Your assertion is totally incorrect

The reported number of 100% BONE stock evos which have failed rods is about equal to that of reflashed ecus.

There have been more AEM cars than any other kind which have failed which I suspect may be due to the higher user defined rev limit

The bottom line is that these are cheaply made made prodcued cars made right along side the normal Lancer in the same facility, you would be suprized how few difefrences there are in the lancer vs. the evo in the production line

In any event the ROD and HEAD bolts are not even TQ'd to spec they are rotated 90 degrees to put them under a constant load per factory spec

What amazes me about the evos is not how bad the rod bolts are - but rather how strong the rest of the motor is. I have not seen ONE crank break thus far and the block also seems very robust.

The weak links in the evo are head and rod studs - oil pump and pistons

The oil pump and pistons only start to have problems after you start to modify the car

However, the rod issue has happend on dozens of stock cars and is without a doubt an item in which the part is not up to task

 

Also consider the fact that a company such as Bently or AMG or NSX adopts practices where one master engine builder assemples each complete engine BY HAND

ONE MAN per engine start to finish

One would expect that mistakes are made in mass produced cars which are built on a lancer assemply line

PS- the lancers also have many reports of rod bearing failures as well

 

"Abuse" = key word

The engine is designed to run efficiently and make good power in a compact package, with acceptable longevity, at a cost that's justifiable to the accountants. It isn't designed to withstand the abuses of racing, nor to support extraordinary power levels. Quite frankly, I'm amazed those cast pistons hold up as well as they do, at the piston speeds to which they are subjected. I'm equally amazed to find them in this motor in the first place. Even my '86 SVO Mustang had forged pistons from the factory.

Andrew (Dyno4mance) and I were discussing a recent demonstration, where someone independently generated some very convincing evidence to support his theory that the weak link in a Subie motor is in fact the softness of the factory bearings. Could it be possible the EVO motor isn't fitted with the best bearings for big power? I don't know, but someone who puts his hands on both the Mitsu factory bearings and better aftermarket types may be able to shed a little insight.

 

I agree with this statement 100%.

The clutch, transfer case, and synchronizers are weak links too, but they aren't part of the engine.

 

new thread up with top end pics: https://www.evolutionm.net/forums/sh....php?p=2885919

 

closed after speaking with Stew. Please post any new thoughts in the follow on thread referred to above. And if you want to cause inter-vendor fights, don't bother posting at all.