5.7L timing chain slack, issue or not?

[tfret]

1984 5.7L Mercruiser with about 850 hours. It's been well maintained and still runs pretty good. I've determined by moving the crank pulley while watching the distributor rotor, that I have 6 degrees of "slack" in the timing chain. My question is: what impact does this have? If it would make a noticable change in performance or economy I'll change it. If I won't notice any difference at all, then I guess it's not worth the effort. Please advise.

 

[wifisher]

Re: 5.7L timing chain slack, issue or not?

I think it would be hard to tell how much slack you have that way. You may be simply see backlash in the dist. gear. If there is play in the timing chain, I would definitely pull the timing cover and check it out. I doubt you will notice a change in performance, but worn engine parts have a way of breaking at the most unfortunate time possible.

 

[Bondo]

Re: 5.7L timing chain slack, issue or not?

Ayuh,... I don't see any Problem...

 

[mkast]

Re: 5.7L timing chain slack, issue or not?

If you are rocking the crankshaft back and forth, to find out how much movement the crankshaft makes before the distributor rotor turns, you're not getting accurate information.
Keep in mind, the engine, when running, only turns in one direction, not both.
If you removed the timing chain cover, while the engine is running, you would see a tight chain in the direction of rotation, and slack on the back side of the chain.
In short, you are worrying about nothing.