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zack_280

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Posts posted by zack_280

    Twin cam head for the L6 from Derek at Datsunworks

    in Nissan L6 Forum

    Posted

    Nice!  The head that I had to trash was done by Jim Thompson (supposedly).  Unfortunately it appeared that the PO blew a head gasket and allowed water to sit in it for a few years.  When I took the motor apart, I found out both the head and block were toast.  So I bought another head from a member here and have been having a few problems that I believe are related to it.  So now I'm hoping this will solve all of my problems.  I'm pretty sure complication and money are usually the best way to solve engine issues.

    Engine Blew at Road Atlanta

    in Nissan L6 Forum

    Posted

    Wow. I wasn't really sure what happened since my buddy didn't see it.  He was just repeating what he heard. It's pretty scary to think about.  Not sure what the actual cause was or if the Mustang driver had any safety equipment, but something like that definitely makes you think twice about safety.

     

    I don't think I would ever get on track again without a Hans.

    Mike Kelly's Zcar Project

    in S30 Series - 240z, 260z, 280z

    Posted · Edited by zack_280

    We are not going to VIR this year either...I really want to do a race there, but we have just gotten to the point where we feel comfortable that we have found all of the bugs...Maybe next year.  Not sure about the 24, though.  We've only got 4 guys on our team and the car owner doesn't really want to trust anybody he doesn't know.  Also we are definitely doing Barber in August and there is no way we would sign up for both of those races since they are so close.  This year has been mostly positive, so we might make it out to VIR next year.

     

    I'm not familiar with Shenandoah, but generally tight courses are better for E30s.  I imagine that the E36s will do pretty good too.  Just tell your drivers to be smart with passing and keep the shiny side up.  Finishing is almost as good as finishing first.  If you have good stops, you can make up a lot of time...I think that's how we ended up so far ahead at NCM.

    Mike Kelly's Zcar Project

    in S30 Series - 240z, 260z, 280z

    Posted

    Good luck.  We just did the NCM race last weekend in my buddy's E30.  Finally got a win on day 1. Day 2 didn't go so good, but we learned to make sure the oil dipstick is completely inserted into the dipstick tube.  Unfortunately we have 3 penalty laps for the next 3 races.  We won by 2 laps and get a 'margin of victory + 1 lap' penalty for the next 3 races.  3 races! That seems pretty harsh, but rules is rules.  We weren't even the fastest E30. 

    Arizona ZCar Rear Suspension - Design, Function, Flaw(?)

    in Brakes, Wheels, Suspension and Chassis

    Posted · Edited by zack_280

    To answer the original question...You have to put a set screw in the AZC rear LCA.  Maybe some setups will be less prone to movement, but mine has pretty tight clearances. At an autocross my outside rear wheel/tire was pushed into my inner fender due to movement of the suspension.  I tried to jack the car up and drop it quickly, but it wouldn't move back to the original loaded position.  I had to add a set screw. 

     

    I discussed this with CobraMatt and he said he installed a set screw from day 1 to keep from having alignment issues.

    L28et ecu upgrade?

    in Nissan L6 Forum

    Posted

    If you are going to install a programmable ECU, you will have some more money in sensors, wiring, etc than just the ECU.  It'll probably end up costing over $1k (unless you find a complete or mostly complete used system).  If you don't want to spend a bit of time on this, your best bet is to find a stock ECU (assuming you now have the sensors you need to make it work).  If necessary, you could buy a wiring harness kit from MS.  It is definitely worth every penny.

     

    If you do not have the sensors you need and you are planning to tinker with the boost, I would probably go the aftermarked route just for the flexibility of the system.

    Heat Soak Question

    in Nissan L6 Forum

    Posted

    Might be worthwhile to isolate the problem.  Bypass the surge tank and go back to just the high pressure pump feeding the fuel line directly from the big tank.  If the problem goes away it's coming from the surge tank system.  If it stays, at least the number of options will be smaller.

    Not a bad idea, but it will take a little bit of effort to do that.  

     

    This will get me to tinkering on the car again (and spending $50 here and $25 there and $200 there).  My wife will be thrilled.

    Heat Soak Question

    in Nissan L6 Forum

    Posted

    I'll let you know the difference between the $19.95 round fits in the palm of your hand IR gun, the $29.99 Auto Zone Pistol IR Gun, and the $757 Fluke IR Gun I have: at the range you use it (less than 6") less than 0.1 degree Celcius.

     

    I stopped carrying my $700+ Fluke when I found this out since most of my measurements are less than 1m anyway, and I can adjust mine for the different emissivity characteristics of stainless steel---know what? Put a flat white spot of high temp bbq paint and it's just as accurate reading it with the AZ Gun! The only real difference is the spot size at a distance and the range of the thermal element. Some read higher than others. My AutoZone Gun was reading 345C Steam today, and 245C on the exhaust of a turbine. I got news.... 0.1 degree C isn't that big a deal.

     

     The "better gun" I was referring to was an IR camera that could discern pretty high temps.  I'm not sure what the range is, but it's more than I would need to worry about.  Again, I see your point with the cheap one.  It could definitely provide some more info (not sure if it would be useful).

