Balancer is "friction welding"

joespanova · 08-22-2011, 08:46 AM

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 · 08-22-2011, 08:52 AM

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 · 08-22-2011, 09:12 AM

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

joespanova · 08-22-2011, 09:37 AM

Quote:

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 · 08-22-2011, 11:12 AM

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 · 08-22-2011, 11:19 AM

Quote:

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 · 08-22-2011, 11:32 AM

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 · 08-22-2011, 01:32 PM

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

Sean

joespanova · 08-22-2011, 02:15 PM

Quote:

Originally Posted by Sean Marconette

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

Sean

Not long , I purposely try to avoid that..........in fact I prefer "pro tree" style index racing ( 6.0 ).

I have always been skeptical of 2 steps and this may seal the deal as far as I'm concerned...............

any body know what kind of rev limiters they use in Pro Stock?

Alan Roehrich · 08-22-2011, 02:46 PM

Joe,
Given what you have posted, I'd say that the problem is that the balancer is past due for a rebuild and has long since ceased to function as a harmonic damper.

First, the elastomer o-rings in the damper will eventually fail due to age, exposure, and thermal fatigue. That is why the balancer should be returned for a rebuild at or before the suggested interval. Honestly, for what ATI charges for an inspection and rebuild, 2 to 5 years is a much better interval, and money well spent. Earlier return for inspection and overhaul can even allow ATI to tell you if your damper is the right one for your application, and if it is performing properly.

Second, if the balancer is moving on the crank, it is no longer absorbing and damping the harmonics. It is obvious that the damper is moving on the crank, that is why it is attempting to weld itself to the crank and the crank gear of the timing set. The most likely cause for this is the lack of a timely rebuild (the decal says "return every ten years for rebuild") has cause the damper to stop working, and once it stopped working, it worked itself loose.

ATI will step up and take care of your damper. They'll either rebuild it for a low price (I'd suggest a new hub, properly sized to your crank snout) or offer you a new balancer at a reduced price. Their service and support after the sale is excellent about 99% of the time.

Solving your balancer problems will probably solve the rest of your problems, as the timing set and valve train problems are most likely the result of the balancer no longer absorbing and damping the harmful harmonic vibrations. Those harmonic vibrations, if they are not absorbed and dampened, have to go some where. The logical place for them to go is into both the crankshaft, and through the timing set into the valve train. You are seeing the expected results of this in the damage done to your engine.

I do not think that the rev limiter is the cause of your problems. However, the rev limiter probably did make your problems worse. The combination of adding a rev limiter that you use on every pass to an engine with a balancer that was at the end of the life cycle between rebuilds is what you're seeing.

I seriously doubt the pushrods had any real effect, other than the stiffer pushrods may have transmitted more of the harmonics not absorbed by the tired balancer to the rest of the valve train. Weight of valve train components on the lifter side of the rocker fulcrum is negligible in comparison to weight on the valve side of the fulcrum. The stiffer pushrods are a good thing, don't take them out. Solving your balancer problems will likely solve the valve train problems as well.

08-22-2011, 08:46 AM	#1
joespanova Senior Member Join Date: Jun 2011 Location: Ga. Posts: 521 Likes: 7 Liked 13 Times in 11 Posts	Balancer is "friction welding" 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?

08-22-2011, 08:52 AM	#2
joespanova Senior Member Join Date: Jun 2011 Location: Ga. Posts: 521 Likes: 7 Liked 13 Times in 11 Posts	Re: Balancer is "friction welding" 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?

08-22-2011, 09:12 AM	#3
Tom Goldman VIP Member Join Date: Jan 2003 Location: Allentown,PA Posts: 2,473 Likes: 879 Liked 858 Times in 234 Posts	Re: Balancer is "friction welding" I used to experiance some of those issues when I was running stock crankshafts and they would crack at the #4 main. __________________ Tom Goldman 1500 SG , 1506 STK

08-22-2011, 11:12 AM	#5
Run to Rund Senior Member Join Date: Sep 2007 Location: Henderson, NV Posts: 583 Likes: 8 Liked 54 Times in 27 Posts	Re: Balancer is "friction welding" 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?

08-22-2011, 11:32 AM	#7
Reed Granrt Member Join Date: Jul 2011 Location: Murfreesboro, Tn Posts: 149 Likes: 0 Liked 1 Time in 1 Post	Re: Balancer is "friction welding" 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

08-22-2011, 01:32 PM	#8
Sean Marconette Senior Member Join Date: Mar 2006 Posts: 977 Likes: 787 Liked 274 Times in 76 Posts	Re: Balancer is "friction welding" Just curious, how long is it sitting on the limiter? That could also be a problem with a load/unload condition. Sean __________________ Sean Marconette 84 Mustang 5060 SS/N

08-22-2011, 02:46 PM	#10
Alan Roehrich Veteran Member Join Date: May 2006 Location: Murfreesboro TN Posts: 5,093 Likes: 1,537 Liked 1,766 Times in 401 Posts	Re: Balancer is "friction welding" Joe, Given what you have posted, I'd say that the problem is that the balancer is past due for a rebuild and has long since ceased to function as a harmonic damper. First, the elastomer o-rings in the damper will eventually fail due to age, exposure, and thermal fatigue. That is why the balancer should be returned for a rebuild at or before the suggested interval. Honestly, for what ATI charges for an inspection and rebuild, 2 to 5 years is a much better interval, and money well spent. Earlier return for inspection and overhaul can even allow ATI to tell you if your damper is the right one for your application, and if it is performing properly. Second, if the balancer is moving on the crank, it is no longer absorbing and damping the harmonics. It is obvious that the damper is moving on the crank, that is why it is attempting to weld itself to the crank and the crank gear of the timing set. The most likely cause for this is the lack of a timely rebuild (the decal says "return every ten years for rebuild") has cause the damper to stop working, and once it stopped working, it worked itself loose. ATI will step up and take care of your damper. They'll either rebuild it for a low price (I'd suggest a new hub, properly sized to your crank snout) or offer you a new balancer at a reduced price. Their service and support after the sale is excellent about 99% of the time. Solving your balancer problems will probably solve the rest of your problems, as the timing set and valve train problems are most likely the result of the balancer no longer absorbing and damping the harmful harmonic vibrations. Those harmonic vibrations, if they are not absorbed and dampened, have to go some where. The logical place for them to go is into both the crankshaft, and through the timing set into the valve train. You are seeing the expected results of this in the damage done to your engine. I do not think that the rev limiter is the cause of your problems. However, the rev limiter probably did make your problems worse. The combination of adding a rev limiter that you use on every pass to an engine with a balancer that was at the end of the life cycle between rebuilds is what you're seeing. I seriously doubt the pushrods had any real effect, other than the stiffer pushrods may have transmitted more of the harmonics not absorbed by the tired balancer to the rest of the valve train. Weight of valve train components on the lifter side of the rocker fulcrum is negligible in comparison to weight on the valve side of the fulcrum. The stiffer pushrods are a good thing, don't take them out. Solving your balancer problems will likely solve the valve train problems as well. __________________ Alan Roehrich 212A G/S Last edited by Alan Roehrich; 08-22-2011 at 02:49 PM.