On a L98 How often are you guys changing the timing chain? I have the Water pump off but really don't feel like doing it.
I read how to check it somewhere without pulling the timing chain cover but have since forgot it.

 

Well I changed it when I did my cam and heads, it broken 6 months later taking out all my push rods and valves. Maybe I should have left the stock one in.

I wouldn't recomend it unless you have very high miles, like 200k

 

Wow! Whose timing chain did you use?

 

I did the chain on my 84 at 145K, and it was VERY sloppy. If you have to remove the water pump anyway, you're a good ways there already. If you have over 100K on the car, it's a good idea. Yeah, it might go 200K before breaking, but are you willing to risk trashing your motor over $30 worth of parts and a few hours labor?? Replacing a worn timing chain is cheap insurance for long engine life.

Things I noticed after I did my timing chain; A noticeable increase in power, smoother idle, higher vacuum signal, and a timing mark that didn't bob all over the map when I put a timing light on it.

I decided to do my chain when the harmonic balancer disintegrated and tore out the timing cover seal as the outer ring did the Macarena on the hub.

It's not a particularly hard job, just time consuming. I do recommend lowering the oil pan. Though some say it can be done with the pan in place, it's much easier with it off. I also recommend removing the power steering lines from the rack.....not necessary to get the balancer off, but necessary to mount the tool to put it back on.

Set the timing marks with the crank sprocket at 12:00 and the cam at 06:00, reassemble the same way. Rotate the engine one time by hand before putting the cover back on to ensure that the marks really do line up. While this job isn't particularly tough, it would suck to have to do it twice.

If you want to get a ballpark idea of how much slack is in the chain, line up the timing mark in relation to the scale on the harmonic balancer. Now pull the distributor cap off and turn the engine by hand until the rotor moves. Stop, mark the location of the balancer, now rotate it backwards until the rotor moves again. Make another mark, and count the number of degrees between movement. Divide that by 2, and you have a rough estimate of how many degrees your timing is retarded from a sloppy chain.

If you have over 100K on the engine, do the chain while it's apart.

 

its not hard, go ahead and do it. My stock one had nylon teeth, some were sheered off. The stock on is crap IMO. Go with a cloyes.

 

not to steal the thread but on the subject of timing chains. im plannong on using the GMPP "extreme duty" timing chain when i do my cam swap. im going a little bit more extreme than the hotcam but i heard this chain will hold up to just about any kind of power you can put to it. is this true?

 

Agree with Frizzle (good post)

My timing chain gear stripped at 180K and took the engine with it.

Yes you can do it without dropping the pan. I have done it on mine and again on a friend's 85. BUT, it is a royal pain and you will use words not normally in your vocabulary. Also, you really need to trim off some of the inside tab on the chain cover to get it to go in. Plus there is some technique to it that is best demonstrated and hard to describe.

My opinion: drop the pan, replace the chain. Or since you have it this far apart just pull the engine and put the 383 stroker in that you wanted anyway.

 

Now THERE is an excellent idea...

Doing the timing chain also gives you a great opportunity to clean things up a bit. Look how nasty mine looked when I tore it down.



Also good time to replace the two rubber fuel lines with new stuff, as they aren't getting any younger.

 

This thread is Gen I oriented. *I* don't know how good that chain is, specifically. I do know you don't have the range of options us Gen Iers have.



One of those "best demonstrated" methods, involves using two Phillips head screw drivers through bolt holes in the timing cover, into their holes in the block. By pushing downward on the screw driver handles, you can compress the seal between the cover and the pan, far enough to slide the cover to the block over the dowel pins. MY method included copious amounts of "The Right Stuff" and no seal.

RACE ON!!!