Datsun Roadster Forum-311s.org

Hi all,

Hopefully this is an acceptable place to post for information, I have seen plenty of discussion around this motor here but not so much anywhere else.

I have a complete H20 motor as I have just purchased a Datsun Cabstar, it's in fairly rough shape and I'll need to get it back up and running to a decent standard.
My main question is, how much compatability is there between the industrial forklift H20 vs the one I currently have in my Cabstar? I'm wondering what I can use, swap out, etc. (Things like electronic ignition, ancilliaries, rebuild kits etc.)

I would also be interested if anyone had some carb recommendations too for use in the Cabstar, and opinions on whether it's even worth keeping this motor to use in a pickup (I plan to kit it out as a camper).
I'm a little concerned about fuel economy

I'm not very familiar with the H and R engines so I can't say how much things will cross over, but many here are... pics would likely help. The engines (R anyway) are pretty robust, simple and reliable. Cam choice will probably make some difference in how well it works for distant driving, and I would imagine that the cam chosen by the factory would favor low end torque more than high rpm horse power for a pick up/delivery truck application. I would want to keep that since you have some weight to move here. Fuel economy could improve more from spark/timing and decent fuel delivery (carb or EFI), and I think you'll have choices there as the later Nissan EI distributor can be merged with the original (or purchased as a unit) and depending on what intake manifold you have (probably not the dual SU) I wonder if a good ol Weber 32/36 DGV downdraft would bolt on. No idea what it would take to swap in a more modern engine, but it would certainly be more complicated than rebuilding the stock motor. Nissan supported these engines for a long time. We look forward to your project!

Is it an h20-1 or -2? Some -1 parts are interchangeable with metric R16, virtually no -2 parts are. Your best bet is a forklift parts company. Those parts are cheaper since they are Chinese and just meant to cruise around the warehouse at 2500 rpms.

Best to post a picture of the engine, along with a close up of the engine serial #...we can go from there.
If it is the early H20, we can steer you towards a good increase in power over stock, while keeping it compatible with the intended truck usage.

I believe that the biggest differences in the industrial to the automotive will be the valve springs, possibly the cam and the advance curve. Rumor has it that it is just the springs, but I cannot verify that.

If you are looking for one, here is a link to the H16[R] & H20 Service Manual: -
http://www.mediafire.com/?nwur7tapf9qaq

Gregs672000 wrote: Wed Apr 07, 2021 10:38 am Fuel economy could improve more from spark/timing and decent fuel delivery (carb or EFI), and I think you'll have choices there as the later Nissan EI distributor can be merged with the original (or purchased as a unit) and depending on what intake manifold you have (probably not the dual SU) I wonder if a good ol Weber 32/36 DGV downdraft would bolt on.

I'd definitely be in favour of bolting on a 32/36 if that's possible, the last owner has bolted this carb to the engine and I'd rather have it off.
What's the deal with swapping the distributor? I've been looking at the electronic forklift dizzys and wondering if it's possible to use one of those.

Nissanman wrote: Wed Apr 07, 2021 8:30 pm If you are looking for one, here is a link to the H16[R] & H20 Service Manual: -
http://www.mediafire.com/?nwur7tapf9qaq

Thank you, that's very helpful

Daryl Smith wrote: Wed Apr 07, 2021 4:20 pm Best to post a picture of the engine, along with a close up of the engine serial #...we can go from there.
If it is the early H20, we can steer you towards a good increase in power over stock, while keeping it compatible with the intended truck usage.

The serial number is H20 931915
Here are a few pics of the engine and gearbox, any ideas what my best bet is here?




Please help!

errrr, I suspect there is an oil leak!

Nissanman wrote: Tue Apr 27, 2021 6:08 am errrr, I suspect there is an oil leak!

Haha, I'd just pressure washed all the gunk off.
I have a full gasket set to go on...

My car doesn't have oil leaks, it just marks its territory

Appears to be h20-1, so all the early (h20-1) forklift parts should be a match.

Wow, single SU carb... unless they made a manifold that will bolt to the head, no downdraft carb is going on there. Did they make a downdraft manifold for R or H motors? I don't think there would be any issue adapting a later Nissan EI distributor to it (will need to make some minor wiring changes but that's well documented). Youll get a hotter spark, more reliable and maintenance free. SU is simple and can be rebuilt or replaced, or it may be fine. Be aware the early brass floats inside the float bowl can sink due to holes, plastic replacements available. The oil pressure sensors can be stupid expensive and often appear to read zero when they have pressure brand new, so be aware of that and consider adapting in an aftermarket mechanical, at least when you're testing to make sure it has pressure (unless you have seen the gauge work before). Otherwise as JT said, it looks like an R/H engine so the forum should be able to help.

Oh Wait! I looked at the pics more closely and it looks like there's some find of adaptor that is bolting on the SU... I bet a downdraft will bolt on... may need an adaptor but I bet they exist if needed...

A downdraft will bolt on. To put on the weber will require and adaptor. That is likely NOT a forklift motor, but rather one out of some other Nissan motor vehicle. An R dual carb intake will bolt on - so you could have dual SUs or even Webers or Mikunis with the available options. The downdraft intake will work as well. Being a pushrod 2000, it would benefit from having more carburetion than it currently has.

Gregs672000 wrote: Tue Apr 27, 2021 10:49 am I don't think there would be any issue adapting a later Nissan EI distributor to it (will need to make some minor wiring changes but that's well documented). Youll get a hotter spark, more reliable and maintenance free.

That sounds great, where can I find this being documented?

spl310 wrote: Tue Apr 27, 2021 11:50 am A downdraft will bolt on. To put on the weber will require and adaptor. That is likely NOT a forklift motor, but rather one out of some other Nissan motor vehicle. An R dual carb intake will bolt on - so you could have dual SUs or even Webers or Mikunis with the available options. The downdraft intake will work as well. Being a pushrod 2000, it would benefit from having more carburetion than it currently has.

It's the engine that came with the pickup as standard I believe (1980 Datsun Cabstar), it's just a case of parts availability.
To be honest I'm not too bothered about much other than fuel economy ! I'd imagine an adaptor isn't much work.