Any way to tell if a timing chain is tight?

[woodie49]

Any way to tell if a timing chain is tight, short of pulling the cover and testing the play?

Since I had to pull the radiator, I am wondering if this is a good time to go a bit further and pull the timing chain and replace it. I don't know how many miles my engine has on it, but it is amazingly free of any sludge and the compression is good across all six. I suspect it might be a fairly recent rebuild, but do not know.

It seems like now would be a good time to check the timing chain as it is pretty accessible and I have a balance puller. If there is a way to determine if this is needed without tearing into it, that would be preferrable. My timing mark stays constant when being timed and I know that on a Packard 8, any bounciness is an indiaction that the chain may be too loose. Does that hold true for our L-heads?

[Niel Hoback]

Take off a valve cover and watch the valves for movement while you bump the crank over with the fan. There shouldn't be a lot of "play" between the movement of the crank and the movement of the cam and valves. You might get an idea of how much slack there is, if any.

I can do it, but I can't explain it.

[cwcars88]

Pull your dist cap off, put a socket on the crank nut, if you use a flex bar with that socket you can move the crank for and aft while watching the dist rotor. When the rotor moves, turn the crank nut the other way and you will see how much slack you have.

[Niel Hoback]

Keep in mind that will also show play in the oil pump drive gear and the tang to pump slot.

[Plymouthy Adams]

best way is with a magnetic stand on the head, dial indicator on the valve head, degree wheel on the crank...raise the valve part way, insert indicator with extension and zero the indicator, sero out the degree wheel on the crank to timing mark..(this is only going to be relative to movement test and in no way needs represent any exact degree or position of crank) and then reverse direction of the cranks and see how many degrees it will turn before moving the vlave in the oposite direction....now that you have the exact amount of degrees of slop...I have no clue what to compare this value with on a new chain as there will always be some slop..

[Don Coatney]

Any way to tell if a timing chain is tight, short of pulling the cover and testing the play?

Since I had to pull the radiator, I am wondering if this is a good time to go a bit further and pull the timing chain and replace it. I don't know how many miles my engine has on it, but it is amazingly free of any sludge and the compression is good across all six. I suspect it might be a fairly recent rebuild, but do not know.

It seems like now would be a good time to check the timing chain as it is pretty accessible and I have a balance puller. If there is a way to determine if this is needed without tearing into it, that would be preferrable. My timing mark stays constant when being timed and I know that on a Packard 8, any bounciness is an indiaction that the chain may be too loose. Does that hold true for our L-heads?

If it aint broke (sure sounds like it aint broke) dont fix it.

[power_hungry]

I'd second Don's opinion.

Don't know if it applies to these cars, but I found older GM V8s tend to run hot when the chain is stretched... valve timing is retarted.

[rustyzman]

Grabbing the crank by hand and moving it back and forth is one way to check the chain stretch. Could use a wrench too, just don't go so far as to move the cam. It is a feel thing. If you have no chain noise and no other indication of a valve timing issue, and do not need to reseal the timing cover for any other reason, you could probably safely leave it be. If the timing cover has to come off for any reason, to seal a leak etc., then I say go for it while you are there. Otherwise, you are probably fine.

[BobT-47P15]

Oh.......I thought you might tell whether a timing chain is tight if it slurs

its words, has bloodshot eyes, and unsteady on its feet.

Welll....."NEV-ER MIND".

[woodie49]

I thought the same thing and began to be concerned, then I realized that was me.