason not 
> to go with the better forged units....
> 
> Mike
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