Picked up an eBay LS1 timing chain dampener (PICS)
04-18-2011, 01:24 AM
#1
Picked up an eBay LS1 timing chain dampener (PICS) So, for those of you that know what a timing chain dampener is, then you can skip the next paragraph. I picked up a timing chain dampener for an LS1/LS6 (not LS2 or LS3) on eBay, since somebody here in the USA decided to reproduce them. The OEM have long been out of stock, and their future availability is in question, so I had to snag one while I still could.
Why?
I was recently doing a forged rebuild on my shortblock, and came across some info about timing chains stretching and breaking in certain continuous RPM ranges (such as during road racing). During my research, I found that GMs solution in 1997 LS1's was to insert a nylon "brace" in between the timing chain and the cam/crank timing sprockets. In the event that the timing chain would want to flex and "wrap" around itself on the cam gear, it would tap/brush on this small piece of nylon and stop the chain from stretching. GM later introduced this technology for the LS2, and redesigned it for the LS3 (which people actually change back to the LS2 style dampener due to poor reliability on the LS3 design).
The problem? GM's bean counters decided at the time that it wasn't necessary, so they only had a limited number of these pieces made for the LS1. On the blocks, they kept the mounting bosses, and on some, the holes are already machined and threaded. All the places that have the OEM dampener listed have long been out of stock, listed for over $100. A guy I know actually contacted the places that had it listed, and was not able to locate one. So, why can't you use the LS2 dampener? The bolt-center for the LS2 mounting points are not the same as the LS1 factory bolt-center for the mounting points.
The solution? Some people have modified the bolt center on the LS2 dampeners using high-temperature oil-resistant epoxy and re-bushing them. I was able to find a person selling these on eBay for under $60 shipped (at the time). Expecting it to be pretty low-quality, I went ahead and ordered one anyways to see how bad it could actually be, despite the sellers claims of "high-temperature oil-resistant epoxy" and "secure metal bushings" to hold it in place. Here are some pictures and a description of what I got in the mail. I was pleasantly surprised with the high-quality piece that I saw:
Unboxing
Package contents, bolts held in place with a rubber band on opposite side. Note the torque spec & liability disclaimer sheet (nice touch). Pen for scale
A shot of the block side, with bolts and removed bushing insert. Pen for scale
Both inserts/bolts removed, block side
Inserts in place, block side
A close-up of the block side, bushing removed. You can see how cleanly the epoxy was set and then machined away, as well as how the bushing works
Bolts/bushings removed, timing cover side. Bolt heads provide even clamping force on the piece
The epoxy passed the basic hardness test done with fingernail, small screwdriver, and other abrasive tools I could find. The hardness was nearly identical to that of the timing chain dampener, with little to no marring of the epoxy. I then contacted the seller regarding the epoxy, and he said that it was the best (of the few) epoxy that met the criteria for temperature resistance, oil resistance, and durability, and is what was recommended to him by an expert in the automotive racing industry for that type of environment. All in all, I'm pretty happy with the piece, and it will definitely be going on the next motor I [re]build. Hope this helps any of you with making the decision to purchase or not.
And a quick quote:
Why?
I was recently doing a forged rebuild on my shortblock, and came across some info about timing chains stretching and breaking in certain continuous RPM ranges (such as during road racing). During my research, I found that GMs solution in 1997 LS1's was to insert a nylon "brace" in between the timing chain and the cam/crank timing sprockets. In the event that the timing chain would want to flex and "wrap" around itself on the cam gear, it would tap/brush on this small piece of nylon and stop the chain from stretching. GM later introduced this technology for the LS2, and redesigned it for the LS3 (which people actually change back to the LS2 style dampener due to poor reliability on the LS3 design).
The problem? GM's bean counters decided at the time that it wasn't necessary, so they only had a limited number of these pieces made for the LS1. On the blocks, they kept the mounting bosses, and on some, the holes are already machined and threaded. All the places that have the OEM dampener listed have long been out of stock, listed for over $100. A guy I know actually contacted the places that had it listed, and was not able to locate one. So, why can't you use the LS2 dampener? The bolt-center for the LS2 mounting points are not the same as the LS1 factory bolt-center for the mounting points.
The solution? Some people have modified the bolt center on the LS2 dampeners using high-temperature oil-resistant epoxy and re-bushing them. I was able to find a person selling these on eBay for under $60 shipped (at the time). Expecting it to be pretty low-quality, I went ahead and ordered one anyways to see how bad it could actually be, despite the sellers claims of "high-temperature oil-resistant epoxy" and "secure metal bushings" to hold it in place. Here are some pictures and a description of what I got in the mail. I was pleasantly surprised with the high-quality piece that I saw:
Unboxing
Package contents, bolts held in place with a rubber band on opposite side. Note the torque spec & liability disclaimer sheet (nice touch). Pen for scale
A shot of the block side, with bolts and removed bushing insert. Pen for scale
Both inserts/bolts removed, block side
Inserts in place, block side
A close-up of the block side, bushing removed. You can see how cleanly the epoxy was set and then machined away, as well as how the bushing works
Bolts/bushings removed, timing cover side. Bolt heads provide even clamping force on the piece
The epoxy passed the basic hardness test done with fingernail, small screwdriver, and other abrasive tools I could find. The hardness was nearly identical to that of the timing chain dampener, with little to no marring of the epoxy. I then contacted the seller regarding the epoxy, and he said that it was the best (of the few) epoxy that met the criteria for temperature resistance, oil resistance, and durability, and is what was recommended to him by an expert in the automotive racing industry for that type of environment. All in all, I'm pretty happy with the piece, and it will definitely be going on the next motor I [re]build. Hope this helps any of you with making the decision to purchase or not.
