G'Day Peoples,

 

Just wondering what type of spark plugs you guys use and how often you change them? Also.....do you think (say that you prefer NGK spark plugs) that their Iridium spark plugs are any more effecient in a 3K/4K/5K engine than standard spark plugs?

 

Your views please.

4k-e uses a real wierd special plug

The 4AGE has to use iridium spark plugs for some bizzare reason (it actually has a sticker on the engine that says to only use iridium plugs). When I took the old ones out of the engine when I got it, they had probably done a good 150000k's (they were original Toyota plugs), but still looked almost as good as new. Chucked in a new set ($80 later...) and haven't looked at them since.

Here is a good link, which explains and answers many of the questions, user of spark plugs find a mystery.

 

Read the FAQ on the top RHS of the page.

 

NGK Spark Plugs !

 

:)

If you think iridium plugs are dear, try buying a pair of double platinum plugs for "waste spark" systems, where the one coil powering two spark plugs results in the spark jumping from the centre to outer in one plug & from the outer to centre in the other.

 

Some manufacturers produce the same plug in two different models. One has centre platinum electrode & the other an outer platinum electrode. This cuts down the amount of platinum required per plug, in that only one electrode is platinum.

So in a 4 cylinder waste spark system where firing would be 1 & 4, & then 2 & 3, plugs 1 & 2 would use one model of plug & 4 & 3 would use the other other model.

 

Confusing ?

 

Here are a good couple of links that describe the waste spark & platinum plugs very well.

 

Double Platinum Spark Plugs

 

 

Waste Spark Explained

Edited July 20, 200521 yr by Banjo

i personally prefer ngk and denso. ngk are just a good solid product, and i have seen densos last well beyond triple their service life, and they're what toyota use stock so they must be good :)

 

i don't think a $25 (EACH!!!) spark plug is going to make a lick of difference in any k motor, with its imprecise and inconsistent air/fuel metering and crappy combustion chamber shape

 

maybe if you were running an efi high compression twinky crossflow thing (100kw 4age for instance) you would have reason to use a decent plug

 

for a K motor, about the most r&d you'd bother doing would be to index the plug and do a few dyno runs with the electrode facing different ways, probably only good for 1 or 2 rwhp anyway

 

that being said, i'd never tried fancy plugs, so if anyone does and likes them, i'd be interested to see some definitive test results (ie: not the "butt dyno")

oh yeah, and those 4 prong spark plugs are crap. they shield the spark from the combustion mixture, leading to worse combustion and drop in power. whatever moron let them slip thru onto the market needs to be shot

Denso

I think Teddy loves DENSO spark plugs !

 

:)

Edited July 20, 200521 yr by Banjo

yup, thats all they use at work, never had any troubles with them at work, and can't say i have ever herd anything bad about them. You would want something good, for how much they cost :) !

I used to use Bosch, but had a few of them foul on me. So i switched over to NGK and they were fine - but then my local auto parts shop stopped stocking them.

Now I only use Denso's in my 5K and have never had a problem with them.

denso or NGK's, all the others i've tried have given problems.

split fire were a good plug until they sold the company and now there shit.

 

we have twin electrode style plugs in the rally car and there great.

 

the right plugs are worth HP.

i have issues with bosch anything, down with bosch

NGKs always have worked the best for me.

 

not only should you consider brand, but also design. from the factory the dished piston 4ks and 5ks have long reach projected nose plugs in them, as the combustion chamber is sunk half into the piston. the factory ND plugs are the equivalent of an XF-EA plug. the only problem is that it is hard getting plugs in different heat ranges with the long nosed plugs.

 

i have tried just running normal styled plugs, like the normal 3k/4k ones which are easily available in different heat ranges. the only problem is they are noticably down on power over the long nosed plugs. guess the spark isn't being fired in the centre of the combustion chamber in a 5k.

NGKs always have worked the best for me.

 

guess the spark isn't being fired in the centre of the combustion chamber in a 5k.

Thats intersting. As requested by Jamie, do you have any hard evidence that we can compare/view?

What is the part number of the spark plugs that you use (i assume your running a 5k)?

Edited July 20, 200521 yr by kangaroosa