anyone try mechanical chain tensioners???

[Garrett]

I see that some places sell mechanical chain tensioners, and even a kit to convert hydraulic ones to a mechanical type. Has anyone tried these??? Or are they not a good idea???

Thanks!

[Tim Walsh]

Are these the solid block type tentioners? If so I don't belive they are recommended at all since they have no "give" in them to take up the slack when the engine becomes warm and the chains strech just a little bit. Do a search and you'll find posts about this.

[West]

I've run for years. The misconception is that you need to adjust them loose for the reason's stated in the previous response, when in all actuality, the exact opposite is true. You need to adjust the chains a little on the loose side so when the block expands, they have the right tension. They are a little noisy until the motor warms up, but really not that bad. I adjust them on the same schedule as my valves, only I adjust the tensioner's before the motor has cooled completely, and the valve's the following morning. I know there not very popular on this board, but they have been widely used by racer's for years. If adjusted properly, they can't fail like conventional tensioners.

[Wayne 962]

Hogwash. Mechanical chain tensioners will strech your chain until it becomes loose and begins to change the timing. See the section in my new book about it. Mechanical tensioners should only be run in race applications. Any good engineer will explain the need to spring-load the chain itself...

-Wayne

[Garrett]

Ok, so it sounds like those nice cheapo tensioners are not a good idea - then how are the rebuild kits for the non-pressure fed types???

Are they as reliable as a new set of tensioners?? Any special tools needed?

Thanks for the advice, since I can't get pressure-feds, I need a reliable option!

[West]

Wayne, in an earlier post he stated that his block was a 65'. What are his options? I went to solid tensioner's after my first rebuild went to crap after stock tensioner failure. My second rebuild has already outlasted my first. Just my experience.

[Mr9146]

Mechanical chain tensioners are no worse for your chains than Carrera tensioners. I run them in my 8000 rpm 2.2S, and my dad runs them in his 8000 rpm 2.8RSR. Never had a lick of trouble; stretched chains result from over adjustment not underadjustment.

[Garrett]

I just disassembled my non-pressure fed hydraulic tensioners, and it seems that the failure of the o-ring at the top of the tensioner is the reason for loosing oil, and therefore failure to keep tension on the chains.

Has anyone rebuilt these things - if it's just an o-ring that needs replacement, then refilling with oil, that's not too bad...

...or should I go with mechanicals??

THanks for the input from everyone!

[Mr9146]

I would go mechanical ... but don't bother rebuilding the one's you've got. If mechanical is too much trouble, just pop for the Carrera pressure fed units. You'll be much happier.

I just noticed that you can't get the Carrera tensioners; how come?

[stormcrow]

My chain tensioners have a plunger that sets in the top with a bolt through it to take up the tension on the chain. The plunger sets down in the tensioner body about 1" and is a snug fit. Beneath the plunger is a void with oil in it. I removed the plunger and installed dual springs to load the plunger. The plunger is pushed up about a 1/8" - 3/16" with the springs beneath it. The springs takes care of the load and allow for expansion/contraction of the engine. There is very little movement on the springs, so there is no problem with spring failure.

The mechanical tensioners from what I remember reading were used primarily for racing with the idea that the engine will be taken apart over short periods of time after hard racing.

Steve

"A Porsche does more then just go fast in a straight line"

[West]

If you have a 65' block, (Alum), then the pressure fed tensioners will not fit in you cam housings. One option is to gut your old tensioners and make them into solid tensioners-what I did. The other option is to buy new tensioners and run the after market clamps that fit on the shafts and stop them from colapsing completely... humm... One option cost a three hundred bucks, the other cost almost nothing. I would like to stress that if you go with solid's you do need to make sure that you adjust then correctly, although; that doesn't mean you have to adjust them every day. I don't believe that properly adjusted solid tensioners cause more chain stretch than carrera tensioners. How can they? If there adjusted properly, there going from a little loose to slightly loose, with no real stress on the chain itself. You know, if you look up cam chain tensioner in the Porsche mech's dictionary their's own a two word definition:Job Security.

[bigdaddycsi]

Sorry to open old wounds, but I have a race motor with mechanical tensioners. What is the proper adjustment procedure? Motor at TDC? Chain how tight?