DB Lagonda spark plug caps

Peter S30

7 June 2011 at 18:43 #48268

I am searching for a supplier for the straight spark plug caps for my DB 3ltr. They have to fit into the rubber covers so outer diameter should be 16-17mm or less, length 63mm, the ones I have (one is cracked and I want some spare) are 1kOhm suppressed and fit on the 4mm thread of the plug directly (not on the SAE 6.3mm screw on nut).
It is difficult to find something that fits. I also could machine down from 18 to 16mm (which I tested on an otherwise wrong cap)
Which 2.6 or 3ltr driver can help?
Yours
Peter

Julian Messent

8 June 2011 at 07:52 #48270

Morning Peter,

Try the bottom of this page!

http://www.holden.co.uk/displayproducts.asp?sg=1&pgCode=030&sgName=Electrical&pgName=Ignition&agCode=0360&agName=Spark+Plug+Caps

Hope it helps,
Regards,
Julian

Peter S30

8 June 2011 at 17:57 #48272

Thank you, Julian. I saw them too but thought the diameter looks to big. I phoned Holden today and diameter is fine but length 69mm, the inside length of my cap covers is 63mm. With my next order there I will get some of them and see if I can machine away a bit from the length.

Peter S30

30 June 2011 at 07:04 #48330

I ordered the two versions available from Holden, one is black modern plastik and has no resistor, the other is brown classical hard resin and has 5kOhm. Both have the SAE 6.3mm connector to the spark plug. The brown classical one is produced by Bremi in Germany, part no 10249N5, Bremi also have other versions

The black one is 21mm diameter and 70mm long and does not fit into the rubber cap
The brown one is 19mm diameter and 62mm long. I ground it down on lathe to 17mm diameter to fit into my rubber caps

I think new rubber caps, also available from Holden, might have solved the problem more easily, the inner diameter looks larger on the Holden homepage.

Some more usefull parts suppliers for the DB Lagonda:

gsparkplug.com have (cheaper than others):
[list]contact breaker Lucas – DSB122C 407050 costs 6 GBP
condensor DCB121C 407044 484261 489244, costs 7.50 GBP
Voltage regulator RB106 12V Screw – Replaces NCB100 costs 22 GBP
spark plug NGK C6HSA or C7HSA 1.6 GBP[/list]
all prices +VAT

distributordoctor.com:
have rotor arm and distributor cap, a bit more expensive than Holden but claim to have better quality, might be also a good address for other distributors (even V12) and repair

Attached files

h14

30 June 2011 at 09:54 #48333

Hi Peter,

Already asked Distributor Doctor re V12 distributors; unfortunately he only works on Lucas types.
Regarding the Voltage Regulators, my understanding is that pattern replacements have a pretty poor reliability record. The RB106 regulator comes up frequently as new old stock on ebay.
Likewise I’d avoid pattern rotor arms. My LG6 currently has 1 distributor & 1 coil. When I bought the car, the coil ignition wasn’t working. Soon found the new “Park” rotor arm had burnt through. No worries, another new one made by Park amongst the spares. That lasted 500 miles. Fortunately the original, but very second-hand Lucas rotor arm was also with the spares. Still working fine.
Laurence

Laurence

ray sherratt

2 October 2012 at 18:56 #49686

Peter.
Lock at http://www.Magnecor.com.uk they make 7 mm resistor lead sets. Phone and order
set for Aston DB2 side entry cap which I presume is fitted to your Lagonda.
All the Astons I build I fit these.
Ray Sherratt