Is This an Indicator of Detonation?
New rebuild 383, for some reason the intermediate shaft bushing got eatten and I can't get the bushing out with the engine in the vehicle, that's another story. Anyways I got the passenger side head off last night, and besides noticing that its running rich. I noticed a light band in the cylinder walls right under where the rings stop at the top of the bore. Then the rest of the bore is a darker color. Its like that in every cylinder on the passenger side. Didn't get the driverside head off yet. Is this a sign of detonation? I couldn't hear any pinging over the exhaust, its on the loud side. Compression ratio is right around 9.8:1. DCR should be around 7.33:1. Iron 906 heads. The smallest MP solid lifter cam.
Also the valve tips. Every intake valve and 2 of the exhaust valves have this kind of pattern on the tip where the roller contacted the valve tip on the passenger side. I am trying to remember it was about 10 years ago, but a machine shop told me that this pattern on the valve stem tip was a sign of detonation. Anyone else hear of this or experience??
New rebuild 383, for some reason the intermediate shaft bushing got eatten and I can't get the bushing out with the engine in the vehicle, that's another story. Anyways I got the passenger side head off last night, and besides noticing that its running rich. I noticed a light band in the cylinder walls right under where the rings stop at the top of the bore. Then the rest of the bore is a darker color. Its like that in every cylinder on the passenger side. Didn't get the driverside head off yet. Is this a sign of detonation? I couldn't hear any pinging over the exhaust, its on the loud side. Compression ratio is right around 9.8:1. DCR should be around 7.33:1. Iron 906 heads. The smallest MP solid lifter cam.
Also the valve tips. Every intake valve and 2 of the exhaust valves have this kind of pattern on the tip where the roller contacted the valve tip on the passenger side. I am trying to remember it was about 10 years ago, but a machine shop told me that this pattern on the valve stem tip was a sign of detonation. Anyone else hear of this or experience??
