Jump to content

Dave WM

  • Posts

  • Joined

  • Last visited

  • Days Won


Everything posted by Dave WM

  1. roger that about blowing up the motor. At this point I just want to see the turbo get oil and be able to spool up to check for boost. I do have the entire turbo FI setup so eventually the plan is to outfit the the test stand with that setup for testing. I will have to dig into it to see if there is any missing parts, it looks pretty complete. I forgot to add the color tune plug, I really want to better understand how that O2 sensor readings relate to actual combustion, I trust my eyes to read the color tune.
  2. I used the cheap poorly rated amazon kit, worked just fine. I can only assume the neg reviews were by folks that do not know how to use a tap. It took a while to ream and tap but nothing extraordinary. I ended up using a punch to stake the insert since there is no mechanical lock and I did not use any thread lock (I cant imagine it working in the high heat of a turbo down pipe. did another video of the engine running this time using the narrow band 02 sensor hooked to a analog voltmeter. I think I am about done testing without the turbo, so that will be added soon. Will use the NA fuel injection and closely monitor the air fuel mix to keep from running lean. Added a variable resistor to the temp sensor to allow for added enrichment.
  3. have not tried that. Its a really old hobby lathe, no auto feed etc. Good for small stuff. I think for now I may just use a big washer to capture the top of the O2 sensor hex and then drill some matching holes that can be used to bolt the wash down to the flange where the heat shield use to go to retain. Not a perm solution but good enough for now. I may try one of those cheapo kits, like you said good for one try prob. I have been thinking (dangerous) about adding closed loop to the existing NA FI. Use a voltage divider to arrive at a .5v bias (maybe get fancy with a zener diode), use that and the output from the single wire O2 sensor to arrive at a 0v difference when AF ration is correct (.5v out from the sensor). Feed that in series with the wiper of the AFM, smoke the computer or have a a closed loop FI. any bets which it is?
  4. You have to be very careful about all the little plastic bushings/washer placement. I goofed on and ended up blowing fuses when activating the washer button
  5. O2 Oxygen Sensor Stepped Weld Bungs (5 Bungs/5 Plugs) M18 x 1.5 | eBay maybe just weld on some mount ears and use something like this. I have not done much drilling into cast iron, maybe that is the expensive trick, tools hard enough to deal with heat cycled cast iron?
  6. Geez louise, I need to repair the 02 sensor hole on the cast iron down pipe from the turbo. Its hopelessly stripped (not enough left to chase). So I figure heli coil etc... BIG bucks I mean like cheap o kit 100$ good stuff 200+. Perhaps its the hard iron that needs some really good taps to work with? there are some cheap kits on amazon for as low as 35$ but they all have terrible reviews. Took it to a machine shop was told 130$. So if any of you guys have some exp with how to fix cast iron O2 sensor hole, please speak up. I have another possible solution, the hole is set in a cast in flange area that had a heat shield bolted to the cast iron. I am pretty sure I can turn a alum piece that woutl fit over the 02 hex and then I could capture the sensor that way. I just can see spending 130$ for what seem like a simple tap and time sert job.
  7. did you take the multi switch apart to clean it?
  8. Ok tested again today, this time with the plugs torque to spec, again passed with flying blue colors. Only thing I can think of is something in the coolant that had to boil off. Perhaps all that WD40 I used (filled it with the stuff then drained it out to prevent rust after rinsing the evaporust out. Maybe there was trace amounts still in there? I guess as a test I could simply dump some WD 40 back in and see if the test for gas comes back positive again. Or I could move on to the turbo install. With the 02 sensor I am able to monitor the Air/fuel ratio pretty well. I could just keep an eye on that and try it with boost on the NA setup. I did test the color change by sampling the exhaust from the muffler, turned yellow right away.
  9. I dont know for sure, but I think it will detect C02 from and I presume C0 as well.
  10. ah, a variable... whilie I was putting the engine away for the day I recalled my plan to look in the cylinders (before doing the last chem test that was a win. My plan had been to inspect for dye in there, in prep for that I had only installed the plugs finger tight to briefly run the engine to circulate the dye. SO, is it possible that some of the exhaust pressure was leaking past a less the fully tighten plug, thereby reducing the combustion chamber pressure enough to allow for the test to pass? Its at least something to go on. Its too late for me to run the engine now, but will make sure the plugs are torqued to spec an will try again tomorrow. Geez I hope is passes, but if not at least the puzzle will be solved. And if it does fail I think I will try running while disabling one cylinder at a time (pull the fuel injector connector off). That should allow me to narrow down the issue. I actually started down the path earlier before running it in the video. I had removed #6 plug, thinking it would lessen the load on the engine to not have to compress just the air, well silly me, engine ran like crap, massive air leak I guess, so I reinstalled the plug (hand tight) and the video was made. Now to be clear the plugs were not loose, fully seated, and I could not detect any odd noises while running making the video, Just snugged up with to the washer.
  11. I wish I knew, only thing I did was add the uv dye to the system. Clearly I will be retesting, I am using the fluid from the same bottle, I should have sniffed from the tail pipe to confirm color change, will do that next time. I will conduct more test over the coming days. Thing is IIRC I had the same thing happen on the N42/MN47 spare engine, failed at 1st then tested fine later and ever since. REALLY bugs me but if I can't get it to fail again (and remember it never overheated when it did indicate fail) then I will take the W, don't want to look a gift horse in the mouth.
