How Lubing SM main timing chain
  • Register
  • Help
Results 1 to 10 of 10
Like Tree2Likes
  • 1 Post By Citroenfan
  • 1 Post By Citjay

Thread: How Lubing SM main timing chain

  1. #1
    Member Houtan's Avatar
    Join Date
    Apr 2014
    Location
    Tehran, Iran
    Posts
    65

    Default How Lubing SM main timing chain

    one of my friends is in the middle of restoring his SM`s engine, The engine is 2.7 carb, the main engine chain have no canal for lubing and like you all know the main chain must be replace every 50000 km, so he wants to made a canal for lubing this chain with engine oil and the reason of Idea is that it can raise this chain`s life.

    Advertisement


    anyone have any Idea about that, It can cause any trouble for engine?

  2. #2
    1000+ Posts George 1/8th's Avatar
    Join Date
    Dec 2003
    Location
    Melbourne, Victoria.
    Posts
    1,388

    Default

    Quote Originally Posted by Houtan View Post
    one of my friends is in the middle of restoring his SM`s engine, The engine is 2.7 carb, the main engine chain have no canal for lubing and like you all know the main chain must be replace every 50000 km, so he wants to made a canal for lubing this chain with engine oil and the reason of Idea is that it can raise this chain`s life.

    anyone have any Idea about that, It can cause any trouble for engine?
    Hello Houtan, I know a guy who has restored one of those, and I think those chains just get oiled by being within the crank-case , without any special oil delivery system. Soak it in oil when you service the car, and it should be ok.
    cheers...

  3. #3
    1000+ Posts Ken W's Avatar
    Join Date
    Sep 2002
    Location
    North Brisbane
    Posts
    1,892

    Default

    If you google on the internet you will find instructions for drilling a hole so that there is an oil spray that will lube the chain. There are also some special chain tensioners that will help the chain last longer. New style 7 piston or scroll aircon compressors also reduce the shock loading on the chain and help it last longer too.

    Cheers,

    Ken W

  4. #4
    Member Houtan's Avatar
    Join Date
    Apr 2014
    Location
    Tehran, Iran
    Posts
    65

    Default

    Thanks George and Ken,

    Making a little hole on one of near oil canals for spraying oil seems possible and easy.
    Also we must forget air condition on SM, It have piston air condition compressor, I saw some of owners removing air condition belt for disabling it, My CX have one of those piston air condition compressors and I don`t use it too.

    Cheers...

  5. #5
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    Symar/ca/usa
    Posts
    607

    Default

    Quote Originally Posted by Ken W View Post
    If you google on the internet you will find instructions for drilling a hole so that there is an oil spray that will lube the chain. There are also some special chain tensioners that will help the chain last longer. New style 7 piston or scroll aircon compressors also reduce the shock loading on the chain and help it last longer too.

    Cheers,

    Ken W

    Many years ago Don James (Ohio, USA) made a replacement chain tensioner (sprocketed) that directed oil onto the main chain from a small hole in the oil galley. Put one in my SM and got some 80,000+ miles out of the main chain I pulled the engine to replace. Though I did, the chain in the engine still had more than a bit of life. Had not stretched all that much. IIRC Maserati copied the designed - some of them may still be available. Will check with John Titus and find out if he has any more info.

    Steve
    JohnW likes this.

  6. #6
    Member Houtan's Avatar
    Join Date
    Apr 2014
    Location
    Tehran, Iran
    Posts
    65

    Default

    Thanks Steve,

    I will check if I can find one of them, 80000 km without chain problem is really good.

    Cheers,

  7. #7
    Too many posts! JohnW's Avatar
    Join Date
    Jul 2001
    Location
    Perth, WA, Australia
    Posts
    10,703

    Default

    Quote Originally Posted by Houtan View Post
    Thanks Steve,

    I will check if I can find one of them, 80000 km without chain problem is really good.

    Cheers,
    It was 80,000 MILES. Even better....
    JohnW

    Renault 4CV 1951
    Renault R8 1965
    Renault Scenic 2005 (wife's)
    Renault Scenic 2007 (mine)
    Renault Scenic 2006 (daughter's)
    CitroŽn CX Pallas 1980

    National Co-ordinator, Renault 4CV Register of Australia

  8. #8
    Fellow Frogger!
    Join Date
    Nov 2010
    Location
    Symar/ca/usa
    Posts
    607

    Default

    Quote Originally Posted by Houtan View Post
    Thanks Steve,

    I will check if I can find one of them, 80000 km without chain problem is really good.

    Cheers,
    I checked with John and his take is to use a standard DS tensioner . He mentioned that, when the oil was cold, both the James and the Maserati version could over tension the chain as they used oil pressure from the engine to provide the tensioning force. OTOH, living in the SF Bay Area and then SoCal having cold oil was never a problem my cars have ever had .

    Primary Chain Tensioner - Citroen-SM-wiki

    Good article and has an engineering drawing John made up.

    Steve

  9. #9
    Member Houtan's Avatar
    Join Date
    Apr 2014
    Location
    Tehran, Iran
    Posts
    65

    Default

    Thanks again Steve, It is really helpful,

    John, yes 80000 Miles is really good,

    I think if we use this chain tentioner, we can use SM`s timing chain same as normal timing chain on other cars.

    Cheers,

  10. #10
    Tadpole
    Join Date
    May 2014
    Location
    Sydney Australia
    Posts
    4

    Default

    I worked on these cars for many years. The factory came out with a service bulletin on drilling a 1mm diameter hole in the oil passageway in the block running between the main and jackshaft bearings, angled so as to spray on the chain. However I found it a lot easier to drill a couple of holes of similar size into the oil galley in the timing cover where it protrudes inside the loop of the chain (and gets sealed with an oring on assembly to the block). Drill the holes right where the chain would rub against this oil galley if it were too worn. Aim for the chain plates. The problem is definitely that the SM lower chain gets way to little oil, only incidental splash and mist. Years ago an SM with a loose oil pump cover spraying oil on the chain continuously went 40,000 miles with *no* chain wear, proving the point (had to re-prime the pump on cold starts, don't recommend that). Adding spray oil makes a huge difference in chain life.
    Personally I don't recommend a tensioner that uses oil pressure; too much tension cold or warm. If the tensioner was only oil damped and spring loaded, that would be fine. The stock tensioner works fine, but replace the stock chain guide opposite with the one from a D, part number 5 411 911 if I remember correctly, with appropriate bolts and washers. Its much stronger, the stock SM ones are known to break around the bolt heads. Personally I'm not a fan of curved guides that some use. That's the side under tension, and the chain will push hard against the guide.
    If you remove the timing cover, be sure to replace the oil pump drive shaft with a thicker one with longer splines. Some of those stock ones are engaging splines by only a few mm.
    denxm likes this.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •