Honda K24A: Everything You Need to Know

in the world of jdm performance honda is probably the most polarizing brand out there you either love them or you hate them and there doesn't really seem to be a middle ground on that. regardless of how you feel about honda and the vehicles that they produce there is no denying that they make some really awesome four-cylinder engines. now in previous videos we've talked about the k20a and we've talked about the k20c but today we're gonna dive in and take a deep look at the k24a and tell you everything you need to know. Honda brought the k24a to life in 2002 shortly after the launch of the k20a. now it was designed as their larger engine that they could use in their larger suvs and sedans because one of the problems with the k20a is that it lacked low-end torque. it's a small 2-liter engine and it really didn't have enough torque to push around larger sedans and at the time honda wasn't producing turbocharged engines at least not in mass as they are now so just going with a larger displacement was their option and that's how the k24a was born what made the k24a so much different than the outgoing b series was its direct fire ignition system reverse engine layout clockwise engine rotation comparing the two engines side by side the big thing that stands out is how the k24a has the intake manifold on the front of the engine rather than on the back where it was on the b series now the clockwise rotating engine design was different than decades of counterclockwise rotating honda engines ultimately it helps improve emissions by improving catalytic converter performance having the intake manifold on the front of the head does make this a little bit more difficult to swap into older honda chassis. Now starting from the top down we can take a look at the cylinder head and pretty much all honda engines are known for having really good cylinder heads and a lot of flow on the intake and the exhaust side and the k series is no different and the k24a is also really good when it comes to flow but it should be noted not all k24a heads are the same without getting into too much detail the tsx type s k24a head is the best head and it's better than the crv/element/accord head major improvements for the k24a2 and the k24a3 cylinder head are the bigger intake valves and the more aggressive intake cam but what's particularly interesting about all k24a heads is the fact that they use different versions of ivtec which we've talked about in other videos but as a refresher there are basically two versions of ivtec one for performance and one for economy and they both use vtec and vtc but they use it in different ways the vtec part of the system has two different camshaft profiles one for low rpm and one for high rpm and the vtc part of the system us to adjust valve overlap at any moment resulting in much greater efficiency and slightly better performance now the performance version of ivtec uses vtec and vtc where the economy version of ivtec combines vtec-e and vtc to make this really easy to understand the a1 a4 and a8 variants of the k24 use the economy version of ivtec and the a2 and a3 variants of the k24 use the performance version of ivtec. i know that's a little bit confusing but if you have any questions about the whole ivtec system, just drop a comment down below and i'll do my best to explain moving from the head down to the block we can find the biggest difference between the k24a and the k20a which is the displacement where the k24a is the larger motor as we talked about it's about 400ccs bigger than the k20a. the k24 uses an 87 millimeter bore and a 99 millimeter stroke making this an under square engine because stroke is significantly larger than bore typically with under square engines you're going to give up a little bit of maximum rpm speed and top-end performance in favor of much better low-end performance and this is somewhat true with the k24a which we'll explain just a little bit but it should be noted that with minor modifications it's pretty easy to make a k24a spin upwards of 8000 or even 9000 or even more in rpm one of the inherent problems with all four cylinder engines is vibration but this problem is quite a bit worse for most large four cylinder engines like the k24 now for this reason the k24 uses balance shafts but not all k24 use balance shafts and eliminating is something that a lot of tuners do especially if you plan on running your engine at high rpm for extended periods of time such as on a track or just a simple high rpm build but it should be noted if you get rid of those balance shafts you are going to end up with a very buzzy motor. The rods are 152 millimeters in length and depending on the variant that you're looking at they're going to be kind of on the weak side when you're pushing a k24 the rods are only going to be able to hold about 300 to 400 wheel horsepower depending on the variant the pistons have a 9.6 to 10.5 to 1 compression ratio depending on the variant that you're looking at one of the problems with the k24a bottom end is the sleeves and it's not necessarily that they're bad or that they're excessively weak because in stock form they're totally fine but if you introduce forced induction to a k24a the sleeves can quickly become an issue most of the issues with the sleeves actually happen when you install forged pistons which is why a lot of boosted k24 builds actually use cast pistons because forged pistons do not play nice with the k24a sleeves if you wanted to run a forged rotating assembly with forged pistons and you didn't want to deal with the sleeves exploding on you you can pretty relatively easily install aftermarket sleeves into a k24a block which is totally going to fix that problem but it requires obviously taking your engine all the way down to the block and it's not a cheap or easy process that being said a lot of people have pushed the oem k24a sleeves upwards of 700 wheel horsepower so they're definitely not excessively weak they're only going to become a problem when you're pushing horsepower upwards of like five times as much as the oem power out now that brings us to the deck where the k24 uses an open deck design which is weaker than a closed deck design but as we've discussed in other videos that doesn't necessarily mean that you're going to run into deck failure and really honda used an open deck rather than closed deck for thermal efficiency the k24 isn't really designed to be a crazy performance engine from the factory it's just their 2.4 liter performance engine and open deck is totally fine and even in most boosted applications that open deck design isn't going to become an issue and if it does you can convert this engine to a semi-closed deck now that brings us to the performance potential of this engine which is probably why you're here most people are only interested in this engine because of the fact that it has a crazy amount of performance potential and not even that the k24 itself has that much potential it's that you can stick a k20a head on a k24 and it's absolutely wild and to demonstrate this we can look at four piston racing with their insane 500 horsepower naturally aspirated k24 built obviously their build is very extreme it has a sleeve block a lightweight aftermarket rotating assembly and a whole bunch of custom work and it's specifically designed for racing but the point is getting 500 horsepower out of a naturally aspirated k24 that's a lot of power naturally aspirated for any engine if we were to take the same power per liter of that four piston racing k24 engine which is around 200 horsepower per liter and apply it to say something else let's look at a ford coyote that's a 5 liter motor we would be talking about a 1 000 horsepower naturally aspirated engine which no matter how much work you do to a ford coyote no matter how much money and how much custom work you do to it you're not ever going to get a ford coyote or pretty much any other modern engine to make that power per liter figure which is what's so impressive about the k24a when it comes to aftermarket performance it simply is the best four cylinder in the world hands down when it comes to naturally aspirated performance there is no other production engine that can make that kind of power naturally aspirated at that size i would just like to clarify really quickly that i'm just talking about production automotive engines in this case i'm not looking at things like motorcycle engines which can make that much power per liter okay back to the video and on top of that it's one of the best forced induction four cylinders in the world when you strap a turbo onto one of these things and build them they make a ton of power very very easily and that's especially true when you swap on a k20 head where you're going to have a massive amount of flow now if you're still looking for more information i have a full guide on this engine on my website which i'll link down below and that's pretty much all i've got for you guys today for this video if there's anything you think i missed or anything you want to add please let me know down in the comments below that way we're all as informed as best as possible and we can have a good discussion while you're down there smash the thumbs up button really helps out the channel and i would really appreciate it get subscribed so you don't miss out on future videos and i'll see you guys in the next one you

Channel: Dust Runners Automotive Journal

Views: 100,536

Keywords: honda, k20a, k24a, k20 frank, k20c, civic, integra, honda k20, k20z, k24z, honda k20a, honda k24a, k20 build, k24 build

Id: iNhEcZmR_WE

Length: 8min 12sec (492 seconds)

Published: Mon Jul 27 2020