Justa6MB

I have an 08 LY6 and I purchased a cam and vvt delete kit among other things from BTR. The kit came with a new timing gear sprocket and a black plastic tensioner block etc. I put it all together using the stock tensioner as it seemed more advanced than the black chunk of plastic. It seemed to be in good shape, no problems. But I thought about it a few times during my build which is close now. So I started reading a bit about them today and found lots of haters out there lol. Plus some chatter about different gear cuts or design? My question is not is it a POS, but rather will it work? Or will something eat something else and cause all kinds of badness?

G Atsma

The plastic block actually works better. The tensioner can be a source of trouble, put plainly.

Johnnystock

iTrader: (6)

The tensionner like the LS3 is a POS; was broke in half after 15k miles on my Stock LS3. Swapped it for a block style when I cammed it.

FormulaBoat

iTrader: (1)

There have been 2 different types of nylon / plastic material used on the spring loaded chain slider leaf type tensioners. Earlier ones were the typical white nylon/plastic, which many have witnesses failure of. The newer most recent in mass production is a black plastic, seems a bit softer? Guessing it does not heat cycle harden as much or at all, compared to the white material. I believe most of the modern production LS engines now use this black plastic. It is also what I have purchased for my LS3 build. I prefer a tensioner vs none or the spacer block type (not a tensioner), but each their own. You'll see raves about the spacer block type, because it really just sits there and just makes an attempt to control the slack and harmonics of such, so not much to break.

There is probably not enough time on the newer black plastic ones to yet determine if they are "junk" as well. If anybody has any pics of a broken black plastic one, I'd be interested to see it posted, and may reconsider my choice, engine is not fully together yet. Thanks.

G Atsma

The block is more of a stabilizer than a tensioner, but face it, if the chain has so much slop that it needs a tensioner, you need a new chain!

FormulaBoat

iTrader: (1)

Disagree. The tensioner greatly damps chain harmonics when running (cam torque is not constant, same with crank constant acceleration/deceleration), as well as takes up any whiplash, especially upon the most violent rotation action which is shutdown (drastic fast engine roll-back/forth). I'd use a tensioner even with a perfectly new best fit chain, to obtain the maximum life out of it, as well as lowering any harmonics/oscillations. But each their own.

dr_whigham

iTrader: (49)

Agree to disagree. That damper can go to hell. I don't care how many revisions they've made or what they say.
Here's what I found in my LSA at 46k miles when I cammed the car:

G Atsma

Thank you! And yours is far from the only instance of dampener failure I've had the displeasure to hear about.

Che70velle

iTrader: (6)

That broken piece of plastic/nylon/composite/whatever it is, usually ends up in the pan. I took mine off my 6liter build, and it wasn’t broken...yet. I go with the dog bone block style which really does nothing, but I also buy the P-series Iwis chains, which are pretty strong. Some of us should get together and design/develop a spring loaded tensioner with a bearing wheel on it and make bank. It would sell like snow shoes to eskimoes.

dr_whigham

iTrader: (49)

Exactly. i got VERY lucky finding it where it was. Pulling the pan on a 2nd Gen CTS-V is not a fun task. AT ALL. I had to start the pickup bolt with dental floss and a pen magnet, and that was with the pan dropped as far as it would go. Not even an inch.
As for the damper, that's what I did. Threw the LS2 on there. I went IWIS also, but don't know which series. Chain by itself was 89 or 99 bucks; can't remember.
The way I look at it, the stock one was more than sufficient for a factory FI vehicle, so pretty much anything has to be better than that.
I'm not trying to break records or even race for that matter. 100% street car.

L78steve

I'm on FormulaBoats side. The tensioner does a better job. The new material should solve the breakage problem.

dr_whigham

iTrader: (49)

To each their own. You shouldn't "need" a tensioner to begin with. I can't name a single engine builder that uses them, new material or not.
It's still thin plastic **** that can (will) fail.

For me, that's a hard pass on "more parts that can break"

G Atsma

As long as the chain is not worn, the tensioner is redundant. The plastic block just keeps the chain from flopping too much if it is a little worn.

FormulaBoat

iTrader: (1)

Nearly every one of today’s automotive engine manufacturers for the past 20 years and going forward use them. Most are tensioned via engine oil pressure.

Each their own to use or not. I see a lot of advantage in having one. I’m going with, and same material as current Gen V is using (black plastic, not white nylon).

I actually really like the one in my snowmobile chain case. Tensioner on each side of the chain, slack and tension sides.

G Atsma

True! HOWEVER, most engines today are OHC, either SOHC or DOHC, which use LOOOONG chains which DO require tensioners because they will whip without them. BUT, in the case of an OHV cam in valley V8, a tensioner as used above is really redundant. A new LS2 chain once installed has next to no slack, if any. The block is all that's needed once a little slack does develop.

flypast111

In the Generation IV Internal Engine Forum - dated 02-17-2020 - under a GM LS Timing Chain Damper title - one can find a description of the set-up used to improve timing chain durability. It is composed of the above title part numbers modified into an installation set-up that will provide stable timing chain performance ... thus improving durability. Be certain to remove the Cloyes 9-5490 tensioner thin steel strip spring from the flexible polymer component prior to installation!

RB04Av

Right: the block is more of a "stabilizer" than a "tensioner". All it does is to help the chain peel off of the crank sprocket smoothly over there on the slack side, and not "whip" as it lets go of the teeth. Not at all the same as the thing that goes on the outside of the system and presses the chain inward.

If you wanna see some "tensioners", go work on a Caddy N* sometime. Those things have about 4 or 5 feet of chain in em. I'd expect the Frod OHC motors are somewhat similar as well.