Balancer is "friction welding"

[joespanova]

I have never had this problem before and I've been in this engine many times.

Only thing changed is the use of a 2 step at launch. ( 7000)

There were also 3 lash caps that were shot ( pitted and erroded in middle ) as well as the bearing retainer in the cam button broken. It was also welding ( fretting ) to the face of the crank gear. The lash caps were observed to be "good" just 2 months ago at a spring change.
One other change was to a .120 wall pushrod from an .080 wall.

Timing chain was also very loose...............these conditions are all unusual for this engine. One more thing , the interference fit on the valve springs , Comp 944 , was looser than they used to be. They tell me they loosened the fit because of heat.........they slip in now , some seem almost too loose................dont know if this is related to anything though.

This is a stick car , the 2 step is a big help for cutting lights BUT , does it have to go.....................is it the reason for my issues?

[joespanova]

BTW , the balancing was done by a reputable shop and have have confidence that is fine....................HOWEVER , my ATI damper is about 15 years old and has never been serviced.......read that rebuilt.

Possible issue here?

[Tom Goldman]

I used to experiance some of those issues when I was running stock crankshafts and they would crack at the #4 main.

[joespanova]

Originally Posted by Tom Goldman

I used to experiance some of those issues when I was running stock crankshafts and they would crack at the #4 main.

This engine uses a BRC 4340 crank and Howards aluminum rods

[Run to Rund]

The pushrods could hurt only if you are getting valve float, not real likely unless you were right at the edge before. I'd look to the damper first. Are you holding the engine rpm against the rev limiter? Could that be introducing vibrations?

[joespanova]

Originally Posted by Run to Rund

The pushrods could hurt only if you are getting valve float, not real likely unless you were right at the edge before. I'd look to the damper first. Are you holding the engine rpm against the rev limiter? Could that be introducing vibrations?

2 step........

high side chip is 8800

low side ( launch ) is 7000........I am on the low side chip at launch.

[Reed Granrt]

I would like to offer and opinion or opinions as I feel u may have two separate problems. It doesnt mean you do have two problems but you COULD. That is all I am referencing. We have all seen particular anomalies when we make changes and get results that we had not seen before.
With your changes you've seen in the valve area this could be a result of where you made a spring change and as a result, moved the rpm of where you picked up harmonics or even spring float that you had never experienced before. Any time you make a spring change, especially when the spring has physical changes, you can alter the rpm where harmonics can or cannot start. Even within a production run of springs, there can be a slight change of rpm harmonics.
Now on the harmonic balancer and or balance. Call ATI and you will find that they will tell you their balancer should be rebuilt ever so often. Also each harmonic balancer(whether it be 2 ring , 3 ring or more)is designed to work in a different RPM range. Also as the elastomers get older, you can see a change in the rpm that the balancer works so again my recommendation is call ATI for what you are doing.
These are strictly observations from the limited data you have given and most definitely not the gospel but may provide you some thought points.
Good luck

[Sean Marconette]

Just curious, how long is it sitting on the limiter? That could also be a problem with a load/unload condition.

Sean