fhturner

Hey Guys--

Sorry to tag onto the end of an older thread, but y'all seem to be talking about something I need help with. After breaking my LS6 chain, I'm debating doing a double roller chain, or just using the LS2 part. Could you weigh in w/ your opinions, given my situation:

- TSP LS2 402 w/ Texas Giant camshaft 248/254, 610/622 lift, LSA 114 (or 112? I forget)...in any case lots o' lift!
- Comp 921 valvesprings on AFR205 heads
- making about 520HP (~440RWHP)
- will probably open up intake tract w/ FAST90, 90mm TB, and better intake, so expect a bit more power
- road racing/HPDE application, so sustained high RPM usage
- no street usage

This motor was a conversion from my '01Z broken LS6, so although I have the LS2 timing chain sprocket w/ the cam sensor "lobe", AFAIK the LS6 chain was left on there. Unfortunately, this broke at Road Atlanta a few weeks back w/ no more than 1500 track miles on new motor.

So, my dilemma is whether to go the simpler, yet possibly still effective route w/ the beefier LS2 chain; or to forge ahead w/ a double roller, given that I may have potential oil-pump shimming and cover clearance issues. Given my usage and setup, could you share your thoughts and recommendations?

Thanks!
Fred

vettenuts

If you are doing a lot of high RPM running, then the GMPP timing chain damper will help as well with broken timing chains. The LS2 chain or the Katech single chain should work. I have the Katech timing chain, same one they used on the C5R but then again when I did my swap the LS2 wasn't available. This is the GMPP damper installed.

fhturner

Thanks for the info, vettenuts! I looked around a bit, and it looks like there's an earlier, more expensive (~$95) LS1/6 timing chain damper, as well as a newer, inexpensive LS2 damper. Just wanted to add that tidbit and list the part, #12588670, for anyone else interested. That one is only about $12.

Thanks again,
Fred

Russ K

The beige damper (early) has a greater distance between the bolt holes than the late damper (black). On my 2001 Z06, I had to drill & tap the block to use the beige damper. The raised bosses on the block were to far apart to use the black damper. My friend's 2004 Z06 block was drilled & tapped from the factory. The black (late) damper bolted right on.

This is the late damper installed on the 2004 Z06.



This is the early damper installed on my 2001 Z06.



Russ Kemp

vettenuts

Nice photo's. If you can envision it, from what I understand, the chain tries to stay wrapped around the lower sprocket and the damper ensures it doesn't. I have read this can lead to broken timing chains.

RED99

I had noticed that too when I put in a LS2 last winter. I wonder if the slack is there because the block is aluminum to allow for thermo expansion? Or what? Does the aftermarket chains fit tighter?

BATM4N

flynbya2

So,is there any advantage between the two of these?
Other than the fact if you choose the correct one,there is no drilling/tapping to be done?

vettenuts

The earlier (beige one) was never installed by GM as a cost savings measure from what I read. So its available for over $100. The black one is standard on the LS2 and in production, hence $12. The only difference is cost and bolt spacing and you either have a block drilled for the earlier one, or if an 04 drilled for the later one, or not drilled at all.

flynbya2

As in a 98 block,for example,you would still need to drill for either one you chose?
If that is the case, the black one is more cost effective.

Also,as far as drilling and tapping goes,you guys do this with the motor in the car? Plenty of meat there for drilling I take it?

Wouldn't want to aerate the block too much

Please excuse the mini-hi- jack

vettenuts

When I bought mine, it actually came with a paper template to drill the block. Tape it on and drill/tap. Not sure if there were any minor changes to the block that would not allow the use of the newer cheaper design on an older block. It seems a little odd that GM would change the spacing, I would have though it would be cheaper to just start making them for the holes already in the block. You should see if you can fish up some photo's of an LS2 block and an older LS1 block in that area to see if there are any readily apparent differences.

flynbya2

Thanks,once again, for your excellent advice

Russ K

Like I said in my earlier post, the bosses in the earlier blocks are too far apart to allow using the black (late) damper. I tried the black damper, but the bolt holes would miss part of the raised bosses.

Russ Kemp

This is my 2001 Z06 before drilling & tapping the block.


After drilling & tapping