Tensioner stiffness

[gjmascoli]

I completed the Carerra tensioner upgrade this past weekend in my stock '76 2.7L. I noticed the following:
- the stock tensioners were sitting at full stroke, i.e. they did not spring out when I removed them;
- the stock tensioners are very stiff. I was surprised how much force it took in a vice to compress them.

Are these two observations normal? Timing chain not stretched?

I ask because the oil fed tensioners are very soft and you can compress them by hand - best way to prime them with oil. I assume they are very stiff once they have oil to them.

Just checking because this engine has been completely rebuilt in its past history (before me) and there are some things that aren't 100% up to code (e.g. blue silicone sealer on every seam!)

[Walt Fricke]

It has been a while since I dealt with new or oilless pressure fed tensioners. But with oil in them, in order to compress them to get the pin in prior to installation, I have to put them in my vice and slowly squeeze.

The oil from the pressure feed line enters the first chamber. It has a relief valve on top -- you can see it under a little sheet metal-like hat, and it restricts how much of the available oil pressure is used. When the piston rises, oil enters the second chamber (under the piston) through a one way valve. Once this chamber is free of air, and full of oil, compressing the piston causes oil to leak out a very small hole up under the piston's working tip. But it takes quite a lot of force to do this.

I've never worried about precharging anything with these pressure tensioners, as it seems that the oiling system promptly takes care of all of this. The chain system is not under a lot of stress or instability at idle, and you can also pull the spark plugs, disable the spark or fuel, and crank the motor until you see oil pressure on the gauge.

The very earlier tensioners, with a sort of splash and drip filling system, look like prefilling was very important. But these are different.

But no harm in prefilling.

[gjmascoli]

Thanks for the reply. I shouldn't say the new oil filled tensioners are "very soft". They are soft relative to the original tensioners. Those were impossible to compress by hand. The oil feds do take a lot of force, but I could get the pin in by hand.