Alright, I've been lurking around for a few days, gleaning what I could, but now it's time to actually become a member and introduce myself. My name is Fil, and I've got a 1970 Datsun 521. For those of you who don't know, it's the pickup version of the 510 (I'm sure most of you know the 510's).

Now, what would a guy with a Datsun want on an RX-7 forum? Well, I read about rotary engines in an old auto book I had, and have been interested in them ever since. I'd never really thought about having a rotary-engined vehicle until I bought the Datsun as a project truck last year. I started thinking about engine swaps, and the thought of a rotary-engined sport-mini-truck just sounded so cool. I never actually thought I would do it, until I was walking out of a rotary shop in my area last week, my wallet lighter save for a reciept for a 12A.

To be honest, I've got no idea what I'm getting into. I've never driven a rotary-engined car, never even sat in one. I may have had a brief encounter with a race RX-7 at a classic Jap auto show here a couple months ago, but I wasn't really paying much attention to it at the time. But, it should be interesting... so far the plan is an '84/'85 (unsure of the year) 12A mated to a 13B four-speed auto. I'm still waiting on the shop to track down the transmission and harness, but I think it may be sorted out fairly quickly.

And now, because I know most threads are useless without pics, here's what it's going into:



p.s.: Sorry for the long rambling post... I'll try to keep it shorter next time...

 

Rotary Datsuns are awesome. My friend has a 510 with a supercharged 13B. I need to get some vids of it sometime. And rotary-powered sport-mini-trucks are awesome, too. Good luck with the swap, and post pics of the progress.

What are you planning for carburetion? Exhaust setup?

 

I love your idea, that is a sweet body choice. Have browser will follow your build!

 

Thanks for the enthusiasm... I wasn't too sure how all this would go over on here...

Right now my main concern is getting everything properly mounted and running acceptably. Like I said, I've been poking around a lot on here, and from what I've found out the stock Nikki carbs seem to be pretty good, so I'll likely just use that. We've got emissions requirements here, but I'm not sure if I might be exempt due to the age of the truck. I'll have to look into that. But, IIRC, The Man doesn't need to know about my little swap, providing the emissions are within allowable limits for the stock engine for the year of the vehicle. But, I'm getting off track.

As for exhaust... I'm aiming to use the stock 12A manifold, then run it through a high-flow cat and a Magnaflow muffler before dumping it in front of the rear wheel on the driver's side. I'm assuming that setup will be alright, although I think I remember reading that the rotary has a higher EGT than piston engines... not sure if that could end up being an issue. As far as size goes... probably 2.25" or 2.5". I don't think I need anything bigger.

 

Love that bodystyle! Good luck on the swap, do ask away if you have any problems.

Oh, pick up a header and ditch the manifold. They are relatively cheap ($100-150) and will make you smile even more


Stu

 

Headers are basically a must on a rotary. Makes a huge difference. (Assuming no emissions requirements.) Also, don't go bigger than 2" or 2.25" exhaust. Some will say 2.5" is fine, but I don't buy it. It'd be best to use either Racing Beat's 2" thickwall exhaust piping, or stainless, as the forceful exhaust pulses of a rotary will cause anything less to ring like a bell.

And only use the cat if you have emissions requirements. Otherwise it'd be better to get a presilencer. Borla mufflers work well for this sort of application. I've heard stories of Magnaflows burning out after a while when used upstream in the exhaust.

The stock Nikki has decent driveability, but once your exhaust setup is done, it will be a choking point for you. I recommend sending it off to Sterling on this forum and have him work his magic on it. (Again, assuming you don't have emissions requirements.)

 

You can put a rotary in a 510...



so I'm sure you can put one in your truck.

 

Thanks for the tips... I'll look into the headers. I know on the 70's Datsun engines the aftermarket headers weren't really an advantage over the stock manifolds, so I wasn't sure if this was the case with the rotarys. I remember hearing in several threads that Racing Beat is the way to go as far as aftermarket parts, so I'll look into that. I'll look into the Borla mufflers as well, although IIRC they're a bit pricey in my neck of the woods.

Jeff: I didn't realize there'd be so much room left over... I was told by the shop I'm dealing with (Staff's Automotive, in North Vancouver, BC) that side-drafts wouldn't fit too well, but it looks like that 510 has a supercharger as well... I suppose I'll just have to see how it all goes together once I start.

Again, thanks everyone for the encouragement... I appreciate everyone's interest in the project. I'm excited to get on it, but I'm also wary of the amount of work it'll take, not to mention the cost.

 

A little update: Apparently, my truck isn't exempt from emissions, but the requirements are, at least in the case of hydrocarbons, quite a bit more lax compared to a 2.4L, 2500 lb passenger car manufactured in '85. So, I may be able to get away with eliminating some of my smog components. I'll try passing emissions perhaps without the rat's nest or cat or whatnot, and if I pass I'll keep everything the way it is. If not, I'll replace a few components until I pass, then keep it as it is.

Jeff: I didn't realize the 510 was yours... Are you on any of the Datsun boards as well? Ratsun, NWDE, 510 Club of BC (other side of the border, I know, but close enough)?

