Industrial/marine engines in pickup?

[85_720]

I have seen somewhere that the nissan industrial engines are not suited to being installed in automotive applications. is there any truth to this? If so, what modifications would need to be made in order to use them?

I am interested putting one of the sd/ld engines into my 720 pickup. I am interested in the smaller engines such as ld20 and sd22, as I am more interested in high MPG than high speed.

any thoughts?

-jon

[philip]

1) The SD has its cam in the block. LD has its cam in the head. Both have only 2 small valves per cylinder.

2) The SD fitted to automotive have two compression rings and one oil ring. The auto pistons have a steel carrier. The industrial and marine version has three compression and two oil rings. No steel carrier except ... when the SD-33 (six cyl) was fitted with a turbo.

The more rings you fit, the more drag and lower limit max rpm. PISTONS

Consider the gearing in a 720 ... as is. 60 mph is about 2500 rpm which leaves the automotive SDxx diesels safe for higher rpm.

3) Horsepower

[85_720]

so if you put regular 3-ring pistons in an industrial sd20, would it have the same characteristics as the automotive model? or are there other things to watch out for?

thanks for the good information so far.

[rlaggren]

so if you put regular 3-ring pistons in an industrial sd20, would it have the same characteristics as the automotive model? or are there other things to watch out for?

Cam; injection timing; injection amount; various possible controls in the IP (eg. altitude); emission and exhaust; manifolds; lube system (pan, filters).

I'm not any kind of expert - this is just a generic list of things that get changed to suit the application.

Rufus

[85_720]

Guess I'll have to look at other options then.

[asavage]

The SD was originally designed for agricultural/marine/industrial use, about 1963.

In 1981, it was modified and sold into the 720 pickup in the US (other countries may have had a different introduction date) and the SD was available through 1986.5 as an option for the 720 in the US.

In Canada, the SD continued to be available in the D21 PU (which replaced the 720 in 1986.5) through 1987, and we have at least three members who have this later combo.

So the SD engine can be driven in a road-going vehicle. The SD22 is a bit light on power, at ~61 HP, but mileage is decent -- you can Search these forums for details.

There are several differences between the SD-as-used-in-720s and the forklift/ag pump/marine versions. Philip mentioned the piston differences, there are also injection pump differences. If you were to put one of the industrial version SDs in a vehicle, you might experience reduced power, reduced top speed, or increased ring wear (if running it above its rated RPM), but it's been done -- see a marine CN6-33 (SD33) in an F150 for a recent example.

If I was starting from a clean slate, I might not choose the SD22 for a transplant, but it's been done, many times. There are turbocharging threads here to pick up some power too.

[85_720]

I am not a big power freak, so the smaller engines actually appeal to me. The two cars that I have driven the most (toyota starlett 1982 and honda civic 1993) both have had 1500CC engines, and I was plenty happy with the lack of power. They always got me and all my crap where I was going eventually.

The turbo threads were what got me interested at first in the sd22, primarily in the interest of making the engine more efficient. I was also thinking it would be cool to get individual electronic injectors so that you could control fuel input, timing, and emissions more accurately. I know some guys who have built/programmed micro-controllers, and there surely must be a way to build an ECU without too much trouble (understatement of the year).

My truck is overall in decent shape (85 720 st 4x4), but there are issues with the z24 engine in it (leaks oil, funky carb, someone monkeyed with the emissions, crappyish milagage, etc.). The couple times I have driven a diesel, I found it very relaxing. It's hard to get road rage, when your top speed is about 65 mph. It encourages a more zen attitude in general, much like riding a motorcycle.


jon

[asavage]

As a hobby, the availability of processor power and ancillaries makes adding electronic controls appealing.

But . . .

The SDs are IDI engines, all injection control is pretty much in the IP, not at the injector. They're not common-rail either. Your electronics are going to have to control how the IP does what it does, and there are a LOT of parameters in diesel injection. It's not just "squirt at the right time".

As a practical matter, if you want to pursue that goal, you'd be money ahead to buy a diesel engine that is already doing electronic controls, then graft in your "overseer" electronics. You'd need more knowledge than I have to do this. I have been fantasizing about the VE-style IPs and electronic timing control, but I doubt I'll ever go anywhere on that path: too much R&D. The VE IPs use hydraulics in a funky way to control timing. I'm thinking a stepper motor tied to the control sleeve. Or maybe not.

The Inline IPs (SD22) have external timing control, a flyweight-and-spring arrangement similar to a scaled-up points-style distributor on a gasser. Hard to imagine converting that to electronic control.

The SD-into-4WD-720 path is well beaten; several members have posted pictures of the mods needed to accomplish this swap (oil pan mod, oil pump pickup mod, various motor mount adaption techniques), so if you're interested in leveraging your current ride and converting to diesel, the SD swap is cheapest and arguably easiest. You'll need the front half of an SD version of a transmission too, just the case.

[85_720]

"You'd need more knowledge than I have to do this." I would need more knowledge than I have to do this, too... this is strictly hobby fun in my head, but I would like to pursue it further at some time.

I was thinking that you could have four smaller pumps/valves and hook them up to the existing injector nozzles in order to keep from messing with the block. my understanding of direct vs. indirect injection had more to do with the combustion chamber design than the actual injection pump type, but I need to do more reading.

[85_720]

What is the difference in terms of functionality of having the cam in the head as opposed to the block? My understanding of gas engines is that it allows less valve lash and therefore better running at higher speeds. is there any other advantage? I would guess a camshaft in the block is harder to service than one in the head, but it would also be easier to keep oiled.

Anything else a person would want to know?

[asavage]

Having an OHC in a diesel is something that has never made sense to me, either. I've asked the same Q as you several times, no good answers appeared.

[philip]

What is the difference in terms of functionality of having the cam in the head as opposed to the block? My understanding of gas engines is that it allows less valve lash and therefore better running at higher speeds. is there any other advantage? I would guess a camshaft in the block is harder to service than one in the head, but it would also be easier to keep oiled.

There are many advantages to Over Head Cam vs. Cam In Block.

OHC comes in a couple of versions. Let me take the most advanced. With OHC, there are no cam push rods, in many cases not rockers, where there are only cam buckets there is no side pressure against the valve stems to their guides. Having OHC permits a narrower block. Designing this way promotes faster RPM limits. Other OHC versions still have rockers. Lash is set depending on heat expansion ie, iron block with aluminum head, and whether the cam is in the block vs. head.

Lubricating cam lobes is usually accomplished by throwing oil off the piston rods. In OHC, cam lobes are directly lubricated in several ways and are more effective and by direct.