1980 SC timing chain tensioner upgrade questions
 

Hello, I am the proud new owner (and first time Porsche owner) of an 80 911 SC in talbot yellow!

She runs great but I know it has stock tensioners and they need upgraded before I feel safe taking it on rallys. I’ve done plenty of research but I have a few remaining questions. Namely which kit should I buy? Is Sebro or OE better? There are kits ranging from $700-$900 that look the same to me. I also planned on buying new timing chain guide rails while I’m in there. Are there any other while I’m in there items I need?

Thanks in advance!

sorry, don't have the answer to your question.
it's already lasted 42 years, without them.
why worry? : )

I intend to drive this car a lot, I’ll do 3-4 weekend rallys across the country and add a minimum of 10k miles a year. The upgrade just gives me the peace of mind that I won’t drop the chain and be on the hook for a 30k engine rebuild. $1,000 in parts feels like cheap insurance with that in mind!

i`d go with creaturecat words....also i have seen lately the hydraulic tensioners going bad...in your case i would not worry too much and drive it...$700-900 for gasoline sounds much better to spend your dough on......

Ivan

The top end of my 1980 SC was rebuilt in 2019. My mechanic who services air cooled 911 engines suggested using Stomski Racing mechanical chain tensioners. If your engine has 60k plus miles the chains are stretched. As mentioned before in discussions on this forum that hydraulic tensioners also fail.
See URL

https://www.stomskiracing.com/search?q=chain+tensioners&submit=

stick to stock tensioners is what I would do. Unnecessary upgrade is what I think, may not be an improvement at all as the hydraulic ones fail too. I lost one or two of the hydraulic ones over the years. And expensive

Correct me if I’m wrong, but If a tensioner fails I’m going to have to rebuild the motor. It will send the valved into the pistons correct? I’m looking into this as a peace of mind issue since my car has 93k on the odometer and I know for certain the odometer has been broken since 2017 so I have no idea how many miles it has. The PPI I had done came back clean on compression and all the head studs are fine but he recommended I upgrade the tensioners quickly. He mentioned it was very obvious the motor had not been opened ever and that leads me to believe my chain could be stretched as well after 100k+ miles.

Install guards on the old tensioners.
Mechanical tensioners are only correct as set.
Nothing changes but the chains from the heat
The guards stop the tensioner from collapsing.
If the tensioner collapses there will be some chain
noise because the guard sits high on the tensioner
and drops to the tensioner top
Bruce

Do not install a solid chain tensioner such as the Stomski..
Either brand of Carrera style tensioner is ok to use, no feedback on if one is better than the other. And yes they do fail.

If you want peace of mind you can take Bruce’s advice one step further and install guards on rebuilt 930 tensioners. Either rebuild yourself or send them off.

Daniel

Congratulations on your new SC! They are great cars. I had the same concern when I bought my SC, 3 years ago. I installed the tensioner collars for a little peace of mind. I like the idea of mechanical chain tensioner but every choice has its positives and negative’s. I too don’t understand the difference in oil fed kits that are available. There is also the chain tensioner idler that was updated with a better design (in 81’ I think) that improved reliability of the tensioners from what I understand.

When the kit was $500, i would just put them on. Now that they are pushing $2,000, I would just use the stock tensioners and install a collar guard.

No, an engine rebuild is not automatic. When the tensioner fails you will hear the chain rattling at idle. As long as you don't keep driving, it shouldn't skip teeth. But it will leave you stranded until you fix it.

There are a number of Youtube videos out there that will let you listen to what it sounds like.

Mark

My 85 Carrera came with factory hydraulic pressure fed tensioners. I will turn 186,000 miles this weekend likely.

They are not bullet proof cure for the problem, but pretty close. If you are really worried, get the mechanical guards installed. The timing chain failure sounds like the chains are dragging over a metal garbage can. A rather loud grumbling.

I just returned from a 3,650 mile road trip, and the 911 never skipped a beat. All the way into New Jersey, and back home, and a side trip to Gettysburg, and Valley Forge. I have no issues with driving my 911 on trips and I have driven it to 41 states, and Canada with a goal of hitting all the lower 48 states in my 911. Drive your car, it is the best thing for it to keep it healthy.