And a quick quote:
The LS1/6 timing chain damper is tan in color and has a 2.187" bolt center. The LS2 timing chain damper is black in color and has a 1.762" bolt center. Unfortunately, some of the '04 LS1/6 blocks were drilled for the narrower LS2 bolt center so the only way to know which is correct is to measure. You should hope it's drilled for the narrower bolt center due to the lower cost of the LS2 damper.
Last edited by ZexGX; 04-18-2011 at 01:50 AM.
04-18-2011, 10:04 PM
#4
I also contacted the seller and asked about any testing that he has done on it. He got back to me and said that he bolted dampener to an aluminum block of metal, submerged that in engine oil on a hot plate, and heat cycled it for about 20 hours from room temp to 350+ degrees fahrenheit with no problems...
04-18-2011, 10:22 PM
#5
You realize there is no good reason to let that expoxy on that piece? Pull it off and use it, that expoxy is going to come apart under heat and loading and get stuck in the oil pickup etc. Its serving no purpose, those bushing will hold that in place just fine.
04-19-2011, 02:28 PM
#6
FWIW, I work on a Indy Car team (for the last 21 years). I had our carbon/composites guys spec the epoxy. We had our choice of a half dozen epoxies, but they said this is the best.
04-19-2011, 03:36 PM
#7
I wooood take a chance without the epoxy before I woooood risk having that epoxy come apart. As the chain slaps the sides of that guide the guide is going to deform and the epoxy not being a native part of that structure is going to deform at a different rate. I'd pull the expoxy and mount it, see if it moves. I don't think it will. I can tell you this, that epoxy is doing NOTHING to add to the stability or strength of that damper-guide. Now if you had a spare guide you could machine plugs from to fill the holes i'd say thats ok to try. At least it couldn't fragment under pressure, that damper-guide is going to be slapped around ALOT.
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04-19-2011, 05:39 PM
#8
I wooood take a chance without the epoxy before I woooood risk having that epoxy come apart. As the chain slaps the sides of that guide the guide is going to deform and the epoxy not being a native part of that structure is going to deform at a different rate. I'd pull the expoxy and mount it, see if it moves. I don't think it will. I can tell you this, that epoxy is doing NOTHING to add to the stability or strength of that damper-guide. Now if you had a spare guide you could machine plugs from to fill the holes i'd say thats ok to try. At least it couldn't fragment under pressure, that damper-guide is going to be slapped around ALOT.
04-19-2011, 05:51 PM
#9
I'm a little confused in the first post it says gm had these in 97 yet I've never seen them on an ls1 only later ls2/3 motors did gm ever fcatoory install them on 98-02 motors? Oh and I've got an 01 ls6 sitting in front of me but I dont see the bosses by the timing chain does anyone have any pics? If they arent tapped isnt it possible to just drill them for the ls2 style damper?
04-19-2011, 06:51 PM
#10
No, because the LS2 dampener bolt centers are too close to each other.
07-21-2011, 07:35 PM
#12
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That epoxy that the seller used is bad ****. I have seen an industrial electronics manufacturing dept. coat circuit boards in it for extreme chemical/heat resistance. It's pretty impressive. It isn't some **** you find next to permatex at the auto parts store. Anyone who doubts it doesn't know what they are talking about.
07-21-2011, 08:06 PM
#13
That epoxy that the seller used is bad ****. I have seen an industrial electronics manufacturing dept. coat circuit boards in it for extreme chemical/heat resistance. It's pretty impressive. It isn't some **** you find next to permatex at the auto parts store. Anyone who doubts it doesn't know what they are talking about.
11-03-2011, 08:43 AM
#14
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Did you ever get around to installing this? I see the "mickey mouse ears" mounting pads you referred to, but I'm having a hard time visualizing how the thing would fit in that tight space.
Edit: Nevermind, found pics in other threads.
Edit: Nevermind, found pics in other threads.
Last edited by AAIIIC; 11-03-2011 at 12:05 PM.
11-03-2011, 03:33 PM
#15
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The epoxy is prob Quick-Steel as it is very strong (18,000 psi) compressive strength and 700 or 800 lbs. lap shear and is oil , gas resistive and can withstand I believe 500 deg fahr continueous ,,,,,,,oh I forget how to spell that word .
The most important step to insure integrity is roughing up the base material even cutting into it with a blade in 2 directions and really pushing it in hard as it's setting up initially and not getting any grease in it which will weaken and slow the curing process greatly so clean hands before mixing/applying .
The most important step to insure integrity is roughing up the base material even cutting into it with a blade in 2 directions and really pushing it in hard as it's setting up initially and not getting any grease in it which will weaken and slow the curing process greatly so clean hands before mixing/applying .
Last edited by chrisfrost; 11-03-2011 at 03:38 PM.
11-03-2011, 09:19 PM
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Katech has the original LS1/LS6 tan version, I just ordered one today. Not cheap, but it's only money. 
Yeah, I saw that last night. I looked at the guy's feedback and it doesn't look like he's sold any of them before. I wouldn't want to be his guinea pig.
Yeah, I saw that last night. I looked at the guy's feedback and it doesn't look like he's sold any of them before. I wouldn't want to be his guinea pig.