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...

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

Time for turbo.

"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!

Pretty awesome how clean that bed is.

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.

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

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

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

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.

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!

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.

nice swap!

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!

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

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

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?

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.

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.

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

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!

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.

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...

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

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.

Hi I know I am pretty late to this thread but the engine swap out process you posted looks impressive and I am teetering on the point of swapping out the engine in my 720 because after replacing the head gasket antifreeze is still getting in the oil. Can’t see any cracks in the block, head was machined and still no difference. I’m replacing the PCV, but I don’t know if that will change much.
How did you decide on the KA24E to use as a replacement? I am looking at Remanufactured engines but have read some bad reviews on those. (Any insight on using a remanufactured 720 engine would be appreciated)
Is it common for 720 blocks to crack? I saw you had mentioned multiple head gasket changes.
Wondering if there is anything else I can try before giving up on this engine.
Thanks