'79 KC Datsun KA Swap Pics and Questions

[Cruzn620]

After 9 years of Datsun ownership, I finally have a KA in the engine bay. No, I didn't get a badass KA24DE motor, but I did buy a '94 hardbody with a SOHC in it that I've been using as my daily driver for a year now. True, the added power and badassness of the DE is certainly appealing, but I couldn't find a good deal on one and what better way to do a swap than to have a complete, perfect, running truck to pluck it from?

 

Honestly I think the worse part so far was getting the wiring out of the Nissan. I took it all out. I was patient and I think I was smart and didn't cut a single wire. I labeled as I went. Pulling the wiring out of a hardbody, if you haven't done it, requires removal of the complete dash, the drivers fender, both seats, door sills, and yeah, this Nissan will never be hitting the road again. 

 

Thanks to RedEye's mounts, the motor bolted into place with the help of a 2-post lift, a floor jack, a transmission jack and 3 extra sets of hands. I will say though that the intake manifold brace has to be trimmed to let the new engine mount install correctly. Sorry I didn't take a picture of it, the guys were ready to go to lunch. It entailed cutting the bottom of the bracket off which only left the upper bolt hole, and then trimming the side up. This mount looked incredibly over engineered to me, but I thought it was still necessary because I didn't want all of that weight pulling down on the head studs as time wore on. Total job time with a cut off wheel on this was about 5 minutes.

 

I removed the power steering pump because I didn't want to change my rack out and I like a good work out while I am parking lot pimping. This also freed up about 400hp I'm pretty sure, from the formula that I have. I also had to remove the a/c compressor, and this bummed me out a lot. While I like to work out during my parking lot pimp sessions, I also like to be cool. Though this freed up about 600hp, comfort is a factor here, so I now ask, is there ANY way I could run an a/c unit on this truck? Does anybody know of a slim line type solution? The A/C compressor was going to hit the steering box...I'd really like to have A/C in this truck at some point down the road.

 

Because my datsun transmission was toast, I used the KA transmission. I found on the site how to modify the crossmember to accept it. The drive shaft needs to be shortened a bit, but that will just give me a chance to have new u-joints professionally installed while I'm at it. I don't know what my issue is, but I'm no good with u-joints. I am WANTING to swap the rear end of my nissan into the datsun. I will be taking measurements for that today, but does somebody know off the top of their head if this swap works??

 

I bought a set of pacesetter headers for the KA motor, thinking it would boost power by at least 200hp and would look nice and also give me more clearance...WRONG!!! The collector was into the torsion bars like Ray Rice in a casino elevator...so...For Sale: Pace Setter Headers, never truly installed, all gaskets included, coated in VHT Super Flame Silver Paint with custom scratches from several installation attempts. Does anyone know of a set of headers that works with this swap or am I doomed to the stock manifold?? *gasps of horror*

 

I will be wiring up the truck little by little. the first step of course is getting the wiring into the bay, and then I will worry about hiding it in the datsun dash and such. I'm already pretty much set on having to run aftermarket gauges unless anybody knows of a way to retrofit the wiring or something like that. What type of resistance does the fuel-tank-o-meter take? I'm not going for show winning glory here, I just want a clean, comfortable, dependable daily driver out of the truck...hence why I started with the less desirable SOHC motor. Pics below...answer the questions if you can. I have to leave town for work for the week, so it will be a bit before you see further updates.

 

I want to thank everybody on the forum for the help over the years with the project. Everybody has been very helpful, never rude, and well, just good people. Of course a big shout out goes to RedEYE for pretty much being the Yoda of KA Motor swaps...his build thread has helped a ton. Make fun because I didn't buy a DE out of a junk yard, but with all of the power robbing accessories that I have ripped off of this bad boy in the name of awesomeness, I'm predicting this thing to be pumping out a solid 110hp to the wheel...single track transmission style. ONE WHEEL BURNIES BABY!

 

 

 

 

 

 

[]2eDeYe]

Looks good in there. 

 

I'd really like to see where the mod took place for the intake support. If you could get a picture that would be cool. 

 

 

If the Hardbody axle is the same as the 620, a H190, you can easily swap the diff over. It's a fairly simple process, unbolt the axle flanges and pull the axles out til you feel them drop free of the diff. Unbolt the 12 or so 12mm nuts around the diff and pry the diff out of the housing. Do the same to the other truck and put the hardbody diff into the 620.  

[]2eDeYe]

Eagle Adam has some good info on a header as well as a radiator in his thread. 

