justin_o_guy wrote on 12/31/69 at 16:00:03:

I guess that it's obvious.

Well, not planning on selling it. I guess there's no explaining how I treat that thing. I try to ride it nice & easy, just can't.

I might just try that. Synth oil , hmm.

Today I was just replacing my timing chain in the '95 engine I have, and thought I would put in my $0.02 since there seems to be some weirdness going on with these chains and tensioners.

I recently bought this engine used, it was still running but was making a hellova racket, which turned out to be severe chain noise.  The tensioner had ratcheted out beyond the end of the plunger rack, popped out and was about to let the main spring loose into the case.

After pulling out the chain and measuring the 20 links as per the SSM, I found the chain was still within tolerances.  128.3 mm vs. the 128.9 wear limit in the book.

Why would the tensioner plunger pop out if the chain was in spec?  This was a factory build, so there was no shaved head or any other apparent goofiness.  Why was the chain so loose?

I put in a different known good chain, but the new tensioner was still about two clicks from bailing out like the last one.  This was unacceptable.

So my solution was to modify the main tensioner guide.  This guide has a metal insert for strength, so I carefully bent it to provide a longer curve in the center.  Adding this mild curve allowed it to take up more chain slack than the stock shape for a given displacement of the tensioner.

Once I installed this mod the plunger of the tensioner ratcheted out to only 10mm (measured between the plunger shoulder and tensioner face) before it tightened the chain completely.  This means that about 2/3 of the plunger rack is still within the tensioner body.  Much better...




If I succeeded in loading the pics right (I am a newbie to this forum stuff, as you might be able to tell) you can see the slight bend in the top one vs the bottom one.

So, I'll fire it up tomorrow and find out whether I fixed it or whether I have a new boat anchor.  

I'll let you know what happens...

Thanks for that input & best of luck.

So, you tweaked the left side chain guide in?

Thanks for the welcome!

Looks like I got the pics in there.  So now you can see the mod (aka tweak) I was talking about.  I think this may also reduce the wear on the guide since its no longer concentrated at the sharp corner at the bottom.

But I'll be happy if the engine runs ok and just doesn't implode on me.

Now I can see why if the chain is with in wear limits that replacing the guide is required!

Thanks Aeres!  

Aeres wrote on 12/31/69 at 16:00:03:

Cool! I will also do that to mine.

The thought about the synth oil is a good one too. I think I'll switch to synth from here on out and see what happens. I haven't made any long term decision on keeping my '02 but I can at least start the long term test.

Ken