Timzcat, I checked the valve timing myself and posted up pictures of the orientation of everything. Ogvw, after speaking with TT, said that the install wasn't the problem. I can't explain how others have had success, but as soon as the HKS set went in, the noise went away with everything else left unchanged. The fact that dsevo is also experiencing the (seemingly) same symptom with these cams tells me that there may be an issue for Revolver to address.

 

It sounds to me like the valves may be making contact with the pistons.

Advancing the intake cam opens the intake valve earlier, which brings the intake valve closer to the piston when the piston is at TDC at the beginning of the intake phase. The -2/0 setting retards the intake cam 4 crankshaft degrees, which would explain why you don't hear the noise at that setting.

I'm not saying this is indeed the case, but this certainly explains it. If Revolver recommends a -2/0 setting, I don't understand why they wouldn't just grind the cams to give the equivalent of that setting when the cams are installed with the factory gears.

 

My thoughts exactly. If that is the case, I just hope I havent' caused any damage to my new head.

 

I just thought of something that makes sense. When I had my head all built, I think they milled a couple thousandths off of the gasket surface, which would make the valves closer to the pistons. I bet the valves open so much with these cams that even a little off of the head will cause them to contact. Sound reasonable?

 

It's possible, especially since a few thousandths is significant when it comes to piston/valve clearance.

Also, I might mention that milling the head even slightly may possibly cause a change in cam timing as a result of a change in geometry that moves the cams to a slightly different position, depending on the placement of the belt tensioner. I have not examined this with a 4G63, but I've seen it with another DOHC engine.

 

Did the mill your head due to it being warped or just to get the gasket off? The gasket should have been able to be scraped off without milling the head.

 

Sounds reasonable - I would definately check the piston to valve clearance. Just for grins I will check in a couple days - we have a motor on the engine stand so I can see exactly when a stock motor will encounter valve and piston contact.

Also, the noise could be other things. As was stated in another thread, the PCV valve can "clatter" when the engine vacuum pulses (like our cams at idle using 0/0 settings). There is a lot of overlap in those cams, additional RPM-fuel-timing are needed to run them at 0/0.

Unfortunately making a camshaft that works well for every car and combo of parts is difficult - this grind is meant to make power, and it has (Buschur has made over 900 wheel HP). We are coming out with a milder drop in cam that will be more suited to cars with less modifications.

 

I know for a fact that it isn't the PCV valve, because I've heard that noise, and it is nothing like the one I encounter at 0,0. I'll do a leak down test tomorrow te make sure my valves are still fine, and then I'll contact the shop that built my head and find out about the mill job.