:cornut: Yeah I see that Nathan. But it appears to me that the male piston was grinding(up and down) in the female cylinder. Doesn't the piston travel in and out of the cylinder also? Jason
There's also scuff marks higher up on the cylinder, too. Was the crankshaft balanced when the engine was rebuilt? I'm thinking the tensioner could be not just the cause but a symptom of something else vibrating.
If this is the third design made on the tensioner.... It's quite possible the piston is supposed to rotate so you don't get a concentrated wear spot like the 100,000 mile example.. If it's not a deliberate design function, well then...... It still bothers me that they are "crunchy" when new..... That shouldn't be the descriptor for a close tolerance part.....
Might have fixed this today with the help of Jan, Chad and Anson of Best Motor Werks. The rattle was back and really bad. Doing some more investigating it was determined that the head was decked at the last rebuild, but only 0.002 was removed. Not enough to really make a difference. However, that's not the first time it was decked and the amount shaved off in total is not known. The brain trust was thinking the tensioner did not have enough reach in it to pick up the slack. Since it had been making the noise on startup for some time it was also determined that there may be wear on the plastic chain guides too. We thought it might be best to give the tensoner a bit more reach before going in and replacing all the guides, sprockets and chain. Figuring it could be an inexpensive fix if it worked. So...how to give the tensioner a bit more reach? A washer! So far, so good. No more chain rattle. I tell ya, it's great to work with people and shops that think outside of the box. Try to get a dealer service dept to add a washer like that.
Wow the head was decked & maybe more than once! Wonder why I never mentioned that to you. Guess I'm getting forgetful. :crazy: Glad you got it working!