fastcar
08-03-2008, 06:16 PM
Thought I'd post some shots of the head back from machining. I dropped them off at Dezracing this afternoon...
Eric put a super fine finish on the head like the factory does, and seemed pretty proud of it. They only needed to take about 4 thousands off...
Check out the wear on some of the lobes. Eric says it's common, and nothing to be worried about on a roller cam. You can't catch the mark with your nail, so it must be micro in depth...
I found someone etched the head on the side, thought that was interesting, and curious what it means...
You can see that when the seat came out, some of it ran around in the cylinder leaving it's mark on the combustion chamber, even after taking 4 thousandths off. Probably left a similar mark on the piston top...
Only problem after machining with head was a very bad burr on chamber edge from the shrapnel. With Lidio's tune, and 10.5:1 compression, I knew this would pre-ignite, so I took it off with a razor blade at the shop, and he blew it out with compressed air...
Another very interesting discovery: our valve seats are POWDERED METAL. Eric discovered this when he went to drive in the new valve seat (which is made of regular steel). He didn't have the right size tool to drive in the new seat, so he used the old seat. When he hit the old seat, it SHATTERED INTO PIECES. :eek: That was weird news. I'm not a big fan of powdered metal...
fastcar:burnout:
Eric put a super fine finish on the head like the factory does, and seemed pretty proud of it. They only needed to take about 4 thousands off...
Check out the wear on some of the lobes. Eric says it's common, and nothing to be worried about on a roller cam. You can't catch the mark with your nail, so it must be micro in depth...
I found someone etched the head on the side, thought that was interesting, and curious what it means...
You can see that when the seat came out, some of it ran around in the cylinder leaving it's mark on the combustion chamber, even after taking 4 thousandths off. Probably left a similar mark on the piston top...
Only problem after machining with head was a very bad burr on chamber edge from the shrapnel. With Lidio's tune, and 10.5:1 compression, I knew this would pre-ignite, so I took it off with a razor blade at the shop, and he blew it out with compressed air...
Another very interesting discovery: our valve seats are POWDERED METAL. Eric discovered this when he went to drive in the new valve seat (which is made of regular steel). He didn't have the right size tool to drive in the new seat, so he used the old seat. When he hit the old seat, it SHATTERED INTO PIECES. :eek: That was weird news. I'm not a big fan of powdered metal...
fastcar:burnout: