Renault 12 Ignition
  • Register
  • Help
Page 1 of 2 12 Last
Results 1 to 25 of 28
  1. #1
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default Renault 12 Ignition

    Just swapped my R12 over to unleaded fuel as the local servos have stopped selling LRP. The car is running like crap in the higher revs so I'm guessing the timing needs to be advanced to cope with the ULP. Anyone here have a rough idea of how advanced the timing should be? The manuals I have all deal with the Ducellier distributor not the Bosch one that the car came with.... Same with the dwell on the points. Anyone tried to set up an electronic ignition in a R12?
    Philip

    Advertisement

  2. #2
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    What fuel are you using? 91, 95 or 98 octane? 12's don't like 91, it isn't high enough octane.

    What is the motor of the car? 810/xx, 842/xx or 847/xx (xx = the index number, also required) . There are about three different types of Bosch distributor fitted, that will also be marked with a 9 (from memory) figure reference number. There were different distributors fitted to the TL and GL 842 motors.

    On my 810/05 Ducellier equipped 12 I've not touched the timing in ages, and it has been through the full regime of petrol. From the early low lead stuff, through LRP, a brief flirt (like half a tank) with 91 octane to try it, until now when it is filled with 95 or if I'm feeling generous 98 octane unleaded. Fuels used have either been Shell or BP with some Mobil on interstate trips. The only fuel it was really fussy with was the early low lead stuff, apart from the 91 octane which just made it ping. No additives, potions, lotions or pills are used. Although the car does have fairly regular oil changes of Castrol GTX 2, it isn't what you would really call a pampered car. It is now basically a test bed to answer the question, do 12's need hardened valve seats.

    Also what age are the plugs, points, condenser, leads, rotor and distributor cap in? Replacing these could also assist in the refurbishment process. Unless you are into competition, or just like spending money, the standard ignition setup on a 12 is pretty reliable. If starting is fussy in winter it is generally just worn points or plugs or a cracked Bosch cap.

  3. #3
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    Simon,
    From memory it is the 810 motor (1972 R1170) (810/02 seems to ring a bell - it is the "poor road" version). The points, plugs etc are all new (<1000 miles) so I'm a little at a loss as to what has changed other than fuel. Feels electrical and only becomes a problem over 2000 revs. Not clutch because it will do it in neutral as well.
    Philip
    Last edited by R12 Fan; 26th September 2005 at 03:39 PM.

  4. #4
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default Help us to help you.

    OK, back to the first questions. I'm lazier than the average lazy person, so can't be bothered typing in the full permutation list of distributors.

    1) What fuel are you using? 91, 95 or 98 octane.

    2) Engine and distributor codes, to be exact. There would be very few 810/02's in Australia, these were only used on the early batches of Australian built 12's to early 1971. As such they wouldn't have been fitted with the Bosch distributor originally, hence the need to find the code on the Bosch distributor to find if it is a 842/02 engine (12TL) type distributor or 842/05 engine (12GL) type distributor that has been fitted later in the cars life to replace a faulty Ducellier.

    3) When did the problem first start, and exactly what was replaced (also what brand and code are the new spark plugs?)? Trying to ascertain whether problem is due to faulty parts or fitment in the recent tune up or if it is due to petrol.

    4) Associated with the above, when did you start running it on unleaded.

  5. #5
    Too many posts! JohnW's Avatar
    Join Date
    Jul 2001
    Location
    Perth, WA, Australia
    Posts
    10,816

    Default

    Quote Originally Posted by R12 Fan
    Simon,
    From memory it is the 810 motor (1972 R1170) (810/02 seems to ring a bell - it is the "poor road" version). The points, plugs etc are all new (<1000 miles) so I'm a little at a loss as to what has changed other than fuel. Feels electrical and only becomes a problem over 2000 revs. Not clutch because it will do it in neutral as well.
    Philip
    I'd echo Simon's experience. Since leaded disappeared, I've run the range of unleaded fuels through our Virage, 16TS and R8, none of which get timing touched from year to year (not just neglect, as they really go a long way between points adjustments). The only problems I've had are with low octane fuel and the terrible LRP, which carboned things up and caused mis-firing and spluttering and poor idling.

    JohnW

  6. #6
    1000+ Posts
    Join Date
    Oct 2002
    Location
    Melbourne Victoria
    Posts
    11,926

    Default Lower octane

    Some where in my foggy brain I seem to recall that lower octane fuel needs retardation slightly, but its so long since I last adjusted for octane rating, I could be wrong.

    If all else is o.k, you could adjust either way, road test if it pings, back it off till it runs o.k..

  7. #7
    1000+ Posts
    Join Date
    Jul 2001
    Location
    Perth, Western Australia
    Posts
    6,314

    Default

    I run mine (810-05) on 98 with three degrees of advance over standard. However, I accidentally put 95 in the other day, and it didn't pink at all...

