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datzenmike

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Everything posted by datzenmike

  1. If you were to put an L20B head, like a U67 or W58 on the flattop pistons would raise the compression to about 9.95. The rods are six inch rather than 5.75" and some would consider this a long rod engine which is rev happy. You would probably run high octane premium gas. The VIN would only be the model year while the actual build date (month and year) is on the driver's door jam and much more accurate for finding parts as things often change during the model year.
  2. It's an '84-'86 Mileage option Z20 (carburetor) engine. Has the small combustion chamber W04 casting head with 9 compression and a knock sensor and electronics for ignition retard in response to pinging, long rod flattop pistons, 240mm clutch, 5 speed and an insane 3.364 differential. Was an option for fleet trucks aimed at higher mileage. VINs are ok but engines can be swapped. This will also have a tag under the passenger side hood hinge on the inner fender saying the same thing.
  3. Replace the filter anyway. Don't cheap out on them, or carry a spare, this could have happened at midnight in a rainstorm 100 miles from home.
  4. Like 'Murica was lied to and went to war over weapons of mass destruction? There, now it's full retard, AND dyslectic. Everyone lies, everyone.....countries more so than most.
  5. datzenmike

    My 1971 521

    A piece of pipe the same diameter that fits over the crankshaft? The installation tool is somewhat like that.
  6. For $40 I would want the door!!!!! The door striker mechanism for the 620 is also used on the Nissan Patrol, Roadster, 521, and 510. Sorry the B-210 is not remotely close.
  7. This is because the original exhaust is just not really that restrictive. No one realizes that to get an improvement it has to be at some level of bad. Restriction to flow increases with the volume of flow so it's only at it worst when the engine is screaming. The rest of the time it's way more than good enough. The cross sectional area of a circle (muffler pipe) increases four times when the pipe diameter is doubled. A 1.75" pipe has a cross section of 2.4 sq. in. When you switch to a 2 inch pipe that's only 1/4 inch larger, the cross section becomes 3.14 sq. in. That's an increase of 30%!!!!! capacity... 1/3!!!!. Just how much exhaust capacity do you really need???? For an L16 that's enough pipe for almost a 2.1 liter engine flow. Small increases equal BIG gains. You can also loose a lot of low and mid range torque from slowing the exhaust speed. Where does most of your driving happen above 5K or below 3K. Be conservative in pipe size increase it really doesn't do that much.
  8. .... hang on I'm busy edging right now....
  9. We have a steady amount of regular Ratsun member visits. Very stable at about 30 (ish) a day for as far back as 10/19 but non member visits were under 600 through Dec petering out till month end then in mid Jan when they spiked suddenly to over 600 Jan 14!!! then tapering off to 100-200 through March tapering to about 100 a day in all of April. Winter would explain some of the non members. Member activity stays constant between 150 and 200 (posts?) a day
  10. My stock (other than R-1 carbs) L20B 5 speed gets 28-30 on long trips to Canby. That's US gallons. Generally the larger the displacement the worse the mileage. Often a larger displacement EFI will give better mileage than a smaller carb engine.
  11. Noticed way more people out for a walk too. My air comes in off the Pacific washed by the ocean and combed through the trees from the west side of the ocean. So it was pretty clean anyway. When I'm on my morning walk I'll stop and it's so quiet without cars, I too think it's Sunday when I was a kid and everything closed. This was into the '60s when everything closed on Sunday because you didn't need to buy shit and people didn't need those jobs to get by. Porn usage in mid March is up 11.6% according to PornHub, that's like 3 weeks old. This is partly more people with time on their hand and also a human coping mechanism response to Terror. When faced with possible extinction we might procreate to counter it.
  12. I was saying that the rim size is meaningless. The tire diameter is what changes your effective gear ratio the engine 'sees'. You can have a 14" tire that is taller than a 15". The tire itself is what determines the diameter. Speedometer error is not constant. It won't be 5 mph out at all speeds, instead, if out 5 at 50 it will be 10 out at 100 and 2.5 at 25. If your tires now are 215/75-15 then the diameter is 27.7". A stock 720 2wd is probably 195/75/14 which are 25.52" can you confirm this is what you had?? If yes then your truck will be going faster than what the speedometer reads... or you could say the speedometer is slow. Going to this taller tire.... at 60 you should be reading exactly 55.28MPH so that checks out almost exactly. This is also almost exactly 9% difference so IF you have a 3.889 differential changing to a 4.24 would cancel this out by slowing you down and making the speedometer accurate. Unfortunately Nissan does not have a 4.24 differential but there is a 4.375 which is a 12.5% increase. This would mean your speedometer would read 3.5% high or 1.75 MPH high at 50. Or reads 51.75 MPH while dong an actual 50MPH. That's pretty damn close I say. And this gives you slightly more torque than the original tire and differential. Cake... and eat it too. The 4.375 was used extensively in the 620 truck. You said '80 but what year truck are you referring to??? What's this going into???
  13. Had drums on my 521. Back then I wasn't that caring of maintenance, they were always out of adjustment and pulled to one side and were a pain in the ass. My 620 had discs and in 8-10 years, IIRC, I once pulled good used pads off something else and used the shit out of them and then did a Toyota SAS. Properly set up and maintained 10" drum brakes will get you stopped every bit as good as the disc brake. The disc brake, other than pad replacement and/or rotor turning needs no real maintenance and zero adjustment. Pad replacement is super easy and fast. Disc brakes will tolerate far more overheating without fade than drums will, but this would never happen in a panic stop. To cause brake fade you would have to be carrying a load down a mountain, it just doesn't happen. Drum brakes should be checked/adjusted every 3-4 months and replacing the shoes is labor intensive and tedious. ,
  14. Sat for at least 5 years in the wrecking yard and 3 with the gas cap off on the side, in the rain and snow of Vancouver Island. It was BRIGHT yellow like a fog light lens. I used a gas filter on a hose and a kitchen funnel. Wayno posted a picture of a container of gas that had separated from sitting. Have never seen or heard of this here. I'm at sea level if that means anything. I drove it and was expecting something but nothing at all happened
  15. datzenmike

