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Old 04-18-2018, 01:24 PM
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Werks
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Originally Posted by Matt Piva View Post
Rule of thumb is if u plan on needing a rebuild make sure itís with an engine that has a dlc coated crank so itís worthy, the rest of the engines without that one important part are useless after the first sleeve wears out because the rod pins get so damaged within 6-8 gallons.
No offense but that's not a correct statement. DLC coating is something that was a necessity for specifically one Asian brand of engines in the past (OS) becuase they had issues with the materials they were using for their cranks and could not get them hard enough which resulted in the crank pins wearing out prematurely (as in before the piston and sleeve even wore out). This coating was initially offered by JP Racing on their modified version of that brand of engines and later (about 15 or so years ago) DLC coating as a fix (and the rest of the tuning mods that JP did too) was pretty much copied by the factory in a production model (the first Speed). The reality of the matter is that the Italian engine companies have metallurgy figured out and never had an issue with premature crank pin wear but because of this one Asian company DLC coating has become a "marketing trend" lately. So if you are using a fuel with quality lubricants, tuning the engine properly and most importantly not sucking in a bunch of dirt a non DLC coated crank from any of the Italian manufacturers should easily last you the life of several piston and sleeve sets too before needing to be replaced. In testing in the past we have regularly gotten 3+ rebuilds out of a crankshaft without seeing excessive crank pin wear.

If you feel that you need a crankshaft that will theoretically last forever (or you plan on rebuilding a engine for the rest of your life) then by all means make sure that you get a DLC coated crank, just realize that around $35-$50 of the cost of the engine that you are paying for is due to the cost of that coating alone and it results in zero performance increase, it just means that you crank pin will never wear out. With motors costing less nowadays than they did 15-20 years ago the cost of a replacement piston/sleeve and rod is often creeping up on 70% or so of the cost to just replace the entire engine! Because of that I have seen the trend changing from back in the day of people owning and rebuilding a single engine multiple times to nowadays at the most replacing the piston and sleeve maybe 1 time before just buying a new engine, in which case being candid having a DLC coated crank is basically a waste of money.
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