Chain tensioners

[dpetteng]

Sp I am having to do a top end rebuild and I am wondering about tensioners. My car is a 1970 2.2t with Zeniths.

In time I may want to go down the e cams and new B&P's.

Should I change the tensioners or rebuild them?

As my heads are to be rebuilt should I go for larger ports?

[Trackrash]

I would rebuild the tensioners, and add the safety collars.

Don't enlarge the ports unless, you are going with larger cylinders. The E models had the same size ports.

[Richey]

Use the newer [1981] timing chain idler gear arms or get the upgraded arm from Supertec .

[cmcfaul]

Good time to upgrade to the oil fed tensionses and not worry about it again.

[Flat6pac]

Oil charged tensioner fail, I’ve changed out about a dozen over the years for chain rattling.
Put a set of guards on the 930 hydraulics and spend the hundreds elsewhere.
Bruce

[dpetteng]

sorry im a dumbass. what are the 930 hydraulics you mentioned? I know about the oil fed upgrade but I will probably do that in the future. I am trying to make this initial rebuild as cheap as possible.

[lvporschepilot]

Just grab a couple rebuild kits ($30 ea) and collars then. I actually think the original tensioners are very good, but tricky to rebuild and set up. There are some good threads out there showing how to do it, but I think they're missing a couple important points when bleeding the piston.

I just did this recently so it's fresh on my mind. Here's how I recently did this: hold the tensioner vertically in a vice. The area where the piston and spring sits, fill that area about half way or so, insert piston/spring with check ball assembly etc, push the piston in until it stops (this should happen quick as the sprung check ball is closing the hole in the piston), make sure the top of the piston is just below where there ring clip installs, hold the depressed piston with some sort of clamping tool, install the inner ring clip (takes patience and a couple screwdrivers of varying size), once clip is in (tensioner still in vice) add a bit more oil and install the outside bleed screw with copper washer and close, fashion a wire to snake its way through one of the 2 holes on top of the piston so it can depress the check ball (can be tricky, but one it's open that wire will stay put thus keeping the ball open until you yank it out), once that check ball is depressed/open (you will know, as that piston won't go down at all) you can move the piston down to bleed air out, as you bleed air you will see air bubbles escaping the hole where the wire is to the oil you earlier squirted on top, once no more bubbles are seen, yank the wire out and try and push that piston down, it should be *very* solid. Tighten external bleed screw. Now add a bit more oil (don't totally fill) and assemble the rest of the guts/spring/retainer/clip. Now go to your motor and get as best an idea as you are able regarding just how long the tensioner can be to get it back in. Put the tensioner in a vice so the vice depresses the piston now, external bleeder side up, open the bleeder a bit, partially close the tensioner *slowly* to the measured amount, make sure to NOT depress the piston too much (only as much is necessary) or it will fail i.e. oil/air will escape past the seal due to too much pressure than the seals can handle internally and you'll have to partially disassemble and bleed again, slide off the vice and onto a tool or your choosing to hold it in that position, then slide into place. That tensioner should be rock solid, zero movement by touch. Install collars.

The job is a pain if you've never done it before. I 100% understand why many prefer to just bite the bullet and go to oil fed tensioners, the old ones can work fine but they can be very challenging to set up. It is a longer job to rebuild the old tensioners then it is to swap them with oil-fed units.

[Trackrash]

Originally Posted by dpetteng

sorry im a dumbass. what are the 930 hydraulics you mentioned? I know about the oil fed upgrade but I will probably do that in the future. I am trying to make this initial rebuild as cheap as possible.

Those are the turbo version of the ones you already have. I'm not sure of the availability or price of those.

Your originals, if rebuilt properly, will do the job.

The only advantage to the Carrera oil fed tensioners is they should last for ever with no maintenance. The old style hydrolics like you have will need to be rebuilt every 50K miles or so, since they have a limited supply of oil in them and it will eventually run out.

[Trackrash]

[Richey]

The 930 tensioners work with the newer style idler gear arms . Don't do one without the other .