All double rollers are not created equal

1980s introduction, the LA 239 V6 (and later the 3.9-liter Magnum V6) engine experienced a rattling or lifter-type noise in the timing chain cover area. As a fix to this problem, Chrysler issued technical service bulletin (TSB) #9-07-97 for the 1990-1997 V6 engines. The TSB required the dealership technicians to verify if chain/lifter noise existed, and if present, they were instructed to install a timing chain tensioner.
Why a link chain? First, we felt a factory-type link chain would provide a greater surface area to ride against the guides of the tensioner. This increased surface area would reduce the wear on the TeflonĀ® surfaces of the guides.

A roller-type chain would dig into the guide surface to the point of the increased surface area of the roller links. Second, a link-type chain reduces chordal action. The term chordal action describes the rise and fall of each link of the chain at the time it makes contact with a sprocket tooth on a timing gear. The rise or fall results in linear variations of the speed of the chain, and if the rise and fall are significant, the camshaft operation may be jerky with excessive noise and rapid chain and sprocket wear. Our chain would have minimal chordal action resulting in smoother camshaft rotation, reduced noise, and increased timing chain longevity.

Lastly, the link chain design has a smooth tooth-to-link action, which reduces the link impact and, again, increases timing chain life. A disadvantage of the link chain design is its reduced ability to work well with increased camshaft loads. A second disadvantage, the link-style chain cannot operate effectively with complex chain layouts. In both cases, we believed our link chain would be acceptable because we were using a stock camshaft and valve train, and the timing chain layout was straightforward.

So if your going to be running a stock camshaft you will be able to run a tensioner safely with a factory type chain and gears. This type of chain is not strong enough for greater spring pressure and lobe lift when using a larger cam and springs as stated above.

You didn't have to ask me to prove anything this info it is available all over the web. I only copied it and pasted it. But guys like you just like calling people out because your probably one of the idiots that wasted your money on one. Before you ask for proof maybe you should fact check yourself.
I am only sharing this info to inform the many members who listen to salesmen like you and waste their money. You all can do what you want but don't say you have not been told.
If you are building a stock engine with a factory type chain and gears the tensioner can be used, If you are building a performance engine with a larger cam and a true roller chain and sprockets the tensioner should not be used . Remember use a "double tru-roller" not a junk "double roller" Double rollers are to look at and say you have a roller chain . Installing it is a waste of time.

As far as mis machined blocks. Why would you think some of the new engines had a chain slap? And why not just install another chain? We see mopar blocks like this getting done. Mopar blocks have a raised cam tunnel and have a problem being out of spec on late 80's and up engines . That is why you can get expensive different length chains for them. My R3 block has this issue as did one of my X blocks.

What am I selling?

A lot of slack in that chain you pictured . Must be a chinese chain or improper fitment . How did you adjust the cam timing? 10 years and no wear on a teflon wear pad? Lifter Failure wiped the cam? and your happy with it?

Chordal action from the chain links rolling over the sprocket could have had something to do with the lifter spin interference. A tight arc in the chain over sprockets cause this.

What I wrote above did not come from me. It was copied and pasted from Hughes Engines. This info is a warning from many mopar engine information outlets recently. My son owns an engine machine shop and was also made aware and he will not use a tensioner on any small block Mopars with a tru-roller. Great to use with a factory style link chain with light tension valve springs where cam timing is not critical.

(quoted from article)

("The rise or fall results in linear variations of the speed of the chain, and if the rise and fall are significant, the camshaft operation may be jerky with excessive noise and rapid chain and sprocket wear. The chain would have minimal chordal action resulting in smoother camshaft rotation with a gear not a sprocket") JERKY CAMSHAFT OPERATION CAN CAUSE LIFTER SPIN INTERFERENCE

Slap a timing light on the damper with a tensioner installed versus not, and get back to us about which camshaft is spinning smoothly and which isn't.

That pad isn't teflon, by the way.


My 408 on a 5.9L engine was built w the double roller chain and a mopar tensioner. I did a refresh after a lifter failure wiped the cam 10 years later. Cleaned up everything and reused the roller chain and tensioner. Almost no wear on the tensioner pad, just polished. Plus I like the bracket for cam retainer better than original.View attachment 1715864990

Careful, after ten years, that lifter failure is clearly related to the tensioner.