installing mechanical tensioners

[rhayes]

I'm rebuilding my '69S engine. Previously, somebody installed solid timing chain tensioners which I am replacing with standard mechanical tensioners (rebuilt) from a '70, and I have the safety collars as well. I'm ready to install, but am stuck at the following step.

The factory service manual says to slide Porsche special tool (gauge ring) P214v over the plunger, loosen the bleed screw on the side of the tensioner, depress the plunger until the gauge ring is flush with the top of the tensioner body, and tighten the screw.

I don't have the tool, and can't find anyone who does or can sell me one. I haven't seen one, but I expect that it is just a 1-2 inch diameter collar, maybe a half inch tall with a hole in the middle. Does anyone have one of these that can give me the dimensions. Has anyone actually done this? The shops say that they just install new mechanical or pressure fed tensioners, so they didn't even know about this procedure.

Any help would be appreciated.

Thanks,

Bob

[911quest]

Bob

Here is a site that shows him using zip-ties I used mechanics wire wrapped tight around the tensioner same principal I put it in a vise with the wire on the plunger compressed it and tightend the wire the removed from the vise


http://www.thesey.com/tensioner.html

[ajwans]

I've read in lots of places that you should replace your tensioners with
930 tensioners as they're much less prone to failure. I've seen plenty
around for sale, I bought a pair for $10 on eBay that I'm going to
rebuild for my 67.

Since you're in there, why not install the beefier tensioners?

andy

[rhayes]

Tony,

Thanks! That's a great link; good write up and good photos about rebuilding the tensioners.

I figured I could do the same as far as the zip ties or wire (or bend a piece of light steel) to hold the plunger partly compressed to install.

However, the step I'm struggling is before that, to actually set the plunger oil fill using the bleed screw. It must be like a preload setting. The article mentions pretty much the same as I found. Porsche indicates that there is a particular fill required (determined by plunger height), but no one seems to know what that height is.

I guess I'll keep looking, or go with the Haynes method (or do like Andy says and replace with pressure fed).

Thanks,

Bob

[jcarpio]

Hi Bob,

If the wire trick doesn't work out, try calling Jerry Woods Enterprises, in Campbell, CA. I watched Jerry take apart and rebuild a tensioner during his workshop class and he may sell the tool.

Good luck,

Jorge

[ajwans]

930 tensioners weren't pressure fed, carrera tensioners were. Porsche
upgraded the tensioners before redesigning them to be oil fed.

andy

[911quest]

Bob when I did mine I got confused on that point too. But the way I figured is getting all the the air out is the biggest concern. At least with the safety collars give a little piece of mind.

[911pcars]

When I rebuilt tensioners years ago, I'd submerge them in a quart can of oil (that's how long it was), then exercise the plunger until all the bubbles were evacuated.

Use a bench vise to partially compress for installation. Thereafter, normal oil splash onto the tensioner supplies enough oil to feed the chamber.

Sherwood

[tomkirkcis]

I have used them for years and have never had to worry for a second about a possible failure. I think Henry at Supertec uses them on some of his builds. He builds a first class motor and would not do it if it deteriorated performance.. Best of luck tom

[edmayo]

Here's my experience on this for what it's worth. I've been dealing with these since the days of the original open top tensioners, here's what I've found. I tried the solid tensioners when they first came out. They don't compensate for wear or normal expansion/contraction of the chain and case. They must be regulary readjusted, maybe okay for frequent maintenance race motor, not for street motor. I only use either a rebuilt hydraulic or the 84 up Carrera pressure fed. There are times, when for appearances, I don't want the later style with their exposed pipes. When I use the earlier style hydraulics I always use the latest style wide based idler sprockets. These put a more centered loading on the tensioners. I use Porsche rebuild kits, I use 60wt oil to fill the tensioners. I have never had the above mentioned tool tool (p214v) it's not needed, all that is for is to set set a volume of oil in the reservoir. You just tilt the tensioner in the vice, open the bleed screw just enough so that as you push the aluminum plunger down oil can trickle out. You only want to push enough oil out to allow you to get the snap ring in the slot. You can see when there is enough groove showing for the ring to fit. Make a tool by bending a piece of 1/8th thick strap steel that will hold the tensioner collapsed while you slide it on. To collapse the tensioner put it in a vice and SLOWLY close the vice to collapse the piston, put on your holding fixture and slip it on the mounting posts in the chain housing. The piston should snap up when you pull out the holding fixture, if it doesn't, remove and repeat the bleeding procedure. I then install tensioner guards as a backup. To the best of my knowledge none of these has failed in 30 some years of doing it this way. I attribute most of the success to the 60 wt oil, and also to the use of the wide based idler sprockets. In two of my cars I have what I considered the best tensioner ever, they were made by a gentleman named Hoeptner. They were actually a mechanical, self adjusting, temperature compensating tensioner, that were virtually failure proof, he eventually stopped making them when sales fell off due to the Carrera tensioner. By the way, one of the idiosynchrocies of the original open top tensioners was that after installing them you couldn't rotate the engine on the stand anymore or the oil would drain out of the open top reservoir!