1PZ vs 1HZ in 2026, better buy?

[Onlysixsyllables]

Hey y'all, wanting to get a 70 series. I have come across a SWB PZJ70 manual in good condition. How are these engines in comparison to a 1HZ? I know its basically a 1HZ with one less cylinder. Does that mean parts availability are generally the same between the 2? I read the fuel economy is better with a 1pz, how is the power for a SWB? Anyone here with long term ownership experiences can chime in?

The main pros for this PZ vs the 1hzs I'm looking at is this one is LHD with 12v system compared to all the RHD/24v I see (not to mention the added cost)


1PZs seem to be MUCH cheaper. I feel like buying the cleanest cruiser is the point to be vs engine choices.

Appreciate it. TIA

 

[dmjay]

If it's a nice clean vehicle at the right price then buy it.
I would then save up to put a 1HZ in it.
Parts for a 1PZ are getting harder to find, they are an uncommon engine.

 

[TheBussman]

the 1pz specific parts are hard to get, usually these are the parts that should not break often too, the wear parts are mostly the same as 1hz. if you really had to you could cut down and weld up a 1hz manifold or something else to fit.

 

[Onlysixsyllables]

the 1pz specific parts are hard to get, usually these are the parts that should not break often too, the wear parts are mostly the same as 1hz. if you really had to you could cut down and weld up a 1hz manifold or something else to fit.

Are the 1pz engines just as reliable as the 1hz? As in I shouldn't have to worry about the hard to get parts since they shouldn't break? I'm tracking it's pretty much a 1hz minus 1 cylinder. This example has about 170k miles. Should go forever like the HZs?

 

[TheBussman]

Are the 1pz engines just as reliable as the 1hz? As in I shouldn't have to worry about the hard to get parts since they shouldn't break? I'm tracking it's pretty much a 1hz minus 1 cylinder. This example has about 170k miles. Should go forever like the HZs?

I don't know of any reason why it would be any less reliable. I don't think that replacement cyl heads are available for the 1pz, that could be an issue. Possible to cut down a 1hz head and braze the back of the head shut. If you ever had water contamination in your fuel system I don't know if the 5cyl injection pump cam plate and plunger is still available or not either. if you ever had a bearing failure it would be hard to get a replacement crank but they can be re-machined a few times. that being said there have been a few good complete 1PZs in the classifieds for a cheap price over the years.

 

[VADUS]

Some points in favor of the 1HZ:

1. An inline‑6 is always better than an inline‑5, because a 6‑cylinder is perfectly balanced, while a 5‑cylinder is not.
2. The 1HZ has more torque and HP [than the 1PZ].
3. If you ever decide to, you can fairly easily convert your 1HZ block into a 1HD‑T/FT/FTE. However, you'll never be able to do the same with a 1PZ.

 

[jayp2]

1HZ is still in production after more than 35 years

Parts are readily avail and will be for a very long time.....you may have to order/wait for some of them but thats life with a Non US vehicle

 

[TreadingLight]

Some points in favor of the 1HZ:

1. If you ever decide to, you can fairly easily convert your 1HZ block into a 1HD‑T/FT/FTE. However, you'll never be able to do the same with a 1PZ.

The word "easily" is doing a lot of heavy lifting here. It is possible. But it is not easy (or cheap) to build one of these from the block up. Almost always better off just buying a running motor and selling off the old one.

Personally, if the 1pz were cheap enough I wouldn't mind having one in a SWB rig.

 

[VADUS]

It depends on the situation. If the 1HZ is due for a rebuild or it suddenly locks up, the work involved in rebuilding a 1HZ or converting it to a turbo 1HD‑T/FT is pretty much the same. The crank is identical — you either replace it or grind it. Oversize turbo pistons are available. The 1HZ head is the weak link, so swapping to a turbo head won't cost you extra. Then you just need a turbo, fuel pump (replace or convert) and some bits like manifolds, which are easy to find used. Plus, this gives you a perfect chance to build a stronger motor while keeping the original block number of the weaker engine. For many folks, that's a big deal.

