Datsun 510 Spec Sheets

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Wiring Diagrams

Externally Regulated Alternator | Internally Regulated Alternator

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My Datsun 510 history

For the longest time, I've been having difficulty keeping my engine alive after running it around the loop in my neighborhood. Each time I'd open it up (probably not the best thing to do in the neighborhood), the engine would rev up just fine, but once it got back to idle, it'd stumble really bad, miss, and then finally sputter out. I assumed that one of the two SU carbs was tuned way off or something, maybe running too rich and fouling out the plugs on one side.

A while back, I learned that the SU carbs came with a set of banjo bolts designed to let the carb floats vent out. My carbs came had the banjo bolts, but it didn't come with the banjo connectors shown in the picture below (connector shown in the middle).



I just loosened the banjo bolt up a bit, hoping that it would provide enough venting as I drove around. As it turns out, the bolts turned themselves in from the vibration of the engine, and sealed up the floats, causing the floats to drain out and starve the engine of any fuel... hence the missing and stumbling.

I looked online for banjo fittings, and they're stupidly expensive, so instead of going that route, I simply replaced the banjo bolts with a similarly sized threaded nipple, like the one seen below, and ran some fuel hose to the side of the engine to catch any runoff gasoline, in the event of carb needle blockage.



Sure enough, that fixed the problem. Vroom vroom.

I've been tinkering on the car nearly every day for the last week, and I'm not sure I'm getting closer to getting the carbs adjusted properly. I thought I did yesterday before I ran out of gas. After filling it up, I thought I had the carbs running correctly until the battery died. So after charging it and rewiring the alternator, the voltage spiked up to 18 volts, which means voltage regulator either blew out or I've got the alternator wired incorrectly.

Bleah.

I need to wire in an O2 sensor, since tuning by ear is getting old. If I have the O2 sensor wired in, I should be able to know instantly which way to adjust the carbs.

My clutch master cylinder came in the mail today. I bought a cheap eBay one... and although I'm sure it'll be fine, it sure does look cheap.

Hrm.

Oh well. After doing a bench-bleed to get the air out of it, I threw it on. I'll have to do a full bleed on it later, but it seems to grab just fine. It's got much more resistance than the leaky cylinder that was on there previously.

:: crosses fingers ::

Here's to hoping.

After sitting for six months, my 510 blazed through the neighborhood again. Well, maybe not blazed... I never took it past second gear, what with neighborhood speed limits and all that. I got a few looks, since the car is pretty loud. I don't have an air cleaner on my SU carburetors, and the lumpy cam makes the engine grumble quite a bit with the open air. In any event, it sure does feel great to know that she runs, and that all the work I've put into her has resulted in a vehicle that's capable of taking me from place to place.

I swapped out the alternator. I'm still not convinced that the one I'm not using is any better, but the folks at Auto Zone say it passed the charge test. I also had to swap out the tension bracket, since the one I was using only fit the bad alternator I was using. Replacing it meant taking off the fan blade, which was a bit of a pain to do with the radiator in place.

I discovered that my clutch master cylinder leaked. Not just a slow trickle, but a gush of brake fluid every time you pumped the clutch pedal. I ordered a new one off eBay for $33.

After the clutch master cylinder broke, I figured I'd stop tinkering and just let it sit until the new part comes in.

Why anybody wouldn't use speed bleeders to bleed their brakes, I have no clue. I'm glad I discovered these.





I haven't installed them yet, but I hope I can get to it this weekend.

After a bit of research to re-learn how to tune the SU carbs, bleeding the brakes (still not completely done, so I bought a set of speed bleeders), hooking up (with a coat-hanger wire) the exhaust, clamping closed the fuel-filler tube, wiring up the alternator, and making sure the battery was secured, I finally drove the car around.

My brother-in-law and I bled the brakes, but it looks like there's still a bunch of air in the system - it takes about two pumps to have the brakes actually engage.

After tinkering with the carbs some more, I tuned it a little tighter, and managed to bring the idle down to about 1500 rpms. I'll see if I can bring it a little lower, but with the Shadbolt camshaft, too low will cause it to die down.

In spite of the carbs not being completely tuned, the car is clearly fast. It's got a healthy amount of get-up-and-go, and managed to get the rear tires to break loose. Sure, the ground was wet, but whatever. I'm really excited that I'm inching closer and closer to getting it done.

Everything is cobbled together at this point; the throttle clevis, the battery mount, the gas filler tube, the radiator, the exhaust... so my next step is to get everything more permanent, and to start working towards an interior.

Maybe wiring up the lights and installing the rear lights would be a good next step.

After welding the cable wheel to the primary throttle linkage, I had to build an end-housing for the same linkage to mount it against the firewall. Also necessary was the clevis for the cable.

Fortunately, I keep a lot of scrap metal sitting around, so it was pretty easy to throw something together. It's hodge podge, but it works. I'll eventually build something more permanent, but in the mean time, here are some pics.

I got the oil sprocket turned back a tooth, and the engine fires up just fine. Excellent. It took me a while to get it started, since the car has sat since the middle of November, but it looks like I've got the timing squared away.

Here's a video of the engine running on youtube:



I still need to fab up the throttle cable. I bought a stock throttle linkage setup, but it turns out that switching to a cable setup makes more sense with the SU carbs. I took the cable wheel off of my old 200sx intake and simply welded it onto the stock primary throttle linkage.

