ka24det vs ka24et

[TomsMR2]

how differently does a ka24det perform vs a ka24et?

obviously, id prefer the newer dohc, as it starts off with more power..

but sohc s13's are ALOT cheaper, both carwise and engine wise...

if the performance is ~15hp or so, after the turbo, i think ill just go sohc... if it blows, its less money to replace, and less initial cost.

btw, "kits" are of no concern in the matter.

[C-Kwik]

The DOHC as a higher flow capabilty through the heads. More flow generally equates to more power. The SOHC also uses an offset sparkplug location. The center located plug of the DOHC would probably provide a more even burn.

[ADAMHU]

the dohc performs slightly better...

i have a sohc turbo however...parts are cheap...and power is still good..

[gh0st]

but by the time me (or anyone else) has set our ka24e motor up for turbo...couldnt we have just bought the sr20?

[7thGear]

uhh... no, sr swaps will always cost more in the end, unless you can get a killer deal on them.

plus if you compare a dohc ka with a sr, you get 0.4 liters extra displacment? and who doesnt want that?

In theory the more restrictive exhaust ports on a SOHC will produce greater low end torque than a DOHC. So thats something to think about *** for the every day driver ***.

considering engine build, the ka comes out on top, but as everyone says the real pain comes in the form of bad engine managment for the KA as soon as you strap a turbo on it, aka, there is non!! So a great deal of investment in proper fuel managment will be required with the ka

but other than that, your comparing a 2.4 liter dohc motor with a 2.0 liter dohc motor.... minus the turbo the ka is better. Its just that the sr is more friendly to turbo, aka easier to handle/modify.

[gh0st]

and this is definately going to be my everyday car. so i must take that into consideration.

[silviaNE]

nice response 7thgear.

[gh0st]

but i have the 2.4 sohc motor VS 2.0 dohc motor

[Titan]

The DOHC as a higher flow capabilty through the heads. More flow generally equates to more power. The SOHC also uses an offset sparkplug location. The center located plug of the DOHC would probably provide a more even burn.

Umm, I'm not sure what you mean by capability. But apparantly the SOHC head flows better, a.k.a has a better volumetric efficiency. This is why it is favoured for N/A applications.

[C-Kwik]

Umm, I'm not sure what you mean by capability. But apparantly the SOHC head flows better, a.k.a has a better volumetric efficiency. This is why it is favoured for N/A applications.

Where did you hear that? As far as I can tell, that is just a rumor. It probably stems from the fact that the NASPORT GT 240sx's use the SOHC motor in them. But that is because they are required to use them, or rather, they are not allowed to use the DOHC motors.

Now on to the VE. This has been discussed before. I can't find a size for the SOHC exhaust valve. But according to my Nissan Motorsports Catalog, it has a 40mm exhaust valve available. The area would be 3.14*(20)^2 = 1256 square mm. The DOHC uses 31.3mm valves from an unconfirmed but reliable source. 3.14*(15.65)^2 = 769.05 square mm. Multiply that by 2 since there is 2 valves and you get 1538.11 square mm. That's getting close to 300 more mm of flow area.

Math has never lied to me. Unless there is something I'm missing, I see more potential from the DOHC set-up.

[7thGear]

once again, high exhaust flow at low rpm = reduced low end torque

the diffrence between the 2 valves is only 0.282 mm too, not really that much.

In my earlier post where i said that comparing a 20 valve four banger with a 12 valve four banger would be worth investigating, but the way i see it one valve is lighter, stronger, and if you custom fabricate your camshaft, you can increase the lift on your exhaust valves to offset the diffrence.

SOHC are simpler, and lighter, and if the diffrence narrows down to 0.282 mm, which could be easily offsetted, id go with the simplistic sohc.

on a side note, would a h22 ( prelude engine) head fit on a ka?? it would probably lower displacement, but you get v-tec, is this possible?

[Jays90240SX]

on a side note, would a h22 ( prelude engine) head fit on a ka?? it would probably lower displacement, but you get v-tec, is this possible?

I REALLY hope this is a JOKE! :help

[C-Kwik]

once again, high exhaust flow at low rpm = reduced low end torque

the diffrence between the 2 valves is only 0.282 mm too, not really that much.

In my earlier post where i said that comparing a 20 valve four banger with a 12 valve four banger would be worth investigating, but the way i see it one valve is lighter, stronger, and if you custom fabricate your camshaft, you can increase the lift on your exhaust valves to offset the diffrence.

SOHC are simpler, and lighter, and if the diffrence narrows down to 0.282 mm, which could be easily offsetted, id go with the simplistic sohc.

on a side note, would a h22 ( prelude engine) head fit on a ka?? it would probably lower displacement, but you get v-tec, is this possible?

First off, reduced low-end torque has to do with the cam profile more than overall area. If you keep port size reasonable, the two smaller exhaust valves should flow more since the velocity will stay fast.

And the difference is 282 mm not 0.282. Quite significant in a motor.

If you want to compare lightness, the DOHC KA uses bucket type direct acting lifters as opposed to hydraulic rocker style lifters. The bucket type are lighter. If you want to talk about cam upgrades, consider that a high lift cam can also be used on a DOHC motor and further increase upper RPM HP.

Keep in mind the DOHC makes about 15 more HP than the SOHC and makes more low-end torque too.

As far as a VTEC head, no. Two completely different manufacturers of motors. I would doubt it would even come close.

[sil80drifter]

7thgear... aww... no frankenstein for you!



sil80

[7thGear]

all i wanted was some v-tec action, you dont understand how awesome it is on my mothers 2003 v6 accord...

