4k-u Spark Plugs

[tioklou]

Hello my engine has the " BRE529Y-11" sparkplugs! i want to put one size colder spark plugs but i can't find the type!!! do you have any ideas or suggestions? thanks!!!!

[Taz_Rx]

I'm not 100% on this but going to make an educated guess - Stock 4k plugs are "BP5EY" and the "5" is the heat rating.

If the number you've provided is a NKG part number that I think its safe to say they are also a "5".

 

To run a colder plug (say for an engine with some work done to it) you need to go up to a 6 or maybe 7. See if you can get a plug with as colse a part number to that you gave, but just with a 6 instead of a 5.

[kiahn]

http://www.ngkspark.com.au/sparkplug_tech.php?div=mod#

 

heat range explained

 

basically lookss like the only way you will know is by buying 1 of the heat range you THINK will be right and road testing it,

seeing if it works better or worse and work from there

 

As mentioned the optimal operating temperature range for a spark plug is 450 – 870°C, 450°C is the spark plug self cleaning temperature at which point carbon deposits will burn off. However, if too cold a spark plug is used and this temperature is not achieved carbon fouling will occur. This is the most common reason for carbon fouling.

Edited September 1, 2009 by kiahn

[Felix]

I think his problem is finding plugs in his desired heat range with the long projection that the dished piston motors run.

 

ie. normal type (flat-top piston motors)

longer projection (4/5k dished piston motors)

[tioklou]

yes my spark plugs are with the longer projection for dished piston engine...but i can't find colder plugs... my problem is with the electric fan. the car run ons after turning it off. but when i put to the mechanical fan i don;t have the dieseling problem... problem...

[tioklou]

yes my spark plugs are with the longer projection for dished piston engine...but i can't find colder plugs... my problem is with the electric fan. the car runs on after turning it off. but when i put to the mechanical fan i don;t have the dieseling problem... maybe because of the lower temperature..

[Ella]

i also have a 4K-U in my DX, having the same problem, Will colder plugs solve this? i thought maybe it was a timing issue, but it behaves itself driving just nicely, never ever pings, so i dunno :P

Edited September 2, 2009 by Ella

[tioklou]

Ella we have tha same problem...but i think if you use spark plugs from the normal 4k i wll lose some little compression because of the smaller projection....

[Bowler]

To create a cooler plug, but keeping the standard style plug that the dished piston engines run, close the gap from 1.1mm, to 1.0mm. This is a technique used by owners of cars on gas, to create a cooler plug if their variety isn't available. The technical reasoning behind this is that the spark surface area is decreased, such that complete ignition takes longer to propagate.

[B-Rad]

yes my spark plugs are with the longer projection for dished piston engine...but i can't find colder plugs... my problem is with the electric fan. the car runs on after turning it off. but when i put to the mechanical fan i don;t have the dieseling problem... maybe because of the lower temperature..

 

Tioklou,

 

your problem is not your spark plugs. The reason that you engine keeps running after it is turned off, is the electric fan is acting like a alternator and supplying power to your coil. To fix the problem you need to fit a relay to the fan that is controled by your key. This will cut out the fan from the electric system causing the engine to stop when swithed off.

[Xany]

To create a cooler plug, but keeping the standard style plug that the dished piston engines run, close the gap from 1.1mm, to 1.0mm. This is a technique used by owners of cars on gas, to create a cooler plug if their variety isn't available. The technical reasoning behind this is that the spark surface area is decreased, such that complete ignition takes longer to propagate.

 

The spark plugs he has in the engine "should" have been regapped to 0.8mm as per standard spark plugs in a normal 4k engine.

[tioklou]

thanks guys a lot!! i will put a relay on my electric fan to close with the key and iwill regap my sparkplugs....but one more question... with which gap i have bettter burn? with 1.1 or 0.8? iam afraid of reducening my engine's power...this is only my opinion!!! thanks again...

[Felix]

The recommended plug gap for a dished piston motor running an electronic dizzy is 1.1mm.

 

If it misfires under heavy load at high rpm, then try reducing the plug gap.

Edited September 28, 2009 by Felix

[rob83ke70]

thats the same part number as an EB/ED/EF/EL falcon isn't it?

 

WR7LCX or WR9LCX in a bosch flavour maybe?? can't quite remember. Bosch numbers go the opposite direction to NGK. I just can't quite remember if thats the right suffix or not...

 

Not a fan of giving things the lawnmower treatment (champion plugs) especially not in a 13/16 hex size, the champion plugs in that size seem dodgier than the 5/8 hex plugs... I could be imagining it though.

 

Any good parts place (ie NOT repco in orange) should be able to get you a cooler plug in whatever brand.

 

Robert.

[Xany]

EA falcon spark plugs actually.....

 

And yeah, i aint running a lecky dizzy.