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Re: Remanufactured Chrankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 8:54 am
by 1bolt
[For whats it's worth/] I was reading some Engine machinist's chatter over on speedtalk.com and most of them were laughing at the prevailing customer attitude that anything over 20 thousandths was junk. The consensus seemed to be that anything out to 60 was not going to impact the strength of the crank, and this is for high stress performance applications. That site is frequented by big name Race engine builders BTW.[/For whats it's worth]

Re: Remanufactured Chrankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 8:59 am
by RAPTORFAN85
1bolt wrote:[For whats it's worth/] I was reading some Engine machinist's chatter over on speedtalk.com and most of them were laughing at the prevailing customer attitude that anything over 20 thousandths was junk. The consensus seemed to be that anything out to 60 was not going to impact the strength of the crank, and this is for high stress performance applications. That site is frequented by big name Race engine builders BTW.[/For whats it's worth]
I totaly agree with that statment, BUT, try finding bearings for our I6's in anything over a .040 size. It's pretty hard. Machining that much won't affect the strength though.

Re: Remanufactured Chrankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 10:45 am
by lafrad
yep. bearing availability is the only thing I could possibly see wrong also.


There are several circles in racing where a full offset grind is done to the rod journals. take a mopar 2.5" rod journal down to a honda 1.889" journal to run a lightweight rod. thats over a HALF AN INCH to turn down. Reharden the surface and there ya have it.

talking about 0.010" or 0.020", even 0.060" is peanuts... especial on a 7 main crank and only 300-400 hp range.

Re: Remanufactured Chrankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 10:46 am
by lafrad
BTW... thats what my 400 ci hemi has done: stock 6.1 forged crank turned down to a honda journal. holds the HP without flinching.

Re: Remanufactured Chrankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 12:36 pm
by IH 392
lafrad wrote:turn down. Reharden the surface and there ya have it.
Virtualy NO production crank is hardened in any way, only he ULTRA Performance and TRUCK! stuff has any form of hardening from the factory.

Re: Remanufactured Crankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 6th, 2009, 3:39 pm
by 1bolt
Yeah definitely want to stay away from anything that would force an import from Israel :) I just put that out there because it seemed interesting.

Re: Remanufactured Crankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 10th, 2009, 9:59 pm
by PolloLoco
My parents opened up the package and the rods are 30 and mains are 20. Now is it listed as main/rod or rod/main?

Question about bearings: I've read that Federal Mogul are the only ones that have the oil passage already there, and that the Clevitte you need to make the oil passage. Am I off my rocker or is that true? Are Sealed Power bearings Federal Mogul brand? I see them on Federal Mogul's website.

Re: Remanufactured Crankshaft Machining? .10/.10 ? .20/.20 ?

Posted: May 12th, 2009, 7:18 pm
by eastin82
i can tell you that the clevite rod bearing for a 91 block do not have passage. i think that its main first then rod. dont listen to me though not 100% sure.