[SOLVED] D21 Z24I to KA24e conversion, and other rambling

[lovot]

My D21 has the Z24 in it, and it came with a blown head gasket, leak stop isn't up to the task. While I could replace the gasket, it would require an unacceptable amount of downtime, like the timing chain and guides did, but worse. With the resources I have available, an engine swap would be way faster than fixing the Z24. A H20 or one of the SD engines would be great, but I'm having some trouble figuring out where to find a transmission to match (preferably 5 speed manual), and I'm not sure which sites would be the best to get the H20 or SD engine.

 

Also how much turbo a H20 or SD engine can take in their stock form would be nice, but it's not my primary concern at the moment.

Edited April 24, 2019 by lovot

[datzenmike]

You're kidding right? You can easily change a head gasket in a morning. Let's double that to a day and about $30 for the gasket..  If you can't do this how are you going to swap an engine???? I would change 2 head gaskets rather than change the timing chain once.

 

A complete changeover to run a diesel? It would take a morning just to run the battery cables over to the starter on the opposite side of the engine bay. What about the throttle cable? A diesel has a different wiring harness than the gas engines. What about the rad and the exhaust hook-up? Glow plug and timer?  Wayno will be able to tell you if the engine mounts are the same and more about how impossibly hard this would be compared to fixing what you have.

 

Never heard of an H20 before, had to look it up.  You must live where they are common? I see no advantage to 2 liter 3 main bearing engine. Your Z24 is better.

[Lockleaf]

There is no benefit to what you suggest and for sure will be WAY more money to swap than to fix. Z24 is fairly common and no one likes them so they are cheap.

 

I've bought complete running trucks for less than I've ever seen even an h20 core price.

 

The 5 speed you mention is the one of the most valuable 5 speed for datsuns.  H20 and SD engines are the same bell housing bolt pattern as datsun roadsters, so they can bring in a premium to those guys.  You could sell the 5 speed for a fair sum.

 

I myself would love an h20 block and 5 speed to put in my roadster.

 

If you insist on engine swap, go KA.  But it will NEVER be cheaper than fixing what you have.

[datzenmike]

What's the advantage of the H20 over the U20?

[Lockleaf]

R16 head and other bits fit it.  WAY cheaper than a U20 rebuild.  Since my roadster is already an R16, its basically just building a stroker for it.  In fact all you really need is crank and rods.  R16 can be used for everything else.

[bananahamuck]

1 hour ago, datzenmike said:

What's the advantage of the H20 over the U20?

\

H20 is way the fuck cheaper to build than a U20 ,, someone said just the timing chains, sprockets and guides for a U20 was something like $1200.(?) Most later H20s had 5 main bearings,, not sure of year switch but it was same a R16......  As for power ,,,,,,,,,,,,,,,,, well nobody needs to be packing around 30-40+ extra horsepower anyways,, thats just showing off. 

 

I'm putting a H20 in a 411 backed by a 85 720 trans with diesel bellhousing,, only because IT was cheaper than a R16 ,,  haha 

 

 

BUT ,, about topic,, As lockerbeef and Datmick said ,,  a Napz24 is cheap,, (example)  my neighbor just bought a 88 D21 4x4 running ( it was totaled out in bed area ) for the transfer case,, that had all the paperwork saying it was rebuilt 800 miles ago.... . i think he paid $400.  Fix what you got or install another Z24 they are everywhere and pretty good motors  if you stay on top of head bolt torque. 

 

 

.

Edited January 5, 2019 by bananahamuck

[bananahamuck]

Lockerleaf,,, just a heads up.. Send a photographer about that SD itch you got,, i'm believing he may be snowed in till spring but he knows,,, he knoooows.  He said he could possibly ship 

Edited January 6, 2019 by bananahamuck

[wayno]

Putting a headgasket in a Z24 will be way easier than converting over to a SD22 engine, and finding everything to do that will be harder and more expensive than to pay someone to fix that Z24 headgasket at a shop.