    Stuey


    2003 PEUGEOT 206 GTi

  8. #8
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Quote Originally Posted by Kenfuego
    Some where in my foggy brain I seem to recall that lower octane fuel needs retardation slightly, but its so long since I last adjusted for octane rating, I could be wrong.
    You are correct Ken, thing is on a 12 the lowest compression in Australia was 8.5:1, which is borderline for 91 octane, Renault recommended at least 92 octane for this version or 95 for the emissionised version (given the age of most 12's, the compression will likely be higher from shaved heads and the like). So retarding the ignition to suit the 91 octane still wouldn't be desirable if you are using 91 octane and it will still ping. 91 octane shouldn't be used in a 12 in Australia.

  9. #9
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Quote Originally Posted by Stuey
    I run mine (810-05) on 98 with three degrees of advance over standard.
    That's about what I run mine at too, I went for the Max Power setting when it was all put together it seems to work too :-)

  10. #10
    Fellow Frogger!
    Join Date
    Oct 2003
    Location
    Hampton Park
    Posts
    523

    Default

    Quote Originally Posted by R12 Fan
    The car is running like crap in the higher revs so I'm guessing the timing needs to be advanced to cope with the ULP.
    Philip
    The 12 should run OK (but not brilliantly) with ULP. The ignition would be retarded not advanced but you shouldn't need to do that unless it is pinging or pinking if you are from the Uk.
    if you want to run on 91 ULP give it a new set of plugs and points just to be sure and it should run fine, but down on power.
    If this doesn't work, what do you mean by it runs badly, is it missing? is it pinging? is it just running out of "go". I have found richening up the idle mixture on my 20 helped it run on 91.

  11. #11
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Quote Originally Posted by Sherman
    The 12 should run OK (but not brilliantly) with ULP. The ignition would be retarded not advanced but you shouldn't need to do that unless it is pinging or pinking if you are from the Uk.
    if you want to run on 91 ULP give it a new set of plugs and points just to be sure and it should run fine, but down on power.
    If this doesn't work, what do you mean by it runs badly, is it missing? is it pinging? is it just running out of "go". I have found richening up the idle mixture on my 20 helped it run on 91.


    I give up!!! A Renault 20 IS NOT A RENAULT 12!!!!!!!!!

    The compression of an 842/05, 810/05, 810/06, 847/05, 847/06 Renault 12 motors is 9.5:1. 91 Octane fuel is too low for the compression ratio, no matter of stuffing around, new plugs or increased richness or not or kind well meaning words on an internet forum will make a Renault 12 so equipped run efficiently or reliably.

    The 810/02 and 842/01 motors are 8.5:1 compression ratios when they came from the factory. Given time and circumstances, most of these motors will have had their heads shaved to a certain extent, likely increasing the compression to a level from where 91 octane would be marginal to a point where 95 octane would be required.

    These motors just do not have the engine management systems which create a flexible environment to ennable them to use such low octane fuels, it is likely that using straight 91 octane fuel will cause damage in the short to medium term, as well as being inefficient in operation, especially by increasing richness.




    Now to a Renault 20, from the factory the 2 litre, all alloy, OHC, Douvrin type motor in Australian spec form has a compression ratio of 9.2:1 which basically mandates the use of at least 95 octane fuel. To use 91 octane is again not to be recommended.

  12. #12
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    Sounds like I need to swap to 95 octane. I've noticed another problem which may be more of the cause of rough running at above 200 revs. There is oil leaking past the spark plug closest to the radiator. The plug is screwed in tightly so I'm wondering if the washer has been crushed or something else.
    Philip

  13. #13
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Quote Originally Posted by R12 Fan
    Sounds like I need to swap to 95 octane. I've noticed another problem which may be more of the cause of rough running at above 200 revs. There is oil leaking past the spark plug closest to the radiator. The plug is screwed in tightly so I'm wondering if the washer has been crushed or something else.
    Philip
    I'd say the fuel is possibly the cause of poor running, and depending on how long you have been using 91 octane for too. It may have burned a piston from pre ignition, or the plug leads have been swapped after your recent tune up mentioned earlier. Yep, OK, Iím a prophet of doom. Iíll start with the worst case scenario and work backwards. In the absence of further info itís hard to know where to start....

    As for the plugs, replace with new and see what happens with a decent batch of 95 or 98 octane fuel.

  14. #14
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    I've been using both 91 and 95 but always with an additive and not for too long on either. LRP was used till a month or two ago. Could there be a crack in the head or something that is allowing oil past the plug?
    Philip

  15. #15
    1000+ Posts
    Join Date
    Mar 2003
    Location
    Location Location
    Posts
    1,576

    Default

    Quote Originally Posted by R12 Fan
    Could there be a crack in the head or something that is allowing oil past the plug?
    Philip
    Could be rings

  16. #16
    Banned Haakon's Avatar
    Join Date
    May 2002
    Location
    canberra...
    Posts
    8,769

    Default

    If there is enough oil in the combustion chamber to leaking past a plug (never heard of this happening and cant see how it is possible), it owuld be billowing very large clouds of blue smoke out the back. I would say a leaking rocker cover gasket leaking down onto the plug.

    Ran my R10 quite happiely on 91, with ignition slightly retarded. OK power and no pinging.