 

http://community.ratsun.net/topic/52622-round-2-fight-now-with-a-de-in-progressfor-real-this-time/page-98

[datzenmike]

I checked and the HB side gear is identical to the '80 and up 720, and they fit the 620 so you're good there.

 

Don't know about the flange to drive shaft size though. Probably the same. I know 4x4 720s were larger on the H-190, 2wds were the same. Hopefully the D-21 was also the same.

 

BTW the 2wd flange would not swap to the 4x4 diff. Un friggin believable but true. The spline on the end of the pinion was changed too.

[Cruzn620]

I was going to take the ENTIRE rear end out guys...leafs, housing...all of it...because I can...hahahaha. You guys are all so badass, I really appreciate all of the input. I am working at my buddy's brake and muffler shop and all I have heard is "if you would have used a small block chevy..." and "a small block chevy only needs 1 wire to run..." or "a small block chevy would give you 400hp pretty easy" and who can forget "i'll sell you a small block chevy that's been on the stand for 4 years..." 

 

so, of course, hearing that all week long, it's nice to hear from some people who understand my mission. Don't worry, I will be cleaning everything up once the motor is running and no intake/exhaust orifices are open for water/chemicals to get into. I'm happy that I redid the entire engine bay while the motor was out, which included welding in a new passenger inner fender. It doesn't look so bad. I will be painting the valve cover when the rest of the truck gets painted. I think it will be 2 tone Black on bottom and Navy blue up top with a lime green dividing line...

 

On the drive shafts, yes, the flange on the driveshaft on the 620 and HB are different if anybody needed that info. Thanks for that link Yoda!

[Cruzn620]

Oh yeah, so Adam used a header of unknown brand and it worked, but he has the super duper cool guy KA24DE...does this mean it will work on my poor little SOHC? Let me know you genius bastards you....

[datzenmike]

The D21 rear axle assy is 1 1/2 to 2" wider per side!!! Skip that idea.

 

Your '79 has a 4.11 so I don't see why you would need to swap it. But if you want lower get something from a 720. They had 3.345, 3.545, 3.70, 3.90 and more..

[Cruzn620]

What does a 94 HB have in it? I hate the 4.11s, would be nice to have a 3.90 or 3.70

[datzenmike]

The '94 2wd? 3.90 auto or 3.545 5 speed. 

 

A 3.90 is only a 5% lowering of revs. That's 3mph faster at 60 mph

A 3.70 is only a 11% lowering of revs. That's 6.6mph faster at 60 mph

 

Earlier 620s had 4.375 gears so the underpowered L20B could haul a load. In '79 they reduced this to 4.11s to help with the mileage. To help get it rolling a much lower 3.592 ratio first gear was used.

 

There's nothing to hate about the 4.11 if used with the much more powerful KA engine. You may hate the 4.11 but will you hate the 4.11 with a KA turning it??? I'd wait and see.

[Farmer]

I've read that if your staying N/A, the sohc is the way to go. Boosted dohc

[Cruzn620]

Thanks guys for the input. I'm back on the road this week but I'm hoping my buddy mounts the trans and runs the exhaust while I'm out of town. That's what friends are for right?

 

I pulled the wiring into the engine bay and hooked everything up....and once the things get done that I need the lift for are finished, I will be bringing the truck home to sort out the interior wiring.

 

Having a complete harness to work with has been a huge help and I really think I won't have any major issues along the way except for what I'm going to do about gauges. Any suggestions there??

 

When all is said and done, I will have a bunch of datsun and hardbody parts for sale. Not trying to make money, trying to help people here, so PM me if there is anything you need and I'll make sure I don't throw it away....thanks again for the help!

[]2eDeYe]

Not sure on the header compatibility.

 

All of the gauges in the truck should work with the senders on that motor. CHG OIL and temp.

 

[Cruzn620]

RedEye, so I can wire my charger oil and temp straight into my datsun cluster? What about the speedometer since I'm using the KA trans? Fuel will stay the same since I'm using the stock tank...lol...forgot that one....

[]2eDeYe]

Use the truck wires to the KA senders for the oil and temp. If you get the alternator hooked up correctly, basically you are doing a voltage regulator delete, the CHG light will function.

 

The speedo depends on the transmission. If it has a gear style sender you can just hook up the truck speedo cable to that. If it has a digital sender you will have to research how to convert it.

