Chain tensioner advice please

[Buzetti]

The engine of my 1976 2.7 is being completely re-built to original specification currently.

My question is, should I upgrade to hydraulic chain tensioners while I have the opportunity?

Any advice gratefully received

[kodioneill]

Yes most definitely.

[911SauCy]

Without a doubt.

[matt gineo]

Absolutely, my original chain tensioners went on me a few months ago. Fortunately it happened when I was about 50 feet from my driveway doing about 5mph at 1,000 rpm when I heard it go. I immediately shut the engine down and fortunately I got away with only having to replace a few valves and of course switching over to carrera tensioners. It would have been a much different outcome if I had been on the highway!!

[Andy911sc]

I bought rebuild kits and rebuilt my old tensioners with the tensioner locks on them. When I eventually get around to rebuilding the entire engine and sporting it up a bit, I am not sure if I will go with the upgrade hydraulic or the mechanical ones that stromski makes where there is no worries of them collapsing.

[bassfishman]

I just upgraded to 930's with collars. Why spend the extra $$$

[tharbert]

Collars can break. Avoid!

[Schmierung]

Never did oil fed. Just used 930's with safety collars for 30 years including racing.

[Scott R]

Originally Posted by tharbert

Collars can break. Avoid!

My engine had a broken collar floating around in the sump, well have of it anyway. The other half was shredded by the chain and ended up in the oil passages and cam spray bar.

These collars should be avoided at all costs.

[RSTarga]

I've been running 930 tensioners for quite a few years without problems, be sure and do the ramps and the spacer mod. I don't have collars but if installed correctly I don't see how they can break.
Blead out and use 90 wt oil too.

[Scott R]

Originally Posted by RSTarga

I've been running 930 tensioners for quite a few years without problems, be sure and do the ramps and the spacer mod. I don't have collars but if installed correctly I don't see how they can break.

The little allen screws shear under heat and vibration.

[SCaircooled]

Hello - In the midst of upgrading my tensioners to oil fed. Wondering how to get enough slack in the chain to get the old tensioners off. Is there a way to compress the old tensioners? Maybe I am over looking the obvious. Wayne's books just say remove the 13mm nut and slide them off - but that is not working. Thank you to anyone's advice!

[RDM]

Originally Posted by Scott R

My engine had a broken collar floating around in the sump, well have of it anyway. The other half was shredded by the chain and ended up in the oil passages and cam spray bar.

These collars should be avoided at all costs.

My experience also. Collar broke and was in the oil sump along with the screws that were supposed to hold it together. I'd go oil fed. Wait- I went oil fed.

[john walker's workshop]

Originally Posted by SCaircooled

Hello - In the midst of upgrading my tensioners to oil fed. Wondering how to get enough slack in the chain to get the old tensioners off. Is there a way to compress the old tensioners? Maybe I am over looking the obvious. Wayne's books just say remove the 13mm nut and slide them off - but that is not working. Thank you to anyone's advice!

no slack needed. set the crank at #1 TDC and the cams stay put as you slip the tensioners out. just don't pry the chains or move the cams when they're out.

[john walker's workshop]

the collar bolts need to be tightened evenly so they don't get stressed sideways. check that the gaps on each side are even for best results. uneven tightening can also beak the end of the collar off eventually.

[keynsham1]

Porsche told me not to upgrage on my 911sc. Hydraulic tensioners apply higher loads than spring ones that can cause premature chain wear on earlier engines. Using collars disguises failure of the tensioner and are also not recommended. Also, according to Porsche, the new spring tensioner they sell differ in some way to the original figment and aren't expected to fail in service. Also remember that hydraylicones can also fail in service but no one ever mentions that! I am sure there are plenty of owners who will disagree with all of this however. If you want a definitive answer, talk to Porsche directly as they are the only people who will not be just offering an opinion without foundation.

[BURN-BROS]

The wide tensioner arms on the "turbo" and pressure fed tensioners are the upgrade.

Early failures were from narrow non-bushed arms galling on the shaft when hot. When the engine would cool, the chain would have a good amount of slack. Upon start up, the chain would hammer the stuck arm and the arm would hammer the tensioner and fail.

The other tensioner failure is from the o-ring in the reservoir. If maintained, there would be little to no failures.



Pressure fed tensioners cannot be serviced and have about the same failure rate as "turbo" tensioners. Smart racing even offered an aluminum plug for the pressure fed tensioners that limited travel in the event it should fail.


Supertec sells a wide tensioner arm for those who want to upgrade.