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sublah

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About sublah

  • Rank
    Standard Member
  • Birthday 03/20/1989

General Info

  • Location
    Australia SA
  • Gender
    Male
  • Car Type
    Nissan Silvia
  • Car Model
    S14
  • Occupation
    software engineer
  1. Correct Donny, the rocker arms were the 'cobalt' unit. The reason I bought this up now was that the engine has already been rebuilt for the second time by the same builder, and thinking he would cover it under warranty, has turned around and sent me a hefty bill for the rebuild. The oil has been long since disposed of, and we have struggled to even get the cams, rocker arms and lifters back from the builder for independent testing. Since the builder did all of the pull down and assessment I have no other option but to take his word for it that he didnt make a mistake during assembly, such as blocking oil galleries as some have mentioned. The main question I wanted answered here though was how likely fuel dilution of the oil would cause cam lobe wear, and not, as some have suggested, destroying big end bearings and other higher stress components first.
  2. The engine builder is known for building SR's, among other engines, so I think we can assume something like that would not have been overlooked.
  3. Interesting note about the big end bearings being worn out first, does make a lot of sense. When the car was actually running properly it didnt put out any more black smoke than you would expect from a SR with no cat.. That said, a few times it was hard to start and needed throttle to get going and at this time it smoked a bit. I should have mentioned, before I drove the car the engine was run in on a dyno to the engine builders guidelines with varying loads on a base tune over a period of a few days to bed in the rings etc. I put the engine in myself and had it trailered to a workshop for first start and run in procedure, as agreed by the engine builder. (Which is why I'm having such a big pain when the knock sensor worked its way loose, everyone is using me as the scapegoat and saying the problem was my fault.) I only drove the car a handful of times, and it had a small weeping of oil out one of the connectors on my oil cooler kit (just needed thread tape), so was constantly monitoring the dipstick to ensure it had adequate oil. Curiously I never noticed an increase on measured oil due to contamination.. The tune was done by the workshop that the engine builder told me to use; the builder does not tune motors first hand. As above, a basic tune was used for run in, which was done over four sessions, and then a final power tune was performed, to which it made absolutely dismal results due to problems that I wont go into right now. PM me if you want the full story regarding the first tune.
  4. This is quite a lengthy read, so I have bolded key points if you cant be bothered reading. I have been intentionally scarce on some points because the problem is still under debate. I have recently had a SR20 built by a reputable builder, notable features include forged pistons and rods, sleeved block, Tomei Procams and valve springs, new (non genuine) rocker arms and lifters, etc, a rather comprehensive rebuild. Accessories include Nistune ECU, 740cc injectors, GTX3071r, Z32 afm, the usual. The car had issues with the tune from day 1, never really ran right (stalling on idle, fouling spark plugs..). I drove the car what would be less than 250kms. I noticed towards the end of this time that the car had developed a miss at ~6k, which I had attributed to spark plugs, after having to replace them a few times. Changing the plug gap made the miss better, but still not completely fixed. I took it to a workshop to have the tune fixed up. Upon putting it on the dyno, the tuner said that the ECU was throwing a fault code and reporting a faulty knock sensor. He ran it up on the dyno anyway, trying to tune it despite the fault code. The car kept missing and could not be tuned because of the knock sensor. The tuner told me, drive it home and fix the knock sensor problem and come back. I decided to change workshops since I wasn't happy with the first one (I was recommended two by the engine builder, both of which I had no experience with). I didnt drive the car at all until the time when I took it to go to the other workshop. Upon trying to drive it, the car would miss and struggle to rev above 3k, the worst it has ever been. I called it quits and had it trailered to the workshop. This is the interesting part.. The workshop pulled the rocker cover off and noted a cam lobe had been chewed out, enough to put metal through the engine and do damage to all the bearings, causing the need for a rebuild. It was identified that the knock sensor had physically fallen off of the engine. After this, the workshop pulled the engine out and gave it to the builder for inspection. The builder identified the problem as being due to overfueling; he reasoned that the oil had become so diluted with fuel that a lifter had failed and destroyed the cam. His reasoning was that when the knock sensor failed, the Nistune ECU returned to a limp mode, not being tuned for the 740cc injectors and pumped so much fuel into the head that fuel had leaked down past the piston rings and into the sump, diluting the oil enough to cause a lifter to fail. How likely is the described scenario in causing a cam lobe to be chewed out? Is it more likely than a non genuine lifter failing? Or a faulty cam? Or any other problem during assembly? On a side note, a friend of mine has had the same issue with his SR20 chewing out a cam, after it had been built by the same engine builder with similar specifications. His opinion is that the builder does not bleed the lifters before assembly which may have caused the issue, or that the rocker arms used were known to be defective in the past. Again, this is under investigation at present.
  5. Probably better to be safe than sorry with a fresh motor, rather than just dumping the oil and hoping.
  6. Funny this came up, my car had a pretty similar sound and experience.. I had an engine built, new cams, valve springs, rocker arms, forged pistons and conrods, you name it. I noticed it sounded a bit more rattly than normal after a few hundred kms after the run in tune. Spoke to the engine builder and he said its probably supposed to be like that because of slacker tolerances and forged pistons etc.. Soon after that it developed a miss up top. You could pull out coilpack on cyl 1 and the idle wouldnt change. They were brand new splitfires, tried different brand new splitfires, no difference. Tested spark by cranking the motor with the plug out, grounding on the rocker cover, had spark etc. Took it to a workshop for a tune and to identify the problem, turns out the cam lobe on cylinder one had been chewed out and wasnt opening the inlet cam enough. Motor has to come out, be stripped down and inspected for damage due to metal flakes floating around in my oil for who knows how many kms (the motor having done less than 1500km though..) Good times!
  7. Online stores

    http://www.npcperformance.com.au/
  8. http://ph11ps.blogspot.com/2009/02/s13rps13-5-stud-conversion-and-brake.html
  9. Gauges

    I installed a oil pressure sensor on a brass T piece off the factory oil pressure switch hole in the block, so I would not lose the factory sensor. After a few weeks of driving the weight of the oil pressure sensor snapped the T piece off and I dumped all my oil in seconds, and left a piece of the brass T piece stuck in the hole in the block... I now run the oil pressure sensor hard mounted with ~10cm of braided line to the sensor location to eliminate any stress. Just thought it was worth noting which ever way you go.
  10. Symptoms of blown turbo?

    Did you check vac lines as well as intercooler hoses? Could have blown the vac line off the wastegate that would cause no boost for example..
  11. WTAC - Aussie Driver shout outs + support messages!

    Cant wait to see the quad rotor.. I mean, go Aussies woo!
  12. SR rebuild?

    I have a pretty comprehensive SR build being done by Lewis Engines at the moment, a few weeks off completion. Darren seems to know his shit and should build me a good motor, that said its still early days! He assured me that if I get a tuner recommended by him to tune it he will offer a decent warranty on his work which is always a plus..
  13. If you hadnt worked out flow directions for the stuff yet, note that oil filters flow from the outside in (ie come out the middle hole).
  14. To BOV or not to BOV

    Sorry if its a hijack, but I have noticed when removing/blocking the bov excessive backfire and overfueling. Can anyone confirm if this can be tuned out with a retune? I plan on not running a bov in my new setup cause its just easier than trying to plumb it back in when making up all new ic/intake piping..
  15. Isle of Man TT

    Watching the drivers reactions in the lower corner is pretty spectacular too, very quick reflexes and steering input!
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