rikhek

A broken LS2 timing chain on my LS1 mild head/cam engine prompted me to install a timing chain dampener. I also put in a Katech C5-R timing chain manufactured by IWIS.

As many know the "beige" LS1 dampeners with ~2.1" bolt hole centers are no longer available. The "black" LS2 dampeners with ~1.7" centers are available. Problem is the bolt hole centers on the "black" dampeners don't match the bosses on the LS1 block.

The solution we came up with was to modify a "black" dampener. We milled out a little of the inner webbing on a "black" dampener and fabricated two 0.125" aluminum inserts and bushings. Measured proper bolt hole spacing and drilled the inserts.

Also had to drill and tap my block to install. Some early LS1 blocks came from the factory drilled. Mine did not.

Probably would have been easier to buy a chunk of nylon and trace out a pattern using a "black" dampener, however, we were unsure of the type of nylon to use which would stand up to the application....

Photos are provided below. I don't have a photo of an unmodified "black" dampener but a link to one is provided.

On a closing note, damage to my engine was limited to the heads. Had to replace all valves and have them milled. Lot of labor and money....

http://www.crateenginedepot.com/stor...P2276C119.aspx


Rick

96CollectorSport

Just out of curiosity what balancer do you have on the car?

rikhek

TSP 5.3L Stage 2.5 heads, TSP 228/228 on 112 LSA cam, Powerbond 25% underdrive pulley, LS7 clutch, K&N FIPK intake, TPIS Headers, Random Tech high flow cats, X pipe, '04 Z06 suspension (i.e., springs, shocks & sways), DRM brake ducts, Phoenix spindle mounts.

96CollectorSport

The reason I ask is because there seems to be a link between broken timing chains, road racing and some aftermarket balancers.

I've been reading over some threads on LS1tech and it seems if you are road racing the only choices for balancers are either stock or ATI with the softer rubber, otherwise you may have issues.

One way to tell if it's a balancer issue is to see if your old chain has stiff links, if some of the links are stiff I would look into replacing the balancer.

Here is a link to the thread on LS1 tech, I know it's a LS3 that they are talking about but there is some good info on chains in this page.

http://www.ls1tech.com/forums/genera...n-failure.html

Just thought it may be relevant to your issues.

rikhek

I was pretty sure you were headed to the "balancer topic" when I read your question. I've read all the posts I could find on the issue and am pretty convinced the balancers are not a contibuting factor. Numerous tuners have checked them out and discount this theory.

LPE are thought highly of and they are on record stating they don't believe the balancer is an issue.

Common thread as far as I can tell on all broken chains is H/C and road racing usage. I don't hear of chains breaking on road raced cars with stock engines, myself included. My stock motor was fine for almost 3 years of RR usage. Fourth track event with my H/C motor and it broke.....

My broken chain was not kinked or stiff.

Here's a "little" more reading material.

http://forums.corvetteforum.com/c5-t...ing-chain.html

http://forums.corvetteforum.com/c6-t...ain-break.html

http://forums.corvetteforum.com/c5-t...-vs-stock.html

http://forums.corvetteforum.com/c5-t...ain-slack.html

http://forums.corvetteforum.com/c5-t...ngest-one.html

http://forums.corvetteforum.com/c5-t...g-chain-2.html

http://forums.corvetteforum.com/c6-t...now-c-o-w.html

http://forums.corvetteforum.com/c6-t...ter-403-a.html

FWIW


Rick

96CollectorSport

Best of luck with the new set-up I just thought I'd share the info.

Oh and IMHO LPE isn't a place you want to build your road race motor, I have first hand experiance with one such example. If you want good solid info on a road race motor don't screw around ask Katech there is a reason that you don't see the C5-R / C6.R's blowing motors.

Joel

redazz

thats right

Rob's 73

Oh Great! My LPE short block is on it's way. I am however using Cloyes IRL chain, Crane billet lifters and an ATI pulley.

Bill Curlee

waddisme

When I was building my h/c/i LS2, there were quite a few threads in C6Tech with timing chain issues. Common denominator seemed to be underdrive pulleys, so I skipped it on mine and also went with IWIS chain. It just seemed like too much risk for small hp gain. I have 8 track days so far with no issues. I didn't want to take a chance with new motor. Good luck with yours.

ZexGX

Not sure this helps the OP much, but it may help others... Somebody is selling (differently) modified LS2 dampeners on eBay (last I checked). Here is my post on the eBay version that I picked up:
http://forums.corvetteforum.com/c5-t...s6-blocks.html

GettReal

Do all LS blocks have a dampener? I can't remember seeing one on mine?

travisnd

This is why I spend the extra coin on an ATI and only get the 10% underdriven unit. For a long time ATI wouldn't make a 25% unit because they couldn't achieve the dampening levels they wanted, but I guess they gave way to market pressure.

I ran a LS2 chain and ATI on my old cam'd Z06 and the same setup on my current TTA/PTA car.

Bill Curlee

Some blocks have the drilled holes but NONE have the damper OEM. You have to add it (If you have the drilled holes)