KA24E Swap 85 720 4x4

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noface
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KA24E Swap 85 720 4x4

Postby noface » Sun Aug 01, 2010 11:38 am

Hey, just wanted to share some info on my current swap of the KA engine into the 720

I know it's probably been done about a bajillion times before, but thought some might be interested anyway.

It's a 1994 Hardbody KA SOHC with about 160k miles. All stock from what I can tell.

I'm using MegaSquirt 2 with a relay board, all stock Nissan KA sensors and air box. MegaSquirt is also controlling ignition as well via the stock Nissan KA distributor.

Mechanically, the engine bolts right up to the stock 4x4 Nissan tranny. No issues there, just a straightforward bolt on.

The engine mounts needed to be modified, and there's a few write-ups here and there on how others have done it. What I did was use the inner KA brackets, and outer 720 mount and set it down on the factory frame pads. Drilled new holes, and bolted it on. Again, pretty straightforward, and all I needed was a drill and bit, magic marker to transfer the hole locations, and a couple 3/8 bolts (yea... not metric... what I had lying around).

In the pics you can see that I used the Z24 power steering pump. It bolts onto the KA mount nicely, though you do omit part of the KA mount which is not needed.

I also used the 720 alternator bolted up in the KA location with the KA mounts. I did have to clearance the fins on the alternator pulley so not to interfere with the upper KA bracket. No big deal...

I relocated the windshield washer reservoir to the drivers side. Extend the wiring and plumb some new lines, and mounted a KA radiator overflow tank next to it.

The major task in doing this swap was the oil pan. Contrary to what you might read, a Z24 pan WILL NOT bolt onto a KA engine. Look at the pics here and you immediately see why. I used the stock KA pan and stock 4x4 Z24 pan and merged them to make a pan that would not interfere with the front diff. Absolutely no way a traditional oil pan will fit in a 720 4x4. KA pan is on the left in the pictures.

I still have some tuning to do on the software to get the best performance and MPG out of the engine, but it runs SO MUCH better than the stock Z24, there's hardly any comparison. The Z24 ran great with the Weber 32/36, but I got tired of replacing head gaskets, even after resurfacing the head.

I'll be glad to answer any questions ya'll might have regarding this swap or the MegaSquirt. I know I've had a tough time getting info on MegaSquirting the KA...

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breadbox
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Re: KA24E Swap 85 720 4x4

Postby breadbox » Sun Aug 01, 2010 11:50 am

Nice swap. Post up some pictures of the whole truck.

Time for turbo.

noface
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Car: 1985 Nissan 720 4x4 King Cab

Re: KA24E Swap 85 720 4x4

Postby noface » Sun Aug 01, 2010 12:19 pm

"Time for turbo."

... I was thinking the same thing! LOL! Let me get this one tuned well, and then we'll see. There's tons of room under the hood for a turbo, so that's no excuse!

Here's a YouTube video of it running. The mic on my camera sucks....

http://www.youtube.com/watch?v=OUH8gRcfLxM

Heres a couple pics of the whole truck.. really clean no rust!

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breadbox
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Re: KA24E Swap 85 720 4x4

Postby breadbox » Sun Aug 01, 2010 5:28 pm

Pretty awesome how clean that bed is.

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Wed Aug 11, 2010 5:53 am

been tuning on the fuel injection system.

It runs real nice, and I'm a happy camper so far.

It's getting 20mpg, and I'm wondering if that's a good number? I know with the Z24 and the Weber 32/36 it was getting 19... so for another 20-30hp kick, I'm diggin it.

I just wanted to see what ya'll are getting in these trucks.

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breadbox
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Re: KA24E Swap 85 720 4x4

Postby breadbox » Wed Aug 11, 2010 5:57 am

idk bout the truck but my 240 seems to get about 23 city.

seang
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Re: KA24E Swap 85 720 4x4

Postby seang » Wed Aug 11, 2010 6:18 am

I'd say 20mpg is a great figure for your truck.

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Thu Aug 12, 2010 5:44 am

thanks for the follow-up.

So with the 4:11 gears and it tach'd up to 3200 at 70mph I'm not doin too bad then...

I do wish it had taller gears, but then it'd be a slug on the bottom end.... trade offs I guess.

Thanks again.

JS

seang
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Re: KA24E Swap 85 720 4x4

Postby seang » Sat Aug 14, 2010 4:59 pm

I think my 97 D21 4x4 turns a little more than 3500rpm at 70mph in 5th gear, so I have heard from other owners. Mine doesn't have a tach, but it sounds about right with 4.63 axles.

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Sat Aug 14, 2010 9:10 pm

that's some good info for a comparison. I was wondering how it compared to others.

The good thing now is that it will actually cruise at Interstate speed. Before, with the Z24, it would do 80 tops, downhill, wind at your back, and to the floor. She'll pull all the way to redline now, so I'm bettin over a 100! -not that I want to drive it that fast, but it's nice now to be able keep up in traffic.

I had some concern how long this thing would live crankin on 3500 at 75mph for a 50 mile commute.

Thanks!

seang
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Re: KA24E Swap 85 720 4x4

Postby seang » Mon Aug 16, 2010 5:58 am

noface wrote:
I had some concern how long this thing would live crankin on 3500 at 75mph for a 50 mile commute.
Easily. As long as the engine is clean with clean oil, good oil pressure, and not overheating.

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MetalFab
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Re: KA24E Swap 85 720 4x4

Postby MetalFab » Tue Aug 17, 2010 6:03 am

nice swap!