     

     

    Part of what you describe is likely the tank getting hot and the fuel density changing. I have seen it go from 11:1 with 21C fuel in the tank to 15 and 17:1 with 45-50C fuel and higher! The AutoX is the fuel sloshing around and the pickup coming uncovered---again something your surge tank should eliminate... if you feel 'boiling' in your surge tank, and you can put your hand on it to feel it---IT'S NOT BOILING! Likely it's air blowing in there from a hole in your pickup line being pushed in by your boost pump. Gas won't boil at only 120-140 generally...but 1-3PSI would definately mitigate the pressure boiling point. 

    I can feel the "boiling" with the car off and the high pressure pump sounds like it's trying to pump air rather than liquid when I turn it on.  However, the "boiling" is still there with no pump running. I'm not sure that it is boiling or if it could be fuel leaking down into the tank and air leaking up from the tank into the surge tank, but the surge tank and fuel lines get pretty hot and the "boiling" feels pretty violent.  I'll get a gauge and verify that there is positive pressure in the surge tank.

     

     

    The stalling you have that goes away after 10-15 minutes should go away if you cycle fuel thorugh the rail for a few seconds before startup. Right at the head, the injectors are well up around 180 F and that will boil the fuel if the check valves are all working---the gas expands, the FPR dumps it...you try to start without a priming pulse and the pressure drops FLASH! To vapor.. Extreme cases the fuel does get to 190+ and the FPR dumps pressure and enough is lost that the fuel does boil in the rail. But this is a function of the pump check valve not holding pressure up in the rail as much as anything else. I run a 160 F thermostat and it greatly reduces this tendency. If it doesn't get that hot, it can't boil the fuel!

    I thought the same thing about circulating the fuel, but that doesn't seem to work.  I have tried it multiple times, but it doesn't seem to have a noticeable effect.  The only thing that seems to work is to let the system cool off.

    Heat Soak Question

    in Nissan L6 Forum

    Posted

    Seems like this is close to your main symptom and you're making assumptions about what the cause is.  You might help your mission by just describing what happens and see if anyone has a suggestion about the cause.  Describe the "vapor lock" under load, for example.  EMS description will help also; stock, MS, etc.

    I am definitely making assumptions about what the cause is, although I believe it is either cavitation as Tony mentioned above or heat soak.  I was going to buy one of the cheap I/R guns, but a friend of mine works at a place and said he could borrow a much better one.  That was 2 months ago.  So maybe I need to go and buy the cheap one.  I am running megasquirt injection, but I don't believe it is in any way related to my EMS.

     

    Here is what happens: I start the car, it runs fine for a little while (less of a while with less than 3/8 of a tank of fuel).  Then my AFRs start getting lean spikes, like there is air in the fuel line.  Then it will basically completely lean out and die.  The engine usually only dies under idle at a stoplight or heavy load at an autox or track event.  I shut off the car, wait 10-15 minutes, start it and drive away.  I have felt the fuel boiling in the surge tank and in the pump and the fuel rail.

     

    Tony,

    I'll check the pressure in the surge tank, although I would be surprised if that was the problem.

    Heat Soak Question

    in Nissan L6 Forum

    Posted

    I have a modified L28ET motor. It seems like the head gets very hot very quick under any driving conditions. For example, this weekend I drove my car for about 5-10 minutes. I pulled into the garage, popped the hood and the valve cover was almost too hot to touch. It was too hot to leave your finger on for longer than 1-2 seconds without pain. Is this within the bounds of normal for these motors?

    The heat soak is leading to vapor lock issues. It will vapor lock while running even while driving under load. Obviously the vapor lock is worse with less fuel in the tank. My intended solution is to get a fuel cooler and install it after the fuel pressure regulator. I just didn't want to do that if it was only a Band-Aid for a potentially larger problem.

    Here is my fuel system...
    Tank->Low Press Pump->Surge Tank->High Press Pump->Fuel Rail->Fuel Press Regulator->Surge Tank->Tank

    Thanks for any help suggestions,

    Zack

    Time For a new snail!

    in Turbo / Supercharger

    Posted

    I'm running a GTX3071R turbo.  My car is running megasquirt and has not been properly tuned, but I have spent a bit of time messing with it on the street.  I did two pulls on an eddy current dyno and it made 245HP and 240lbft at 10PSI (but it did creep up to about 10.7PSI).  This was a conservative dyno.  I have a 1.01A/R turbine housing and was at full boost at ~3500RPM.  I am quite happy with it and it will have no problem supporting 400HP.  Hopefully this info is helpful.

    My Dream LS7GTZ.......project underway

    in S30 Series - 240z, 260z, 280z

    Posted

    I'll be at Daytona in our E30 also.  Really hoping the new motor makes more power than the old one.  Granted the old motor didn't have perfect compression numbers and had about 250k miles on the clock. We were having trouble keeping up with a number of Miatas on the straights.  We confirmed the low numbers on a dyno.  We were 15hp below a spec E30 and another Chump E30 on the same dyno on the same day.

    My Dream LS7GTZ.......project underway

    in S30 Series - 240z, 260z, 280z

    Posted · Edited by zack_280

    Matt, After we blew up and realized there was no fixing the car, we went to 10a/10b and watched the cars coming down the hill through the turn and going up.  It had to be you driving around 3PM b/c we watched you take the lead.  Me and my buddies all said "whoever is driving that E30 can really drive."  I was sure it had to be a pro driver.  It was impressive watching you storm up the hill passing just about everything and holding off the SC300 and even pulling away.  The battle with the SC300 for the lead that lasted for 5 laps or so was pretty awesome to watch. When you got by, you blew through a pack of cars and the SC300 was history.  Definitely the best racing I saw this weekend. 

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