Primary Chain Tensioner
There are several options for the primary chain tensioner, from the original spec to various levels of replacement.
This is an attempt to lay out all the options in one place so that you can tell what you have, what the weaknesses are, what you might wish to change to, and how to do so.
Note -- If the owners of photos of the various tensioners ship me copies, I will be happy to integrate the images into this page so that you can see what each looks like. Brucem 00:11, 1 August 2008 (EDT)
Regardless of which is selected, be sure to consider a chain oil spray as described in Primary Chain Oil Spray.
Also, fit an Air Conditioner Cutout, and if possible a 'Trinary' switch.
- Original Chain Limiter
- * Flat guide
- Strongly recommended to be replaced with the Renold later design version as shown.
- Citroen factory approved recommendation
- Small curved pivoted shoe held against the chain by a scissor type ratcheting tensioner
- Two fitment types of tensioner and moving shoe. Renold modification suggests a third
- (Obviously) no modifications necessary to install or replace
- Once Curved Fixed Limiter is installed, this is sufficient to allow any combination of OE parts to be used on the tensioner side if they will fit, as stresses are so much lower.
- Rubbing surface is Nitrile, this does eventually go hard and may break up. Correct automotive chain is much gentler on this surface, so will extend life. There are on exchange refinished items where the lining is Nylatron, which will likely last a very long time.
- True hydraulic (although possibly not intended to be so) with ratchet & spring back-up
- Can be used with Curved fixed tension side limiter without modification
- Oil drip hole in ram can become obstructed as it presses on the lever arm which can cause oil pressure to build up. This will cause excessive wear on chain, Mk1 arm is subject to cracking and needs modifying to Mk2 status. Very expensive, requires engine modification to use on SM block, requires care when setting cam timing, does not prevent chain vibration on its own, does not prevent straight limiter on tension side being knocked off by vibrating chain. Does not lubricate chain - oil spray hole modification should be performed
- Spring tensioner with hydraulic spray through shoe
- Provides precisely metered chain oiling without drilling 0.5mm holes in block. All steel design is more robust than OE plastic ratchet. Eliminates "leading shoe" chain tensioner for more consistent tensioning as chain wears.
- Requires drilling oil feed hole and drilling/tapping mounting holes in block as shown here Media:DS_SM_Tensioner_drawing_ABX.pdf
- True hydraulic(?)
- (fill me in)
- Is this still available?
- (fill me in)