hencini
07-31-2002, 07:09 AM
Hey... I would really appreciate some input here from those with knowledge/experience greater than mine... Flame this weenie topic if you must , but I could really use the help...
I am in the process of rebuilding my AMC 258... My machinist, who has always been very helpful and competent in the past, sublets cranks to a different shop, also of decent reputation, but apparently not always the most professional... At any rate, my crank came back to the machinist with two nicks in the #3 (possibly #4, I forget) rod journal... I came in to inspect it, and he sent it back to be polished again, and now the top edges of the nicks have been smoothed over, but there are two little craters in the rod journal...
The machinist is not trying to push me either way, but suggests that on principle I demand to have the nicks taken out completely by having it re-ground (no charge); however, at the same time, told me that he has seen cranks with far more damage go on to lead a perfectly long and healthy life... The flipside to having the nicks taken all the way out is that I am already at .010" undergrind, and the machinist advised that .020" undergrind on a rod journal can be a little much on an inline 6, but still passable...
What do I do here? Is .020" undergrind too much? Can it live with the small nicks? I will be using the Jeep to get to work 5 days a week, and on the trails on the weekend, I'm relatively gentle on it across the board, and I'm going to be running a 4.0L head, Crane RV cam, and .040" overbore...
Much thanks,
Hencini
I am in the process of rebuilding my AMC 258... My machinist, who has always been very helpful and competent in the past, sublets cranks to a different shop, also of decent reputation, but apparently not always the most professional... At any rate, my crank came back to the machinist with two nicks in the #3 (possibly #4, I forget) rod journal... I came in to inspect it, and he sent it back to be polished again, and now the top edges of the nicks have been smoothed over, but there are two little craters in the rod journal...
The machinist is not trying to push me either way, but suggests that on principle I demand to have the nicks taken out completely by having it re-ground (no charge); however, at the same time, told me that he has seen cranks with far more damage go on to lead a perfectly long and healthy life... The flipside to having the nicks taken all the way out is that I am already at .010" undergrind, and the machinist advised that .020" undergrind on a rod journal can be a little much on an inline 6, but still passable...
What do I do here? Is .020" undergrind too much? Can it live with the small nicks? I will be using the Jeep to get to work 5 days a week, and on the trails on the weekend, I'm relatively gentle on it across the board, and I'm going to be running a 4.0L head, Crane RV cam, and .040" overbore...
Much thanks,
Hencini