Experienced engine builders advice sought, crank scarring
#1
Experienced engine builders advice sought, crank scarring
So I am in the process of rebuilding my b18c1 for boost. Set up is gsr crank, eagle rods, 81.5 weiscos and will be looking for 450hp w turbo.
My issue is this. Original crank came back from machine shop micro polished and balanced. Upon further inspection there was scarring to half of the journals, and shop told me it was drop in ready. Needless to say I don't trust them anymore. After a bit of searching I came to the conclusion that I should just replace it with one w no scarring. Low and behold, the second crank I bought also is scarred on one main journal. I have not had a second opinion at another shop yet as I am worried that I will not get good advice from them seeing as most shops near me deal with domestics 95% of the time.
So my question is, Is grinding of Honda crank to pull out scarring ok? And if so how much is ok? There seemed to be a lot of "just replace it" or "grinding is fine on Honda cranks" when searching without real explanation, so I'm looking for answers from someone with experience.
I want to make reliable safe power, but with that's said I don't want to just replace a part because someone THINKS it may cause a problem. I have two gsr cranks already and am not looking forward to buying another one especially if I don't need too.
My issue is this. Original crank came back from machine shop micro polished and balanced. Upon further inspection there was scarring to half of the journals, and shop told me it was drop in ready. Needless to say I don't trust them anymore. After a bit of searching I came to the conclusion that I should just replace it with one w no scarring. Low and behold, the second crank I bought also is scarred on one main journal. I have not had a second opinion at another shop yet as I am worried that I will not get good advice from them seeing as most shops near me deal with domestics 95% of the time.
So my question is, Is grinding of Honda crank to pull out scarring ok? And if so how much is ok? There seemed to be a lot of "just replace it" or "grinding is fine on Honda cranks" when searching without real explanation, so I'm looking for answers from someone with experience.
I want to make reliable safe power, but with that's said I don't want to just replace a part because someone THINKS it may cause a problem. I have two gsr cranks already and am not looking forward to buying another one especially if I don't need too.
#2
Re: Experienced engine builders advice sought, crank scarring
I would only have the crank micro-polished. If the "scoring" isn't removed with a micro-polish then I would get another crank. Can u post pics of the cranks?
#3
Re: Experienced engine builders advice sought, crank scarring
I recently had a crank with scarring on the rod journal from a spun bearing reground. i first did some research to see what the limit for oversize bearings was for my motor (D16). I shared this info with the guys at the machine shop. they ground incrementally until the scarring was gone. then they went to the next closest bearing size. they ended up taking 0.05" off of the rod journals and 0.025" off of the mains. I ordered my replacement bearings accordingly and have had no issues from the motor since the rebuild.
to be clear, micro-polishing and regrinding are different processes with different end goals. Grinding is meant to restore good geometry to the surface by removing material while keeping tolerances tight and surface finish relatively useable. micropolishing is a surface finish process that shouldn't change the geometry nor remove much material.
to be clear, micro-polishing and regrinding are different processes with different end goals. Grinding is meant to restore good geometry to the surface by removing material while keeping tolerances tight and surface finish relatively useable. micropolishing is a surface finish process that shouldn't change the geometry nor remove much material.
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mike1114
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04-01-2008 06:47 PM