What are the correct plugs for a D2 Bristol engine?
Lodge 2HL10 with short thread and exposed electrode
NGK C6HSA with short thread and exposed electrode
Lodge 10RL49 with long thread and non exposed electrode
Thanks in advance!
Fred
Welcome to the ACOC Forum
I run my 100D2 on NGK C7HSA plugs, no problems over the past 10 /11 years. Compression approx 10.2
Used in UK and Europe, can pink on steep inclines on poor quality petrol hence use of additive.
Hopefully info of use.
What's the 100D2 in .. Ace Bristol BEX???
Keith..[:)]
Thanks for the welcome Keith,
Two different Bristol 100D2 engines, one in BEX1210, the other in a Tojeiro TAD 2/55.
Both of these were running the shorter reach plugs but BEX1210 had some used long reach Lodge 10RL49's in the spares.
Did the factory spec the long reach originally? The cylinder head sure could use the longer reach plug.
Cheers, Fred
Fred
Nice pair of Cars, the ExM Gessler Ace BEX1210 and the 2/55 Tojeiro-Turner which has a fasinating full history, reference Toj..... John Tojeiro and his cars.. ( page 75 )
Getting Back to:- PLUGS.
The NGK C7HSA has a 12 mm reach same as CR7HIX ( Iradium upgrade -resisted plug)
C7E has a 19mm reach and the CR7EIX (Iradium upgrade)
A thread on the subject of Plugs of various reach was on this Forum some time ago, might be worth scrolling back into the Forum Archives.
Your 6s are softer than the 7s I use and therefore have a higher heat rating.
Extract/s from NGK Catalogue 2009.
NGK'S Heart of COPPER
Copper wire used in place of the Iron core in conventional plugs is the secret of NGKs Wide Heat Range. Coppers superior heat conductivity dissipates heat quiker. It cools the electrode tip and insulator which prevents hot spots that could cause pre-ignition.
HEAT RANGE & HEAT DISSIPATION
Spark plugs do not produce heat in the combustionchamber.
One of the functions of the spark plug is to dissipate some of the heat produced during combustion. This is mostly transferred into the cylinder head. The "Heat Range" indicates the measure of the spark plugs ability to do this. A "hot" spark plug is designed to maintain a sufficientl high temperature at the insulator nose to burn off carbon and oil deposits.
A "cold" spark plug is designed to allow a faster transfer of heat to the cylinder head thus preventing overheating and premature fialure.
Firing end Temperature
FOULING AREA. .. Idle Temp.... 150 /250 degrees C
Carbon accumulates on the insulator nose forming a leakage path to earth. Engine misfires, bad starting and poor acceleration.
OPTIMUM TEMP AREA. .. 450/ 870 degrees C
The insulator is brown or light grey.
OVER HEATING AREA. .. 870 degrees C and above.
The insulator is white and sometimes blistered. If insulator is over 870C pre ignition may occur. Engine power reduced and piston may be damaged.
Keith.