Stock timing chain crank sprocket p/n NG!

[Keller]

Against my better judgement, I'm going to dig in and do a timing chain on my '87 T before the Nats. While I'm at it, I have a new set of radiator hoses, water pump, and a few other goodies. I'll also get the radiator rebuilt while the motor is down. There are also a set of RJC pullies to reward the car for putting up with the surgery.

So I went to order the chain and such. You have to order each piece separate from GM: chain, cam sprocket, crank sprocket, cam button (yes, I'm using the roller one), dampener, dampener spring.

So, Mr. Goodwrench is typing away and...turns out the crank sprocket is not available anymore. *sigh* Now, this is the same chain used on all the RWD V6 cars (4.1 Buicks, too) so there are a lot of them out there. How could they discontinue this?

So...what to do? I've got the rest of it coming. Use the existing crank sprocket? (Nearly 70k on it) Go with an aftermarket piece? (This is a car that is just in the high 11s and won't be going much faster, but I don't like surprises.) Use an aftermarket crank sprocket with this whole shebang?

[Keller]

Well...the rest of my goodies are here. Any suggestions before I get the wrenches out?

I'm in a clue-free zone here...

[turbowanabe]

Scott- I ran into the same exact problem as you on the timing chain crank sproket, however, Eric aka turbofish38@hotmail.com has some new GM crank sprockets left and he was nice enough to sell me one. He said he still had some left, so give him a try- he is a really nice fellow- HTH's

[arthdgls]

Scott HARD DECISION TO MAKE THE CALL. JACK MERKEL RECOMENDS A TRUE ROLLER CHAIN AND DOING AWAY WITH THE DAMPER. BUT I UNDERSTAND THE STOCK CHAIN IS MORE COMPUTER FREINDLY (KNOCK SENSOR).I KNOW A TUNING TRICK FOR OTHER INJECTED GM ENGINES THAT WORKS GREAT AND MAY APPLY TO THE TR AS WELL. WHEN REINSTALLING THE KNOCK SENSOR PUT AN EXTRA LAYER OF TEFLON TAPE ON THE THREADS AND TORQUE BACK SLIGHTLY LESS THAN SPEC THIS WILL DESENSITIZE THE KNOCK SENSOR A BIT, BUT BEFORE ANYONE TRIES THIS ON A TURBO CAR THEY SHOULDE BE CAUTIOUS AND KEEP IT OUT OF DETONATION. ALSO I HAD A BAD EXPERIENCE IN THE PAST BY NOT INSTALLING A NEW CRANK GEAR WITH TIMING SET, THE NEW CHAIN WORE PREMATURELY. ARE THE NORMALLY HIGH QUALITY CLOYES AND MELLING TIMING KITS JUNK FOR THE TR

[Keller]

Could go with a new Clevite crank gear, ordered separately, and add it to the mix. See http://www.partsamerica.com/ProductD...pe=164&ptset=A The stock style chain is unique because the plasic teeth on the cam gear avoid noise to the knock sensor. Better idea than trying to deaden its sensitivity

Would rather avoid the roller chain. This is only an occasional racer, and just a high 11 car, so its not working the motor that hard.

I may just order up that crank gear while I work on an angle or two to get a GM one.

Any opinions or thoughts appreciated.

[Keller]

Through lots of finagle-ing I now have both a GM and Clevite crank gear. Both are discontinued. I will get pictures of both up on the site with analysis of each. Its a tough call.

I will probably wait awhile and do nothing for now.