Beware stock timing chain tensioner!

[PQ]

I can think of a handful of guys on here that found broken tensioners when they did their cam swaps. Moss man for one.

[FLP]

I think about 50% of the ones I have opened up were busted...

[PQ]

Originally Posted by FLP

I think about 50% of the ones I have opened up were busted...

[bannonm]

So the fact that guys have found broken tensioners when opening up the timing cover for cams, is this a problem that someone who doesn't plan on doing a cam? I'm thinking at some point it is, especially if 50% of what FLP found were already broken.

I run my engine at high RPM on the road course. So this isn't just a daily driver for me. Am I asking for trouble? And how much is it to replace this with something that won't break? Labor too?

[Dennis SS]

Im going to have to keep this in mind, my 2010 SS just hit 10,000 miles. I had problems when I snapped a half axle and the transmission had to be replaced due to a bent input shaft that was discovered after the half shaft was fixed, I had a really bad vibration. I wonder if my tensioner is about to go due to the axle snap causing something to happen for some crazy reason?

[Dennis SS]

50%!!!!!! How many have you opened? Are we talking 50% of two cars or 50% of 100+ cars?

[Dennis SS]

I dont want to drive my car now until I check it!

[CFD]

I did a cam swap at about 38,000 miles and retained the stock tensioner. Mine showed minimal wear and I prefer a tensioner to a dampner. I am not concerned of failure.

[MikeOD]

Originally Posted by Fiftydriver

Is a dual timing chain a good idea?

No

Originally Posted by ULTRAZLS1

Yes except you cant use the melling 10296 high volume oil pump. Might be a problem with other pumps as well. Their is not enough clearance with the double chain in their.

It can be made to fit but I forget the details. Seemed like a headache...combined with the fact that the single katech c5r chain has never been broken even in racing aps was enough for me to forget about the double roller.

I don't think the Melling pump should be a concern in a timing chain selection. On a stock bottom end, I prefer a stock oil pump. I made sure my stock pump was machined/built ok, and I put it right back on. The aftermarket stuff that's high volume or high pressure is going to be more of a parasitic drag on the engine (less power/mpg) and could actually suck the oil pan dry at sustained high RPM.

Originally Posted by litle88

It's not needed sir, dual timing chain is so Chevy 350's lol all you need is a C5r single row. Besides harmonics are what really breaks chains. Ls2 dampner a c5r t/c and a good crank pulley.

Exactly, only run stock crank pulleys, or ones made by ATI and other such companies that really really know their stuff.

Originally Posted by ULTRAZLS1

Ya stock motor except for bolt ons. Well...it has H/C installed now but just waiting for numbers any time.

It has had an slp/powerbond UD pulley on it since about 1k miles and the car has about 10k on it now. I have read an aftermarket underdrive pulley can change harmonics and contribute to the ls3 tensioner failure as well. But it has also happened with the stock balancer so who knows.

Now that you're revving a good deal higher, and have a much bumpier cam, you might want to re-think the crank pulley situation.

Originally Posted by CFD

I did a cam swap at about 38,000 miles and retained the stock tensioner. Mine showed minimal wear and I prefer a tensioner to a dampner. I am not concerned of failure.

Mine was also fine, also right around 38K, but I prefer the damper so I switched. I've had a lot of personal experience with the C5-R chain, and you can't fault their track record. Where in MA are you from?

[CFD]

Originally Posted by MikeOD

No



I don't think the Melling pump should be a concern in a timing chain selection. On a stock bottom end, I prefer a stock oil pump. I made sure my stock pump was machined/built ok, and I put it right back on. The aftermarket stuff that's high volume or high pressure is going to be more of a parasitic drag on the engine (less power/mpg) and could actually suck the oil pan dry at sustained high RPM.



Exactly, only run stock crank pulleys, or ones made by ATI and other such companies that really really know their stuff.



Now that you're revving a good deal higher, and have a much bumpier cam, you might want to re-think the crank pulley situation.



Mine was also fine, also right around 38K, but I prefer the damper so I switched. I've had a lot of personal experience with the C5-R chain, and you can't fault their track record. Where in MA are you from?

I live in Foxborough,my shop is in Dedham

[MikeOD]

I'll have to try to meet up with you some time, I'm in Worcester.

[MTI Racing Kevin]

I do not know about 50% but we have seen more then our fair share of broken tensioners when doing cam jobs.

[Dennis SS]

What can happen? I imagine the chain can come off and cause some serious damage like bent valves and putting holes in pistions. I wonder if there is going to be a recall? Not a fan of dealers working on my car, had some really bad experience. Is there anyone close to N. Carolina that can replace the tensioner with a more reliable system?

[MTI Racing Kevin]

The engine in your Camaro is an interference engine, so if the timing chain goes you can do considerable damage.