Civic Type-R Owners Club & Forum

typerboy wrote:
FRANKENSTEIN RETURNS?
The K24A is more closely related to the K20A3 and K20A. While it uses the same i-VTEC tuning as those engines, it's the long stroke design that's intriguing. The difference is in the block. The K24's deck height is roughly 19 mm higher than its smaller siblings. It's also slightly bored, with 1 mm larger cylinders. The compression ratio is also down slightly from the non-Type-S engines, 9.6.1 vs. 9.8:1. So what? Well, the natural temptation is to throw the K20A2's efficient head onto the K24A1 block, raise the redline and have a torquey, ultra-powerful i-VTEC stroker Frankenstein monster engine.

The actual bolting on part wouldn't be too difficult, as the heads should mount right up. However, you do run into an issue with piston speed. At its 7900-rpm redline, the K20A2 in the Type-S has a piston speed of 4464 feet per minute (fpm). Thanks to its long stroke, the K24A1 comes close to that, running at 4225 fpm at its much lower redline of 6500 rpm. By the time you've spun your K24 up to just 6900 rpm, you're already at 4485 fpm, and at the 7900 rpm redline of the K20A2, you're at a crazy 5135 fpm. For comparison, even the hyperkinetic S2000 with its 9000 rpm redline doesn't exceed 5000 fpm (it maxes out at 49% fpm). And the Integra's B18C1 only reached 4573 fpm. Translation: If you're going to plunk a K20A2 head on a K24A1 block and redline the concoction to 7900 rpm without seriously building up the bottom end.. duck.

I appreciate this is a very old thread i have pulled this quote from but what im looking to find out is what would be required so i wouldnt have to "duck" as it was so well put?

Couldn't you use a k20 crank

sadly i have no idea so im looking to be shown the light by the more experienced members on here as i know people like Tuf have done some crazy things with their motors

So, you will need a k24 Block. if you would like to run a stock bottom you can get a k24a1 crv or k24a2 or a3 accord block. k24a3 is the best way, it has 10.5cr, oil sqirters, oil cooler already. To make it work you'll need k24 timing chain, chain guides, k24 oilpump chain, k24 chaincase, k24 headgasket, i guess thats all. if u want to run the k20a2 oilpump you'll have to modify it to make it fit.

Is there a way to raise the redline from 7700rpm as i know standard parts on a swap wont take the high rpm

http://civictype-r.co.uk/forum/viewtopi ... d&start=20

link in here to another thread also.

PM TDI north also they'll be able to give you the info you crave fella

Provided you use a k24a3 bottom end and k20a2 oil pump you should be good for 7600-7800 rev limit, although using the k24a3 bottem end and k20a2 head my peak power is made at 7200rpm.

The k24a1 from the crv has weaker rods so wouldn't risk it with that.

I've been rolling the k24/k20 stock internal and head setup for over a year now with at least 7 track days and many many drags even blasting a 75bhp dry shot of nitrous and so far all is well.

Everyday limit for mine is 7600rpm and track is 7800.

andy18s wrote:Provided you use a k24a3 bottom end and k20a2 oil pump you should be good for 7600-7800 rev limit, although using the k24a3 bottem end and k20a2 head my peak power is made at 7200rpm.

The k24a1 from the crv has weaker rods so wouldn't risk it with that.

I've been rolling the k24/k20 stock internal and head setup for over a year now with at least 7 track days and many many drags even blasting a 75bhp dry shot of nitrous and so far all is well.

Everyday limit for mine is 7600rpm and track is 7800.

What if i replace the rods in the K24A1?? As that bottom end produces the most power..

If you want to rev it then you need a fully built forged engine to cope with it.

If you just want to make 260ish bhp and rev to 7500 you can do if fairly cheaply without changing all the internals.

Well i have 240bhp already on stock internal'd K20A2, is it worth me going through the hassle of sourcing the bottom end? what if i want to reach say 8200rpm?

or do you mean 260bhp at the wheels?!!

RsAMD wrote:So, you will need a k24 Block. if you would like to run a stock bottom you can get a k24a1 crv or k24a2 or a3 accord block. k24a3 is the best way, it has 10.5cr, oil sqirters, oil cooler already. To make it work you'll need k24 timing chain, chain guides, k24 oilpump chain, k24 chaincase, k24 headgasket, i guess thats all. if u want to run the k20a2 oilpump you'll have to modify it to make it fit.

Why doesnt anyone use the K24A1?? Looking at the figures it produces more power?

andy18s wrote:Provided you use a k24a3 bottom end and k20a2 oil pump you should be good for 7600-7800 rev limit, although using the k24a3 bottem end and k20a2 head my peak power is made at 7200rpm.