[McAdam]

well, this is something I have been looking into. It seems as tho the KAE has more room to work with in the ports, better angles, and all that garbage, but the DE does have a better combustion chamber. there is a reason that NISMO only sells HI-PO parts for the E. It was designed with modifications in mind.

that and if you REALLY wanted to frankenstein a motor, you could bolt on a E head to a Z24 truck block and stuff an old *** L20B crank in there with FULL counterweights (I love old school datsun stuff) and some nice custom length rods and a 90mm bore and have a 2.2l motor that'll rev to hell and back.or you could even offset grind the L20B crank to get a bit more stroke out of it.

just an idea,

McAdam

[SingleCamSam]

I've always heard that the SOHC head flows more air as well. Could be a rumor though. I'm looking at the heads right now, and the only thing i can see wrong with it is the afforementioned offset spark plug. Doesn't look like it's choked or even close.

McAdam, what else do you know about swappable parts in the E engines? I'd like to brush up on it.

[sil80drifter]

i was thinking maybe you know... weld two E heads together, make an inline 8... 480SX, how cool does that sound. ok enough of sillyness. What kind of Hi-PO parts does Nismo sell for our KA-E engines, and where can I get them besides the ultra expensive site.... oh waitaminute... lookie here:

http://www.nismoparts.com/catalog/?section=324

sweet!

sil80

[TrunkMonkey]

there is a reason that NISMO only sells HI-PO parts for the E. It was designed with modifications in mind.

nope.

nissan motorsports (not NISMO) offers more parts for the E because that's the engine all their R&D was put into for racing.

-demetrius

[TrunkMonkey]

that and if you REALLY wanted to frankenstein a motor, you could bolt on a E head to a Z24 truck block and stuff an old *** L20B crank in there with FULL counterweights (I love old school datsun stuff) and some nice custom length rods and a 90mm bore and have a 2.2l motor that'll rev to hell and back.or you could even offset grind the L20B crank to get a bit more stroke out of it.

this has been discussed before. do a search. the L20B crank won't work with the KA block without some considerable customizing...almost to the point of not being worth the effort.

-demetrius

[7thGear]

almost

also if you have your own shop, i think it would greatly reduce the cost.

[sil80drifter]

he DID say to a CHEVY Z24 TRUCK BLOCK, not KA block.

Also, I believe NISMO stands for Nissan Motorsports, and although the group in the US which has the same name is a little different from their Japanese counterpart, they can be called NISMO as well, because they serve a very similar purpose.

sil80

[TomsMR2]

btw, im talking about sub 10psi turbos, and the power difference between the dohc and sohc.. simplicity, cam grinds, ports, angles, etc etc dont matter.

so.. back on topic.. does anyone know how different a turbo'd sohc and dohc are? :P

and c-quik, the valve difference is NOT 282mm. grab a ruler, that would be a GIGANTIC valve.

[TrunkMonkey]

he DID say to a CHEVY Z24 TRUCK BLOCK, not KA block.

hmmm...right and wrong.

he didn't say KA, my bad.

but the block he's talking about is not from a chevy.

-demetrius

[hannibal]

the difference in valve area is 282 square mm (2.82 square cm). thats a little more than 1 square inch...

[McAdam]

singlecamsam>>> well, I have no first hand experiience about swapability, I only know what I know from reading haynes shop manuals and spec charts and internet pages (well, whaddya know, it IS good for something other than p0rn!) but, everyone I talk to says that cranks are interchangeable between nissan Z (motors, not the car) series motors and L series motors. AND the Z series motors and the KA series motors use the same headgasket. so, you can put a L crank into a Z block and top it off with a KAE head. but then again the Z24 is a weak block. blah. I have ALSO read that the KA head will bolt on to a L block if you use a Z series timing cover. so, go get a L crank, they are INDESTRUCTABLE!

hey SIL80drifter>>>>> you stole my idea!! actually I was going to weld 3/4 of a head to 3/4 of a head and put it on my L28ET that I have sitting in my garage, I guess it would be a KAL28ET then? thats the one thing the L6's need is a crossflow head with more valves!!! I mean, hey if a stock short block can push a heavy 280zx to 11.49 in the 1/4, with a side flow head, imagine what it could do with the KAE's flow. I have matched teh headgaskets between the two motors up, its scary how close they are. bore centers, coolant passages, head bolts, oil jet. well,, other than the whole 4 cyl vs 6 thing. All I need to do now is find a REALLY good aluminum welder and someone who makes complete custom camshafts.

sorry for the thread jacking. KAE is cheaper and can be MADE better than the KADE, but out of the box, KAde will make more power. P.S. I just wish the KA24DE head would fit on the L blocks, too bad the KAE's and KAde's are almost completely different motors

McAdam

[7thGear]

how about we agree on this:

the dohc is has slightly more capability, in theory.

BUT

if you already have a SOHC in your car, the cost of doing a DOHC swap outweigh the benefits.

So if you have a SOHC, you stick with it, and if you have a DOHC you stick with it.

Both engines are perfectly good to work on.

[brokeashell]

I just bought a 91 240sx with a ka24de and i wanted to turbo it using a t3 turbo from the z31 and a front mount from a SAAB 9000, but i am not sure what else i would need to upgrade or modify besides my MAF and injectors; how much would it cost? Will other mods need to be done prior to this install?...some1 please help!!!! It would be great if someone could give me an in-depth breakdown...thanx

[brokeashell]

also what 1/4 mi times would i expect with a good install(lookin to spend $1500) with fine tuning

[7thGear]

aside from new and more powerfull injectors, a stand alone managment system is IMO the first thing you should invest in before you even dare flipping on the turbo

go to a reputable programer and spend a week tweeking the turbo.