ok guys plz help cars has serious misfire at high revs what the plug gap setting on these plugs
thanks

 

anyone?

 

UP

 

FFS ANY1 THOUGHT YOU LOT WERE HELPFULL?

 

we are helpfull

you are a new user and you are demanding that we tell you what you want to know


it would be helpfull if you said PLEASE - or is that not in your vocabulary?

also it would help many people who will glance to tell us what car you have and a general spec of it so we can gain an idea of the problem

and with regards to plug gap - bin the C57's and use a set of motorcraft 071's gapped to 0.6mm for your power - assuming that isn't mickymouse pub power you have as your username

 

at last thankyou graceland can only use the c57s in it as all other plugs i have to nail it hard apparently it needs to be a hot plug,so what gap would u say 4 the 57s then

 

huge spec too much to list general idea running greys,wrc head,bd10,db14,low comp,etc

 

i had no problems with 071's and 26psi boost - have gone for coilpack conversion and now use Denso iridium plugs at 60 odd quid a set - but they never need to be gapped as they are 0.8mm and i never see a misfire at all


Upgrade to coilpacks and all your misfires will be gone into the past forever

 

is that 0.08mm
cause the plug gap at mo on 57 is set to 0.60mm?

 

MY plug gap is 0.8mm - but i have binned the distributor and gone for solid state ignition


your plug gap should be around 0.6mm if using conventional distributor and coil

 

hold on confused cause the feeler gauges i have are e.g.0.30mm-0.20mm etc so do i set the spark plug to 0.06mm?

 

0.06mm would be incredibly tiny and no gap at all


you need to set the gap to 0.60mm


if you are still having misfire problems, then clean the crank sensor face with a soft cloth and white spirits, and also check the HT leads, distributor cap, rotor arm and coil to make sure they are all spot on

 

or 0.60mm?

 

I set my 071 plugs to 0.6mm and they are spot on m8.

 

.6MM will be fine m8
although i do run 0.7mm gap on mine with no problems

 

ok guys car is runnuing 33psi approx 430bhp
its only when i race and rev her to about 6900 ok 7k that i get a horrible missfire could the plugs need replacing

 

at them sorts of engine speeds i'd bin the whole conventional ignition system and replace it with coilpacks - MUCH more reliable