SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: JAY on May 14, 2009, 05:28:59 PM

Title: timing chain slack how much?
Post by: JAY on May 14, 2009, 05:28:59 PM: on the slack side of my timing chain how much play is accepable??

thanks
jason
Title: Re: timing chain slack how much?
Post by: GT Jets on May 14, 2009, 06:31:59 PM: Jay, what kind of motor bro? A big block Chevy approx 3/8", a small block Chevy like 1/4", dont know about the Ford stuff, but betting this is close...

A good way to test this is with a degree wheel on the crank and rotate the crank with a breaker bar, you should not see more than 2-3* of crank rotation before the rotor moves...May need to move it back and forth to get a good read.

GT
Title: Re: timing chain slack how much?
Post by: beerjet on May 14, 2009, 07:31:14 PM: Really Glen ???
I had a timing chain once that resembled a bicycle chain.
I replaced it and my shut down issues went away.
As a side note, the new chain was tighter than a snare drum.

-beerjet-
Title: Re: timing chain slack how much?
Post by: GT Jets on May 14, 2009, 09:07:53 PM: Quote from: beerjet on May 14, 2009, 07:31:14 PM
Really Glen ???
I had a timing chain once that resembled a bicycle chain.
I replaced it and my shut down issues went away.
As a side note, the new chain was tighter than a snare drum.

-beerjet-

Clarification/disclaimer.......... ;)

I was assuming we were talking about a "broken in" deal, not new....That being said, a timing chain stretches like you can't believe, they can go from very tight to really loose in a very short amount of run time....

The knarlier the valve spring/cam, the more they stretch.....The degree wheel check is the tell tale...BTW, I never heard of a loose TC giving "shut down issues", only funky idle problems and torn up distributor gears.

GT
Title: Re: timing chain slack how much?
Post by: IRRebel on May 14, 2009, 09:51:59 PM: You mighta hit it there Glenn., and answered the riddle. If the TC was bad enough to fugg up the dizzy gear a bit (and prolly the cam gear as well), new TC, well cures the "problem", at least momentarily in my lil brain.

Ray
Title: Re: timing chain slack how much?
Post by: JAY on May 15, 2009, 12:08:56 AM: Quote from: GT Jets on May 14, 2009, 06:31:59 PM
Jay, what kind of motor bro? A big block Chevy approx 3/8", a small block Chevy like 1/4", dont know about the Ford stuff, but betting this is close...

A good way to test this is with a degree wheel on the crank and rotate the crank with a breaker bar, you should not see more than 2-3* of crank rotation before the rotor moves...May need to move it back and forth to get a good read.

GT

ya its a bbc and its at 3/8 much apperciated..
Title: Re: timing chain slack how much?
Post by: HDriderTH on May 15, 2009, 10:14:15 AM: Quote from: JAY on May 14, 2009, 05:28:59 PM
on the slack side of my timing chain how much play is accepable??

thanks
jason

If it's in question, change it. Was your timing light bouncing all over the place? Another thing you can do while it's together is take off you dist. cap and rotate motor by hand then reverse it, see how far you can turn crank before rotor starts to move...The end
Title: Re: timing chain slack how much?
Post by: HDriderTH on May 15, 2009, 10:17:13 AM: I've seen 'em waer a hole in the cover before...Nice