Please visit the Club's website https://www.dloc.org.uk/ to join. Visit https://www.dloc.org.uk/adhoc to DONATE towards the cost of the forum.
Please don't post someone's email address to avoid it being harvested by spambots and it's against GDPR regulations.
Always look at "ACTIVE TOPICS" to see all posts in date & time order as they are sometimes moved; or look at "Your Posts".
Please add Reg. nrs. when posting a photo or anything about a car as this will help searches. Don't add punctuation next to nr. as this negates search.
CHANGED YOUR EMAIL ADDRESS since registering?, click your username and check your address in User Control Panel, Profile, Account Settings.
If you want help to register, use "contact us" at page bottom for help.

LQ2/20 HELP PLEASE...

Post Reply
JedFurneaux
Posts: 96
Joined: Tue Jul 11, 2017 5:50 pm
Location: Tregoss Cornwall

LQ2/20 HELP PLEASE...

Post by JedFurneaux »

Hi All.
My LQ2/20 is fitted with Champion D16 plugs that I guess are as close to the originals as is reasonable. My handbook gives no info as to the recommended gap...nor that for the points. Can anyone help please? Also, try as I might I cannot locate where the engine number is stamped.
Thanks in anticipation,
Jeremy.

Simon Hyslop

Re: LQ2/20 HELP PLEASE...

Post by Simon Hyslop »

If the car has D16 plugs fitted, chances are the original plugs would either be Champion 7 COM or KLG M50, both of which have become rather rare and expensive in recent times- there's a new M50 on ebay tonight which has been bid up to £16. They do, most unfortunately for us today, tend to be better than the modern equivalents, in the eyes of many. The NGK AB6 is that firm's current offering, which has a smaller hex on it than its predecessor, the A6, which was a pretty good plug for running well in engines that otherwise had spark plug problems.

In general, Lucas pre war coil systems ran with a distributor setting of between 10 and 12 thou of a gap and a plug gap as an average of 25 thou. I bow to the superior knowledge of those with this specific car, they will know what their car runs best at, but what I have writ (like Ernie Wise) is intended as a starting point tonight. It is a bit of a beggar when you read the book and it says "set the plugs/ignition/tappets with the gauge provided, great when the car was new but not so useful now.

JedFurneaux
Posts: 96
Joined: Tue Jul 11, 2017 5:50 pm
Location: Tregoss Cornwall

Re: LQ2/20 HELP PLEASE...

Post by JedFurneaux »

Thank you, Simon!

Stan Thomas
Wise Man
Wise Man
Posts: 795
Joined: Sat Feb 13, 2016 2:14 pm
Location: Penkridge. Staffs.

Re: LQ2/20 HELP PLEASE...

Post by Stan Thomas »

Hi Jeremy,

An ideal plug for your engine to replace the D16's is a Champion D21 - (18mm x 1/2 inch) which are more readily available and not expensive (try Ebay or "The Green Spark Plug" company) - as from the inquiries I have made, they are better suited for modern petrol.

Gap them at 25 "thou" - and the points at 15 "thou" - the latter being the standard Lucas figure to provide the correct dwell.

Above all - avoid the temptation to use those 'orrible reducers to use 14mm plugs at all costs!!!

Regards,

Stan.

JedFurneaux
Posts: 96
Joined: Tue Jul 11, 2017 5:50 pm
Location: Tregoss Cornwall

Re: LQ2/20 HELP PLEASE...

Post by JedFurneaux »

Thank you, Stan.

Stan Thomas
Wise Man
Wise Man
Posts: 795
Joined: Sat Feb 13, 2016 2:14 pm
Location: Penkridge. Staffs.

Re: LQ2/20 HELP PLEASE...

Post by Stan Thomas »

Just found a further reference to points gap in another publication which says your car should be 12 "thou" although the Lucas reference book says 15 "thou" - so apologies to Simon - and yer teks yer pick (as they say in Bermingum).

To put it in lay terms, if the gap is too large, the points are not closed long enough to "charge up" the primary winding of the coil, and a weak spark ensues. If on the otherhand the points are too close, they can arc (the spike voltage across the points being about 250v) causing poor running or misfire. It is realy all down to having a good capacitor, also called a condenser by people ove 95 years of age.

Check the condenser by puting a voltmeter across the terminal and the case - then apply battery voltage for a few seconds. Upon disconnecting the power, the volt meter reading should drop slowly over a few seconds as the condenser discharges.

JedFurneaux
Posts: 96
Joined: Tue Jul 11, 2017 5:50 pm
Location: Tregoss Cornwall

Re: LQ2/20 HELP PLEASE...

Post by JedFurneaux »

Thanks again, Stan.
I have managed to source a new rotor arm to replace the cobbled together one but have had no luck sourcing a new points set. The distributor is a Lucas DQ6-A. Do you have any idea as to what contact set I should be looking for? (Lucas part number?). My intention is to fit a Sparkrite 4000 kit which greatly extends points life and makes old cars run better but I need a new set of points to start with.

Simon Hyslop

Re: LQ2/20 HELP PLEASE...

Post by Simon Hyslop »

Unfortunately, the pre war Lucas parts list doesn't give the number for this. It does for the rotor arm M2799/3 but makes no reference to the DQ6A contact set. There is a listing for the DQ8A - 402488, but no information on the 6A. Strange. I'll keep searching but maybe someone else will have better info. Modifying to a later design can be possible. The other thing is that a lot of these early sets were made of better material and may last much longer than the modern stuff.

JedFurneaux
Posts: 96
Joined: Tue Jul 11, 2017 5:50 pm
Location: Tregoss Cornwall

Re: LQ2/20 HELP PLEASE...

Post by JedFurneaux »

Thank you, Simon. Another good reason to use the Sparkrite kit, I think.

Post Reply