Timing Belt Tension - Hear me out

Okay I know this is a pretty well covered topic, but let me explain.

Years and years ago, I did my own timing belt using the 90° twist method to tension and it was fine forever after.

Recently, I finished a rebuild and slapped on a new belt. Gave it the 1/4 turn test and away I went. However, I noticed the belt riding quite to the outside after the engine warmed up (expanded).

So, I got the special tool to tension the belt, which ended up being almost exactly the same as what I had set. Still, belt seemed tight.

So I loosened the belt tension even a little bit more. I'm not sure if it'd be safe to go any looser, but when the engine warms up the belt rides on the outsides still.

The only difference here other than a new belt is that I put on a fidanza adjustable cam sprocket I bought from TU. I know the aluminum is going to expand more than the original sprocket would, but this seems excessive.

Below is a link to a Google album containing 4 videos.

1: Belt tension cold engine (77°F outside)

2: Belt position running cold - seems fine here.

3: Belt position running hot - also I rev it a couple times, was hearing a somewhat metallic sounding resonance from the valve cover area. You hear it most when the engine comes back to idle in the video. Not sure if that's from the forged pistons, the 3.3 springs and GM retainer mod, just a normal sound for these engines, or something to be worried about lol.

4: belt tension after shutting down hot engine.

Is this going to be a problem?

Should I loosen the belt even more? I don't particularly like how snug it gets when warmed up, but I'm just not sure how loose you can go on these belts..it seems so sloppy when cold already.

https://photos.app.goo.gl/mYy1xoJqiGc92Nk99

I would check and make sure you crank sprocket is on all the way on the crank. Not totally sure if the applies to you since my experience is with the 2.4 but I know that this will determine where the belt rides on the cam gear.

Pretty sure it's on there all the way
You can see in video #2 (engine running cold) the belt rides dead center.

Tension it with the correct tool.

Quote:

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Originally Posted by ajakeski

Tension it with the correct tool.

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From my first post: "So, I got the special tool to tension the belt, which ended up being almost exactly the same as what I had set."

Please take a closer look, the videos and explanation should provide enough detail to merit more than suggesting to use a tool.

Quote:

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Originally Posted by Mudman

Pretty sure it's on there all the way
You can see in video #2 (engine running cold) the belt rides dead center.

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So that's the cam sprocket/gear I'm talking about the crank sprocket that's behind the harmonic balancer. Also that belt is really loose

"EDIT" I just reread the post that you were talking about the belt not the sprocket. But I would still suspect the sprocket as it heats up it expands and could be the movment your seeing with the belt. I would either try and use a sprocket tool to move it on the crank a litter further or just roll with it because your belt should't move anymore than it moving now. I set my sprocket deep on the crank so the belt rides on the inside.

I believe there is a difference the pre common block and common block tensioners in regard to how far they sit off the block. Do you think that could have something to do with it? I’ve always wondered how often situations like this are the result of that situation. I haven’t researched it enough to have any real info…

Yeah I am aware of the difference in spacing, but I never replaced the tensioner pulley for this engine. If it's the wrong one, it's been that way for the 15 years I've had this car lol

I think it's the correct part though because the belt rides dead center before the engine warms up.