with the groups help I eliminated the smoke belching

[spstan]

You may recall I had white smoke belching out the carburetor throat on first startup. My mechanic installed a new MSD distributor and claimed I didn't need the vacuum advance. Turns out I reconnected the vacuum advance and the smoke belching disappeared and the car starts right up on the first or second try. I haven't had the opportunity to check for pinging on hard acceleration but I will do that. I think the mechanic eliminated the vacuum advance cause he's a racer and racers only use the mechanical advance on a distributor.

Anyway the car is running well and now I'm faced with whether I should replace the timing chain or let it slide for another year or two.

Thanks for your input and your help. Paul

 

[413]

Glad it worked out. No surprise, I Told you it wasn’t the timing chain.

 

[CBODY67]

Thanks for the update!

As for the timing chain . . . how old (years and miles) is the motor now? Do yiou know if the existing chain is stock (as old as the car) or might have been changed already?

Think of the timing chain as "an insurance factor" against future engine longevity. If you wait until it fails, you'll be stranded somewhere (at best) and need a (getting to be much more expensive than in the past) tow to get home. IF you go ahead and do it now or soon, you might never know how much longer you could have put it off, BUT you know it has been done and can give another 75K or so more miles without having to worry about it. This is if you do just a normal stock-replacement timing set, but something like a Cloyes roller timing set will last well past 400K miles, from my own experiences, for just a few dollars more.

A roller chain might seem like overkill, BUT then you can enjoy the car much longer before having to worry about that timing chain again. Might even make the car worth more money to a later purchaser, IF they know about those things?

The first roller chain I bought was from Mopar Performance back in the middle 1970s for my recently-purchased '70 Monaco Brougham "N" car. The car had about 80K miles on it and by most measures, back then, the timing chain was getting to be in the "replacement range" then.

The second roller timing chain I bought was a Cloyes Plus-Roller timing set for my '77 Camaro 305. It had 92K miles on it (I bought the car new) and was in the replacement range, too. When we pulled that engine out (all of the block core plugs were leaking) at 525K, that timing chain set was still going strong.

When you do replace the timing chain, be sure to douse the chain and sprocket(s) with assy lube, just like you'd do with a new cam installation, plus some moly paste on the backside of the cam sprocket, where it touches the cyl block. That way, there is good initial lube upon start-up.

Take care,
CBODY67

 

[spstan]

Thanks for the update!

As for the timing chain . . . how old (years and miles) is the motor now? Do yiou know if the existing chain is stock (as old as the car) or might have been changed already?

Think of the timing chain as "an insurance factor" against future engine longevity. If you wait until it fails, you'll be stranded somewhere (at best) and need a (getting to be much more expensive than in the past) tow to get home. IF you go ahead and do it now or soon, you might never know how much longer you could have put it off, BUT you know it has been done and can give another 75K or so more miles without having to worry about it. This is if you do just a normal stock-replacement timing set, but something like a Cloyes roller timing set will last well past 400K miles, from my own experiences, for just a few dollars more.

A roller chain might seem like overkill, BUT then you can enjoy the car much longer before having to worry about that timing chain again. Might even make the car worth more money to a later purchaser, IF they know about those things?

The first roller chain I bought was from Mopar Performance back in the middle 1970s for my recently-purchased '70 Monaco Brougham "N" car. The car had about 80K miles on it and by most measures, back then, the timing chain was getting to be in the "replacement range" then.

The second roller timing chain I bought was a Cloyes Plus-Roller timing set for my '77 Camaro 305. It had 92K miles on it (I bought the car new) and was in the replacement range, too. When we pulled that engine out (all of the block core plugs were leaking) at 525K, that timing chain set was still going strong.

When you do replace the timing chain, be sure to douse the chain and sprocket(s) with assy lube, just like you'd do with a new cam installation, plus some moly paste on the backside of the cam sprocket, where it touches the cyl block. That way, there is good initial lube upon start-up.

Take care,
CBODY67

CBO; I wanted to test for timing chain failure before I dive into the project. My understanding is that if you turn the engine crank until the distributor rotor starts moving and the turn the crank in the opposite direction, the rotor should start moving within a few degrees of turning the crank. My neighbor also said if the timing chain is bad and you put a timing light on the engine, you will see a "flutter" or unsteadiness of the light as it hits the timing mark. So far I can't hear any noise coming from the timing chain (rattling etc.).

The car has around 78,000 miles but I was hoping to delay work on the chain for another year cause I have a lot on my plate right now. Paul

 

[CBODY67]

Thanks for the update. I certainly understand the financial situation, too.

Over the years, I've read of procedures to check for timing chain wear. To me, the variability in how the engines were built, how much "slack" is designed into the various chain systems, etc. can tend to make me suspect of what is good and what is not. Just my orientation. Others might have other orientations, which I respect.

During engine disassembly, many people will punch the slack-side of the chain to see how much it deflects, usually. There usually is a general rule of thumb on that checking method, as I recall.

In THIS case, it's not specifically about timing chain slack or wear, it's about the unseen condition of the nylon-coated timing chain sprocket. Nylon teeth and how they have weathered, so to speak, over the years. How much they have worn-down, but ALSO if there might be some fissures in the nylon as it ages BEFORE the teeth start to crack and fail. The only way to determine those things is by physically looking at them. If you disassemble things far enough to look at them, you might as well replace them while you're there.

The other side of the deal is that usually, 80K miles was when the "on borrowed time" orientation could start to kick in. Some brands/engine families more than others, as I recall. BTAIM. When I changed the timing set in my '77 Camaro at 92K miles (about 4 years old at that time), it still looked good with no deterioration of the nylon sprockets, but I knew how it had been serviced since new and that it had never been overheated in its life, with a high-quality motor oil since its first oil change at 3000 miles.

Many things to consider. Your judgment call.

Take care,
CBODY67