[Cruzn620]

Well, I'm heading down to work on the truck some more tomorrow, but I was just kind of researching a few things and found out that if I can't figure out how to make the speedometer work and I don't even want to start to try using a typical aftermarket speedo, Autometer sells a GPS speedometer in a few of their popular model lines. Of course, if I go that route it's going to be really expensive and I will be forced for the sake of coolness to also add in a Tach and one of their quad gauges to complete the dash...money and time people, it's just money and time...

[Cruzn620]

Hey RedEye, Here's a pic of the intake manifold mount that I modified. I put a cute little arrow showing where I cut it. This is the best picture I could get of it, but not only did I notch the side, but I also cut off the bottom, which eliminates the lower bolt hole on that mount. 

[Cruzn620]

Progress today...but it will be pictures tomorrow...I started mounting things in the engine bay, relays and such. The Transmission mount was built and welded up and then tomorrow we will do the exhaust, hook up the clutch, and measure for the custom one piece drive shaft I am having built. Nissan front, Datsun rear.

 

I did find one plug in the engine bay that I couldn't find a mount to though. I looked at pictures I took of the nissan before I tore into it and of couse, it wasn't a close up shot, but it looked like even in the nissan it wasn't hooked up. I'm going to have to look at my wiring charts and see what it was supposed to go to, but it was near the fuel filter and brake hose in the nissan. It's not the wiper motor, and it's nothing for the power steering...I just can't seem to find it. The connector has a yellow and blue wire and a black and green wire going to it. If any of you guys know off hand, awesome, if not, I have the wiring diagrams and can research it. 

 

I am hoping tomorrow or thursday, depending on how fast the drive shaft shop works, my truck will be done on the lift and will be brought back home. Sure, it won't be running, but I can work on it at my leisure when it is home instead of driving 84 miles each way to get to the shop! From there it is sorting out the wiring from the nissan in the datsun cab, eliminating what I don't need, and then hiding the harness in the dash. Then I'll cry in agony when it comes time to figure out my heater situation...so be ready for that one...

[]2eDeYe]

Hey RedEye, Here's a pic of the intake manifold mount that I modified. I put a cute little arrow showing where I cut it. This is the best picture I could get of it, but not only did I notch the side, but I also cut off the bottom, which eliminates the lower bolt hole on that mount. 

 

 

Thanks for that. Looks like going to the larger plate has created some clearance issues. I will have to adjust my cut files. How much did you trim off of the end there? Would say a 1/4" more clearance on the mount have allowed you to run without cutting the end?

[kaoss]

Is there anyway you could get me a measurement? Take some thing flat like a long 2x4 and lay it across your fenders and position it over the highest point of the rocker arm cover. What is the distance between the bottom of the 2x4 and the top of the motor? 

[Cruzn620]

RedEye,if the plate that touches the frame rails was wider by 1/2" the manifold support would have slid under the mount no problem I think. I probably cut 2" off the bottom.

 

As for hood clearance I will try to measure but honestly the battery is higher than the motor, unless you relocated that.

[kaoss]

No, I lowered the body to touch the ground. So the battery dropped with it, but the motor stayed in the same spot. 

[]2eDeYe]

RedEye,if the plate that touches the frame rails was wider by 1/2" the manifold support would have slid under the mount no problem I think. I probably cut 2" off the bottom.

 

As for hood clearance I will try to measure but honestly the battery is higher than the motor, unless you relocated that.

 

 

Thanks :)

[Cruzn620]

I can't find my USB cable to get the pics off my camera which have the good stuff...However, I have exhaust pics from my phone. Oh, and on the clearance thing, It was about 2" from the top of the fender to the top of the valve cover on the motor if that helps at all. Enjoy the oics

 

 

What the hell is this thing and what does this one hook to? No matter how many pics you take, you never take the right ones! 

 

 

Exhaust...no I'm not going for power obviously, but I like where it exits, it's nearly hidden.

 

 

 

 

 

Yes, the truck has a TON of cancer...I've located a really nice bed that I think I can get cheaply and then the frame will be getting some light clean up, some "rust stop" and then a shot of under coating as the build progresses. Thanks for all of the help you guys. Once I get the photos off my camera you can see that the radiator is mounted with the fan and shroud and such.

 

Tomorrow we will be taking measurements for the new drive shaft, mounting and plumbing the fuel pump, tracing down the couple of loose ends in the wiring and then it's headed to the house for me to finish up the wiring. 

[kaoss]

sweet, thanks!

[]2eDeYe]

Nice exhaust!

I'll look and see where that connector runs on my truck this afternoon.