L28ET Timing Chain guides

[Oddmanout84]

So for a while now (since about mid winter when I replaced my clutch is when I first noticed) I'd been hearing a strange rattling sound from within my motor. Usually it just did it while it was cold, then the sound lessened and went away once it heated up to running temps. Now since last Friday its been doing it at all temperatures. I went to a Car/Food/Beer meet over the weekend and started the motor up so I could get some others to lend their opinions. Even a Datsun vet with more experience than years in my life could not pinpoint the noise with my stethoscope, however someone remarked that it sort of sounded like timing chain noise. So when I got home I popped the valve cover to check everything. This is what I've found so far.

 

 

Its difficult to see, but that guide on the left "tight" side of the motor looks to be worn all the way through the friction coating to the metal. This would explain the noise. What it doesn't quite explain is that this motor only has about 5000 miles on it since it was rebuilt. This seems quite excessive for that low amount of mileage. You also can't see it, but the tight side chain guide has a slight curve to it. Looking at the guide I recently pulled from another L28ET, I can see that its perfectly straight. Is there a difference between the timing chain guides over the years? Possibly this being the guide meant for and earlier L24 or L26?

 

I wasn't the one who rebuilt the motor, I was lucky enough to get it from a friend who pulled it out of a car that used to frequent Limerock and Watkins Glen. I've talked to the guy who used to own the motor, but he doesn't remember everything about what he did to the motor since it was around 10 years ago. I've done minimal work to it, only checking torque on the essential bolts and studs before it was installed. Everything else I've done has been on exterior ancillary components.

 

If anyone has any input about what could have caused this at such low mileage (incorrect timing, incorrect parts, etc.) I'd appreciate it. I'm currently taking the motor apart and trying to avoid removing the oil pan (if possible) since I recently put in new synthetic.

[yetterben]

I too am getting some unknown noise that i also think is guide related. Took my valve cover off today and noticed some slight wear on the guide. Chocking mine up to stretched chain. Only does it on mine at the magic rpm of 1350.

Edited April 27, 2010 by yetterben

[Ruiz Racing]

I would get a new timming kit from autozone. It comes with everything to fix your problem.

[Oddmanout84]

I don't trust autozone to have the Japanese timing kit.

 

So I got it from motorsport.

 

Here's the guide: