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Help with engine compatibility 93 d21


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Read my post below...I have abandoned the idea of the 86 yet i still have questions if you can help.


I have a 93 D21 and I am preparing to replace my seized engine with an engine from an 86 d21 what should I be expecting? utter failure or maddening success. The first thing that jumps out at me is the 6 spark plugs vs my measly 4 (and they are both 4 cyl) I was told that the extra plugs were for emission purposes. If I take the top end off my engine (93) will it marry to the one that I am putting in (86)? and what other potential problems should I be prepared for?

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The D21 only has a VG30E V6 (6 plugs)

A Z24i 4 cylinder (8 plugs) or

A KA24E 4 cylinder (4 plugs)


You'd better count the plugs again there should be 8.


As to the swap (assuming it is a Z24i) it will bolt up to the KA24E transmission but not much else will. The Z24i and KA are totally different engines. Yours is multi port fuel injection, while the Z24i is throttle body, All EFI wiring will be different, sensors, exhaust......

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I would expect a fair amount of hassle. Mounts are different, about the only thing GOOD is the transmission is similar enough to not need changing. You really want to use another KA engine, not the NAPS-Z. You're looking at 30% HP loss, plus the 2 engines have very different fuel delivery systems (throttle body injection for the '86 and SEFI for the '93). Extremely different wiring, different control computers, it'd be a lot easier to just swap your tires, body panels, and interior to the '86 and use it.


It's also 8 plugs. 2 per cylinder on the '86.


I'm assuming you don't live where the smog-check or safety check vehicles, because the swap to the earlier engine isn't technically legal.


The heads aren't a direct swap. There's a fair amount of mods needed to make the block work. They're CLOSE, in that the cylinder bore size and spacing is the same, so it's technically feasable, but it takes some machining.

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  • 3 months later...

Well thank you all for your input as a result I have steered away from the Z2. I have however come across a newer Nissan frontier. KA engine that I am sure of (95-98 I believe). My concerns are as follows:

1. It appears that the top end of the engines differ i.e. throttle body injection vs multiport.

2. The frontier is a regular cab and my 93 D21 is an extended cab.

Keep in mind that I am repairing the 93 to be a daily driver and cant afford a lot of mod cost at this time (new baby due next month). I am looking for the easiest drop in type fix so I can get back into a more fuel efficient vehicle and out of my C2500 Suburban.

As funds free up i will be looking to soup up the D21 but for now I just need her running.

P.S. the frontier is totaled but the engine and tranny are great and thats all I need for the D21 (Hopefully).

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  • 1 year later...

Ok, so I guess there is no such thing as an easy fix. I picked up a wrecked (but running) 1997 d21 with the ka24e. I swapped over the engine and trans together and now I have a whole new set of problems. The most pressing issues are:

1) The speed sensor is for an electronic speedometer set up and mine is analog. I would just swap sensors but the analog sensor I had in the old trans was badly scarred when I lost 5th gear and no longer spins. I have looked at all of the parts places in my area including a scrap yard with no success. Nissan tells me that the part is discontinued and obsolete. Any ideas?

2) Different distributors. I have resigned myself to swapping them out , however, before I attempt this I would like tips to make sure I can do this without seriously screwing up the timing.


On a side note: in case anyone else attempts this same type of project with as little experience as I have/had, it is extremely helpful if the transmission is in neutral before trying to drop in the engine trans combo and line up the driveshaft. The cuss words were flying until I figured out why it wouldn't line up, then I just felt stupid. 

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What color was the plastic cog that drives your speedo cable? All you need do is get another the same color. Wrecking yard or ask members here. It's relatively small and cheap to ship.


The CAS (distributor) should be the same but either way it can only fit the engine in one position. You can't put it in backwards or anything. You should be able to slip out and slip in.

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What color was the plastic cog that drives your speedo cable? All you need do is get another the same color. Wrecking yard or ask members here. It's relatively small and cheap to ship.

The cog was black but unlike the newer (electronic) speed sensor which the cog was hemispherical and held in place by a C-clip, the cog on the older (cable driven) speed sensor was molded onto a splined shaft making it a single piece unit. I will post pics when I get home.


Thank you for easing my anxiety about the distributor.

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