 

[TreadingLight]

Possible, yes. Easy, no. And I'm not buying the same price angle either.

Once you buy the pistons, rods, rings, direct injection head, pump, turbo, and manifolds, the fact that you didn't have to buy a block or crank becomes negligible. Not to mention how hard some of these parts are to find, at least in north america.

It would be cheaper and easier to buy a running 1hdt from the classifieds than to buy a 1hz with plans to convert to 1hdt.

The only good reasons to do this yourself are for amusement, confidence in the build, and the prospect for upgrades.

 

[TheBussman]

Possible, yes. Easy, no. And I'm not buying the same price angle either.

Once you buy the pistons, rods, rings, direct injection head, pump, turbo, and manifolds, the fact that you didn't have to buy a block or crank becomes negligible. Not to mention how hard some of these parts are to find, at least in north america.

It would be cheaper and easier to buy a running 1hdt from the classifieds than to buy a 1hz with plans to convert to 1hdt.

The only good reasons to do this yourself are for amusement, confidence in the build, and the prospect for upgrades.

it depends, if you want to get running as quick and cheap as possible buy a used engine and put it in. If you want a nice fresh rebuilt engine it's cheaper to get a 1hz and convert it. I've already rebuilt one 1hdt and I'm in the process of building a 1hz into a 1hdt. This time around it's going to be better (more brand new parts) and cheaper as i found a seized 1hz to build for cheap. both engines I bought had cracked heads, both needed injection pumps, both needed pistons. bought the rods used.

 

[Eurasiaoverland]

For me, body/chassis condition would be the decider. Doing body repairs properly requires either a good bit of experience or finding the right shop and paying a lot of money.

Both the 1PZ and 1HZ are dinosaur engines where nothing exciting happens when you press the accelerator pedal and you'll be trailing a line of cars on a highway incline.

Look for a model with original paint, no visible repairs or rust in the arches and sills, good shut lines, same paint in the doorslams, under the carpet, in the engine bay etc. Original tyre pressure sticker etc

 

[TreadingLight]

it's cheaper to get a 1hz and convert it. I've already rebuilt one 1hdt and I'm in the process of building a 1hz into a 1hdt.

I don't see how it could possibly be cheaper to convert a 1hz than rebuild an existing 1hdt unless you have a ton of cheap donor parts on hand. There are too many parts to buy.

Converting 1hz: needs internals, head, pump and injectors, manifold, turbos

Rebuilding 1hdt: machine work and maybe some engine internals

Just don't overpay for the 1hdt.

But back on topic for the OP, I don't think one would notice the difference between a 1pz and a 1hz in a swb 70. The body, chassis, interior, and amount of deferred maintenance would be the deciding factors for me.

If it were a Troopy being driven in the mountains I might feel differently.

 

[TheBussman]

I don't see how it could possibly be cheaper to convert a 1hz than rebuild an existing 1hdt unless you have a ton of cheap donor parts on hand. There are too many parts to buy.

Converting 1hz: needs internals, head, pump and injectors, manifold, turbos

Rebuilding 1hdt: machine work and maybe some engine internals

Just don't overpay for the 1hdt.

But back on topic for the OP, I don't think one would notice the difference between a 1pz and a 1hz in a swb 70. The body, chassis, interior, and amount of deferred maintenance would be the deciding factors for me.

If it were a Troopy being driven in the mountains I might feel differently.

if your rebuilding a 1hdt that doesn't need to be rebuilt then sure it could be less (freshen up, ball hone, rings, bearings and gaskets) but then your putting a used injection pump, used injectors, used head that may have some small fissure cracks that aren't all the way though yet back on. I bought the 1hdt for $5000 and 1hz for $1000 shipped. both were listed as bad motors, for my purposes i want aftermarket manifold and turbos, manifold on the 1hdt was cracked anyway, i think i got $150 for the used turbo.

I agree, get the cruiser thats in the best condition. In the unlikely event you end up with major engine issues you can always convert it to a different engine as a worst case scenario if the parts problems are too great.