 

Not mine.

 

I like the truck, I like the motor choice... but please, please, dont go with an auto tranny. A stock 12A with header and exhaust, MIGHT get somewhere towards 110-120whp, probably less. You throw a slush box behind it, and it will be a total dog.

 

I'd love to go with a manual, but I can't drive a stick. Not that I don't know how, I just can't. I have a disability, so it's hard to move my foot from the gas to the brake pedal. Otherwise, I'd leave my stock engine in there. A semi-auto would be great, but I don't know of any rotary-compatible ones. So's, I'm stuck with the auto, at least until I find some way to use a hand-clutch rather than a foot pedal.

 

Looks to be the same size as a REPU. Should be a relatively easy swap. Only thing I would worry about is the transmission tunnel.


Good luck with your swap, and keep us updated. It's always good to have more information on motor swap's.

 

It probably is about the same size... it seems to me most of the '70's Jap pickups were about pretty similar to each other. I haven't taken a look at the RX7 transmissions, but it should be fine. If not, I'll cut out what needs to be removed and weld in a new tunnel.

My biggest concern with the whole project is lining everything up... making sure the gearshift is in a good position relative to the seat, then making sure the engine isn't too close to the firewall or the rad support, and trying to set up the transmission at just the right distance from the rear axle so I can either directly bolt in or slightly modify a driveshaft to fit. It's not going to be a super inexpensive project, but a custom driveshaft would probably be a major cost, so I'd rather avoid going that route.

 

Custom driveshaft's should not be that expensive? I have never had to look it up, as all my cars have been stock.

 

Yeah, it shouldn't be too big an expense to get a driveshaft resized to your specification.

 

Ah, alright. I thought a driveshaft would run me a couple grand. I'll look into the costs of aftermarket ones and getting a stock one resized. Hopefully I'll be able to sort it out so that I don't need a custom driveshaft though.

 

Oh god no. It's just steel. If a driveshaft was a few grand, it'd be more than the motor swap most of the time. lol

 

Row: Thanks... I wasn't sure what all would go into making a custom driveshaft, so I wasn't about to make estimates. Good to know that it shouldn't be too expensive.

Other than that... updates are slow, as I'm on vacation and don't get back until Friday. But, I've managed to track down a transmission, along with the ECU and harness, so hopefully that'll get picked up along with the engine once I get back. Then, I get to tear the original engine out and try a test fit.

One of the things I didn't consider with this engine is the actual fit of it... I assume I'm going to have to modify the transmission crossmember and put in new motor mounts, but I didn't think about anything else. Does anyone know if it's a front- or rear-sump engine? I don't mind moving things like master cylinders and electronics and whatnot, but I'm really hoping I don't have to modify any of the steering components...

 

I am unsure of steering components or the suspension and even the shock towers. You will most likely need to make custom motor mounts and modify the transmission tunnel.

When you can, post pictures of the engine bay, and I am sure somebody would be able to tell you if things would fit with a small amount of ease.

 

Alright, I picked up the transmission yesterday. I don't really know anything about them, but it looks good enough. I've got no idea how many kilometers it's got on it though... I'm debating whether or not to take it into a shop to get it checked over before I install it. It's out of an '86, as I wanted the overdrive.

Now, it was brought in for me from out of town, so I didn't actually see or do the removal myself. Right now it's the whole case, torque convertor, and starter. All the oil lines and whatnot have been removed. I won't have a chance to take a good look at all the parts until I can get out to my garage. So, I have a few questions (if anyone can help me out):

It looks like the transmission is hydraulically controlled, but do I need any sort of harness or control unit for it as well? I thought one was going to be included, but I didn't see one.

The gear selector linkage is there, but there's no gearshift for inside the car. I'll come up with my own, but does anyone know whether the linkage is supposed to move from front to back (engine to tail) to cycle from Park to 1st? Or is it the other way around?

Finally, and possibly a stupid question, but in order to move the gearshift on an automatic you have to depress a button... does anyone know if this button locks the gearshift to the body, or the linkage to the transmission case?

I've downloaded all the FSMs that I thought could be remotely useful, so I'll look through those when I have time. I could only find '85 and '88 FSMs that had the automatic transmission section... was there any significant changes between the first and second generation automatics, and/or between '86 and '88?

On a side note, I'm getting excited about this project... I've finally got most of the components I need to start assembling it. I'll try to get pictures and measurements of the engine bay this weekend, and maybe someone could help me figure out what needs to be changed.

 

Alright, yesterday I emailed Greg at Staff's Auto, up here in North Vancouver. He sold me the engine, as well as organizing the transmission for me. He passed along a number to a transmission guy, who I talked to today. The guy said he'd strip the transmission down and do a check and basic maintenance on it for about $400... he also told me I don't need an ECU, and that the wires coming off the case should be enough for what I need. I'm too broke to take it in right now, so I'll have a couple weeks to try a test fit of the transmission. It'll also give Greg some time to get my engine ready to be picked up, and then I can start the fun bits...

 

Sounds like you have a great start on your project!

 

sounds like a good idea... never hurts to try

 

do u guys think that would work on a 89 toyota pick up?