[Healeys] BJ8 Ignition knocking

[lists]

Hi Niels,

knocking is always a matter of multiple things. Octane, compression, ignition timing and load of engine (and maybe some more). So, if Tim Ward told you he's running his BJ8 on regular with no problems it is most likely that he had his ignition timing adjusted accordingly (i. e. retarded a bit).
An ignition timing of 15 deg BTDC @ idle is not wrong, but more important is the ignition timing while revving up the engine. If the springs in the bottom of your distributor have weakened (likely after having done their duty for years) and the ignition timing is set on idle you'll get most likely knocking in higher revs (dangerous, because it's likely not to be heard and it causes serious damage to your engine).
Possible solutions:
a) Have the springs replaced with new ones and the distributor "recurved" (a good source is Jeff Schlemmer @ http://advanceddistributors.com/)
b) Install an electronic ignition system like the 123ignition (http://www.brits-n-pieces.com/product-detail/123ignition-distributor-jaguar-austin-healey-aston-martin-triumph.aspx)
If you decide in favor of b), use carbon core cables, which are a much better choice with electronic ignition, even for our old cars.

Eric Frenken
Germany


Hi Josef

I have the copper wires. I use 99 octane in Denmark, not sure what regular
is in England, perhaps 95.
I met an Englishman, Tim Ward, with a golden Austin Healey BJ8, he was
running regular he said, with no problems.

Niels

-----Oprindelig meddelelse-----
Fra: Healeys [mailto:healeys-bounces at autox.team.net] Pe vegne af
josef-eckert at t-online.de
Sendt: 17. august 2014 21:03
Til: Healeys, Forum
Emne: [Healeys] BJ8 Ignition knocking

Hi Niels,
Six cylinder Austin-Healeys usually need todays super petrol, better super
plus 98 or 100 Octane, not Euro Super.
Your shock may be causeed by using wrong ignition cables with high
resistance. Don`t use carbon core cables. Much better are copper core cables
for our old cars.

Josef Eckert
Germany.




Was on holiday in UK this year with my BJ8. Have a couple of questions I
need your help me with.
I normally use super octane fuel but couldnt get it and filled up with
regular. I guess and old car with low compression should be able to use
regular, but big was my surprise when it started knocking under load at low
rpm in third and fourth. Filled up with super again and the problem
disappeared.
Checked the ignition when I returned home, it4s set at 15 deg BTDC @ 650rpm.
I recall having read somewhere thats the right number, so what is wrong.
Have altered it to 13 deg now on the little wheel on the distributor, did
that with the engine running, wow got a shock, high voltage in my arm. How
can that be, dont recall having had problems with that on other cars.

Niels
Denmark