  12. leaking oil is a good thing when it sprays the underside of the car, keeping rust away. Check those hubcaps often, they have a way of getting loose and a hard turn or pothole will send them off to hubcap heaven, never to be seen again.
  13. going to try adding some UV coolant dye to the rad, pump it up with a pressure tester, let it sit for a long while, then spin with plugs out and see if any dye is expelled thru plug holes. I tried already with pressure and then examine with borescope, but its not the best and could not really see well enough to call it. I figure the compression stroke will aerosol any accumulated coolant and spray will show the dye. I will spin the engine with the plugs out to hopefully disburse the dye, that may not do it though.
  14. here is the water overflow test. Note I did the same test with my car that does NOT change the fluid color, and I had the same results, water started to over flow within the same time span as this video. So as CO mentioned, the water apparently was expanding enough to start flowing with out the introduction of gases (in my good engine in the car).
  15. roger that CO. well I will have the videos soon, both of the water expansion and the chem test. Not looking good... let you guys have a look. tell me what you think. will post here soon.
  16. leak down test done, passed with ony about 5-8% max loss. I suspect the combustion pressures are way higher so doubt I could pick up on a small leak. I am going to try the top off with water test again. seems like NO water should flow out of the rad top on a cold start for at least a few min. IF any comes out at all then it seems must be gases displacing water. I figure it must be done cold to avoid any trapped air in the water jacket heating up. I assume IF no air at all in the water jacket, NOTHING should overflow as I dont think water expands from heat, at least until it shifts into steam.
  17. 1st off tic is gone, pulled the pivot, reassembled under oil bath, all good. Now the odd stuff. installed T stat, put funnel in rad, made sure it was the high point, filled to the max, no instant overflow. as the engine heated up I got a slow expansion and push out of coolant but no bubbles. by the time it hit about 185f it was just a bit of water coming out. Not sure I understand how that could happen unless there is gas filling somewhere, but decided to do the chem test again, before draining coolant (with it still running) I just pulled some garage air thur the test kit, opps blue is starting to turn green.... So before ANY more messing the engine is going out to the sidewalk for the next test. I cant imagine that enough exhaust gases were accumulating inside an open garage, but before any more moves, its going WAY out in the open air. Perhaps some of my recent decisions may be explained by the garage air test......... ZH I will add that to the list of to do IF i get another L after an OUTDOOR test of the chem test.
  18. sounds like the issue, I just was not able to get it to running speed. I wonder if nissan used these hyd pivots on ohter models?
  19. Not sure exactly what it looks for. the puzzling thing is I sorta went thru this with the Non turbo, one day went out and test it again and IIRC i tested ok with the MN47 and then did with no changes made. Never failed since (i have tried it many times to confirm). Its NOT overheating (stayed right at 180-185 max on a super hot day with air temps over 100f, no thermostat mind you but no shroud either and not the best fan placement with respect to the rad. I will try filling the rad up to the top, then starting and see if water boils out. I think I have seen where if gases are getting in, esp on a cold engine then the water will quickly overflow the filler neck as gas displaces coolant.
  20. I got nothing to lose on the the spray on the used OE HG, its going to get tossed anyway. May as well have fun while the engine is easy to work on and test (with the test stand). Here is something new, it had a loud valve tapping sound, this is with the hyd pivots. I used the stethoscope and decided it was on #2. pull the valve cover and sure enough there was play at the pivot even as the lope was starting to make contact with the ramp. The pivots use oil and have a spring as well (weak) I will purge the air out of the pivot, and also verify the well it sits in is getting oil (crank engine ign off, plugs out). My guess is it would have eventually purged the air out, in time if it had been normal driving speeds. Idle testing for gas means low pressure and volume, it never cleared up even with me running it for 30 min screwing with the testing. My guess is with the engine off there is always going to be at least one valve that is open (the pivot under pressure). Over time the oil inside will leak down. So I presume any time an engine is shut down for an extended time, this will happen. Anyone with a P90a head can confirm?
  21. I had assumed that would be something I could see, I recall looking them both over, perhaps not well enough... I was thinking of applying some bluing to the surfaces and then running them over some 220 wet/dry on a flat stone (marble or granite) as a better way to see imperfections. I am pretty unsure about a machine shop. Its not something they routinely do, dont want them running .010 off the tops if it only needs .002 etc... Just dont know how to tell if they are competent as I have NO exp with a machine shop.
  22. I will pull the head soon, will take a look, see if I can find a shop that can do for me. Thanks!
  23. Yea I know sounds like a dumb idea, but hear me out. Just installed a new OE nissan head gasket on to what I think is a good head and block, well prepped, torqued pre fsm etc... Still getting a exhaust gas leak in the radiator per the blue chem test. I was going to try another head gasket (yea I know the definition of crazy) to see if that stops it. But since the engine is on the test stand and very easy to work on AND I want to try it out, I am going to remove the head, and try some copper spray on the just installed and tested gasket. If nothing else I can add another L to the record book. After that L is recorded I will try a different make of HG. Again I have check the block and head for warpage cleaned well before install. I am at a loss as to why this is going on. I will also break out the magnify glass to inspect the head combustion chambers.
  • Create New...

Important Information

By using this site, you agree to our Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.