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1983 720 KA24DE Swap

Datsun boi 720

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Hello, I am fairly new to Ratsun Forums and since I am doing a KA swap in my 1983 Datsun 720 I figured I would post on here so I can inform people on how it goes and also take feedback from others on what to do. To start off this engine came out of a s14 240sx. The engine was sitting in my friends garage, mainly intact. It was a free engine so I decided to get it up on an engine stand and start tearing it down to hopefully then put it in my 720. Here is my truck as it sits right now with a Z22.






Now here is the engine and the beginning of the tear down. The head has been redone in the past year. 


Got a new stage 2 Exedy clutch and pressure plate yesterday.
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Dat oil Doh.


Looks like a lot of water in that oil, probably blown head gasket. Front cylinder looks a little rusty. Check the head isn't warped. This is probably why your friend took it out and you got it for free. The KA will bolt right up to your 5 speed but you will need to modify the oil pan and oil pick up tube.

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He took the engine out because the guys that bought it wanted to ls swap it. He got the car for free because the guy didn't know what was wrong. The head gasket was blown at one point so he rebuilt the head and didn't have time to get everything going on it before he sold it. I am going to check everything before I start pouring money into it. My truck is a 4 speed and I don't want a 4 speed anymore so I'm gonna try to find a hard body 5 speed and the oil pan off a d21.

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D21 oil pan will not work without significant modification. S chassis ka have a girdle on the main crank bearings. The d21 pan will not clear this without significant grinding to it. From what I've heard it's a serious chore, but technically can be made to work.

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D21 oil pan won't fit, sorry. Besides the 240sx having a huge crank girdle the truck has an external oil pump, the S14 is internal. Pans have different shape. You'll have to cut one up and weld it.


D21 Hardbody 5 speed is different length but otherwise same bolt pattern.

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D21 5 speed? I think are slightly shorter than the 31.5" long 4 speed you have. Easiest thing is to get a 31.5" long 5 speed from a 720. Drops right in, bolts right up to the engine.




I would look at some build threads and see what other's did. Probably most just used a D21 engine but some may have used the much heavier S14 engine. Perhaps cut the bottom off a D21 and weld it to the S14 pan. Cars have the sump more to the front and the trucks more to the back.




D-21s didn't have the crank girdle, this is why it fits.
S13/14 KA24E and KA24DE engines have a 'front sump' oil pan and a crank girdle that sticks down
S13 only KA24E engines have external oil pumps just like the L and Z series engines. Oil pan will not fit the DE engine below.
S13/14 KA24DE engines have internal oil pumps. Oil pan will not fit the E engine above.
D-21 KA24E and KA24DE engines have 'rear sump' oil pans that are shallower because there is no crank girdle. Both engines have external oil pumps just like the L and Z series engines. Very likely the E and DE oil pans will swap on the D-21.
S13 240sx KA24E oil pan top. Note front sump and deeper. Top left beveled corner for external oil pump clearance.
D-21 Hardbody KA24E oil pan bottom. Note rear sump and shallower. Top left corner beveled for external oil pump clearance.
These two pans would interchange but the crank girdle will hit the D-21 pan.
S13 KA24E crank girdle...




These are my two KA24E oil pans.



In the two pictures above, the top pan is from the '89-'90 S13 240sx. Only made the two? years. It's a front sump pan and the engine has an external oil pump just like the L and the Z series engines. You'll notice that the top pan in the bottom picture, you can see that the pan is deeper at it's shallowest point that the one below it. This is because the S13 KA24E had a crank girdle and needed deeper clearance for it.

The bottom pan in both pictures is from a '90-'97 D21 Hardbody KA24E engine. It is a rear sump pan and the engine has the same external oil pump. In the bottom picture you can see the upper left corner of both pans is missing, or cut slightly diagonal across, this is where the external oil pump sits. As you can see both would use the same gasket.

The '91 and up S13 and the S14 use a KA24DE engine which does have a squared off pan corner because the oil pump is internal.

The '98 Hardbody also used the KA24DE but continued with the same external oil pump. These two DE engines will not share the pan gasket.
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So what oil pan can be used without significant modification?


Simple answer, none.


The KADE in the 98 - 08 Frontier / D22 used a truck single cam block mated to the dual cam head.  It required Nissan to re-engineer the entire front cover setup to make it work in a rear sump configuration.  With work, lots of it, it can be done with scavenged parts but is usually more expensive than just buying the Frontier motor.  It is the only rear sump KADE that will, with low level fabrication, fit easily into a 720 or D21.  Yes, people have modded the oil pans in a frankenstein process and turned a front sump S series KA into a rear sump, and every one that did and made a follow up post that I found has had oil starvation issues while driving.  The S series KA and the truck KA are, in the area of swapability, 2 entirely different motors and not meant to be interchangeable.  Just like the FWD version KA in an Altima is about useless in any RWD application.


Bottomline, to swap an S series KA into a truck is not an easy, bolt-in process in any way, shape, or form.  It will require considerable fabrication skills to make it work, and even more skills to make it work reliably in a daily driver.  If, as most people in recent years, the desire is to drift or auto-cross the truck after the swap, it will require even higher fabrication skills to have any sort of reliability at all.


Datzenmike has already covered the transmissions and I don't have anything to add.

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Or what if i just found a good block from a truck and put all the stuff off this engine onto that one.


No, it doesn't work like that. Dual cam head on a single head block only works, reliably and easily, if it's a Frontier head on a single cam block.  AND it still requires the use of the Frontier front cover setup and more.  There are dual row timing chain vs. single row issues and blah, blah, blah that have to be sorted out.  Trust me, unless you have access to random Frontier KADE's just sitting in peoples yards waiting to be picked clean of the needed individual parts, the whole engine is the only way to do this easily.


S series dual cam heads no worky worky on truck single cam blocks. And they aren't the best swap onto a truck dual cam block either because, wait for it, it's the same block.



Oh, and to answer your other question look at the beginning of the second sentence of my other post, it tells you what the year range of the truck KADE is available in. 


And just for the sake of teaching, no "Hardbody" ever came from the factory with a KADE installed in it, the earliest were in the first gen Frontier's which although they attempted to carry the distinct Hardbody body line are not "Hardbody" trucks.

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Where its an s chassis engine, it should pull a decent amount of money.


Sell it, and buy a truck engine


^ This




Although the most plentiful truck engine you're going to find, and in the budget build price range, is going to be a KAE, not a KADE. 



And just to possibly confuse you more...the KAE is in the Hardbody lol

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So what oil pan can be used without significant modification? And what will have to be done to fit that tranny?


Most guys doing a 720, that I know of, have been building custom pans and moving the oil pickup back. It's not to difficult a job if you can fab or know a fabricator. 


Otherwise your best bet is going to the truck KA as stated before, but it will be harder to find a dual cam KA and it will likely not have the multiport intake. 

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  • 2 years later...
On 2/10/2017 at 6:59 PM, bottomwatcher said:

I am doing the ka24e swap into a 720 4x4 right now. 2eDeYe your mounts are spot on. The oil pan is a hurdle along with the ps pump mount. The there are several other fights but I will post what I can when completed.



What is the ps pump issue? Haven't heard of this before. Let me know any other issues that come up as well. 


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On 10/23/2019 at 7:44 AM, ]2eDeYe said:

It isn't just the cross member. The steering and swaybar are all right where the front sump sits in the 720. You would have to redo all of that stuff.


Much easier to do the oil pan and pickup. 

ya after looking underneath my truck one day I realized all that stuff was in the way lol

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