    '80 720 Axle ID

    You have already started this same topic. Now you have two and will end up with multiple answers that others aren't aware off were tried. Keep track of your posts and add to them.
  16. datzenmike

    8 plugs at once?

    First stop buying things and putting them on. It's wasteful of money and time and more like trying to win the lottery. There are several thinge that can cause the tach to not work and they are much easier to fix. For example the tach is wireds to the intake coil... if it's not firing... no tach. Fix the firing and you fix the tach. Never throw away old parts. Second, the intake and the exhaust plugs fire at ALL times. The only condition when the exhaust side is shut off is at full throttle when the vacuum drops below a set amount. A switch turns the exhaust side off. That's it. You should have +12 volts on both coil positive terminals. Get a $5 test lamp and check that the light comes on with the ignition. If no power check or change the first fuse on the far left of the fuse box. It must have 12v on both sides of the fuse. Test for 12v on both sides of the 20 below. You don't have to remove the fuse to do this unless one side is dead. Ignition must be ON. This is the power source for the exhaust side coil. Without power, no spark. There's no need to jumper and switch to fix. Everything should be there to make it work. Find the problem.
  17. datzenmike

    720 turn signal

    https://ratsun.net/classifieds/category/9-datsun-parts/ best bet for one from a member, otherwise a wrecking yard. You might find one on e-bay or the like I doubt anyone still makes a 35 year old part, there's no demand. If not working properly (signals or headlight switch) try flushing it with a spray can of contact cleaner. The original contact grease collects dust and hardens.
  18. As wayno pointed out the L20B, Z20 are identical blocks even using the same crankshaft. The Z22 is still the same basic block but with a larger bore and a longer stroke crank and uses L20B rods still. You could even bore an L20B out to the Z22 size and the Z22 to Z24 size but the cylinder walls would be thinner. The Z24 is, again, the same basic block as the L20B BUT, the bore is even larger than the Z22 and the cylinders taller by 2cm or 3/4" to compensate for the, again, increased stroke and longer rods. Should be noted that Z22 (or even an L20B block can be bored out to Z24 but cylinder walls are thin) and instead of Z24 pistons, KA24E pistons can be used.This will have a much higher compression. About compression. Higher compression will raise the temperature of the combustion chamber making it more likely to set off the gas air mix when you don't want it to... called pinging. The cure is to run a higher octane gas which makes the gas less sensitive to self ignition. Generally a higher compression is more efficient because the combustion chamber area will be smaller than a lower compression engine. A smaller combustion chamber won't absorb as much heat and the heat saved goes into doing more work turning the engine. On top of this a tightly compressed gas/air mix will explode and burn faster reaching higher cylinder pressures than a low compression engine, pushing down on the piston with more force. Now that said if you capture more of the gasoline's energy and put it to work moving your vehicle it's very possible to increase your mileage enough to more than pay for the additional cost of having to rum premium or high octane gas. It seems harsh to be paying 35 cents more per gallon but if you get 20 MPG on regular, but get just 10% better (22MPG) with your high compression engine on premium they both cost $0.13 cents per mile to drive An LZ engine mixture of parts is great if you cannot locate a complete engine to rebuild. You could call them 'stroker engines'
  19. Maybe we should steer this over toward covid19 updates and experiences? You know.... before it goes more full retard. (not that any of these comments are too retarded or foil hat or anything) Maybe tap the brakes.
  20. The Z head doesn't breath very well and no way to fix. I haven't finished it yet but the L head breaths very well. If an L20B makes an easy 95 HP then increasing the displacement by 20% would increase the HP by 20% or 114HP. One day I'll put it in my 710 which has R-1 bike carbs, and L16 cast exhaust. I also have an Isky cam laying around. Byron on the Realm had an LZ22 with cam and side drafts and it was 135 HP. Have the dyno chart somewhere.
  21. Like 911, things didn't change right away. Gotta survive this first then make changes. If you were infectious you could travel around the world in what? a day and a half?? two days? Stuffed in a tuna can with hundreds of people who get off and fly somewhere else in tuna cans. That's got to change. Anyone buy gas lately???? Do you really know where that nozzle's has been?
  22. Wasn't there a virology lab in Hunan? The 'shit' got loose.
  23. Good catch. I usually say the L20B is 3/4" taller than the L16/18. Carry on BTW I used the Z24 timing cover and put an L head right over it. There was only one corner that was close to not sealing and a little JB took care of that. Naturally you can't use those small bolts but it only has to seal fumes and oil splash in. Chain needed two links
  24. Seems kind of high, oh well.
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