Cuda, this may sound like another dumb question, but are you sure you don't have an exhaust leak?

 

Yes, stock 88" motor other than the cams. I did have a slight exhaust leak on the front cylinder, so I wonder if that may be the cause of clean spot on the piston?

That actually crossed my mind the other day, but I'll be damned if I can feel it. I even held a lit cigarette around both heads at the exhaust flange looking for the smoke to puff. It has a similar sound, but it doesn't seem to be coming from the exhaust.

I'm gonna change the oil today, and run some Mobil one 15/50 in it, and see if there's any change in sound.

Here's a short film clip from last night. I never got it up to fully hot, as I didn't want to just sit there letting it run, and didn't feel like riding it. There's several different short clips together, at different levels of engine temp. You can definitely tell the difference in sound from the beginning after first starting it, to the end when it has gained some temp. It never got hot enough though to get as loud as what I'm referring to. I'll shoot another clip after changing the oil and going for a spin, to compare.

http://www.youtube.com/watch?v=oW_E-56lVFU

 

On my latest build the vlv seats were radius-ed to improve flow. The added benefit to this is less carbon buildup. The added compression (10.5:1) with a cam overlap for opening /closing of the vlv's also helps with fill and speeds exit gases from the combustion chamber quicker. So changing the vlv angle is just part of the solution for decreasing carbon buildup. Of course, twisting the throttle also helps to blow out excessive buildup.

 

It's hard to say from the video but it sounds like it's coming from the front cylinder...if there is a problem. It almost sounds like it's just that high lift cam doing it's thing. That's what I would say it is except you said it runs doggy. That being said, I see you are in Georgia and I'm guessing it's pretty toasty down there. We've had heat indexes around 105 here in Oklahoma. The oil change may quiet the noise down if it's really hot or if the oil is getting old and breaking down but obviously that doesn't explain it not running hard.

 

The cam is only .510 lift.....
Been in the high 90's here lately, and it's miserable with the humidity. As I said before, it's much louder when the bike heats up. I could live with it if it stayed like the video. Gonna change the oil shortly and see what happens.

 

I was just looking at the cam specs and realized that. As you said, try the oil change and see where you're at and it that doesn't fix it, maybe adjust the pushrods again back to 2 and 1/2 turns out and try again. Are you running stock lifters and how many miles are on them?

 

Yes, stock lifters. Changed them when I changed the cam, maybe 6k miles ago.

 

Got the oil changed and went for a quick spin. The noise is still there, but maybe not quite as loud as before. I didn't ride real far though, and didn't ride hard. It definitely seems to be the front cylinder. The rear cylinder has the typical "clacking" sound, while the front is more of a "tink" sound. Weird, but I'm not gonna sweat it anymore right now. The bike actually seems to be running a bit better than the other day, but nowhere near as well as I hoped. I hope the tune makes up for it, cause right now I'm not seeing enough of a difference to justify the money I just spent. I have a feeling I'm gonna end up having to change cams again wake this thing up.

 

Give us the prognosis Monday night. With an added 10 inches of displacement, you'd think the performance gain would have you smiling from ear to ear.

 

10 more cubic inches and head work should be like night and day, even with that cam.