Its the Ca18 springs and retainers that are interchangable with the ka. Im not positive, but i think it would be better to de-stroke the motor for extremely high revs. Short stroke motors are much more rev-happy, i.e. honda motors. not to say that you couldnt rev a stroked ka that high.

 

Alright guys, what if I just put sr 370cc injectors in there after putting the E pistons in without doing anything to the ECU, would that work or would it still run too lean and just crap out on me?

 

no, thats not how it works. Just because you put bigger injectors doesnt mean problem solved. At that point, you may be running too rich. The reason people swap out larger injectors is a sort of failsafe. The stockers will get the job done if memory serves me right, but you will need to do some tuning with an SAFC. Doing so will mean going up on the duty cycle, which means (generally) a shorter injector lifespan past certain duty cycle durations. This is where the 370s come in. The 370s run on a shorter duty cycle, but they still need to be tuned with an SAFC (cheapest way) or have the ECU reflashed in order to have to correct fuel ratio... Hope that helps.

 

Pulse width of the injectors and there duty cycle needs to be controlled (SAFC). Just adding the injectors won't solve your problem it would actually need to be tuned and calibrated properly. You would then be running tooooo rich with SR injectors and would have to calibrate to have them run stoich to lean.
Theres no cutting corners on this one unless you want to blow up, or stall your engine. Wideband O2 and SAFC is about as good as it gets for affordable archaic tuning.....

 

Thats not true either. The KA can rev pretty high in stock form, as long as alot of restrictions are removed, and replaced.
Intake short runner plenum system will allow for more high rev, as well as higher compression pistons, advanced timing, and removing torque stopping inertia parts such as belt driven fan assembly, crank pulley and even changing the massively heavy fly wheel in exchange for aluminum (fidanza).
Honda is alot of torqueless mumbo jumbo.

 

The majority of the fuel that the american market is supplied with comes with a minimum of a 5% ethanol mixture(in some states 10%), it actually retards knocking and pinging from ocuring, but also slightly drops the BTU energy content during combustion. With a mild non aggressive, timing cycle and high compression pistons, 91 octane can be used. If the timing is to far out of a specific tuned range then 96 to 101 octane would possibly need to be used.
FYI about the cam questions earlier anything I believe that is past 165 duration cam spec will need retainers, and would be dangerous to use flat top pistons. I don't recommend anyone using the pre production 89 pistons at all since they use a raised dish.

 

So bigvin you don't recommend doing the E piston swap?

 

i think he meant with a cam bigger than a 265 duration. but what if you were to get grooves made in the top so the vales dont hit the piston? the only after market high comp pistons ive seen for ka are 10.5:1. sohc pistons would be alot cheaper and would raise the comp a tad bit more. but im not really sure how much a machine shop would charge to "groove" the top of the pistons.

 

Not if youre not willing to finish the job, and not half *** it.

 

Ok, guess I'll just have to save a little more and do the job right but thanks guys for all the help you pointed out everything I'd need for the swap.

 

I never said don't use E pistons, just don't use e pistons with too high of a lift cam, and definitely don't use the pre 89 KAE pistons because they have a raised dish and are bad to use even with stock cams.

 

I believe you mean fly cutting the piston...
Some do that but it will weaken the strength of the piston.
Most after market pistons such as wiseco's, or super tech's already have them designed in the precast, so that it doesn't weaken the strength.

 

you mean the single cam motors from the hardbodies?

 

You would have to be more specific..
Hardbody trucks came with NAPS-z, and KA24e engine's and either of those engine pistons are interchangeable with different CR rating's.
PRE production 89 pistons started in the 240sx. Which means if you look at the production date on the chassis it should have a date on it from NOV~DEC of 1988.
Hardbody trucks didn't use the KA24e until a production date of 1989, which was a 1990 hardbody truck....

 

i dunno if i understood you right, you said pre production e pistons, so i assumed the pistons from the hardbody. lol im not thinking right, trying to get my homwork done while also wanting to go to sleep. bear with me, lol. so what your saying is dont use the e pistons from a 240 with the nov-dec of 1988 date on it?