Cam Chain Tensioner Part question

[sdmcoupe]

While doing some updating to the car i opened up the cam chain tensioner covers and found these tensioners in the car. They aren't OEM obviously.
Does anyone know what these are or can tell me something about them? The collar around the shaft is different and has a set screw in it. The shaft itself appears to have a larger diameter than the regular tensioner as well.


Thanks,
Rob
1970 911S

[porschyard]

Originally Posted by sdmcoupe

While doing some updating to the car i opened up the cam chain tensioner covers and found these tensioners in the car. They aren't OEM obviously.
Does anyone know what these are or can tell me something about them? The collar around the shaft is different and has a set screw in it. The shaft itself appears to have a larger diameter than the regular tensioner as well.


Thanks,
Rob
1970 911S

Hoeptners, old school ratcheting style mechanical tensioner from back in the eighties.

[ed mayo]

They were a self adjusting, temperature compensating. mechanical tensioner invented by a man named Hoeptner as an engineering school project. In my opinion they were what Porsche should have created. If you don't want them, throw them my way.

[sdmcoupe]

Wow...very cool.

Nothing much on the internet about these so thanks for the info!

[proporsche]

similar device as these 2 .Back in the days(1980`s) you gut the old one out and inserted this type...

Ivan

[mike sampsel]

Originally Posted by ed mayo

They were a self adjusting, temperature compensating. mechanical tensioner invented by a man named Hoeptner as an engineering school project. In my opinion they were what Porsche should have created. If you don't want them, throw them my way.

You guys put these on my 911 in the 80’s or early 90’s (I’d need to check). I went to oil fed in my rebuild. Need to look, but I think I discarded my Hoeptner’s.

[gled49]

I would also be concerned about idler chain sprockets, possibly non bushed, by appearance.

[ed mayo]

Originally Posted by proporsche

similar device as these 2 .Back in the days(1980`s) you gut the old one out and inserted this type...

Ivan

Not the same in function. Your picture shows a pure mechanical tensioner, it stays where ever you set it. The beauty of the Hoeptner was that it did all the chain wear and temperature compensation like a hydraulic, but was entirely mechanical,,,,and fail safe.

[proporsche]

Originally Posted by ed mayo

Not the same in function. Your picture shows a pure mechanical tensioner, it stays where ever you set it. The beauty of the Hoeptner was that it did all the chain wear and temperature compensation like a hydraulic, but was entirely mechanical,,,,and fail safe.

yup i said similar;-) know them both...

Ivan

[David Inc.]

Originally Posted by ed mayo

Not the same in function. Your picture shows a pure mechanical tensioner, it stays where ever you set it. The beauty of the Hoeptner was that it did all the chain wear and temperature compensation like a hydraulic, but was entirely mechanical,,,,and fail safe.

What was the primary mechanism in there? Was it some sort of ratcheting spring?

[ed mayo]

Ivan, you must be an old guy also

David,,,it was a ramp and roller affair, the piston could always go up, but it couldn't go back down as the roller(s) would wedge against the ramp stopping motion. However as the chain tightened from engine cooldown the entire inner assembly would be forced downward against a spring pressure relaxing pressure against the chain.

[proporsche]

[QUOTE=ed mayo;11741652]Ivan, you must be an old guy also


well ,old dude i`m it just depend on who is asking;-))))))))working on these beast for 40 years........i did see some funny stuff... one guy drove his 1969 911 to Siberia and back (after shipped to CA)car was so rusty in Russia they welded rail road on bottom of the shasi (each side)to keep it strait.....i did ended up working on it..But the story from the guy was priceless;-)
Ivan