Need Sense Talked into Me: K24 engine swap

[Noshaq Sar]

Hello, brand new here! Long story short, I recently snagged myself a 1972 Datsun 510 (4 door) for a killer price. It doesn't have an engine (might explain the deal). I'm pretty stupid when it comes to working on engines, but what I lack in knowledge, I make up in confidence. As I've been planning on how I'm going to get her up and running, I've wrestled with the numerous options out there for engines. Do I go for an original engine, do a KA24DE swap, or do something wildly stupid and try a k24 swap. I know purists won't approve, but I seriously need help better understanding why it's not really done. I've seen one forum on here about a k24 swap...but I guess my question is, why can't I just do what all the Miata folks do? Plenty of transmission adapters, wiring harnesses, and ECU's on the market.  I just don't know if I'm missing something. Forgive my ignorance, I'm eager to learn and really want to restore this car.

 

[bottomwatcher]

It's going to be expensive whatever route you take. If you don't have mechanical skills, tools and a place to work it gets worse. If you are up to the challenge your best bet is to buy the engine donor car complete so you have all the components to make the car run. Then there are the custom mounts,exhaust, driveshaft, ect. Read about the different swaps done on this forum. Sadly most get started and never finished. Reality.

[john510]

How bad do you want it running ? The stock engine or even the L20B will get you up and running a lot faster and easier than the other options you listed. And with a lack of mechanical skills conversions are tougher. Not to mention expensive.

[Fat510]

Best best is an L series while you build up parts

[Ranman72]

you can put anything in that fits in the engine bay 

all custom fab work can get pricey 

ECU and wiring can be simple or difficult as you make it 

if you do something that has been done hundreds of times like a KA or SR there is lots of info and possible bolt in solutions 

if you do something exotic or different the possibilities of trouble and lack of info can be endless 

go the direction your heart tells you but be ready for some expense to make it happen 

[datzenmike]

Have you done an engine transplant before? If not, now is not the time to start. The absolute best engine for a 510 is the stock L16 or the L18 (with stock transmission) which are physically identical. The the later L20B, also is identical but is 2cm taller. 

[Stoffregen Motorsports]

Ok, don't call me a hater, but I'm not a Honda swap fan. Power per dollar? Sure, but Honda???

 

I don't even like the KA24DE swap much either.

 

I'm ok with a KA24E, but if I had my choice, I'd stick with an L motor.

 

The difference is that I can build a hot L motor, so it's not a really fair argument.

 

Mike asked a great question - have you swapped engines before? Doing an engine swap is not entirely difficult, but to do it right takes some experience. What do you want to see when you open the hood?

 

[Icehouse]

Having done all the listed swaps I would vote L series.  You can pick one cheap and get it swapped with low skill level in a couple weeks.   Having done many other swaps including the K series, they are all much more expensive.   Our K swap using many stock parts and building lots of it ourselves the cost has exceeded 5k!  I would imagine if you bough every part it would easily come in at 10k.  
 

the problem is the engine is the heart of the rig.  So it’s a personal choice and no matter what people say you have already chosen what you want regardless of the road ahead.  Either way we look forward to the build thread.  
 

[ByStickel]

I'm in a similar boat. I have a basically-free K24a2. After looking into the swap, I don't think I could ever pay what the engine-swap companies are charging for the bits and pieces to make it work. 

 

I agree with those saying to go with an L-series for now, and decide of you want to swap later on. You don't want a stalled project you can't enjoy.

[Noshaq Sar]

Man, already a lot of input, and that means a lot! I want to make this a fun to drive and reasonable to upkeep car. The reason I have steered away from L16/18/20B is mostly an issue of finding any near me (Montana isn't a great place for sourcing stuff). If I go the L-route, is it worth going for a 5-speed over the stock 4-speed? I'll be sure to dig into the resources you all shared. Cheers! 

[datzenmike]

If you do a lot of highway driving a 5 speed might be considered. But it would tale a long long time to see any savings for gas mileage. Five speeds are just for lowering engine RPMs on the highway.

[Stoffregen Motorsports]

The stock 4 speed is not very strong. Neither is the "dogleg" 5 speed.

 

Z car 5 speeds are plentiful and very strong.

[datzenmike]

More than good enough for an L16/18. They were used with L20Bs. The 71B 4 or 5 speed is definitely much stronger but expensive and you have to modify the car, custom mount and shorten the driveshaft to fit.

[Icehouse]

On 5/4/2024 at 8:58 AM, Stoffregen Motorsports said:

Ok, don't call me a hater, but I'm not a Honda swap fan. Power per dollar? Sure, but Honda???

 

I don't even like the KA24DE swap much either.

 

I'm ok with a KA24E, but if I had my choice, I'd stick with an L motor.

 

The difference is that I can build a hot L motor, so it's not a really fair argument.

 

Mike asked a great question - have you swapped engines before? Doing an engine swap is not entirely difficult, but to do it right takes some experience. What do you want to see when you open the hood?

 

I think HP per dollar the SR is still cheaper then the Honda K motor.  I can't believe how fast ours added in cost and it's not even done.  If it's over 180hp to the wheels I will be happy, but that's not very good HP to dollars.  

 

I didn't realize you were an L series guy. 

