Marker1989
02-11-2011, 04:03 PM
So I got a call from my engine builder today with some very interesting information. Last year I took a chunk of ring land out of my #5 piston shortly after a fresh rebuild. It still ran pretty good for another few months before I took it back to him. He went thru it again and put a new piston in it and I just got it back and in the car.
However when he was going thru it he said the #5 bearing was basically trashed too.. We had no idea what had caused all this mayhem in that one cylinder. Well today he calls me about an article he found in a magazine of his about SBF's. Apparently with a 351/H.O. firing order your number 5 and 6 pistons are on a rather close cycle, and if you get ANY cross fire between those plug wires it could pre-detonate one of those two cylinders.
Thus causing ring land breaks and beating up that cylinders bearing, which was my case. So if there's one thing to remember when putting your motor back together its to make sure you keep #5 and #6 plug wires far away from each other.. Who would have thought something so simple could cost you a motor?
However when he was going thru it he said the #5 bearing was basically trashed too.. We had no idea what had caused all this mayhem in that one cylinder. Well today he calls me about an article he found in a magazine of his about SBF's. Apparently with a 351/H.O. firing order your number 5 and 6 pistons are on a rather close cycle, and if you get ANY cross fire between those plug wires it could pre-detonate one of those two cylinders.
Thus causing ring land breaks and beating up that cylinders bearing, which was my case. So if there's one thing to remember when putting your motor back together its to make sure you keep #5 and #6 plug wires far away from each other.. Who would have thought something so simple could cost you a motor?