Rafi Casas

I've read on older threads on here of the possibility of being able to use a crank from a ka20de on the ka24 in order to destroke the engine to 2200 cc, which would mean higher revving capabilities for the engine, was wondering if anyone has tried it since I can't seem to get any information on it or anyone who has done it. I'm interested on the results

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Peruvian 240sx Coupe

PeaceOnesxWai

Good luck finding a KA20... and the knowledge to build the thing. The bore and stroke is different on that block, so blueprinting and custom rods are involved.

There is really no point in destroking a 4 cylinder.. V8 guys only do it to pull more power at higher rpm but they loose low end torque in trade off.

racepar1

I have heard of this, but have no specific information to offer. I do agree that there wouldn't be much of a point though. In the end you're spending a LOT of money to get a smaller engine. Yeah, it will rev better, but you'll lose torque. Where the hell are you going to find a ka20 anyways?

Rafi Casas

Well the engine is pretty common japan, don't think it would be expensie to get one, doesn't even have to run, there is very limited information on these engines, maybe you can ven use ka20 rods on ka24 pistons, who knows, I'm not building or thinking of building one, just thought it might be a good way to get more power out of an na ka and I'm curious on te subject

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Peruvian 240sx Coupe

corkscrew

Why not just build the ka24 to rev higher?

Rafi Casas

I know nismo built a race spec ka24de for baja trucks, but don't recall what rpm it got too, this might be a good route to take if someone is building an na ka24

I found a ka20de on yahoo japan:
ã‚Â*ャラãƒÂ�ン VPE25 エンジンＡｓｓï½ â„¢ KA20DE - Yahoo!オークション - ヤフオク!

although I gotta say that $2600 is really steep....

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Peruvian 240sx Coupe

PeaceOnesxWai

The stroke is way too short on a KA20, it wont run in a KA24 block. Why not just go SR20.. its 2.0 liter, theres low compression pistons, and thick gaskets. In a sense if basically destroking... What your saying is destroking a long stroke motor into a square.. which is what a SR20 is in a sense compared to a KA24.

If you want to draw out some more power, throw SOHC pistons into the DE to get more compression.. SOHC pistons are flat top, DOHC are dipped in. Also variations of cams will help. This is all in sense of using OEM parts.

Even if you can find a KA20 block for cheap in japan, the shipping would jack up the price to $1k+ (IE : RB30 blocks)

slatesekx

I do agree that there wouldn't be much of a point though.

Agamemnon

I remember like 5-6 years ago the guys at www.ka-t.org :: tried just about every crank they could find to de-stroke the KA. It turns out that nothing was a even close to a bolt in job.

Q.Smooth127

A really worthless task you tryin to accomplish
Spend a grand on an sr20det longblock ... Or waste a lot of money lookin for the ka20, get the crank, and machine workin to get everything to work... Only to pretty much have about the same thing as an sr20?
I mean if you truely want to do it, do it, cause its your money...

Super_OK_S13

I read a thread somewhere on NICOclub and KAT.org that an older Datsun L20B has the closest Blueprints on fitting a smaller crank to de-stroke the KA24 block. but still like Agamemnon said, its still going to take more machine work than its worth..

superdorifto

I actually priced it out with my machinist, and you need custom rods made...when it's all said and done, it's no better than a built Sr...you need to spend 5-6k in machine work and parts to get an extra 1500rpm at the top end...and all of that it's at the expense of what the ka is known for...torque.

Trap Star

Why not just do a stroker SR build? Essentially the same thing but you'll be able to find someone who knows how to build it and replacement parts won't be hard to come by.

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86 300zx/90 240sx/97 240sx/96 LS400/03 350z
-Shake N' Break Racing-