NewZed

Major edit - stuck a hose in the oil sender port and blew air while blocking the filter center feed. A strong stream comes from the middle hole, but nothing from the front hole. So Tim Z's description seems right. Nissan runs oil up through the head then back down in to the block through another restrictor jet to the tensioner. So if your font jet is too open you could probably lose pressure to the tensioner. Looks to me like a finely tuned system that probably shouldn't be messed with, too many ways to go wrong.

You're right, my mistake. And I've made the same mistake before, trying to figure things out from the Engine Lubrication diagram and casting shapes on the block (I think you replied that time also). I went out and stuck a hose in the oil sender hole in a short block I have and it blows out the center hole where the filter sits. Which is also a direct shot to the oil jet at the top of the block, you can see a thin wire jammed down the jet through the oil filter center hole. There's a casting bump between the sender boss and the passage from the pump but it's not what it looks like, that 's what got me, plus the black on black diagram in the FSM.. So pumping oil in to the oil sender hole then could push oil backward through the filter toward the pump, assuming the check valve (anti-drain-back valve) in the filter can't hold 120 psi. Could be where some of the pressure was going. I don't know how much could squeeze past the pump. A rig that feeds oil through the filter center hole would mimic what the system does in use and might make things more clear, to me anyway. I don't really know much about the L6 oiling system, just giving the neophytes view, and learning a tittle bit more along the way.

Tony D brings up a good point. You're pumping the oil in before the filter. Assuming the pressure relief valve behind the filter works, it shouldn't matter much, but, who knows, maybe there's a problem at the filter area. That would starve both the head and the crank. Another thought - remove the cam and towers and see if oil is coming up through the block orifice in to the channels under the towers. It's one step back from removing the head, but should be a lot easier. If you have oil there, then the problem is probably in the towers. And, as mentioned, the other possibility is that there is plenty of flow up through the head, it's just going somewhere else before entering the camshaft and spray bars. And thanks for the puzzle. It beats Sudoku.

Another thought - since you have a way to push oil and you're thinking about pulling the threaded plug on the camshaft, you might run some oil backward from the camshaft down. Maybe there's debris blocking the jet in the top of the block and you can push it back down. You'll want to make sure you divert the oil out from the head supply channel so the debris doesn't travel down to the crank bearings. I get the impression you're avoiding removing the head so that might offer a solution. Good luck.

I have an engine on a stand (old used JY engine), with a mechanical gauge in the pressure sender hole, so went out and hooked up a battery to the starter, pulled the spark plugs and the valve cover, and gave it a spin. It spun for about 20 seconds before any oil pressure showed on the gauge. 20 seconds seems like forever watching a fairly dry cam spin with no oil supply, especially after reading threads like this one. The engine has been sitting for months since I last started it. Oil pressure finally came up to 20 psi, with the slow RPM of a gear reduction starter. Once pressure came up, oil flowed freely from the internally oiled camshaft, stock N47 head, but did not shoot out, only caused an oil bump on the cam lobe about as big as the bumps in your first video, maybe even a little bigger. Looked like more flow at 20 psi than yours. The engine wasn't even spinning fast enough to fling the oil off of the camshaft either. So, basically, at 20 psi through the oil pump, I was getting what looked like about your oil flow rate, or better. The above should give people with gear reduction starters on new engines something to think about. They don't spin fast and don't build pressure fast so the cam will be dry for a while if the engine doesn't start right up. I'd take a video but also found that the drain back holes on top of the head are pretty small and the oil would rather run over the edge, so I had to put the valve cover back on to avoid a mess. Think of it as I pumped more oil than could drain back through the small holes in the top of the head. At 20 psi. Hope that gives you more to think about. I would run your test again but at about 20 psi to see if any pressure builds in the camshaft at all. If there's not enough flow to fill the camshaft and build some pressure at idle, braking or sitting on a hill could leave one end of the shaft dry. Edit - sidenote - looking around about gear reduction starters I see that many people say that they spin the engine faster. I don't see how you can have higher torque and higher speed, that seems incorrect. Regardless, my engine was spinning slowly.

