Destroking

[xonn]

Are there any kits available for destroking a KA? Say from 2.4 litres to 2.2 litres?

[j-z]

for what purpose?

[Ubernoober]

I would imagine he seeks to increase the rev range of the lower end by shortening the stroke. There is a lot of historical precident in the automotive world for doing something like that. I doubt it would provide a good return on the cost for anything not exclusively a track car.

[nlzmo400r]

well, mechanically speaking- shorter stroke= higher revs but less torque on low end. But no i havent heard of destroking the KA

[xonn]

more revs...

[Checkered-Member]

more revs...

then buy a god dam Honda, leave the Nissans alone :pface

[Ubernoober]

I sense angst in this one called "Checkered-Member".Perhaps a little Initial-D will tame the beast inside.

[Checkered-Member]

Perhaps a little Initial-D will tame the beast inside.

eh? WTF?

[Projex240]

out of all the retarded responses, why hasnt there beena good answer to his question?

In response to the question--no. There is not a commercially available destroking kit. You would have tot have a custom crank cut, and have the bottom end redone entirely.

-Josh

[xonn]

out of all the retarded responses, why hasnt there beena good answer to his question?

In response to the question--no. There is not a commercially available destroking kit. You would have tot have a custom crank cut, and have the bottom end redone entirely.

-Josh

Thanks mate...

[red240ne]

stupid idea, BANNED.

Don't destroke a KA.

[Chingon]

actually, I heard someone say that there was one produced by a reputable company...something along the line of toda or hks...

[deviousKA]

Modified by deviousKA at 4:39 AM 9/17/2005

[Red Lightning]

Nissan made a KA20DE in Japan, but I don't know if that engine fits the KA24 block. If it fits, you can probably order that crank from Japan and get custom rods and pistons. But if you want high revs, just get a SR or RB20.

[xonn]

Here is the issue. Although I would love to do an RB, the car will no pass emissions with it. The county that I currently live in doesn't have emissions testing but there's talk that next year they'll start. A 400whp daily driver than I can't drive is useless hence why I'm focusing alot of my research on getting more out of the KA. I'm going to build a KA, (new rods, slugs, bearings throughout) along with the balancing and blueprinting of tolerences that goes into any serious buildup. Although the stock rev limit is 6800 I can't see why the same engine couldn't turn to say 7500 reliably with better internals and a valvetrain that'll make power that high. Destroking it to say a 2.2 liter would increase reliability somewhat but if I can keep the same reliability with the engine at 2.4 litres, I'll leave it alone and just build what I have. I'm not building an engine to last 30 or 50k miles. This is a car that I'm going to drive everyday so I want as close to stock reliabily as possible...

[deviousKA]

Modified by deviousKA at 4:43 AM 9/17/2005

[xonn]

So you'd recommend the Z24 block with the KA head as the best overall compromise?

[deviousKA]

Modified by deviousKA at 4:44 AM 9/17/2005

[Red Lightning]

Problem with a ka20 crank (86mm) in a tall deck height block like the ka24, is the piston height. Even when using the 165mm 2.4 rods the piston would need to be about 39mm tall to come to deck height. This would be a very heavy setup and not a good idea. KA/Z24 deck ht. 247mm

Thats where the medium deck ht. blocks come in (227mm). These allow better piston and rod combos along with the short stroke crankshaft. Medium ht. blocks are l20b, z20, z22.

It all boils down to swapping a ka head to the older sohc blocks, the options are many after that. Cranks of interest are the z20/l20 crank fully counterweighted 86mm, or the z22 92mm crankshaft.

note that the 92mm crank can be used more easily in the tall deck ht block (tall blocks also have 90mm bores). Although the only option for this is using the z24 block. This combo keeps displacement up to 2.3/2.4 (when using large bore) and shaves 4mm off the standard ka stroke.

What about using custom longer rods or maybe custom high compression (domed) pistons. It seems like he needs to keep the KA24 block for emmission purpose (although a $100 bills works the same ). So he can't switch blocks.

[j-z]

move a lil further down south. we dont got no stinkin emissions here in fl.