Just bought a 70 delta 88 custom 455 a week ago. She's got just under 68,000 miles and drives great. Just had a tune up and timing is dead on. Everything seems ok but I am still worried about the timing chain... pretty sure its the original stock chain. I am going to have the engine totally rebuilt in the next year(I hope). If the chain broke would it ruin the engine? Does this car have the plastic coated timing gears? What was the recommended timing chain replacement interval? Can i drive for another 10,000 miles without to much worry? Thanks in advance!

 

My rule of thumb is 80,000 miles for an OEM timing chain with the plastic-tooth cam gear. It's the cam gear that goes first. The two Olds motors I've had that threw their chains were both over 100,000 miles when it happened.

 

Like i have always told my kids You dont know the history on the engine & just call it cheap insurance (wish i would have listen to my self many times} & it will tell some history

 

It won't ruin the engine, you'll just coast to the side of the road after you lose power.

 

When I pulled the front cover off of my engine, the first time, I was horrified to see that there was a plastic gear for the cam. Seems like that design was built for failure.

 

It was done to keep the engine quiet. Personally I never really understood that line of thinking, especially on the more hi-perf engines.

 

It's your engine, but if it was me and I planed on rebuilding within the next year. I would leave it alone till then. It doesn't sound like a worn out engine just old.

 

With only 68,000 miles I would not worry about another 10k as long as your going to rebuild anyway. If you decide to wait longer to rebuild then I would replace the chain and gears. Just don't keep putting it of with the "I do it later" thing. Thats when a guy gets in trouble.

 

thanks to everyone that responded. I really appreciate it. I feel a little better now. I have heard so many horror stories about newer cars and timing belts, but not too much about timing chains and these dreaded plastic coated gears. Its an amazing engine and with the tune up, new air and fuel filters and trans service and the removal of the A/C compressor the engine has already gained a lot of power. I know that there is a lot more potential in there. Thanks again.