Still seems like you have too much restriction between the main head supply passage and the oil pump. Since there's a restriction at the head/block interface there should really be another measurement point in the head to show if the cam is getting proper oil pressure. Pressure is generated by restriction to flow. If you could measure there you'd probably get a low number. Did you get a pressure reading from the car's gauge, showing what it was in the main gallery, or just have 120 psi in the tank? And did you plumb in to the center port to the where the oil filter mounts to pressurize and feed the oil? Not really clear. Seems like 120 psi would blow oil all over the place, even cold, if it was the main gallery at 120.

Left side steering versus right side steering maybe? From what I've read, things seem to fit together much better on the right side cars.

If you mean the rubber sandwich mount that sits on the cross member, they're the same for the 71B type 4 and 5 speeds. I've used the same one for both, 1976 4 speed, 1978 5 speed, 1983 5 speed, 1980 5 speed. Don't know about the T5 type. The 71C 5 speed mount, like the 300ZX uses, is different. I've used O'Reilly Auto's compatibility tab on their web site, and RockAuto's alos to determine compatibility. Might help if you're still thinking.

Sorry Pb, I'm guilty of contributing to the mess in Post #37. Tried to chill things out in Post #47 and was surprised to see Tony D referring to my comments since he has me on Ignore. Maybe he is omniscient after all. Must be torture. Still, there is enough in the thread for the OP to get a little ahead of where he is. I think that he needs to learn more about what he has, for instance, what is the "unknown ECU"? Based on his comments, he might not even recognize a decent ECU if he had one. Most of the advice he's getting about EMS is way beyond his current state of knowledge, with the questions about injectors and the MSD BTM and "whats the degree of timing you have to set for around 11-12lbs of boost". Probably should have been referred directly to the Turbo FAQs for starters - http://forums.hybridz.org/topic/50208-the-ultimate-l28et-guidewhat-you-need-for-350whp/

Most axles are heat-treated after machining. So most shops would rather build a new axle than machine a used factory axle. You might be spending a lot of time and effort on something that isn't recommended and rarely done, and may be more expensive than just having a new axle built. You must have come across the threads about building new axles in your searches. On the Pathfinder axles, be aware that the aftermarket CV axle suppliers build their own in-house axles with non-factory spline counts and diameters. You may or may not have been looking at a Nissan axle.

This doesn't sound right. Sounds like your problem is in the master cylinder, maybe a blown seal on the front brake master cylinder piston. Even with no air in the lines, there is fluid movement, just not the large quantity you would see with air in the lines.

Tony D has posted a good trick over on zcar.com, maybe here also, about connecting a jumper wire to your negative coil terminal, turning the key On, then tapping (quickly) the jumper wire to ground. Every third tap should make all six injectors click. That will test the wiring from the coil to the ECU and also what the ECU does with the pulse from the coil firing. Every tap to ground does the same thing that the ignition module does (except "dwell time" control), and the ECU opens the injector every third spark (three sparks per engine revolution). I've tried it, it works. It's convenient also since there's no noise from the starter motor, just the small zap of the wire hitting ground. Easy to hear the injectors. You could also take a meter and test continuity to Pin 1 from coil negative first since that needs to be there for the ECU to do its job. Finally, one thing that I've found but some people have difficulty accepting is that the ECU won't fire the injectors if the tachometer and it's resistor are not wired in. I've had the resistor fall out and the engine won't run, also tried to start two cars with tachs removed and they wouldn't start until the tachs were plugged in.

Sounds like your nephew could figure out what's up with your race engine. You should get it dyno'ed with race gas just to see where you're starting. Should be a good winter project. Good luck.

Quantity matters also. There shouldn't be a huge imbalance between the two though. The rear reservoir may be supplying the front brakes.

Now you know a little bit more about what you have. From the initial purpose of the thread timing would be one of the most important pieces of information. You still have the major problem of owning a sensitive, possibly high-performance engine, but with very little knowledge of the basics of how an engine works. No offense, I'm no expert myself, but that seems to be the situation. The timing that you measured is 32-34 degrees advanced. If the engine is still pinging while you're driving, adjust your timing back to 10 degrees or less while you're trying to figure out what to do. I would make a friend of someone who knows these engines and learn while he/she works on it. It will save you money and if you pick the right friend you'll be able to drive the car while getting it right. What kind of shop do you work at, and which area do you work in? Curious, since you're surrounded by timing lights. Edit - curious also as to why someone would build such a high compression ratio L6 engine. It's not one of those Datsun Parts LLC engines is it?

