[squidmarks]

I started my engine for the first time after finally getting it installed. After a few ignition and fuel supply issues that I got sorted out it fired up and ran. After reving it up to 2000rpm to start the break in procedure, I noticed a bit of a knock, knock, knock that I isolated to the right side of the engine. It pretty much went away below 1000rpm, but got louder with higher RPM's. It didn't sound like anything catastrophic and did not change in pitch over time. I ran it for ~10 min then shut it down and drained the oil. My first thought was a tight valve that might be kissing the piston, so I took off the valve covers and checked all the valves. All were in spec except for cylinder 5 which were a bit tight. But as I was adjusting them, I noticed that I was able to depress the #5 valves (i.e. compress the springs) easier than all the other ones, both exhaust and intake. I've been scratching my head for awhile on this one. I had a well respected Porsche machinist do the heads for me, so they were fully assembled when I got them, but I don't remember specifically testing how hard it was to depress each valve before installing them.

Does anyone know why these two valves might depress easier than all the other ones? I just checked and it was cylinder #5 that was the bad one when I rebuilt it (severely scored piston/cylinder). While all pistons/cylinders were replaced, is it possible that the valve springs were on that cylinder were compromised? I will check with the machinist whether he would have checked each spring prior to reassembly.

Any other ideas?

Thanks.

Geoff