Timing chain tensioner?

[Ctwidle]

I’m up to reassembling after replacing chains and head gaskets. I have watched Tony Hart’s video and the Rimmers YouTube clip and read the ROM, Haynes manual and Practical Classics. All very useful for a first timer. However, I may still have a problem....
On p58 of the Practical Classics book, in a caption below an image, it states: “To adjust the chain tensioner, remove the packing piece from the tensioner, fitting 40-thou feeler gauges into the gap as you do so.” That is pretty much the method I adopted although at the time it felt uncomfortably tight and I was quite generous with the slackness. However, I neglected to check that the tensioner had actuated. The other sources all seem to allow for a more generous amount of slackness.

a) will the tensioner automatically actuate when the chains are rotated and the oil pressure builds?
b) how far out do they need to be to ensure the oil holes are clear?

The cover and crank pulley are back on and I need to decide if I should remove them again for peace of mind. Unless one of the experienced hands can put my mind at rest I guess I know how I will be spending the morning....

[richardthestag]

when you remove the packing piece from being the tensioner shoe, you should pull the tensioner closed so that it releases from its "in transit" locked position.

If you dont do this you may find that the tensioner does nothing

check out the way the chap here squeezes the tensioner after removing the packing piece

https://youtu.be/k-xuBE_A9nQ?t=28m50s

on the other hand I am not sure I lack the sound of your slack chain, perhaps I misread you

are you doing them like this?

https://youtu.be/k-xuBE_A9nQ?t=24m46s

[milothedog]

Just to add to what RTS said, when you remove the transit thingy, be it plastic or whatever. you need to push the moving part inwards to allow it to release. you may or may not be able to confirm this by being able feel a little bit of spring tension on the moving part of the tensioner.


The same as RTS said but put differently

[trunt]

I have seen quite a few different versions, some say leave the red packing piece in and it "sets" the gap, others (rimmer video), said the same and added a 40 thou feeler between the chain and the shoe. The ROM says just a 40 thou feeler between shoe and body of tensioner, (but that was the old style with oil hole in the shoe)

Given that the new versions have the oiling hole in the shaft (rather than the shoe) I just used the packing piece, I didn't see the point of the extra feeler and felt it was a hangover from the original style/way of setting it.

The important thing with the new style is to ensure that the oiling hole in the shaft is clear and able to shoot oil onto the chain, mine was when I used the packing piece alone, and yes, it was a bit tight and almost at the limits of the loosest adjustment, giving me plenty of scope to tighten things later on!

As to setting it, I think I read somewhere that the initial startup will rattle it around enough to set it but its wise to set it anyways.
Terry

[trunt]

Wow

I just dug up my red packing pieces, with the little "nipples" they measure about 2.3mm

So if you removed the packing piece and only used 40thou (1mm) in its place then it may be a bit tight given that you need that oil hole exposed.

[Ctwidle]

Thanks guys, all valid points. I think Terry has directed me towards going back in with his reference to the oil holes being in the rubber face of the earlier guides. With mine being on the shaft I have to be certain that they are uncovered with the ‘slackness’ (which is probably tighter than Hans’ version) that I have set them to. I think I must have read the “Practical Classics” version last and forgotten the points about releasing them from the installation setting. It’s logical that the initial rattling will probably actuate them (it must have been that way with the “Practical Classics” version as there is no mention of doing it manually, nor is it in the ROM).

I’ve got (had!) a spare day as I am waiting for the vacuum advance to be returned after having a new diaphragm put in. The distributor part of the ‘piranha’ ignition is looking quite flimsy and will be replaced (parts still readily available from Melbourne) which is going to cause me a further headache as I will need to figure out a way to do a static timing without a set of points.

At least it will be good to know that this particular light at the end of the tunnel is not another train...

thanks again for the prompt replies,

Chris

[Ctwidle]

Resolved! 😀
The RH tensioner was activated and on its first extension. 😇
The LH tensioner was not activated and appeared to be just over 1mm exposed. (It’s behind the RH chain and was hard to see) 😚

For future reference:
The oil hole was fully exposed with 1.2mm of extension.
At the first notch there is 2.4mm of extension.

All the planets are now in alignment (rotated crank x6 to check) so it’s onwards and upwards....

thanks again for taking king the time to fill in the gaps.
chris

[Mark Serj]

FWIW Tony Hart doesn't use the 1mm setting packer

[richardthestag]

good work Chris