Let's reopen the Carrera tensioners debate.

[Rick Lee]

I'm about to become the SCWDP's newest member and the prospective car is as cherry as they come, except for no tensioner update. This will be a track car, since the 993 and accident repairs will have cost me too much to track anymore. I've heard a few folks say the Carrera tensioners are just as prone to fail. The car I'm buying is an '83 SC, has 89k miles on her and has been very well cared for. Should I absolutely do tensioner update befoe she sees the track? Or can I spend money refreshing suspension first? Thanks.

[Bill Verburg]

Should I absolutely do tensioner update befoe she sees the track?

Absolutely, what failures there have been are rare.

You are risking the engine vs shaving a few seconds off the lap times w/ suspension work.

[Bill Verburg]

I agree that the idler arms w/ the larger bearing support area are essential but they were oem from around '80 on

[still2slow]

Not to step on toes but the entire chain tensioner debate is a waste of time. Having worked on thousands of 911's over the last 30 years I have seen maybe 3 engines that actually had damage because the owners ignored the clattering of a slapping chain (the same kind of drivers who run their engines out of oil). Unless you have magnesium chain boxes (the pins get loose) I will ALWAYS recommend mechanical tensioners. They're fail safe, inexpensive, they require adjusting VERY infrequently (about every 40-50k and contrary to popular myth they do not loosen the pins on aluminum housings.
If you have oil fed tensioners keep them (although they do fail quite a bit), if you have early hydraulic tensioners replace them with mechanicals.
Sorry. I had to say something. This has to be one of the worst urban Porsche myths that I battle on a regular basis.

[Jim Richards]

Originally posted by Rick Lee
I'm about to become the SCWDP's newest member

Oh RL, that's sick!

I'm sticking with 930 tensioners & collars. Less stuff to go wrong.

[Wil Ferch]

Anderson in his latest post in Excellence pretty much endorses these but goes on to say that for *racing* use they should be modified with limit stops to assure that the engine will survive *if* the hydraulic tensioners should fail ........

Wil

[Rick Lee]

Thanks guys. Jim, I even got the SCWDP license plate reserved for me at DMV. I hope my 993 doesn't get jealous and start acting up the way my Carrera did when I brought the 993 home.

[Jim Richards]

RL, you're sick.

[notmytarga]

Collars fail too. See the crack?? The tensioner was fine. Luckily it stayed together, because the loose parts would have made a mess.

[targa911man]

Originally posted by Jim Richards
RL, you're sick.

With, what else, LeSchanderitis.

[VincentVega]

RL, glad to hear you are joining the fold. The car looks very, very nice.

[Bill Verburg]

I'm sticking with 930 tensioners & collars. Less stuff to go wrong

But it will go wrong more often. I lived through the days when those things were new. The wereee trouble then and are trouble now. The collars saved me more than 1 rebuild. I have only heard of a few pressure fed tensioners w/ failures compared to hundreds of 930 and earlier version failures. BAck in those days everyone I knew had jad an issue at one time or another. This is no urban myth

[arrivederci]

Last time I had the engine out of my '72, the chain tensioner update was on my project list. But when I pulled the cam covers off, this is what I found.



I asked around and many thought I would be fine with what I had as long as I -listened- to the motor...kinda hard not to without any sound dampening and a rusting firewall. Somebody got a killer deal on a new chain tensioner update kit.

[sammyg2]

Why not re-design the flat six to use timing belts off a 944, everyone knows they are good for at least 30,000 miles

[911pcars]

Someone should make the limit stops out of steel, not aluminum. I never saw the advantage of using aluminum other than the ease of manufacturing.

Sherwood

[Tyson Schmidt]

Those cracked hydra-stops are from over-torquing.

I use 930 tensioners, updated idlers and (properly installed) hydra-stops on my own engines. But I also check them every other valve adjust and replace the tensioners at 40K miles.

For those who don't work on their own cars, the pressure-fed tensioners are the way to go.

[ckissick]

I'm more than a little annoyed at the oil-fed tensioners right now. I had a new one fail on a brand new engine. I replaced it yesterday, but the chain had slipped at some point during the job, and I didn't notice. Bent valves. Now I have to rebuild the heads on an engine with 300 miles on it.

[IROC]

FWIW, I asked Bruce Anderson once whether or not he had ever seen an engine damaged from failed tensioner that had the "stops" installed. He said "No.".

If there's nothing wrong with the existing tensioners, I would install the stops and live happily ever after - track miles and all.

Mike

[still2slow]

Nothing against Mr. Anderson but he hasn't seen it all. Unfortunately the aluminum collars DO IN FACT SLIP on occasion when a tensioner collapses causing a possible failure. Again you have to be deaf or brain dead not to notice the chain slapping noise so engine damage will only result if you continue running the engine for quite a while with a collapsed tensioner.
The better mousetrap has been around a long time (Mechanical tensioners). For those of you still trying to justify old hydraulic tensioners, give it up. You're fighting a battle that you simply won't win.

[CliffBrown]