Well the motor blew up tonight...

Discussion in 'SN95 4.6 Talk' started by SHOWTIME!!, Feb 5, 2009.

  1. bhuff30 Founding Member

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    The engine clearly failed because it went lean. I know it went lean because that is the only way you melt the top of a plug. Even if it has a lot of miles, you can NOT blame this failure on age or weak parts. It went very lean and that probably burnt the piston and the top ring.

    Showtime, did you have a WOT switch?

    I have sprayed after the throttle body before, into the upper plenum. I spray a 75 shot into my N/A 2.3 like that with no problems. If you are spraying into the throttle body, long as the throttle blade can still move as normal, it shouldn't be an issue.

    I still blame this on fuel supply and very possibly the fuel pump. While many can have have successfully run 100 shot on similar combinations, every car is different.

    The SVT focus fuel pump has a much higher flow rate than your stocker, and for a lot of people, it is only good for around 400hp. So if the SVT pump is good for around 400hp, how will the stocker flow? I'd say 300rwhp is the upper limit. There are a lot of factors that effect when the fuel pump can't keep up... base fuel pressure, boost pressure, fuel filter condition, debris in the tank, ect, ect. My point is, even if the stock pump *might* be able to keep up, it is too expensive to risk it. It is so easy to change out the fuel pump that is should be the first thing you do when you add a power adder!! Weather or not insufficient fuel pump caused the failure, it is not a good idea to rely on the stock pump for these power levels.

    As for lessons learned... always start at lower hp pills and work your way up and monitor the AF ratio.
  2. Gearbanger 101 That's my secret, Captain. I'm always angry!!!

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    Not necessarily. Excessive timing will melt a spark plug electrode and ground strap in a hurry as well. I know....I've done it. :(
  3. BurningRubber Active Member

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    My $ is on detonation and a blown out rings and/or a broken ringland. Something came loose and destroyed the spark plug.

    JMO. A 100 shot isnt moving THAT much fuel, especially since it's just coming from the fuel rails and the extra demand isn't that as a dry shot would be.
  4. Nitrous03GT New Member

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    we shall agree to disagree, by your theory i should have blown my engine 99 bottles ago when i put nearly 100 extra hp strain on the fuel pump.... its easy to say fuel pumps are "rated" to a certain HP, but thats not necessarily the way it works, they are based on flow #'s. a small 100shot isnt adding so much fuel that it overloads the pump can definitely say that i haven't met someone who went lean on a 100shot because of the fuel pump in our cars.


    i'm interested in knowing exactly what plugs you had in there as well, running stock heat range plugs or even hotter plat plugs can certainly be the root of your problems.
  5. 04GTMustang New Member

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    dang man thats insane. everytime i read these i feel like i cheated death of my motor. spraying a 150 shot all the time then pushing it to a 200 shot on a stock motor. keep us posted.
  6. Nitrous03GT New Member

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    you know, i just though of something else, take some of the lines off and see if he used teflon tape to seal any of the fittings...its a BIG no no, should always use paste. the tape can break off and clog lines or jetting causing boom boom.
  7. SHOWTIME!! New Member

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    the plugs i were using were a step hotter than stock. They were NGK platinums. The car/motor had 130k miles on it. I might have found a motor tho, just can't decide on what to do. If i want to put a used motor in it and trade it in on a 09/10 mustang GT or build the **** out of my motor.
  8. bhuff30 Founding Member

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    Next time, you may want to read the owners manual for the nitrous kit. It will tell you to use plugs COLDER than stock and to slowly step up on the nitrous sizes. So were you even running premium gas?
  9. BurningRubber Active Member

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    Nitrous plugs are supposed to be a step colder, and copper.

    I can't remember if it is platinum, or irridium, but one of those types of plugs you CANNOT run with nitrous because of a negative chemical reaction between the two.
  10. SHOWTIME!! New Member

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    yep running premium gas. I knew to put colder plugs in it, but the guy that put the nitrous kit on said "hey man it wont hurt to go make 2 pulls on the car with these plugs" so i believed him. I just can't decide what to do. Build the motor and spend 3k+ or put a junk yard motor in it and just trade it in on a brand new mustang. WHAT SHOULD I DO??????
  11. eliteJAE Member

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    dood, explain to me how that guy wasn't liable for some of this? lol

    sounds like he didn't know what he was doing and it led to your car blowing up :notnice:
  12. Flghtmstr1 Member

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    +1
  13. CENTENNIALSTANG New Member

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    I think its irridium, back in my NO2 days I used NGK TR6 plugs. I also ran 93 octane.
  14. Nitrous03GT New Member

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    yea step hotter plugs are a no no. i would sue this shop for damages. guy sounds like he has no clue
  15. 98COBRA281 Active Member

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    sounds like he just wanted to ride in the car when he sprayed it....
  16. bhuff30 Founding Member

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    In my opinion, you should get a junk yard motor and KEEP the car. You can get one with reasonably low miles for pretty cheap, and in truth, if you do everything correctly it will hold 400-450rwhp. No matter what, that's a lot of power and will get the lighter GT moving quickly. Why put a bunch of money into a car just to sell it? Also, why put a bunch of uneeded money in the car to make 500+hp when you won't make anywhere near that power level for a while. It isn't so easy as bolting on parts to make 500+rwhp. You already invested a lot of time and money into the car. Don't take that as a loss too, but learn from your experience. Follow the instructions and always have it tuned before driving it hard if you don't know how to tune it.


  17. Mike97gt it doe snot

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    You guys are right that he should not have had him run the car with those plugs..

    The plugs on these cars are so easy to do there is no excuse for running it with the wrong plugs even just to test..


    NOW about suing him

    No chance in hell.. The guy will just lie and say he warned you.. plus they are going to have very little sympathy in court for your nitrous test runs on public roads.
  18. eliteJAE Member

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    i wasn't thinking lawsuit, i was thinking maybe the shop would own up to it or at least part of it on behalf of their employee :shrug:

    same thing happened to me with a burnt headgasket. the car lot said they checked everything out, everything was fine, they replaced the t-stat etc. Car spews coolant about 50 miles later, i check the t-stat myself its the stock one, nothing was done to the car. Bust in the managers door next day, and they pay for half the repair bill for the head gasket change :shrug: maybe i got lucky.

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