KA Stroker with overbore

[Iamjohnhayes]

i plan on stroking my KA24E to 2.6 and doing a .030 over bore. i was just wondering if anyone would know what final displacement i would end up with.

[:: orion ::]

1) "i plan on stroking my KA24E to 2.6"...I'll bet your final displacement is right around 2.6L...hehe.

2) Stroking a KA is a waste of time and $$$...you don't have enough cubes to gain to really make more HP, espcially since it's a rev-limited motor anyway (stock stroke is TOO long).

But...stock is 89mm bore X 96mm stroke.

If you want 2.6 L and .030" overbore, you'll need 89.75mm bore and 100mm stroke...which is a whopping TEN (that's right, 10) whole cubic inches. And to boot, you will have lowered your safe redline to something more like ~6500 rather than ~7250.

Not worth it.

- Brian

[Ni2s4s0aSnX]

Yeah I agree stroking the Ka is a waste of time. Its way too much money, and you won't get the results that you're looking for.

[90SXSE KA24ET DREAMS]

also agree too...

[s14 2510's]

go rb26 if you want a 2.6L engine. Ka's are waste of time.

[ians-ka]

go rb26 if you want a 2.6L engine. Ka's are waste of time.

bore it and destroke it, thats right i said destroke it. get an L20 crank, not sure what they came in and get a machine shop to grind it down and make it fit. don't know the name of the guy, but he-s running 10's in the quarter with this setup, and his redline is something crazy like 11,000, its sick.

[Bigvinnie]

Most effective power for a good price is to Knife edge the crank, 90mm bore, and 96mm stroke (keep the stock stroke and almost come close too 2.5litres). Then just get some forged H beam style rods, and you are good to go.

[pregmantis]

you guys think its the stroke limiting our rpm or is it our "supposedly" not fully counterweighted crankshaft? I think it might be the crank. maybe someond makes a billet crank now for our application. lots of money but may be an option.

[4gotn1]

it is the stroke and tall deck height of the ka.

[naed240sx]

This topic has been beaten to death. Does it really matter what causes the 7k redline? Reving higher will not make your car faster. The ka makes good midrange power.

[JDMEnthused]

exactly, Nissan made the KA24DE for torque.. meaning, it wasnt meant to rev like a little bitchy 1.8 liter.. Torque=pulling.. pulling = trucks, KA24DE = Truck motor ( can be good)

[Bigvinnie]

exactly, Nissan made the KA24DE for torque.. meaning, it wasnt meant to rev like a little bitchy 1.8 liter.. Torque=pulling.. pulling = trucks, KA24DE = Truck motor ( can be good)

How many "truck" engines do you know of that have oil squirters in them?Agreed, the SOHC defenitely was intended for truck use as it succeeded it's NAPS-Z 2.4litre predecesor, but that wasn't at all the intention of the DOHC. Thats like saying the VG 30e was designed as a truck engine, for it's low rev, and torque. It's just funny that it was made for the 300z, and 200sx first. Some statments just sound moronic. An engine is an engine depending on the application you want to use it for. Chevy guys use 350 blocks for cars and trucks, what makes that any different for the applications of Japanese automobiles? Just leave the statement that it is a torquey engine, not a truck engine, it just sounds ignorant.

[driftoy]

oooooooooooooooooooooooo.. ouch!

[Mikoriad]

You guys are some crazy mofo's I seem to be getting a kick out of most of the posts I've read today. Anyways, glad my post could be productive....

[4gotn1]

How many "truck" engines do you know of that have oil squirters in them?Agreed, the SOHC defenitely was intended for truck use as it succeeded it's NAPS-Z 2.4litre predecesor, but that wasn't at all the intention of the DOHC. Thats like saying the VG 30e was designed as a truck engine, for it's low rev, and torque. It's just funny that it was made for the 300z, and 200sx first. Some statments just sound moronic. An engine is an engine depending on the application you want to use it for. Chevy guys use 350 blocks for cars and trucks, what makes that any different for the applications of Japanese automobiles? Just leave the statement that it is a torquey engine, not a truck engine, it just sounds ignorant.

[sunnys14]

oOoOo burned...

[Kouks]

what limits the KA in rpm is it being oversquare, also piston speed is so high on a motor with an 89x96mm b &s, that it would blow going any higher than about 7200.

On a sohc, you can go .o80 over to make it a 2.5L as long as it stays n/a.Doesnt work on DOHC's.

[SimpleEnigma]

I also agree that stroking the KA is a waste of time and money. Though i dont think you can go wrong with bore. I think deviousKA runs the stock rod length, but with a 91.1mm bore which brought him up to 2502cc displacement.

