Things with the Troika are slow going. Why, you ask? Well, allow me to tell you.
Everything that everyone says about the J13 Datsun Engine is a dirty fucking lie.
No, the intake and exhaust manifolds don’t interchange with the MG Midget. No, they don’t interchange with the MGB. Do they interchange with the MGA? I don’t fucking know because I’m not throwing any more money down this particular bit of forum-lie.
No, the transmission bellhousing pattern does not match the L-series engines. Nor does it match the bellhousing pattern on the MG engines (the MG engine bit is quite frequently repeated and while I’m no MG expert, I haven’t seen a fucking BIT of truth to it other than it shares the poorly designed single-sided head – but none of the common valvetrain internals – with centerline-of-port-shared-post manifold mounting.) As best I can figure, someone once said “These engines were built by Nissan based on licensing the MG design but with all their own parts and measurements” and then the internet version of “playing telephone” happened and it became “The engine is a clone of the MG engine”.
And lets talk about that manifold some more, while I’m good and angry. First off, it appears to be impossible to take off the carburetor without removing the intake manifold. Secondly, it appears to be impossible to take off the intake manifold without removing the exhaust manifold. Thirdly, it seems to be impossible to replace just the intake manifold without also going to exhaust headers (they aren’t exactly cast in one piece, but it looks like there’s an open “heater plenum” in the central runner that just connects to a pad on the bottom of the intake), and finally, and most disconcertingly, it seems to be impossible to take off the exhaust manifold period. There are bolts which could only be successfully removed if you had a scimitar-length ratcheting box end wrench. Half of the manifold bolts are bolts, the other half are studs. They all use oddball 5mm thick concave washers. The first bolt back from the front of the engine appears to thread into an OIL PASSAGE. Note I said bolt, not stud, so it’s not like I can put any yamabond on there and make it oiltight. Every single thing I’ve read about the J13 is either about how it’s impossible to find parts for it, or it’s a thread asking what the best engine to simply fucking replace it with is. It’s like all of the fun of working on a british car but without the enthusiastic support group.
Another interesting bit is I found out that while the 520 and 521 look very similar and are only separated by one year (again, this fact is possibly based on internet lies, the earliest 521’s HAD J13 engines), and they share suspension design, components, interiors, and many other things, the 521 has FIVE EXTRA INCHES of radiator-support-to-firewall space. This, of course, means that all of the common engine swaps are more difficult and almost all involve cutting the firewall.
This isn’t really a big problem, since I’m not really looking to do a super-common swap into it (L20B? I mean, I’m going to have to fab up new mounts for the engine and tranny anyways, I’m not gonna do all that and only get 15hp out of it), but it does mean that I’m gonna be abandoning the J13 sooner than I had hoped and doing more work to get any engine installed. That’s not necessarily a bad thing from a fangle and fun standpoint but it means more money and time.
I have a couple other interesting ideas going right now too. For example… did you know that the Datsun 280zx has almost exactly the same track width as the truck (it’s actually about an inch wider but that just means more clearance on the frame rail)? And it’s got a fancy IRS with lots of available lockers and geegaws. I mean, a triangulated four link and a Ford Motorsport 9″ is pretty trick, but IRS… I think it’s pretty doable. Plus it’d keep the pinion angle exactly and I wouldn’t have to worry about nasty resonance in a solid driveshaft (the stock shaft is a two-piece unit with a cradle just ahead of the bed). I could just find a 280zx donor, whack out the rear subframe, then do some cut and paste on the rear frame rails… Fancy diff, better handling, coilovers? Kind of a good proposition. Especially since rust-eaten 280zx’s are not exactly rare. (I briefly considered the second gen 300zx just because then I could justify the whole vg30de thing, but the track is like ten inches too wide and the R200 diff is bigger, heavier, and less common).
I’m still pretty excited about the Duratec/q4r/T5 combo for the powertrain. I keep finding VG30DEs (and less commonly, VG30Es, which would actually be easier to fit) for dirt cheap and they make 220hp stock, but that would involve all manner of crazy shit. I’d have to install a u-jointed steering column, the firewall would have to be cut and moved back maybe six inches (not easy with a standard cab, which is just barely big enough for me to drive anyways). Not to mention that getting the exhaust to go around the torsion bars would be a trick (still looking into solutions for the front end suspension – there’s a Ratsun guy who makes a weld-in kit to convert to QA1 coilovers but why would I go to that trouble and keep the kingpin front suspension?). There’s a dude who welded in a whole Miata k-member, which is an interesting idea. I’m not sure what else out there has the right track width (other than the aforementioned 280zx, which is still on the table). There’s also the “just cut off front frame rails, weld in a toyota front clip and reinforce” minitrucker route which is kind of a cop out I think.
Other than all the trouble I’ve had trying to get this stupid J13 into driveable shape, the truck is still very fun for me. I go out and wrench on it for half an hour and come back in with a head full of ideas and a smile on my face. Hell, even the problems are fun.