The Z24 engine mounts on the frame are too far back for the SD series engines, but you could likely make adapter plates to fix that, but first you would need to find a SD series engine and transmission, I have bought a few 720 diesel trucks because the transmission was broken and they could not find a diesel transmission to replace their broken one.

Also the diesels sold in the US have this weird system for starting and shutting down the engine, it requires either an abnormal ability to understand and wire automobiles, or you will need an SD series wiring harness, or you could just control it all with a choke cable.

You do realize that the SD22 engine only has 61hp, on the freeway they are gutless above 60mph, and after turbocharged it is kinda hard to find the proper rear end gearing, well that may be just me, I have two turbocharged SD25 engines and I would like another set of 3.30 gears, but they are hard to find, I have been looking for another set for years.

Unless you already have everything you need and have done conversions in the past, I would just fix the Z24.

The H20, well that is kinda a small engine for a D21 truck, but that is a point of view I guess, it kinda depends on where you live(Australia?) and the pace people move around you, I can drive with fast drivers as I am one of them, slow people drive me crazy, especially if they are in any other lane than the slow lane.

Turbocharging the SD series engine is actually easy if you know what is going on, in the US the inline injection pump has been a wall for years, but the biggest issue has been the bigger is better mindset, with these SD series engines bigger is not better, my 521 kingcab SD25 engine has an 1800cc Subie gas turbocharger on it, it drives great and I have built as much as 20psi, I have it adjusted to not go much over 12psi, my 720 with an SD25 has a modified 1600cc BMW turbocharger on it, I have seen 20psi on it also, but the guy that modified the turbo made a mistake in my opinion, he built that engine for low RPMs, it really is not freeway friendly as whatever psi the turbo is adjusted for is what I have, if I want 15psi while building up speed, that is also what I have on the freeway, while the 521 kingcab has 12psi when I get on it, but while on the freeway I am at 4/6psi.

The point is that I believe that a 1600cc gas turbocharger is all the larger you want to go with an SD22 engine.

 

[lovot]

datzenmike: Too much of the truck has to come apart to get to the gasket, I tried while doing the timing chain and guides, but the EGR pipe was rusted in there, so the exhaust and intake headers wouldn't come off, I was going to cut it off and remove that system from the engine entirely, but there wasn't enough time. Maybe it wouldn't take you very long to do a head gasket, but it takes too long for me. The H20 has earned my respect, it's still in production (it's very easy to get H20 parts, and H20s are easy to work on due to being OHV), and I have personally put one through enough abuse to blow up most engines. I was considering an engine swap eventually, but the problems with the stock engine and transmission made that decision for me. Modifications in the engine bay aren't difficult, especially battery cables, and I am going to make sure everything works before attempting the swap, I can work on things as long as they don't require more than 2 days in a row to do. The SD engines have the same bell-housing as the H engines because they are based on the H engines (as Lockleaf pointed out, it's also the same as the U engine, which is just an OHC H20 and R engine, which is the predecessor for the H SD and U engines), a transmission that fits one will fit the other, turbos extend the power band of such engines. Old diesels aren't complicated, often times they don't have any wires besides the starter, and glow plugs (or intake heater), both of which can be attached to push buttons, I have done a new throttle arm and return spring for a different diesel before, not complicated, glow plugs go to a push button, push while cranking until it fires up.

 

 

Wayno: Consecutive days in a row is what I lack, with an engine swap I don't need them provided I plan it out properly, with the head gasket I can't do it in a weekend, I'm just not fast enough. The H20 is built like a tank (which is why I want it, I'm planning to keep this truck), it's not big, but the heads are strong as fuck, and it's OHV, so if I DO manage to blow the head gasket out of it, it's not difficult to swap it out (personal experience with the H20) If it's that hard to get components and the actual SD engine, I might have to stay away from the SD engines, if I knew what is required to adapt the bell housing on a Z or KA transmission to mount to the , or SD engines, I would do that, but since I don't I have to assume they did something that would make it excessively difficult, just screw with people.

