Timing chain failure
01-29-2009, 06:36 PM
#21
Staging Lane
Thread Starter
iTrader: (1)
Join Date: Mar 2008
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
I checked my receipt from Vengeance racing today when the pulley was installed. It was an ASP 25% underdrive pulley. Thought I would let everyone know. Funny thing is that the guy that does my work on the car locally has installed several ASP pulleys and has never experienced a chain failure, even with the same chain that I was running. I guess that's just my hard luck.
01-29-2009, 06:41 PM
#22
Staging Lane
Thread Starter
iTrader: (1)
Join Date: Mar 2008
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
I guess that the best thing for me to do is to go back to the stock pulley. This sure hurts since I was at 491RWHP and was installing electric cutouts to try to see that magical 500RWHP. I guess the 346 at 500 will elud me now. It is not important enough to sacrifice breaking parts to do it. I guess I should have tried to do it with a vehicle that has a solid rear axle versus trying to do it with this CTSV drivetrain. I probably could have done it with a different car. Oh well, it is what it is.
01-29-2009, 08:04 PM
#24
Staging Lane
Thread Starter
iTrader: (1)
Join Date: Mar 2008
Posts: 91
Likes: 0
Received 0 Likes
on
0 Posts
It is no more than a 10 RWHP loss. I can't afford to run it, when my shortblock and a fine set of heads are at risk. That amount of horsepower is just not worth it to me. If I were in racing class than 5 RWHP were to make the difference between winning and losing, it would be different.
01-31-2009, 12:31 AM
#25
On The Tree
iTrader: (8)
Join Date: Apr 2007
Location: Missouri to Georgia
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
SO are we just saying its just ASP or all underdrive pulleys?? I have a Summit underdrive pulley on my car that has 107XXX miles. I'm sure that I broke or jumped time on my 01 Camaro. I will have more info tomorrow when I have it all apart.
02-10-2009, 01:48 PM
#27
Launching!
With great respect to all whom posted (and there are some notable, knowledgeable posters in this thread), and no, I have ZERO affiliation with ASP (would be good to have them chime in actually), I think it may be "fuzzy logic" to suddenly condemn ASP pulleys, claiming they are the "smoking gun" to cam chain failures..
Point #1 - I would put money on this - for every 100 ASP pulley sold, 3 Powerbond's and 2 ATI's are sold. Just on sheer volume, and considering ASP is by far the most popular aftermarket pulley (or was until very recently), it makes sense that *most* motors suffering cam chain failures will occur with an ASP pulley installed because *most* cars running aftermarket cams used in a performance situation have an ASP pulley installed.
Point #2 - I am not discounting the importance of a properly designed dampener, however.. The stock dampener has an aluminum hub / center, and is around as light as one of the lightest aftermarket pullies (ASP). Yes, I understand there is much more to this than shear weight, I am sure ATI can explain the complexities in great detail, and I know they are vast. Still, just look at racing motors that basically eliminate any sort of crank-mounted dampener. Yes, race motors have parts swapped all the time, and that brings me to the next point.
Point #3 - Making the logic jump that employing race-bred parts (whether it be a timing chain, dampener, valve springs or anything else for that matter) results in a "bullet-proof" build when subjecting said parts to the same conditions experienced by a racing team (say, road race track car (like the 04 Z06 mentioned in this thread) but without the aggressive (impractical for most of us) component replacement schedule.. Think about it - I have no proof (Jason does), but do you really think the GM team manager saves a few bucks by leaving in that super expensive - heavy duty "bullet proof" TC between rebuilds (which happen in hundreds of miles, not tens of thousands)? Its apples to oranges folks.. Saying "GM racing has never had a failure with XYZ TC" is like saying "my African Elephant repellant works great; haven't seen one in my back yard yet"..
Bottom line IMHO..
When it comes to timing chain reliability / survivability, I would think the order of importance is as follows;
1. Use - driving style and type - road racing / constant wrapping up to redline / downshifting for hours at a time is certainly harder on components than 1/4 mile runs and street driving.
2. Valve springs - if they float and valve meets piston, that creates way more load than a timing chain was designed to handle.
3. TC quality - obviously of major importance.
4. TC dampener - I am kicking myself for not installing one when I did my cam swap, but to be fair I would have had to tap the block.. And now it appears GM stopped making them, so 2 strikes for me. I have a background / understanding of chain harmonics / dynamics, and I can say with some confidence that a TC dampener is a GREAT idea, hence they are on newer GM designs from the factory, and we all know they do only what is absolutely necessary ($$).
5. Crank dampener - I am sure the size, type and design does play a factor in ALL aspects of bottom end reliability, but it is my understanding an improperly designed dampener has greater impact on crank / bearing longevity than being the likely cause of TC failures.
Point #1 - I would put money on this - for every 100 ASP pulley sold, 3 Powerbond's and 2 ATI's are sold. Just on sheer volume, and considering ASP is by far the most popular aftermarket pulley (or was until very recently), it makes sense that *most* motors suffering cam chain failures will occur with an ASP pulley installed because *most* cars running aftermarket cams used in a performance situation have an ASP pulley installed.
Point #2 - I am not discounting the importance of a properly designed dampener, however.. The stock dampener has an aluminum hub / center, and is around as light as one of the lightest aftermarket pullies (ASP). Yes, I understand there is much more to this than shear weight, I am sure ATI can explain the complexities in great detail, and I know they are vast. Still, just look at racing motors that basically eliminate any sort of crank-mounted dampener. Yes, race motors have parts swapped all the time, and that brings me to the next point.