Anybody here have an account on zcar.com? I was going to give advice to a guy who's car broke down as he was on his way to be deployed from Seattle, but find that I have been banned. Presumably for starting a new thread to give advice to someone that the admin, Heroe, decided was unworthy, because he did not search hard enough. Here's the thread - http://www.zcar.com/forum/10-70-83-tech-discussion-forum/336898-emergency-need-help-asap.html The advice is "put the car in to 5th gear and turn a wheel to move the car. This will turn the engine. If the engine or transmission is damaged, you'll hear noise or it won't move because it's locked up. If it's an electrical problem, the engine will turn over easily." Just passing it on, trying to help a guy in need, stuck in Oklahoma.

The nerve might be that you're blindly following general suggestions from the FSM or some other source, possibly leading to unnecessary work. There is no "requirement" to do anything. You're free to make your own decisions. You say the engine runs well, gets decent mileage, and has sufficient power, but you're still talking about doing work and spending money to get numbers on a gauge. A kind of a bureaucratize mentality, in a free-thinking forum. It sounds like you're waiting for someone to chime in and tell you to rebuild, but it's probably not going to happen. In post #8 I linked to a thread about a large volume head on a dished piston motor. What engine are you working with? You never said. Get the head numbers and the block numbers and see if it looks like it's been messed with (new gaskets, etc.). Who knows, you might have P79 head on a dished piston block. That might explain the lack of response at low RPM and the low numbers. Don't get offended, it's all part of the learning process. Get some more data and come back.

The distributors that use the "matchbox" modules tend to break the circular magnet under the pickup coil. One possibility. Test all of the distributor parts and check the gap between reluctor and pickup points. There's a whole series of tests in the Electrical chapter of the ZX FSM's, Ignition system section. 1980 would be a good one. http://www.nicoclub.com/FSM/

It's only a 16th but the guy in post #2 said 25/32" not 23/32". May not matter, just sayin'... Feb 2001. Pretty good detective work.

Set up a mirror so that you can in the reservoir. Put a little boat in there with a flag on it that you can see moving up and down. Something. I have a broken shovel handle that is perfect length for actuating the clutch and brake pedals. I use it all the time for bleeding.

The basics aren't being addressed, it seems way premature to be planning a new head gasket, or an E85 conversion. Sticking the E85 nozzle in the tank isn't really experience. No offense but you don't even know what your static timing is and the engine has been described as "pinging". Damage is occurring every time it's driven. At least buy a decent timing light and take a measurement before starting a discussion about modifying the engine.

You'll make a lot more progress if you get methodical and test each potential problem area individually. There's three areas right here, above. Test each one - 1. Eyeball the hose while someone pumps the brakes. Does the line expand like it's collecting fluid? It's probably not orientation but it could be a bad hose. I've not seen any red brake hose, where did it come from? 2. Watch the reservoirs as someone pumps the brakes. Which reservoir is moving more fluid? That's the system that has air in it. Unless... 3. Watch the fluid. Does it transfer from one reservoir to another? If so, your master cylinder is messed up. Does it drop and never come back? If so, you have a leak, either internal or external. You have enough clues now to focus on exactly where the source of the problem is. You just have to pick one area at a time and dig in to each one.

My memory dragged up the cavitation prevention concept after I posted. I had read that same thread in the past. Maybe I'll find one and retrofit............

The stock cap is vented to let air in but not out. The hose to the charcoal canister takes the overpressure and holds the gas vapor until vacuum from the engine running pulls it in to the intake manifold. The problem you would have with drilling holes in the cap is gas leaking through the holes when you corner as the liquid sloshes up to the filler cap. It's called a reservoir tank, not a vapor tank. Implying that it collects liquid at times. Watch out for liquid coming out of your vent hose, wherever you decide to put it. The location will determine where the gas fume smell originates also.

On the 75-78 illustration, there is also an AAR mounting block coolant supply line like the throttle body heater in 79-80. I think that it may also exist in the 79-83 engines also, maybe not. My 95 Pathfinder still has an AAR. Nice work, what did you use to draw them? Anybody know the purpose of the pressure relief valve from 79 on? Is it for pressure-actuated bypass of the heater core? I wonder if a retrofit to early engines would be some cheap insurance.