[datzenmike]

Two days is twice what you need for this. Cut the EGR pipe and seal the exhaust manifold end with a pipe plug or crimp and roll the pipe. Disconnect the rubber hose to the EGR to disable it. Unbolt the exhaust manifold and hang to the side. Leave the intake manifold on and lift away with the head. Get help if you have to but this is only 60-70 pounds. Clean both surfaces, install gasket dry and clamp it back together. I guarantee an engine swap will take weeks to do, longer.

 

If your goal is to swap the engine, the Z24 head gasket replacement is a poor excuse. Fix it now and you can be driving it while you wait for your engine and transmission to show up.

 

The 71B (used on L, Z, SD, CA series) and the 71C (used on KA, Z, CA, VG) front cases can be swapped. This gives you the correct bolt patterns to make the rest of the transmission fit any of these series of engines.

[Lockleaf]

It would require the exact same amount of work to adapt a ka transmission to an sd an to adapt a muncie 4 speed to an sd.  Custom built adapters for bellhousing.

 

Unless you have the proper sd/h20/r16 bellhousing already.  The sd transmission is a normal 71b.  It just has the odd bellhousing bolt pattern.  Put that bell housing on any 71b or 71c and you have a 5 speed.

 

Do you have a line on good used h20s?  Because rebuilt are the same price as a z24 rebuilt.

 

I'm afraid your logic just doesn't work for us.  None of us have ever seen a swap to a whole other engine go faster than a headgasket, unless you need machining i guess.  But then you are still cheaper to get another head, get it prepped, then swap.

 

I put a z22 in place of an L16 which is about as close as 2 engines can be while not being exact.  It was definitely not a 2 day experience to get it in and work out the kinks.

 

If you do install an h20 do a build thread.  I want to see it.

 

 

Also.  lockerbeef.  Heh heh heh.  Thanks Hammuck ?.

Edited January 5, 2019 by Lockleaf

[wayno]

It sounds like you know them engines, I have always wondered, would an SD22 diesel crank in a R16 make a H20 out of that engine?

 

 

 

[lovot]

datzenmike: do you just unbolt the cam sprocket to deal with the timing chain? If that's an option than doing the head gasket would not require taking apart half the engine and a bunch of other shit. I already have the gasket, so whenever I get a weekend off I'll go for it. Probably switch from electronic injection to carb while I'm at it since the electronic injection system has basically gone full retard on me, need an adapter plate to do that, a printout with the electronic injection module bolt pattern would help. Then it's just the transmission, something came loose in there and it's rattling around, it seems to be partly blocking 5th gear, sometimes blocks reverse, and one time it bound up the gears so it didn't want to go anywhere, it's sketching me out. How hard is it to drop the transmission, and possibly rebuild it if whatever broke loose was important? End goal is an engine swap, but it's not urgent if the Z24 and transmission are working properly.

 

Lockleaf: objective is long term reliability, H20 is extremely reliable, and should have more power through it's entire operating range if it has a couple PSI of turbo, although if doing a head gasket on a KA24 doesn't require taking apart the timing system, I might go with that instead since it drops right in, after modding it so it doesn't have an ECM of course.

 

Wayno: no idea if that would work.

 

If I do the H20 at some point, I'll definitely do a build thread, may be able to find one in a scrapped forklift since that's where they are typically used now, that may also have the bell housing I would need to mount a 5 speed on it.

[datzenmike]

Set the parking brake and the truck in 1st gear, Block the wheels.

 

Loosen the cam sprocket bolt but DON'T remove it yet.

 

Set the engine to TDC compression or exhaust stroke using the timing mark, either one but once set, it must not be turned till the head goes back on. You must not turn the cam either.

 

Now block the tensioner from falling out. You do not need to remove the timing chain cover. This makes it easier...

 

Apparently you can fold a garden hose and jam tightly down between the chains. The tensioner must NOT be allowed to fall out. Jam that hose down in there... you can't hurt anything.

 

Mark the chain and cam sprocket so it will go back together on the same tooth.

Remove the cam sprocket bolt and the cam sprocket. Let the chain settle between the chain guides.

 

Remove the head.

 

Assembly is the reverse.

 

Again, do not turn the engine or the cam when the head is off.

