Should I replace this timing chain?

[brianstrange]

68 289 (originally, not sure if it's original motor) 155K The timing cover was off before, and it has a nylon cam gear. The pictures below show the slack in the chain. I'm scratching my head. This was in a container for 10 years in New England. It doesn't smoke at all, and runs smooth. I forget how much slack is acceptable, but this seems like a lot to me.

Thanks!

 

[bronconut73]

Timing chains are cheap. If you have the timing cover off just do it.

 

[AZ73]

Timing chains are cheap. If you have the timing cover off just do it.

X2

No slack there (what you're seeing is what a new chain has after 5 min), but as long as the cover's off, replace it. I'm not a fan of nylon teeth. I am a fan of Cloyes timing chains. But do it right with press-on tool, not a hammer. Soak chain in oil before you put on, and heat the crank gear in boiling water first to expand it. You might get it on without the tool.

 

[Kbpony]

If you still have a nylon gear, I would replace it. I had one come apart on me once and it is not worth the hassle.

 

[brianstrange]

X2

No slack there (what you're seeing is what a new chain has after 5 min), but as long as the cover's off, replace it. But do it right with press-on tool, not a hammer.

Thanks guys.... will any SB Ford single chain work? I can't be certain what this motor is out of. Also, I need to button this up tomorrow, so I may have to use Autozone.

 

[AZ73]

Take block number to autozone. 65-88 small block 289-302 SHOULD be the same, but there were some specific ones for 72-2002 302-351

 

[akafrankcastle]

This is timing chain slack. Not to brag. Engine still ran, with like 20* of timing variance at idle. Burned oil like crazy. Around 105k original at the time.

 

[brianstrange]

I found some info on the Comp Cams site. I have a two piece eccentric so I can only assume I have a newer motor. "Two different length dowel pins were used in the front of the cams in 221-351W engines. In 1972 and earlier engines, a longer (1.375”) dowel pin was used so that it would extend through the one piece fuel pump eccentric used on these engines. The 1973 and later engines utilized a two piece fuel pump eccentric which required a shorter (1.125”) dowel pin. If no eccentric is used, a thicker than standard retaining washer must be used to make up for the thickness of the eccentric."

 

[904Bronco]

Nylon gears were made to keep noise down... I had a 69 Mustang that had all the teeth come off and where in the pan.

As others have said, you are there, parts are cheap, just do it. ;D

 

[dave67fd]

Brian,
Replace the chain/gears no matter what. Get rid of the nylon. I chewed mine up and clogged my oil pump. Oreilly's has them as well as I believe most others. they may have without order.

http://www.oreillyauto.com/site/c/d...ch_timing+set_5174157_4541&keyword=timing+set

 

[Pa PITT]

Wow I can't believe they are still that cheap. I was going to post that back when I had my parts store I could SELL YOU A COMPLETE CHAIN & BOTH GEARS for about 20 bucks.
Not worth ever thinking about it again.
... So just replace them.

 

[Broncobowsher]

It has a nylon gear, you have it apart, change it now.
The nylon gears were not one of the better ideas.

 

[broncogt]

Old engine with nylon gear jumped a tooth around 175,000.

I put a new chain on and it was so tight it wiped out the front cam bearing. If I was to do it over I would put on a quality double roller chain. The roller chain in the replacement engine was much looser than the new OEM style in the old engine.

 

[brianstrange]

I blew it off. I couldn't get the right style chain, and had to button it up today. Hopefully it holds up. Thanks guys...