  17. #17
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    I'll check the tappet cover but it always oil appears to be under the plug not dripping from above. To give some perspective this is a motor with only 12000 miles on it from new (genuine). It sat for nearly ten years in a garage before I restored it. I can't see the rings being a problem even if they are 30 years old but maybe age and sitting have become a problem.
    Philip

  18. #18
    1000+ Posts
    Join Date
    Mar 2003
    Location
    Location Location
    Posts
    1,576

    Default

    Quote Originally Posted by R12 Fan
    I'll check the tappet cover but it always oil appears to be under the plug not dripping from above. To give some perspective this is a motor with only 12000 miles on it from new (genuine). It sat for nearly ten years in a garage before I restored it. I can't see the rings being a problem even if they are 30 years old but maybe age and sitting have become a problem.
    Philip
    How was the motor stored and was it frequently turned over in the ten years that it sat? Acids in the oil can eat into white metal over time (or so I've heard)

    But hang on, is the plug wet? Or are you simply getting drips down the side of the block? If so then I'd agree with Haakon.

  19. #19
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    The motor wasn't turned over until the last two years of the ten years so it sat for quite some time. There is oil pooled under the plug but I'll check if it is coming from somewhere else.
    Philip

  20. #20
    1000+ Posts
    Join Date
    Mar 2003
    Location
    Location Location
    Posts
    1,576

    Default

    Quote Originally Posted by R12 Fan
    The motor wasn't turned over until the last two years of the ten years so it sat for quite some time. There is oil pooled under the plug but I'll check if it is coming from somewhere else.
    Philip
    Gees it's a wonder it wasn't seized.

  21. #21
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    We were very gentle with it. Cleaned out the cooling system etc and pumped lubricant down each bore and let it sit. Cranked it over by hand first to make sure it wasn't seized. Started fairly readily when the time came to fire her up.

  22. #22
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Hmm, now things are getting tricky. Iím wondering if the rings have become stuck in its long dormant period, or if the bores had very slight corrosion (not enough to seize) and the rings have worn prematurely. I have seen the leaky plug thing before, but usually it is from a dirty sealing surface on the head and the plug washer hasnít seated correctly, or as Graham has said from worn rings. The oil travelling through the threads by a sort of pressured capillary action. Were the plugs fitted new in the tune up or just cleaned and refitted? It could be that the old washers have become squashed and no longer seal properly.

    Those early Renault engines are cool in the oil burning respect, they rarely burn oil until they are on the verge of collapse. I love the tolerances in them, where not even valve stem seals are needed. Yet not until they have a good many kís under their belt do they start to puff oil on hot startups.

    Be careful with additives, whilst they may lubricate the valve seats, not all of them increase the octane. So whilst you may use an additive, the octane rating of the fuel, especially 91 octane in a 12, will still be too low. Certainly use at least 95 octane in a Renault 12.

  23. #23
    Fellow Frogger!
    Join Date
    Nov 2003
    Posts
    136

    Default

    The plugs were changed but I might dig out one of the old ones and try it instead on that cylinder. The head looks a little rough in places as though it has been machined at some point. No idea why though....
    Philip

  24. #24
    Simon's Avatar
    Join Date
    Jul 2000
    Location
    Adelaide
    Posts
    6,174

    Default

    Really I wouldnít worry about it unless the leak is really bad, like it is wet, not just a spot that attracts road dust. But did the poor running coincide with the tune up?

    Renault Sierra heads are usually rough looking in places, but where they are machined generally they are quite well done.

  25. #25
    Fellow Frogger!
    Join Date
    Oct 2003
    Location
    Hampton Park
    Posts
    523

    Default

    Quote Originally Posted by Simon
    I give up!!! A Renault 20 IS NOT A RENAULT 12!!!!!!!!!

    The compression of an 842/05, 810/05, 810/06, 847/05, 847/06 Renault 12 motors is 9.5:1. 91 Octane fuel is too low for the compression ratio, no matter of stuffing around, new plugs or increased richness or not or kind well meaning words on an internet forum will make a Renault 12 so equipped run efficiently or reliably.

    The 810/02 and 842/01 motors are 8.5:1 compression ratios when they came from the factory. Given time and circumstances, most of these motors will have had their heads shaved to a certain extent, likely increasing the compression to a level from where 91 octane would be marginal to a point where 95 octane would be required.

    These motors just do not have the engine management systems which create a flexible environment to ennable them to use such low octane fuels, it is likely that using straight 91 octane fuel will cause damage in the short to medium term, as well as being inefficient in operation, especially by increasing richness.




    Now to a Renault 20, from the factory the 2 litre, all alloy, OHC, Douvrin type motor in Australian spec form has a compression ratio of 9.2:1 which basically mandates the use of at least 95 octane fuel. To use 91 octane is again not to be recommended.
    Bit touchy Simon,
    Perhaps you miss the point.
    Both engines are not suitable for 91 ULP in ideal circumstances.
    But they can run satisfactorily with a bit of tweeking.
    I presume the openeniing comment is one of rudeness towards me.
    Please be assured you may be as rude as you like I am beyond caring.
    Perhaps to put it another way "don't bother".

Page 1 of 2 12 Last

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
  •