K20a Aus spec or Jdm H22A type S

[fatboyz39]

revs easily to 8000rpm

H series are the BOMB!!

All the way bro.

[barefootbonzai]

oh can't wait jimmy! i should have my turbo d-series done by then, so make sure you come and so we can race.

[ginganggooly]

With a 99mm stroke? I think it would need resleeving every 100,000km.

Are the harmonics that bad?

I've been told a few times that the weak link in the package is the valvetrain, and that the bottom end is good for 8k all day, every day...

[grumpy rooster]

Our H22A goes to 8k every gear change. It loves it.

You've made the right choice.

[aaronng]

Are the harmonics that bad?

I've been told a few times that the weak link in the package is the valvetrain, and that the bottom end is good for 8k all day, every day...

It's not the harmonics. It's the piston speed of 99mm stroke going at 8500rpm. That exceeds most Ferraris. The k24a doesn't have low friction liners like the other high revving engines, it's just a cast iron liner. To compare, an S2000's F20C at 9000rpm is pushing 4965 ft/min. A JDM k20A at 8400rpm does 4746 ft/min. A k24a at only 8000rpm is doing 5196 ft/min. You push it to 8500rpm, it's 5512 ft/min. That is much higher than an F20C, which was designed to live at high rpm since it has a ladder brace and a proper high RPM oil pump. Coupled with a long stroke with gives more side loading on the liners because of the short rods, the liners are going to be taking quite a bit of punishment.

The valvetrain has to be uprated, that is the first thing you should do if your k24a is going to be living at even 7000rpm for long durations. Easy way is to get k20a2 springs and swap them in.

[bal]

with upgraded valvetrain (lets say JDM k20a) and upgraded conrods and rod bolts still using the stock pistons etc in the k24a will this help the motor handle the higher revs?

[aaronng]

with upgraded valvetrain (lets say JDM k20a) and upgraded conrods and rod bolts still using the stock pistons etc in the k24a will this help the motor handle the higher revs?

Your rods/pistons won't disco dance in the block, the valves won't float, but it still doesn't solve the high piston speed at 8400rpm If you are changing the rods, you can destroke instead (Prototype Racing in the US had a k24a running at 2.3L). Not sure which crank they used, could have been an f23's, but I think I'm mistaken as the bore-to-bore distances for both engines should be different.

[BADHBT]

from experience
I’ve had both engines jdm h22 type s and a jdm k20a
I wouldn’t do an aus h22 unless your planning to open it up and build it.

h22 was heavy for my dc2, had to order stiffer rated springs for the front and a few other upgrades mainly to the front of the car to balance the cars characteristics, also its a taller motor so the pan sits quiet low, be cautious about the headers

but if i were you i would stock up on 2 min noodles and get your self a jdm k20

[bal]

Your rods/pistons won't disco dance in the block, the valves won't float, but it still doesn't solve the high piston speed at 8400rpm If you are changing the rods, you can destroke instead (Prototype Racing in the US had a k24a running at 2.3L). Not sure which crank they used, could have been an f23's, but I think I'm mistaken as the bore-to-bore distances for both engines should be different.

wow ok thats interesting i was under the impression that the rod and bolts would allow the 2.4 to rev much higher without being unsafe to the engine.

im currently getting a k24 put into my EG and the ECU that im getting unfortuatly does not have a rev limiter which means im going to have to be very careful when driving hard. what would you suggest i keep my rpm to?

by the way sorry for hi-jacking the thread

[EG5]

wow ok thats interesting i was under the impression that the rod and bolts would allow the 2.4 to rev much higher without being unsafe to the engine.

im currently getting a k24 put into my EG and the ECU that im getting unfortuatly does not have a rev limiter which means im going to have to be very careful when driving hard. what would you suggest i keep my rpm to?

by the way sorry for hi-jacking the thread

7500 rpm

dude run hondata kpro ecu for your K swap

[aaronng]

Yup, even for the TSX race car in the SCCA Touring Car championship which has aftermarket internals and cams, they limit the rev to 7800rpm for reliability.

[pkn-xtc]

Your rods/pistons won't disco dance in the block, the valves won't float, but it still doesn't solve the high piston speed at 8400rpm If you are changing the rods, you can destroke instead (Prototype Racing in the US had a k24a running at 2.3L). Not sure which crank they used, could have been an f23's, but I think I'm mistaken as the bore-to-bore distances for both engines should be different.

You're right, a K24 running a '04 S2K crank (with a deckplate or custom rods) will destroke it to 2.3L. It will produce lower piston speeds and a good rod/stroke ratio that will let you rev the crap out of it. Bore to bore distances should be the same for both motors, RSRs drift S2K is stroked using a K24 crank, and H22 pistons and rods to produce a 2.4L.