Walked 7bolt 2.4 Results

[JET]

There was talk of crank differences on NABR. It looks as if the 7 bolt cranks may not be nitrided at all! This isn't a very scientific test, but if a 7 bolt crank is left outside for any length of time, it will rust. You can leave a 6 bolt crank outside for years and it looks like new.

Allan was supposed to take my 6 bolt crank that walked several months ago. It sat ouside for about 6 weeks. It looks like new except for the surfaces that were damaged from the crank walk. So there is definately a coating on the 6 bolt cranks.

Also not totally related to this situation, but another data point to look at. When my engine crank walked it wore much worse on one side than the other. The bearing was still about 3/4 original thickness on one side, but wore into the block a good .030" on the other side.

I am thinking you should have the new crank sent out and nitride coated, because the 7 bolt crank is either not coated or it has a substandard coating that is causing a problem. This is just my 2 cents, YMMV.

JET