 

 

[Stoffregen Motorsports]

13 hours ago, Icehouse said:

 

 

I didn't realize you were an L series guy. 

 

 

That's a joke, right? 😁

[ByStickel]

I have really good news for you:

 

Synnes Auto Wrecking in Helena has a low-ish mile 200SX. It's nearly complete. I took the trans before I moved away. (the trans was bad, [wouldn't engage reverse; I made a thread on it] and I am convinced that it is the reason why the car was junked) I wish I had that engine, and am 90% confident that it's good to go. Go in, BE KIND, let him know what your project is, and I am certain that he will treat you very fairly.

 

He also has a couple of 280zx, so grab the struts. 

 

There isn't a ton of Datsun to be found in MT, but, luckily, there are approximately 3 people in Montana looking for Datsun parts. I found plenty when I was there, much easier than trying to find anything here in the rust belt. Most of my best scores were in MT, actually.

 

edit: and if you need the trans splash shield, there's one hanging in the open shed to the right as you enter the yard from the work area. After busting my ass to get the one (that I forgot the first time), I saw one, already removed, hanging on the wall as I walked out. 

Edited May 9 by ByStickel

[Noshaq Sar]

14 hours ago, ByStickel said:

I have really good news for you:

 

Synnes Auto Wrecking in Helena has a low-ish mile 200SX. It's nearly complete. I took the trans before I moved away. (the trans was bad, [wouldn't engage reverse; I made a thread on it] and I am convinced that it is the reason why the car was junked) I wish I had that engine, and am 90% confident that it's good to go. Go in, BE KIND, let him know what your project is, and I am certain that he will treat you very fairly.

 

He also has a couple of 280zx, so grab the struts. 

 

There isn't a ton of Datsun to be found in MT, but, luckily, there are approximately 3 people in Montana looking for Datsun parts. I found plenty when I was there, much easier than trying to find anything here in the rust belt. Most of my best scores were in MT, actually.

 

edit: and if you need the trans splash shield, there's one hanging in the open shed to the right as you enter the yard from the work area. After busting my ass to get the one (that I forgot the first time), I saw one, already removed, hanging on the wall as I walked out. 

The internet is a beautiful place. Sounds like I might need to take a trip with my buddy to Helena! I'll definitely grab those struts. As far as the engine goes, not sure that's in my price range, but maybe I can snag a killer deal. I'll dig around, see if there might be a transmission to use.

 

edit: Should I also grab the 280 rear diff/etc? Current setup has no engine/transmission/DT, I believe it actually has an old STi r180 diff (but still learning about what components can be used together, so not sure if it has any use for me).

Edited May 9 by Noshaq Sar
needed to add question

[ByStickel]

If you want to do an L-series, I think it'd be about as affordable as you'll find.

 

I don't think you want a 280zx diff.  The STI R180 would be optimal. Or look for an older Subaru with CLSD R160 (marked 'LSD' on the diff with a foil sticker)

 

Synnes also has 2-3 720 trucks, and one might have the L-series engine, (earliest ones did) which means you might be able to grab a 5-speed trans. 

 

A&B on the NW side of town is also great, but I do not recall exactly what they had.

 

Either place could might parts for you, but they do allow self-service, so bring tools.

[datzenmike]

The '80 only 720 had the L20B engine. The 4 speed was standard and the 5 speed an option go no guarantee of a 5 speed.

 

I assume the 200sx is the original S10 with L20B and the dogleg 5 speed? A zx transmission is longer and would need the 510 driveshaft shortened.

 

The ZX R-180s would have terrible gearing

 

Struts are slightly shorter but the calipers are massive and the rotors are vented and big as dinner plates. You'll need 14" rims to clear them. Even if you don't use them save them from the crusher and sell them

[bottomwatcher]

On 5/9/2024 at 12:52 PM, Noshaq Sar said:

The internet is a beautiful place. Sounds like I might need to take a trip with my buddy to Helena! I'll definitely grab those struts. As far as the engine goes, not sure that's in my price range, but maybe I can snag a killer deal. I'll dig around, see if there might be a transmission to use.

 

edit: Should I also grab the 280 rear diff/etc? Current setup has no engine/transmission/DT, I believe it actually has an old STi r180 diff (but still learning about what components can be used together, so not sure if it has any use for me).

Ok Noshaq you keep coming back so glad you have enthusiasm for the project.

1. Show us some pics so we know exactly what you have to work with.

2. On the info you have supplied it seems this is rolling on a tight budget.

My 2 cents is the same as before. Find a whole donor vehicle for parts. What you are going to run into buying parts piecemeal is you will spend way more in the end. If you buy an engine you will have to replace all the hoses and wiring the seller cut to make it easy getting out. The risk is also whatever you buy may be bad but you won't know it until later after you track down the other parts to get it running. Starter included? $$$. Alternator or other accessories included? $$$. Intact wiring harness, clutch, carb. Various linkages and cables? $$$. This is an old vehicle and not like chasing parts for a chevy silverado. Non running vehicles are cheap. Don't fall for someone telling you " it just needs the carb cleaned" if it was so simple the owner would have done it. Test drive or a couple of bucks above scrap is all it is worth. 

[bananahamuck]