Point #3 - Making the logic jump that employing race-bred parts (whether it be a timing chain, dampener, valve springs or anything else for that matter) results in a "bullet-proof" build when subjecting said parts to the same conditions experienced by a racing team (say, road race track car (like the 04 Z06 mentioned in this thread) but without the aggressive (impractical for most of us) component replacement schedule.. Think about it - I have no proof (Jason does), but do you really think the GM team manager saves a few bucks by leaving in that super expensive - heavy duty "bullet proof" TC between rebuilds (which happen in hundreds of miles, not tens of thousands)? Its apples to oranges folks.. Saying "GM racing has never had a failure with XYZ TC" is like saying "my African Elephant repellant works great; haven't seen one in my back yard yet"..
Bottom line IMHO..
When it comes to timing chain reliability / survivability, I would think the order of importance is as follows;
1. Use - driving style and type - road racing / constant wrapping up to redline / downshifting for hours at a time is certainly harder on components than 1/4 mile runs and street driving.
2. Valve springs - if they float and valve meets piston, that creates way more load than a timing chain was designed to handle.
3. TC quality - obviously of major importance.
4. TC dampener - I am kicking myself for not installing one when I did my cam swap, but to be fair I would have had to tap the block.. And now it appears GM stopped making them, so 2 strikes for me. I have a background / understanding of chain harmonics / dynamics, and I can say with some confidence that a TC dampener is a GREAT idea, hence they are on newer GM designs from the factory, and we all know they do only what is absolutely necessary ($$).
5. Crank dampener - I am sure the size, type and design does play a factor in ALL aspects of bottom end reliability, but it is my understanding an improperly designed dampener has greater impact on crank / bearing longevity than being the likely cause of TC failures.
Last edited by Dan_the_C5_Man; 02-10-2009 at 11:44 PM.
The following users liked this post:
grinder11 (03-27-2022)
02-10-2009, 01:59 PM
#28
Launching!
02-10-2009, 02:22 PM
#29
TECH Enthusiast
iTrader: (1)
Join Date: Dec 2006
Location: Shelbyville, IN
Posts: 525
Likes: 0
Received 0 Likes
on
0 Posts
I would also say that although you may be right about the 100:1 ASP/ATI thing...I would say that ratio is MUCH lower in racing applications.
Somebody that's going to race their car hard and competitively is not going to throw the "cheap" stuff on. I'd say the ratio may be in the single digits as far as that goes. And absolutely NO reports of a motor with a ATI balancer snapping a chain.
Just playing Devils Advocate.
Somebody that's going to race their car hard and competitively is not going to throw the "cheap" stuff on. I'd say the ratio may be in the single digits as far as that goes. And absolutely NO reports of a motor with a ATI balancer snapping a chain.
Just playing Devils Advocate.
02-10-2009, 04:30 PM
#31
Launching!
Here is an (apparent) ATI - involved failure.. I am sure it will be blamed on the underdrive percentage. Enjoy.
http://forums.corvetteforum.com/c5-t...n-pistons.html
http://forums.corvetteforum.com/c5-t...n-pistons.html
02-10-2009, 05:00 PM
#32
Here is an (apparent) ATI - involved failure.. I am sure it will be blamed on the underdrive percentage. Enjoy.
http://forums.corvetteforum.com/c5-t...n-pistons.html
http://forums.corvetteforum.com/c5-t...n-pistons.html
02-10-2009, 07:03 PM
#34
TECH Senior Member
iTrader: (96)
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,240
Likes: 0
Received 81 Likes
on
72 Posts
i agree with dan the man, i hate to see the widespread bashing that will follow all the "i can almost guarantee you it was the pulleys fault" post. if you cant 100% prove it...
02-10-2009, 08:43 PM
#36
Teching In
Join Date: Dec 2008
Posts: 29
Likes: 0
Received 0 Likes
on
0 Posts
Katech's are on sale, 20% off till the end of the month. Just bought one today paid $111.95 plus shipping
02-10-2009, 10:36 PM
#37
TECH Senior Member
iTrader: (18)
Join Date: Jun 2002
Location: NW Houston, TX
Posts: 10,036
Likes: 0
Received 0 Likes
on
0 Posts
What some people don't realize is that the ASP is not a dampener, its simply a pulley. Also, as long as you have the same spring on every valve, the timing chain will see pretty much the same load.
02-10-2009, 11:18 PM
#38
TECH Senior Member
iTrader: (96)
Join Date: Aug 2007
Location: Turnin' Wrenches Infractions: 005
Posts: 24,240
Likes: 0
Received 81 Likes
on
72 Posts
can you show any proof???i didn't think so.....my point is every thread i read from you is labeling asp for these failures, even though you say it in a round about way. and im starting to notice that others are following your advice with no proof of what you are saying is true. i never said they were or werent responsible but until you have proof dont bash what could be a completely innocent company.
02-11-2009, 11:26 AM
#39
Guys, this was a hard lesson to run. I have a CTSV with cnc trickflows and boy did I mess this up bad. I was running a 236/240 605/610 cam and did not change the timing chain. I know, you can save the remarks about how stupid that might have been. Don't crash me to bad, having to get the engine torn apart and replace the bent parts is enough ridicule. I sort of got lucky though, I only have to replace 6 valves. The pistons, push rods, and the rest of the valve train along with the rotating assembly is OK. I got lucky and the timing chain broke at only 3000 rpms. As stupid as I look, I thought I would share this to help somebody not make the same mistake that I did. Of course it will be replaced with a damn good double roller when it is put back together. Just thought I would share this to help anyone who wants to read it.