Oh boy.

For the longest time, I've had trouble getting my engine to start up easily, and just figured that it was a problem with my carburetor settings. I'd spray some carb cleaner into the engine, and the engine would kick over, but it would take forever to get it really going.

I chatted with my brother-in-law (a VW mechanic) he suggested that my ignition timing might be WAY off. He was skeptical of his own answer at first, since I mentioned that I could eventually get the engine running, but he recommended that I take the bolt off the distributor and turn it clockwise past what the housing typically allows you to go. Sure enough, it fired up right away.

After asking some of the folks on the datsun mailing list, that means that the distributor spindle coming up from the oil pump is off, and that I can simply pop off the distributor, grab a hold of the spindle, drop the oil pump, and lower the spindle and rotate it and bring it back up.

Well, it sounds easy. We'll see.

Ugh. Sometimes my lack of knowledge in the nitty-gritty of auto mechanics causes me a lot of frustration.

It took me FOREVER to finally get the electronic distributor working in the 510. I'm not 100% to blame, though -- the DQ magazine article that explains how to install the distributor says that the pos/neg wires are opposite of how they happen to work on my car. I'm not sure if the article is incorrect, or if I've got my car wired backwards... but in any event, I got that sorted out.

For about half an hour, I kept trying to troubleshoot a lack of spark, and after toying with it, I finally noticed that the ignition switch was turned off. It turns out that I can hotwire my starter even if the ignition switch is off, which is just fine for cranking the engine, but not exactly useful for trying to get a spark. Finally got that figured out.

Also, looking into a spark plug hole for top-dead-center to figure out where to place spark plug wire #1 on the distributor cap isn't terribly useful unless you can determine that you're at top-dead-center on the compression stroke. I had that backwards for quite a while before I figured that out.

Ugh. But now I got that work, and I can get the car fired up pretty easily. Now it's time to finish up the exhaust, so I can start up the car without deafening my neighbors.

I picked up an electronic matchbox distributor and got it installed today. I also replaced the upper radiator hose on the dime to replace the twisted attempt at a junkyard hose that I had in there.

The progress is going pretty slowly lately, but I hope things pick up soon.

I lost the bid on the Fiero radiator, which turned out to be just fine, because I found yet another radiator in my collection of things. I have no clue of the source of this radiator, but it appears to be a 3-core with the inlet/outlet ports in the right places. It's not as wide as the 510 radiator, but it's thicker, which means I have to make some modifications to keep my radiator fan from digging into it.

... I think it's time to clean up and inventory the parts I have in my garage. This whole radiator fiasco has been on the edge of lunacy.

Anyhow, this radiator is not a perfect drop-in. I'm going to have to weld up some mounting tabs, and probably cut into the shell of the 510 to scoot the radiator forward just a bit. Also, the stock 510 radiator's lower port has a 90-bend in it to allow the radiator hose to miss the alternator. This radiator's lower port goes straight out... so I'll probably just scavenge the 510's lower port and weld it onto the new radiator.

It looks like I was wrong about the radiator... in more ways than one.

After my initial frustration at having the wrong radiator handy (although I did wonder why it was included in the list of 510 parts I own; I haven't pulled parts off of non-Datsun cars), I got onto eBay and looked around for a Pontiac Fiero radiator, and then decided to call the Pull-a-Part junkyard in Tacoma to see if they had any.

The lady on the phone at the junkyard listed off several years worth of Fieros, so I packed up the family and drove up through thick traffic, only to find that the lady completely misunderstood me. They had no Fieros, but plenty of other Pontiac cars. Frustrating. They did, however, have a gutted 72 Datsun 510 in the yard, and I pulled the slave cylinder hose off of it. The junkyard hose was longer than the one I have on my car, and my car's hose is being pulled rather tightly.

Anyhow, I went home and got back on eBay and bid $30 on a Fiero radiator on there, and then browsed around some radiator swap articles and discovered that the spare radiator I currently have is a VW Rabbit radiator, and it's actually a common swap for the 510. The only thing I need is a longer hose, since both the outlet and inlet port are on the same side (unlike the cross-flow radiators that come stock on the 510).

$30 is a fair price for the Fiero radiator, so if I win the bid, I'll just use that one; it'll be easier to install, and it has a cross-flow port. If I lose the bid, I'll use the VW radiator instead.

Blast.

I planned to swap out my radiator, as the one I have has a leak in it. I have a spare radiator in my garage, so I went out this morning to take a look at it, and it turns out that it's a fantastic radiator... but not for my car.

I can't go any further with the radiator swap at this time, but I suppose I can wire up the alternator, and start some work towards the fuel filler cap. The car has been shaved clean, and the gas fill-up tube was redirected to inside the car, such that the rear windshield can't be in place. I'm currently filling up the car through the trunk, but I also have the battery back there, which could result in an explosion if there's any spark from the battery. Yikes.

Here's the first video of my 510 actually running with the SU carbs.

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It's got quite a bit to go before it's done -- the engine is still backfiring like crazy, and the radiator has a small leak, and there's a little bit of an oil leak on the front cover. I also need to get the throttle linkage hooked up, which will require fabbing up some new parts.

Anyhow, good stuff. It's running, and it feels like the engine is comfortable revving pretty high. I'll have to watch the timing, though -- running as far as advance as it was today, I was pushing 230 degrees, which is pretty close to head-warping temperature...