FINALLY the machinist speaks!!

[josh1095]

so as some may know, i had an engine built and got rod knock after 330 miles. and whined like hell about it every post on here . so i got off the phone with the machinist who finally took it apart today. he says QUOTE "theres alot of wear on the tops of the rod bearings and the bottoms of the mains, rod #4 was bad enough it started knocking. i cant blame the guy who cut the crank, it looks like you werent pulling timing far enough while boosting"

now theres where i jumped in. ya see, that makes no ###ing sense. theres no signs of detonation... ANYWHERE. even he admitted that. i told him i didnt change anything in the timing tables and ran a MAX of 11psi i.e. stock ###ing boost levels on a fully built engine.

his excuse seems lame and the fact that all the bearings are showing excessive wear seems odd too. i think the guy who cut the crank messed up, or the machinist didnt use the right spec bearings. i asked if he used acl. he said ""no i got clevites, but it looks like im going to get a set of acl race bearings this time""

again, what is going on here? i did the motoman then changed oil about 45 miles, then 100 miles, then again about 150 miles later. thats when i noticed gold in th oil.
long story longer: hes doing all labor free but charging me parts. full set of bearings plus another cometic MLS hg. FML FML FML, over 3100 bucks now just in the goddamn mother ####ing engine. around 10 bucks a mile, not counting all the other little stuff.
sorry to rant

 

[BogusSVO]

2 things wrong with this thread: Quaker State, and cut crank.

Quaker State out of the bottle is about as good as straight water and ashes.

You cut/turn a Mitsu crank, you ruin the factory hardening of the material and are asking for failure.

I would like to hear more, and see the links to your information.

 

[jmelocik]

Fact just in case you did not know.
2g/Evo cranks are not nitride coated(this is the hardening process)

I run a cut crank in my 2g without issues.
The issue arises when you cut the crank, if not done properly you will ruin bearings.

Most issues arrise because the machine shop normally does what you ask them. If you tell them cut 0.010" off the rod journals but you do not ask them to check the final clearance then they won't.

You are correct, 2g and Evo cranks aren't nitrided, they are induction hardened, which is also a hardening process but goes further into the metal than nitriding. There have been a few tests done, one of which I was a part of, that proved that Evo cranks can be turned over .020 before they start to significantly lose there "hardness". Feel free to PM me if you have any questions on this. I will try to find the article.

Josh