Opinions wanted on solid tensioners

[A Quiet Boom]

My 3.0SC engine doesn't have the tensioner upgrade and sometime over the winter it's going into my '73 shell for use as a track and occasional street car. Rear fiberglass bumper will be installed with Dzus fasteners so rear engine access will be easy. Comparing the cost of pressure fed tensioners against my ability to make a set of the solid adjustable tensioners in my machine shop make me wonder about either buying or making the solid ones. Question is how often will they need adjusted. I can only assume they'll be noisy in a cold engine and quiet down when warmed up, is this true? Anyone have experience with solid tensioners?

[Early_S_Man]

Christian,

You may not have seen the thread on tensioner rebuild kits:

Chain tensioner rebuild kit part number?

My suggestion would be to get a set of the double-bushing 1980.5 chain-wheel carriers ... mill 10.0 mm off the lug of your old tensioner bodies, and rebuild with three locally-obtained O-rings. I did a rebuild of a failed tensioner in 1979 and it lasted just fine for the three months I was waiting on back-ordered '930' tensioners from Germany! My suspicion is that rebuilds without the factory rebuild kit should be good for a year or two, maybe more, and for no more than about $5 worth of O-rings! That is a lot less trouble than keeping tabs on mechanical tensioners, and lots less $$$ in chain cover gaskets, too!

[A Quiet Boom]

Warren,

I think you mis-understood the question, my current tensioners are fine, I just want some insurance against a failure and was thinking the solid ones might be the way to do it inexpensively. The engine is an '81 and does have the newer chain-wheel carriers. I've heard of racers using the solid ones and I'm just curious about usage on a car that will see 3000-4000 miles a year tops.

Thanks for the thread though. If I where to rebuild them so I know they're in good shape isn't there a bushing or something that can be added as protection against total collapse?

[Mukilteo911]

Hi Boom,

I read some good stuff on solid tensioners about a year ago. Do a search to find it. Basic feeling was that most people thought it caused chain wear issues that could lead to failure. Although that really did not make much sence to me. I supose the spring ones give some and help prevent chain strech?

[A Quiet Boom]

I did a search here on Pelican and what I found is that they are fine to run as long as they are properly adjusted. They have to be loose at startup otherwise the chains will put a lot of stress on the cam bearings etc. when the engine is hot and the chains get tighter.

[2.7RACER]

The early tensioners as well as the "Carrera" tensioners work the best because they maintain a constant designed tension on the timing chains.
A bolt type tensioner can be set for the proper tension for a SHORT time. As the chains stretch the fixed bolt type tensioner doesn't respond, so the chain runs looser than design dictates.
Actually the chains don't stretch. Each bearing surface wears slightly. With 98 bearing surfaces, (yes 98), even slight wear loosens the chain.
If you are concerned; use the safety collars.

[A Quiet Boom]

Originally posted by 2.7RACER
.....
If you are concerned; use the safety collars.

That's what I figured I'd do although I've heard of a mod for the early tensioners where you put a bushing inside to prevent total collapse.

[competentone]

Originally posted by A Quiet Boom
That's what I figured I'd do although I've heard of a mod for the early tensioners where you put a bushing inside to prevent total collapse.

The $23 solution sounds easier:

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_ENGcam_pg5.htm#item13

Chain Tensioner Guards
Protect your engine from premature failure by installing a set of failure prevention guards. The guard slips around the tensioner shaft and prevents complete failure and collapse of the chain. NOTE: Not for pressure-fed tensioners.

Chain Tensioner Slip Prevention Collars, set of 2 [Photo] [Photo]

99-0458-053-M230 $23.00

[exhaustfumes]

the mod where you put a bushing inside is for the pressure tensioners. it is called the jerry woods conversion. i saw it on this site, and just did it to my tensioners this weekend. it keeps them from collapsing too far, yet you can still get them installed.

[FLATTOP]

Christian.

It is not called an upgrade for nothing. On my track 2.7 the previous owner ran solid tensioners on a 2.7 motor. On opening the covers we noticed that the gears seemed to take the most pounding. I vote for the hydraulic tensioners even at the cost premium. IMHO

Johan