Northstar Engines and System Technical Discussion Discussion, chain tension between cams in Cadillac Engine Technical Discussion; i have a 99 northstar motor with twin turbos in my sandrail. it was built by redline performance in 2004. ...
i have a 99 northstar motor with twin turbos in my sandrail. it was built by redline performance in 2004. i am replacing the head a head gasket on the right bank and while i was rotating the motor by hand i noticed that between the cam sprockets that there was differnt amounts of tension on the chain as i rotated the motor. could it be the chain has streched ? and is it something i should replace ?
thanks for any input on this !
would that make a differnce when its between the 2 cam sprockets ? i would think the chain should keep the same tension between the cam sprockets and it goes from i/16'' of slack to about i/2'' slack in a couple places while rotating the motor. the tensioner keeps the rest of the chain tight ?
Automobile(s): 2002.5 F55 STS/64500mi, 2004 Ford F150 SuperCab4x4
MD Eastern Shore - Kent Island
Re: chain tension between cams
Depending on the orientation of the cams as the engine is rolled over it is likely there would be one or more "soft spots" in the cam timing: valve spring pressure is what a cam works against, so it's entirely possible that the long (tension) side of the chain run could have a tad of slack at some point. That's what the slippers (chain guides) do - damp out the slack spots. The tensioners take the slack out of the non-working side of the chains, and there is no way the crank or cams can rotate backwards enough to prevent that slack spot.
I believe it's a non-issue. You could always line up all the timing marks, pull the sprockets and chains and replace the chains, tensioners and slippers - but that's an expensive PITA.