The K20A / K24A thread

[Roman]

Hey,

 

So a few members of the forum are K motor fanboys.

 

These are a modern 2 - 2.4 litre Honda 4 cylinder engine with VTEC and all that jazz... Which go quite well and are reasonably cheap, so perhaps a good option for a grunty NA oldschool ride?

 

So I thought we could have a thread to discuss them without polluting side tracking other threads.

 

So the purpose of this thread is:

 

-Post information regarding specifically what you would need to fit a K motor to an older car.

-Pros and cons of doing so.

-Post links to parts/information which would help as per above and expected prices for a swap in total.

-Post how tos, problems you might face, etc.

-Post tech info about K motors and the variations available.

-Dyno plots and other cool stuff.

 

The purpose of this thread is not:

-For arguments that K motor is better/worse than blah blah blah

-For Telling people their current other motor is shitty and they should get a K motor.

-Just chuck one in bro

-Other tiresome conversations similar to above.

 

I dont know too much about them, apart from that they seem to make awesome power with basic mods compared to other NA motors...

 

Although I'm not sure if this isnt just because people have thrown a truck tonne of money at them, and you could acheive similar with other engines.

Some basic info to kick things off:

 

http://en.wikipedia.org/wiki/Honda_K_engine

[Roman]

Looks as though there's a W5* gearbox bellhousing adaptor available from Convert Motorsports... Or at least will be soon?

 

http://convertmotorsport.co.nz/conversion-parts/

K20A to W5*- NZ$649
Niteparts alloy K-W bellhousing. Suits use of W55/56/57/58 Supra or G52 Hiace/Hilux gearboxes behind Honda K20A., K24A series engines to allow for rear wheel drive applications!
Uses factory W55 fork, pivot, release bearing & slave cylinder.

 

 

On trademe it looks like a Type R K20A + fancy FWD LSD gearbox is ~$5-6k... Not particularly cheap for the fancy version of the engine.

 

[CaMpylobacter]

I have a few questions about these. As with anything, I'm sure 'chucking a k24 in' isn't as easily done as some make out.

Referring to the wikpedia page I'm not as impressed as I thought I'd be with factory power figures and whatnot but I'm keen to hear how they're made to make decent power easily (and most importantly, reliably... although I'm sure being a Honda engine this wont be a problem after seeing what the earlier B16 type engines will stand up to!) 

 

What transmission is required to fit these to an os rwd vehicle?

 

What other modifications are required to 'RWDise' these, if any? 

(example: fwd 4ages/4g62s etc etc require intake and exhaust manifold alterations, as well as cooling pipe alterations)

 

I've heard they're quite a tall engine. Comparitively, how much taller than the venerable Toyota 4k/4age, a Ford Kent, or a Vauxhall 1256 are these? (probably the most commonly converted smaller cars on os)

 

They seem like they may be a fairly decent engine for use in coversions on older jap utes too, to replace 12rs and things like that in Hiluxes. If used as an engine for a parts hauler/tow vehicle I'd be interested to see how they stack up.

[HighLUX]

Rookie likes this

 

But seriously some measurements on engine size would be good. If they are a comparable size to a BEAMS 3S then should fit sweet in a hilux or similar sized ute.

Also can you use factory ecu? Cause a cheap engine aint cheap when it turns out it needs a $1800 link to run it

[Roman]

Yeah first things first is finding out if there's a bellhousing or adaptor plate that's available for RWD'ing without costing millions.

 

If not, it's probably not particularly economical to spend the price of an engine again on custom clutch/flywheel/adaptor plate/etc.

As best I know you would need to remake or cut and shut the intake manifold (points the wrong way?) and remake exhaust manifold (points wrong way)

 

And possibly the sump if it's a motor that runs tipped over from factory (not sure?)


 

[Roman]

Rookie likes this

 

But seriously some measurements on engine size would be good. If they are a comparable size to a BEAMS 3S then should fit sweet in a hilux or similar sized ute.

Also can you use factory ecu? Cause a cheap engine aint cheap when it turns out it needs a $1800 link to run it

I believe(?) the K20A is slightly taller overall than a beams motor, and a K24 is taller again due to having a longer block as they get most of the extra displacement from a longer stroke. I think they are chain driven rather than belt, which makes the covers a little taller.

It might be that they need to be leaned over slightly to fit reasonably in a RWD car... In my car there's no way I could run a taller engine than I already have, I've already bashed the oil pan into the oil pickup despite my grandpa spec ride height.

K motors have the extractors come out on the drivers side, which can mean it's a pain getting around the steering column/box depending on the car.

For ECU, they need something that can both run continuous valve timing with PWM, and also trigger the solenoid which activates the VTEC cutover. Which means no chance of using any of the cheaper links etc unfortunately, although this seems to be the case with just about all modern engine options now. Not sure if you can run the standard ECU without dramas.

 

[Snoozin]

http://www.superstreetonline.com/how-to/engine/1402-k-series-engine-family-breakdown/

Good insight into what K series to choose. The Yanks by and large are the best informed on these things.

[mjrstar]

i like the idea of a highly strung RWD na, but i'm not convinced that a W* is the box to nail 9000+rpm shifting (depending on clutch selection) or have agreeable ratios depending of diff and rear tyre diameter.. (shit that can easily be overlooked) The cd009 I used in the mazda is nice with the match of diif ratio and wheel diameter BUT the bellhousing size is massive as you would expect for it to hang off a sizable v6. Plus the 6 speed gate for 5th gets some getting used to.