The k24a1 from the crv has weaker rods so wouldn't risk it with that.

I've been rolling the k24/k20 stock internal and head setup for over a year now with at least 7 track days and many many drags even blasting a 75bhp dry shot of nitrous and so far all is well.

Everyday limit for mine is 7600rpm and track is 7800.

Hey andy what was your last dyno result, like 240 @ the wheels wasnt it?

hovblackctr wrote:If you want to rev it then you need a fully built forged engine to cope with it.

If you just want to make 260ish bhp and rev to 7500 you can do if fairly cheaply without changing all the internals.

Just a set of cheap H-beams would let you rev it pretty hard (9k), but without some dirty great cams you wont make power past 7k odd anyway.

this is why i love this forum.... Users to the rescue

Well this is my requirements, id like the ability to rev high (mainly for down shifts)...safely

More torque and more hp.... but reliability is a must as im selling my race impreza to fund the repairs.

Wikipedia shows that the K24A1 engine produced the most torque and power of the K24's , so im hoping that coupled with the K20A2 head i should be pretty near what im looking for?? (obviously some internals swapped out for forged parts...but which??)

Please point out any blundering mistakes i have made

If your going to bore & build the block it doesnt matter which flavor k24 you use. Just buy the cheapest one you can find!

If it was my money... I'd go for these pistons: http://www.clubrsx.com/cr/SUP-P4-HK87-P15.html
And these rods: http://www.clubrsx.com/cr/BC-MA6045.html

pulpmelon_r wrote:If your going to bore & build the block it doesnt matter which flavor k24 you use. Just buy the cheapest one you can find!

If it was my money... I'd go for these pistons: http://www.clubrsx.com/cr/SUP-P4-HK87-P15.html
And these rods: http://www.clubrsx.com/cr/BC-MA6045.html

cant find any right now, not for under £1200 anyway.... as its just the bottom end..can i use an automatic k24 bottom?

well im getting royally confused about which bottom is best i think K24A1, but some forums are say A2/A3??

Any advice

pulpmelon_r wrote:If your going to bore & build the block it doesnt matter which flavor k24 you use. Just buy the cheapest one you can find!

If it was my money... I'd go for these pistons: http://www.clubrsx.com/cr/SUP-P4-HK87-P15.html
And these rods: http://www.clubrsx.com/cr/BC-MA6045.html

Are these for FI only?

This is what im talking about!!
http://honda-tech.com/showthread.php?t=1718890

phunkmasterd wrote:

pulpmelon_r wrote:If your going to bore & build the block it doesnt matter which flavor k24 you use. Just buy the cheapest one you can find!

If it was my money... I'd go for these pistons: http://www.clubrsx.com/cr/SUP-P4-HK87-P15.html
And these rods: http://www.clubrsx.com/cr/BC-MA6045.html

cant find any right now, not for under £1200 anyway.... as its just the bottom end..can i use an automatic k24 bottom?

well im getting royally confused about which bottom is best i think K24A1, but some forums are say A2/A3??

Any advice

The A3 is the equivalent of the U.S A2. Actually the A3 is better as it has an oil cooler;)

If you going A1 and want a reliable setup, go with the aftermarket rods and the new tsx pistons which are 11 comp.

Ultimately, unless you plan on adding cams. there really is no point in needing to rev any higher than 7800, and you'll be safe with the above.

The nice thing about the 2.4 is the power comes in earlier and the torque is mindblowing, compared to k20. Im sure there's a dyno graph on my post that shows the differnce between my k20 and k24 setup with identical mods so should give you an indication of the power differences.

Lastly rather spend another addition cash on good air filter setup and exhaust. You'll need a new header, 3" exhaust and 3" intake system to get the most from the k24.

Im currently standing on 260fwhp and 210lb.ft which translates very nicely on the road and is personally more than adequate as a street setup.

Definitely worth the effort.

Also bear in mind you will be using your clutch and flywheel which bolts straight on from your k20. If you need a new clutch and lightened flywheel, or LSD, now would be the time.

For that you could stick with the stock exedy clutch, cheap as chips on ebay, and keeps that great stock light feel. Mine's was in the k20 for 5000 miles and has now been on the k24 and taken tons of abuse and not even as much slipped when blasting nitrous.

I got mass respect for these clutches

Anyways, hope that cleared things up a bit for you, any other questions just ask away.

Would there be noticeable differences between the A1 and A3 power wise... I have this fixation with high power figures thanks to Wikipedia but if the A2/3 block will do about the same but for loads cheaper then I might as well go that route