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Honda K24 and K20 Spark Plugs

K series Civic race car spark plugs spal fans

What Makes the Honda K24 & K20 Engines so Great?

The Honda K series engines (k24 and K20) are well both proven powerplants in either NA and forced inductions layouts. The 2.0L k20 and 2.4L k24 are found in a wide range of Hondas from the early 2000s to current such as the Civic type R, Integra type R, tsx, crv, Civic Si, TSX and more. Those of you working with the K20C engines be sure to check out this article: K20c Spark Plugs.
With a few basic mods and general maintenance the Honda K20 and K24 are reliable powerplants ready to make you smile with every drive. In NA form the K series will easily produce 200-350whp on pump fuel/e85. While 400-500 Hp is possible from a high compression k24 that type of engine build is strictly meant for drag racing and will require race fuel. The easy way to BIG power with any K series is with the help of a good turbo kit. Even a bone stock K20 or K24 can easily support 400-600whp with a well matched turbo/supporting mods. 600 HP not enough for you? Our Built engines using forged pistons, rods and Darton Sleeves can hold 1600+ HP and if that still isn’t enough we offer Billet K series blocks that are capable of holding over 2000HP . For this reason the K series engines are one of the most popular engine swaps for both FWD and AWD Hondas as well as hybrid RWD conversions popular for 240sx, RX7, Silvia and Skylines.

K24 Honda

K20 & K24 Spark Plugs

To help ensure you get the most out of your K24 or K20 it is key to run a high quality set of spark plugs. Spark plugs are responsible for starting the combustion cycle that powers your engine. With NGK spark plugs you are assured your plugs are providing a hot reliable spark to ignite the air/fuel mixture in each cylinder. Below is a list of the best ngk spark plugs for the K24 and K20 engines. These iridium core plugs are available in 3 popular heat ranges to suit any K20 engine build. To make things easy we have listed out the correct NGK spark plug based on horsepower output from your K series. If you have any questions feel free to comment below or give us a call we are always happy to support your build.

Honda K20 and K24 NGK Iridium spark plugs:

NA k20 & k24

  • Stock – 300hp BKR7eix-11
  • 300 – 350hp BKR8eix-11
  • 350hp+ BKR9eix-11

Turbo and Supercharged K20 & K24

  • 200 – 300hp BKR7eix-11
  • 300 – 450hp BKR8eix-11
  • 450hp+ BKR9eix-11

Why use Iridium Spark Plugs:

Using the Iridium core ngk plugs is an easy bolt-in upgrade for any K series the BKR7eix-11 means the plugs come pre gapped to 1.1mm the BKR7EIX (no -11 in the part #) are pre gapped to 0.8mm. If your engine suffers from spark blow out we recommend running the tighter gap BKR7eix plugs that feature a 0.8mm gap. If you find you need to a gap the plugs down tighter than 0.8mm you should consider upgrading your ignition coils to either the NGK R35 coils, haltech IGN1 coils or AEM IGN1 smart coils. Check out the video below to see just how easy it is to install a fresh set of NGK spark plugs in your K20 or K24 at home or in your garage.

Iridium core plugs hold up to heat better and last longer than their copper core brothers such as the ngk bkr7e spark plugs. For these 2 reasons you can find the Iridium core ngk plugs in everything from our purpose-built K series powered track cars to turbo street cars.

We keep a large inventory of all the popular ngk spark plugs in stock and ready to ship. If you don’t remember the last time you changed your plugs or you simply want to ensure your car is running perfectly, swap in a fresh set of ngk plugs and enjoy! 

Fixing spark blow out:

Any high power K series engine makes its power through high cylinder pressures and great airflow through the cylinder head. The high cylinder pressures put the spark plug and ignition coil to the test. As spark plugs wear out the resistance increases this increased resistance combined with high cylinder pressures results in “spark blow out”. Spark blow out is a situation where the spark fails to arc from the spark plug’s electrode to the grounding strap causing a misfire and loss of power. Running NGK iridium plugs helps to ensure your engine will not suffer from spark blow out even under high boost high cylinder pressure situations. NGK iridium plugs have proven to last longer and perform better than any other spark plug option on the market both on and off the race track.
So you enjoy your K series but you want more power and you want a LOT more power? Then it is time to turbo your K20 or K24 and make an easy 400-500HP on the stock engine! Check out this Turbo K24 & K20 Tuning guide for a complete run down of all the parts you need to build a reliable turbo K series.

K20, K24 NGK Copper Core Spark plugs:

200-350hp BKR7E Spark Plug
450hp + BKR8eix-11 (For any K series making 450+ whp we highly recommend running Iridium core plugs linked above. At this power level the copper core plugs will not last long and cause spark blow out issues. Using the correct Iridium plug and a good set of ignition coils is key to reliably making over 100HP per cylinder.)

k24a vs k20c exhaust ports

K20c VS K24a Exhaust Ports

Here is a great comparison of the K24a vs K20c exhaust ports. While the K20C single port offers a very simple solution for adding a turbocharger is does start to restrict airflow when making above 450whp. The K20c will absolutely support well over 600WHP BUT the restrictive single port head will become a limitation and start to effect long term reliability. (As the power goes up so does the exhaust temps and back pressure. The single port design traps this heat and pressure in the cylinder head where as the 4 port K24 head is able to let the heat/pressure out MUCH easier do to the 4 port design flowing much better than the single port design above the 450whp mark.

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