Stupid Timing chain questions

[Imp558]

Doing the timing set on the next L67 and the removal/install of the can sprocket has me a little perplexed.

 

 

 

 

I see 1 method to remove the 1 1/8" bolt on the cam sprocket, clamp the flywheel to stall the engine and allow the timing chain to hold the camshaft in place while loosening.

 

That means the same procedure for tightening but I'm not really wild about doing that to my new timing set!

 

 

 

 

The cam sprocket gets tightened to 74+ 90*, then there's the matter of 116 ft Lbs on the tensioner bolt which is about 3/8" going into cast iron but I saw specs online that call it 16, so I'm sure (hoping) that's a typo.

 

My plan unless somebody chimes in is to stall the flywheel and do the job, re-installing the old chain and crank sprocket to tighten, then changing the rest of the components after using the old chain twice to hold the camshaft. Still not liking doing that to my new cam sprocket though.

 

Help!

Edited May 21, 2016 by Imp558

[Heartbeat1991]

There's no way that tensioner is 116 ft lbs.  It would snap like a toothpick.  

 

Is there enough slack in the chain to remove it with the cam sprocket on there?  

 

I would guess that the torque to tighten the bolt isn't really enough to damage the new chain anyway.  I would think it sees more abuse from normal operation.

[RobertISaar]

tensioner/damper bolt is 16 lb-ft(looking at an 04 GTP manual for reference).

 

I would assume the crank pulley would be far more likely to have issues than the cam pulley for that installation though.... the same amount of force spread out over 40 teeth as opposed to 20 is a significant difference.

[Imp558]

I don't know if there's enough slack in the chain to pull it off without taking the whole set-out. I'll be finding out here as soon as I'm done scraping gaskets. As for that torque spec I'm going to go with 16, I've also seen 18 online now, hell 30 wouldn't even bother me but I'm just going to stick with 16.

[Imp558]

the answer is no, the chain will not slip a tooth and come off on its own. so I just had to do it with my new timing set. seemed awful tight doing the 90-degree part.The 16 foot pounds on the tensioner didn't seem very tight at all so I did 16 and then another 45 degrees or so.

[Padgett]

GM really liked those torque-to-yield bolts.

 

ps GM also tried to go metric. 22 Newton Meters is about 16 lb-ft.

Edited May 22, 2016 by Padgett