510 L20B EFI conversion - the project is finished!

[HRH]

Check back one page for the other video, it's the best for an idea of acceleration. Not sure how fast we were going, I'd guess about 90, but the speedo isn't accurate. Seems to be about 20 mph off though, and it was at 110 when I decided not to go any faster.

 

 

[Farmer Joe]

that is

 

badass...

 

 

 

 

does that have balanced bottom end? it just runs so smooth through the rpms

[fisch]

Woah! That sounds so damn good!!!! Big thumbs up!!!!!

[HRH]

The bottom end is not balanced, but is a fully counterweighted 20B crank, with Z20 rods and pistons (car version). Matched set of rods as well. So technically it was balanced from the factory, but not rebalanced to exacting tolerances by myself.

[Farmer Joe]

hmm, well it sounds good!

 

i think the most of the vibration im prolly feeling is the stupid clutch fan. i hate that noisy damn thing...

[HRH]

Yeah, I'm not a fan of the airplane fans. Have Altima electric fans on my D21, and a flex a lite on the 510. May need a bigger one this summer, we'll see.

[Creepy Cruiser]

Nice!!!

[HRH]

I figured out what the issue was with having it run a little shitty after short turn off, then starting up again. Joe said it happens on his truck too. The fuel pump needs to be turned on and the fuel cycled through for 10 seconds or so. Reason being is the incoming fuel line heatsoaks. Heat shielding on the manifold helps this. Currently I don't have any heatshields on anything. I'll probably figure something out before summer, but for right now the more heat the better.

[LenRobertson]

I figured out what the issue was with having it run a little shitty after short turn off, then starting up again. Joe said it happens on his truck too. The fuel pump needs to be turned on and the fuel cycled through for 10 seconds or so. Reason being is the incoming fuel line heatsoaks. Heat shielding on the manifold helps this. Currently I don't have any heatshields on anything. I'll probably figure something out before summer, but for right now the more heat the better.

 

I've always wondered why Nissan abandoned the proven L series head design for the Z20 series cross-flow. There was a JDM FI version of the L head engine that wasn't imported to the US. Maybe Nissan thought there would be hot weather starting or running problems in the American southwest, and decided the exhaust manifold had to be moved away from the intake. Of course the cross-flow decision may have been emissions related. Also, engineers often have to "improve" things whether there is a need or not, in order to justify their jobs. I don't remember ever seeing a post on any of the various Datsun forums from someone running the stock JDM FI system on an L motor. I know when the JDM manifolds show up on eBay, people pay quite a bit for them, but I don't know if they are actually installed and used.

 

Len

[HRH]

Simple physics really. Trying to keep even temperatures with a cast iron stove under the intake doesn't bode well. :) Not to say you can't make it work, and well at that. Hell the Jeep 4.0 is still non-crossflow, or at least it was unless they recently changed it. Regardless, look at any race motor built today. In order to manage everything effectively, you stick intake on one side, and exhaust on the other. No fuel heating issues, no exhaust heat causing the intake manifold to swell.

 

You'll actually have better head flow with a properly designed cross-flow head. For one, you can arrange the valves a lot better. Look at the SR20. It has better flow characteristics than the L by far. Granted, the L is one of the better non-crossflow heads, but it still can't compete with newer technology.

[HRH]

So after the 510 started having idle issues this past couple days, I started looking around and noticed the manifold seemed extra hot, even though it wasn't glowing red or anything and water temp was fine.

 

Anyway, realized the plug for the air regulator had slid out of the body about 3/4 of an inch and was making a bigger air leak! Ended up bypassing the air regulator entirely, and she's running better now. Idles at 8-900 at cold startup, then stays around 1300 at full warm up.

 

EDIT, see two more posts down.

 

I think the reason I can't use the idle portion of the TPS switch is because my fuel pressure is too high at idle. Likely because my return still runs through the vapor tank before dropping into the fuel tank. Apparently a way to fix this is bypass the vapor tank and run the return directly into the top of the fuel tank. And a bigger return line also wouldn't hurt. Those are projects for this summer though as it's running fine now.

[HRH]

Is anyone else running their 200sx setup without the air regulator? It seems to run fine, but definitely runs a little richer. Doesn't smell as nice. I'm debating fixing the AR with some silicone and putting back in. It does run great though, but almost seems as if it's slightly slower. Hard to tell with the butt dyno though.

[HRH]

Damn, with the forum screwing up, it didn't post this. After two days of driving with the AR not connected, I put it back on this morning. Siliconed the housing to make sure it stays in this time. It seems to run better and harder with the AR in. Guess it needs that little bit of an air leak to get the mixture just right.

 

The only thing I've really noticed is a different smell from the exhaust. About the only other thing I messed with was the idle air bypass screw on the AFM. Going to mess with it a little more. When I romp the throttle I get a bit of almost sulfur smell. Nothing wrong, exhaust color is good, no engine running issues whatsoever. I don't have a catalytic converter either so it's not that. Think perhaps I have it set a little too low. Of course since I'm bypassing the idle portion of the switch it's pretty hard to tell anyway.

 

I'll keep dicking with it, but for right now having the AR hooked up is the way to go.