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Sat Aug 28, 2010 7:50 am

I'm wondering if anyone here might know the spark advance requirments of the KA24E motors? What max advance the motor likes/needs and how it compares to engine load? I realize not many here have the KA motors in the 720, but figured I'd throw it out there.

I'm getting a little ping at part throttle and high load (dogging it going up hill say...) and I'm slowly sorting it out via the spark advance table knocking down the advance numbers at given MAP and rpm numbers.

I didn't know I had any ping issues before, since the exhaust was only a cherry bomb that dumped with a turn down just past the cab... well now I've got a Slowmaster and tail pipe all the way out the back, and I can hear what's going on better. Flowmaster sounds great btw, plus, it seems to have really improved the powerband with this motor. Quite a bit more grunt on the the bottom end.

I'll check around the KA forums too.

Thnx!

720
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Re: KA24E Swap 85 720 4x4

Postby 720 » Thu Sep 02, 2010 3:07 pm

dude im almost done with this swap but cant figure how to wire the gauge cluster can you help?

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Fri Sep 03, 2010 11:34 am

I can say that I had very little wiring to do to get my dash/gauge cluster done, considering it was fine when I started.

I hooked up the factory temp gauge plug/wiring to the Z24 sensor. The sensor from the Z bolted right into the KA.

I used the Z oil pressure sensor and installed it on the KA so the stock wiring plug would fit.

And the factory tach wire connected to the tach output on the MegaSquirt relay board (I can get you the pin out if you need).

That's all I had to do...

Be glad to help with what else I can.

JS

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mys13240
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Re: KA24E Swap 85 720 4x4

Postby mys13240 » Tue Oct 19, 2010 2:51 pm

hey noface - I got my ka24de stabbed on the tranny and the pass side motor mount lines up, but the drivers side doesn't. After reading your writeup i was gonna just redrill the holes on that side but i have an issue. The back of the head is touching the firewall. Did you have any issues with that? Maybe it just in A bind. Did your pass side mount line up or did you redrill both sides?

noface
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Re: KA24E Swap 85 720 4x4

Postby noface » Wed Oct 20, 2010 2:54 pm

The engine on mine has approx 2" of clearance between the rear of the head and firewall.

Remember I have a TRUCK block. I'm using the 1994 KA inner motor mount bracket, and the outer 1985 Z24 mount.

I had to drill both sides on the frame pads.

Sounds to me like your engine is sitting too high up. Is it in there straight and level?

Here's a pic of the clearance on mine.

Image

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mys13240
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Re: KA24E Swap 85 720 4x4

Postby mys13240 » Thu Oct 21, 2010 2:40 pm

Yea, I think it is too high and is in a bind. I'm using the same mounts as you. The inner metal mounts have the same part number for the '95 240sx and the '94 d21. I'm gonna go mess with it some more this evening.

720
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Re: KA24E Swap 85 720 4x4

Postby 720 » Fri Dec 03, 2010 8:21 pm

what did you do with the carbon canister and all the emissions stuff i dont see it in the pics?

eyoder79
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Re: KA24E Swap 85 720 4x4

Postby eyoder79 » Mon Jan 31, 2011 3:32 pm

Z24 motor to a KA24E motor swap??? 1994 motor into a 1989 body...

I am trying to put a KA24E into a 1989 Nissan. What steps and or changes do I need in order to do that? I need to know about the wiring harness/ignition issues mostly. Both trucks are 2.4L 5 speeds with 4x4. The motor is coming from a 1994. Any help would be greatly appreciated. Thanks!

synack7350
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Re: KA24E Swap 85 720 4x4

Postby synack7350 » Wed Feb 02, 2011 7:44 am

noface wrote:that's some good info for a comparison. I was wondering how it compared to others.

The good thing now is that it will actually cruise at Interstate speed. Before, with the Z24, it would do 80 tops, downhill, wind at your back, and to the floor. She'll pull all the way to redline now, so I'm bettin over a 100! -not that I want to drive it that fast, but it's nice now to be able keep up in traffic.

I had some concern how long this thing would live crankin on 3500 at 75mph for a 50 mile commute.

Thanks!
lol yeah I drove the interstate for a couple of hours 80 mph was like the top end. had a nice rhythmic humming at 75. floored on hills to try to maintain that speed. Not winning any races in this bad boy. Slow and steady. tortoise and the hare comes to mind.

TAMU_QR25DE
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Re: KA24E Swap 85 720 4x4

Postby TAMU_QR25DE » Wed Jan 22, 2014 1:36 pm

mys13240, are you still selling that stock 240sx?

I am currently interviewing with Tulsa Terracon Consultants Inc, wish to get the job.
Maybe when I make a few bucks, if you still have the car, I'll ask your 240sx' availability.
Always wanted a car I can play wish. Hope the parts are sufficient. Otherwise 350z might be a better choice...

Kmt10
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Car: 83 nissan 720 2wd

Re: KA24E Swap 85 720 4x4

Postby Kmt10 » Wed Jun 17, 2015 4:04 pm

Hey noface. I need some info on the z24 to ka24 swap. The wiring is my main concern. Can you help?

Bradleyboi
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Re: KA24E Swap 85 720 4x4

Postby Bradleyboi » Tue Mar 08, 2022 5:02 pm

Could you post some clearer pictures of the actual welds on the oil pan? In those pictures It looks to me like the z24 bowl is bigger than the ka24e bowl.


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