 

There was a weapon silver F20 powered bugeye starlet around the traps a while back..

 

Colant flow design is imperitive if you are looking to do sustained high load, not just jamming together some pipes that may make some coolant circulate...

 

Physical mount provisions - similar to later model evo blocks which do not go well in n/s orientation, is there something strudy on the sides to hang mounts off?? (hence the use of an early vr4 block in the mazda)

[Rookie]

Here is the bell housing Mcgregor Motorsport in CHCH have made to fit a w55/6/7/8 to a K.

 

 

And here it is bolted int a lotus 7 esq chassis.

 

[Snoozin]

http://www.stanceworks.com/forums/showthread.php?t=45026

K series into an S13 - F20C gearbox, modded stock inlet manifold

http://motormavens.com/2011/05/garage-life-jsp-fab-k24-powered-ae86-rebuild/

K series into AE86, similar deal with the manifold, just cut and shut.

There are many different factory manifolds also, with differing flow capabilities. The most popular from memoery is the "RBC" manifold found on CL7 Euro R's

[Rookie]

I too am not on board with using a w series. If I was doing it I would use an adaptor plate and a J160, they are a much nicer gearbox.

 

Here is measured head flow for the different stock heads.

 

[Spencer]

I wrote a big blurb and lost it.

Yes you have to pay more initially to get one which seems to be the devil around here. People would rather get a cheaper engine then spend 8x its value turd polishing.

K24a's heads aren't as good as a K20a but they still have all the potential in the world, the heads are great and after market parts are everywhere. IF you score a K24a3 (I think, the accord euro one) they are sweet, 140KW and 2.4l torque would go amazing in a old car.

Ghetto price break down

K24a = $500-$1500

Gearbox setup - $1000-1500 (there are J160 and W55 options)

Intake and exhaust - China ITB's are like $400, they flow shit but its a good start, then make a exhaust so $200? if you are durp then $800??

ECU - These aren't expensive at all, the beauty of Honda (K series especially) is the aftermarket is insane. There are specific K series ECU's (like AEM?) for $1000 that do all the VVT etc. Or you can use the factory one and buy the tuning software stuff.

Yes they are massive.

If you can make one fit and have some balls to actually spend ~4-5K to get initially setup they are better than any other NA 4 banger out there.

[flyingbrick]

How come nobody likes the h22a (I think) in the 90s preludes. They go real damn well for the money

[DB8-TypeR]

_{^ They do (my writing looks really small on this PC?)}

 

_{Usually what holds them back is that H22a Gearboxes are gay (long ratios), so you buy a H2B kit so you can fit a S80 Integra Type R gearbox (close ratio, but means it will be doing 4000+ RPM @100kp/h) and they come alive.}

_{i.e. pick up a $200 H22a from a wrecker, Bolt it to Bseries gearbox, fit intake/headers/exhaust, burn a chip for OBD1 ECU with a tune and have 150kw+ ATW. Then if it blows u buy another H22a for $200}

[Snoozin]

I love H22A.

In this instance though they spin the wrong way

[Rookie]

I love this.

 

http://www.k20a.org/forum/showthread.php?t=84605

 

Stock k24 with cams and inlet manifold, add a gt4202 turbo and it puts down 680 whp hahaha

[Spencer]

Yea H22's are great but yea they spin the wrong way, K-series has cheaper aftermarket parts now and has better heads.

I bought a K24a3 for this accord I had (to build a BTCC stz touring car, but I had no space for such a project) and the heads are just awesome. After having Toyotas it is so good to have parts catalogues of actually affordable aftermarket bits available from a whole swag of manufacturers.

[Spencer]

K24's also defy science by somehow reaching insane piston speeds (when modified, cams etc) and holding together no problems.

[Rookie]

Yea there is a dude on K20a.org who has a k24 with 13.5:1 pistons, ported head and cams, revs to 10k and makes 330 whp, just mental...

[Roman]

Ghetto price break down

K24a = $500-$1500

Gearbox setup - $1000-1500 (there are J160 and W55 options)

Intake and exhaust - China ITB's are like $400, they flow shit but its a good start, then make a exhaust so $200? if you are durp then $800??

ECU - These aren't expensive at all, the beauty of Honda (K series especially) is the aftermarket is insane. There are specific K series ECU's (like AEM?) for $1000 that do all the VVT etc. Or you can use the factory one and buy the tuning software stuff.

I doubt anyone in the real world could get a certed near standard K20A/K24A in their RWD car for less than $10k.

As per my link there's a bellhousing to W box but it's $700, then about that again for a gearbox. So that's the gearbox budget gone without any consideration to what clutch or flywheel or whatever you're able to use. Which is about another $1000 for something worth putting in / probably needs something custom?

Then custom driveshaft, custom gearbox cross member, getting the speedo to work with an electronic output, and a shit tonne of other niggly things which cost time and money.

I'm not saying that you dont have these same issues with other motors too... But sorting out these things alone and various other unexpected issues and you can easily blow a $5k budged without even buying a motor yet.

I dont know how you expect to build an exhaust including extractors for $200...

Excluding extractors I just recently made a 2.5" exhaust setup with mandrel bends and it was about $500 worth of bits when including mufflers/hangers/etc.