 

 

 

The Electro-Injection intake is different from the Carb intake and the fuel pump is high pressure or 10 times too high. You need about 3 PSI.  The Z24i also uses a crank angle sensor (CAS) which needs the fuel injection box to generate a timed ignition. Best thing here is to get a regular distributor, the electric fuel pump and the intake from a carb engine

 

[Lockleaf]

Again, hard to process how building a custom blow through turbo system is easier than an OHC head gasket.

 

But you do you man.

[lovot]

datzenmike: Thanks for the garden hose tip, I forgot why I thought I was going to have to take off the timing cover again. Didn't know the injector pump was medium pressure, but I can get a good low pressure lift pump pretty easily, going to switch to an inline spin on filter with a sediment bowl while I'm at it. The places I would normally go to get an old distributor got destroyed recently, so I would have to order one online, they only have 1 wire per cylinder on the old version, should still work anyway. Got any recommended parts sites, or just eBay it?

 

Still wondering how hard it is to get the transmission off the truck

 

Lockleaf: I can do basically everything with an engine swap out of frame, even the turbo and it's intercooler I have ways to apply a load to the engine to make sure it works as intended without it being inside the truck, so that route only required the truck to be down long enough for the swap after all the difficult, time consuming stuff had been taken care of, without the info from datzenmike the head gasket would have required the disassembly, repair, then reassembly of most of the engine, and part of the truck which takes a few days to do. Same for a KA24. For some reason (nearly) every time I get a hold of an engine it comes with a blown head gasket or requires a rebuild in order to work, or there are ghosts in the computer (this Z24 is a prime example, it had 2.5/3 I'm counting the timing system as half a rebuild because of how much shit had to come apart to get to it) so I was going to go with the most durable, easy to work on engine I know of that doesn't need a computer in it's stock form, then fix the Z24, convert it so it's standalone, use it as a power plant for other projects. It was never about easy, besides I always learn a lot from projects like that.

[datzenmike]

The EFI pump is about 35-45 PSI you want about 3 PSI pump for a carburetor. Use an inline paper fuel filter mounted in line before the pump to protect it.

 

The Z series engines on the 720 were all 8 plug. Don't a run 4 wire one. I don't know where you are. Try a want ad here... https://ratsun.net/classifieds/category/9-datsun-parts/

[lovot]

It needs 8+2 wires and the vacuum advance strapped directly to the distributor to be what I'm looking for, right?

[datzenmike]

Yes.... 8 plug wires and two coil wires.

 

The Z24i with the CAS doesn't have the vacuum advance because that is computed from sensor inputs by the fuel injection circuitry. You will have to wire the distributor to the coils as this is also fired by the EFI.

[lovot]

Thank you, I'll try submitting an AD

[datsunrides]

So, you are thinking of doing a turbo H20? And by the sounds of it maybe a “simple” system? A “simple” system, whether draw through or blow through with a carb is not really that simple unless you are talking really low boost pressure, which in that case it kinda doesn’t make sense vs doing something like a KA/SR swap that would have the same power level without the complexity. Now, if you want to do it just to do it, I can understand that. I have a turbo/efi U20 in my roadster. Doesn’t really make sense, but I did it because I could. 

[lovot]

datsunrides

Would probably have to switch to a non-factory carb that could handle the flowrate, other than that it shouldn't be particularly complex.

 

Draw through is the simplest, and I don't see how it could get super complex. Most difficult part is doing up all the adapters required to put a turbo on something, especially something like the H20 where there isn't much information from other modders.

[datsunrides]

Well, it’s not super complex, but you do need to find a turbo with carbon seals for a draw thru setup. Just guessing that the best carb for a draw thru, based on what I have read and seen would be a large SU carb. Where I would think the complexity would rear its head is timing control. The oil supply and return to the turbo can be an issue, but probably not bad for someone with good fab skills. I mean if you can do the fab work for the manifolds and such, the rest is fairly straight forward. Would definitely be easier on a crossflow design.

[lovot]

 

datzenmike: This is it, right?

[wayno]

Here is a photo of what Mike needs to tell you what it is and what it came from.

 

Edited January 6, 2019 by wayno