I think in order for you to best spend your money, get your crankshaft knife-edged (or get a full-counterweighted crank, knife-edge it, and then let the rest of us know where you found one) and have your whole lower rotating assembly balanced (crank, rods, and piston heads). Drop in a set of solid lifters, and those things in combination should allow you to eek out a few more RPMs. That would probably net better gains than trying to stroke an already long stroke motor.

[JDMEnthused]

flame flame flame

heh... but yeah.. stroking a KA is a waste of time and money.. i mean.. RB26's are expensive but hell.. i would rather have something that can handle some horsepower and steal rev like something. the stroked KA idle would be ****ty also. im not sure whats the worse idea.. stroking a Rb20 out to RB22,23,24 or stroking a KA out to 2.5 or 2.6...

[Ni2s4s0aSnX]

Yeah, stroking a KA is definately a waste of time, and especially a waste of money, you can buy an RB for half of what you would spend on a KA stroker kit.

[AeonTorpor]

I remember a couple of things limiting the RPM's of the KA. I think they were the valve springs weren't meant to be used above 7500RPM, The long stroke relates to high piston speed which reduces the RPM, and the lower end isn't balanced for hardcore performace. There's probably more, but that's what I remember.

And yeah, because of the long stroke as it has, stroking the KA doesn't seem like a good idea. I can see destroking, but a new crank would cost ya. Unless you were able to even find a compatible crank and get the work done for cheap. And I'd say getting it done for cheap is probably more likely than finding the right crank.

[Bigvinnie]

I remember a couple of things limiting the RPM's of the KA. I think they were the valve springs weren't meant to be used above 7500RPM, The long stroke relates to high piston speed which reduces the RPM, and the lower end isn't balanced for hardcore performace. There's probably more, but that's what I remember.

And yeah, because of the long stroke as it has, stroking the KA doesn't seem like a good idea. I can see destroking, but a new crank would cost ya. Unless you were able to even find a compatible crank and get the work done for cheap. And I'd say getting it done for cheap is probably more likely than finding the right crank.

Bingo... Summed it all up... Baja series KA's hit about 8000RPM's.These engines use a fully counter weighed crank, forged rods, and forged steel pistons. Titanium retainers are set in place to achieve the high rev. Question is why are fully counter weighed cranks not in demand for the KA or even available to the market??? Or are they available and are people just with holding the truth????? Spill the beans Gabe!!!!!! LOL Just kidding.....

[deviousKA]

I found a whole lot of billet race cranks for ka24 (truckload), I purchased them all for cheap and do not want to sell, sorry everyone

jk

Go hybrid LZK, luckily we have very choice parts here in the US to build them.

I have block and crank (same as used in this le mans car), I will sell. I have a lot of them actually.



Edit: I have said to much.

[vvaffle]

See, now I'm not sure if your'e being serious. Also, which car in the US came with the Z20 or equivolent bottom end and what years?

[deviousKA]

I was being relatively serious, consider the thread.

Z20e81-83 200sx (240rs body style)Z20s81-83 720 (both z20/z22 option)Z20s84 720 (z20/z22/z24 option, z20 rare)

[vvaffle]

So what does power that lemans car? And the z20e is fuel injected as opposed to the z20s right? I assume this makes no difference if you are just taking the bottom end.

[deviousKA]

An LZ twincam powers that Lemans car, a turbocharged version.

The LZ twin cam is a race only package that is applied to a l/z sohc engine. The block and crank are used, with upgraded rods and pistons. Race only twin cam head of course.

Z20e is efi, Z20s is carb, same longblock.

[Ni2s4s0aSnX]

How many "truck" engines do you know of that have oil squirters in them?Agreed, the SOHC defenitely was intended for truck use as it succeeded it's NAPS-Z 2.4litre predecesor, but that wasn't at all the intention of the DOHC. Thats like saying the VG 30e was designed as a truck engine, for it's low rev, and torque. It's just funny that it was made for the 300z, and 200sx first. Some statments just sound moronic. An engine is an engine depending on the application you want to use it for. Chevy guys use 350 blocks for cars and trucks, what makes that any different for the applications of Japanese automobiles? Just leave the statement that it is a torquey engine, not a truck engine, it just sounds ignorant.

But the KA24E was a truck engine. It was designed for a truck, and was put in a truck before is was put in the 240sx. It makes sense, torque=truck=faster car.

[vvaffle]

The LZ twin cam is a race only package that is applied to a l/z sohc engine. The block and crank are used, with upgraded rods and pistons. Race only twin cam head of course.

So kind of like putting a KA24DE head on an l/z engine... but better, alot better.

[deviousKA]

The ka24e came in the 240sx before the D21 truck, the ka24e was first offered in the truck in 1990 (1989) along with the stanza/axxess.

The ka24e was first manufactured for the 240sx in early 1988, this first early version was identical to the others aside from half a point higher compression ratio.