By any chance did the bottle go empty? That will cause a really rich condition. Don't laugh, I had a buddy chase his tail for two weeks on a bike system. He tried everything until I asked if there was anything in the bottle.
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| Deadly Burnout https://www.slantsix.org/forum/viewtopic.php?t=4497 |
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| Author: | Jason Kobos [ Wed Nov 20, 2002 4:52 pm ] |
| Post subject: | Deadly Burnout |
First of all, this is the best slant six sight bar none. Now, on to my dilema. Last night at the track, I ran into a little problem. Heres my cars Bio. 68' 4 door dart 270 with of course the good ol'slant six. The motor is B&B, 30 over, offy intake, holly 390, 5 way valve job, msd 6A, clifford true dulls, keith Black flat tops, 10.5 to 1 comp. Nos cheater system. 8 3/4 with sure grip and 4.10 gears. M/T 28x9x15 slicks.The tranny is 904 with 3500 stall. Heres what happened. I went to the track with the timing set at 30 degrees for the juice, and decided to run all motor first to get into the 9's in the 1/8th, so I set to timing back to 38 degrees, and ran a 10.19, 10.14, 10.02, and finally a 9.95 at 69mph with a 60' of 2.23. Well I decided to juice it, so I set the timing back to 30 degrees for the 150 shot, went to the line, did the burn out with juice, went to the line and she just died. I pushed her back out and tried to start it. Well, it would only start with the pedal all the way down, and when it finally started it sounded like I put a hole in the number 1 cylinder, there was no power, she would die on her own. There was fuel in the oil or it smelt like it and it was real runny. Not milky, but runny. So today, I pulled the head and there doesn't appear to be anything wrong with it, or the number 1 piston. Any suggestions or advice. I think I may have gotten ahead of my self by pulling the head before checking the wire, but I had a good time doing it. Thanks in advance for any guidance. |
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| Author: | bud L. [ Wed Nov 20, 2002 5:20 pm ] |
| Post subject: | just guessing |
Boy, what I know about NOS could be put in a thimble with room left over. It sounds like you have seriously flooded the motor. Stuck float? Stuck fuel solenoid? |
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| Author: | Doc [ Wed Nov 20, 2002 5:23 pm ] |
| Post subject: | What did the spark plugs look like? |
NOS is a "balancing act" to get the jet size, fuel pressure and timing advance all worked -out for max performance without burning stuff up. The fuel octane is also an important factor to this formula. In general, I was a little concerned about the 38 degrees of total advance, most Slants run better with less total, 30-34 degrees on the motor. I have been working with a NOS system and always pull the sparkplugs after a "test shot" just because the electrodes can tell you a lot. Were any of the electrodes burned-off on your plugs? I just "melted" a engine with NOS a couple of weeks back. (See "Doc's 68 Cuda Dragcar" in the Virtual Dragstrip) Just to give you an idea, I ran a 80 HP shot with 26 degrees timing with no problems. (91 octane fuel) went to a 120 HP shot and still OK with 26 degrees total. Advanced the timing to 29 and everything burned-up! I worked with a plate system a while back that would only take 27 degrees total before burning plugs. In you case, put it back together, turn the timing back more and try some colder spark plugs. What are other NOS users running for total advance? DD |
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| Author: | Jason Kobos [ Wed Nov 20, 2002 5:49 pm ] |
| Post subject: | Deadly Burnout cont. |
Thanks guys for the timely responses. I had the fuel presssure from the holly blue pump set at 5 psi through the regulator. I was running 110 race gas for extra safety. The reason I had the car set at 38 degrees was because I wanted to get into the nines and I ran the 10.14 at 36.5 degrees, and the 10.02 at 37.5,so I figured a little more wouldn't hurt, and I ended up running the 9.95 with a tad over 38. That was the all motor runs. Hey Doc, I ran the car at 30 degrees and only cut a 10.19. So since I was going to run the 150 shot from the cheater plate system I figured I would go back to 30 degrees(2degrees for every 50hp+1 degree for extra precaution). The regulator was still set at 5 psi. I kept the same plugs in because I had two slightly illegal street runs on the bottle and the plugs had no pitting, and they were slightly gray. So I figured they would be fine. |
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| Author: | Doctor Dodge [ Wed Nov 20, 2002 8:02 pm ] |
| Post subject: | Seems OK |
Sounds like you have everything right. My guess is that the 110 fuel and the 1/8 mile allows you to run more advance. (I run on the 1/4 and have the car geared to run to redline at the finish. That makes for a long "pull" in 3rd gear aand less total gets a better MPH) I would put it back together and try it again. This time make sure the ignition system is real strong, a big shot needs a strong spark. DD |
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| Author: | slantzilla [ Wed Nov 20, 2002 8:52 pm ] |
| Post subject: | |
By any chance did the bottle go empty? That will cause a really rich condition. Don't laugh, I had a buddy chase his tail for two weeks on a bike system. He tried everything until I asked if there was anything in the bottle.
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| Author: | Will [ Wed Nov 20, 2002 10:10 pm ] |
| Post subject: | |
I agree with Doug-I run 30 deg. on the motor and i pull the timing back 16 deg. on a shot no where near that big. Will |
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| Author: | bud L. [ Wed Nov 20, 2002 11:30 pm ] |
| Post subject: | Ps |
Just another thought: When you came out of the burnout did you have to climb on the brakes pretty hard? Maybe you had some severe fuel sloshing going on. |
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| Author: | Jason Kobos [ Wed Nov 20, 2002 11:36 pm ] |
| Post subject: | Deadly Burnout 3 |
I talked it over with a friend, and with the input from bud L. I believe I might have found the problem, and I wanted to know what you guys thought about my reasoning. If the fuel solenoid was stuck open, wouldn't that cause the motor to run so rich that it wouldn't stay running, and maybe even cause fuel to find it's way into the oil pan past the rings. Just a thought, I will hook up the fuel lines again tomorrow and disconnect the line from the fuel solenoid to the plate and turn on the fuel pump, and hopefully that will tell me what's going on. If that is the problem, would it cause the number 1 cylinder to not fire? So, far I have done every bit of work to this car myself and now I need the help, obviously with the tuning. I just don't have the experience yet to know exactly what to do, and I knew that this was the place to turn to. Again guys, thanks for all the help. Oh, the nitrous bottle had only two short bursts out of it. So I am pretty sure it still had enough available. However since it was a little chilly, and I don't have the warmer yet, my bottle pressure was only 700 psi. Also doc, on the 1/8th, I'm at about 5600 rpm in second right at the finish line. Also, where would you guys recommend getting a set of 30 over forged pistons for my 225? I have full intentions of spraying this beast with a 210 shot by the time it's all said and done. Thanks, Jason. |
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| Author: | Jason Kobos [ Wed Nov 20, 2002 11:39 pm ] |
| Post subject: | Deadly Burnout 4 |
Yea bud, I had to get on the brakes pretty hard, but after atleast an hour it still wouldn't run right. I didn't try once I got home, because not knowing what was going on inside the motor, I didn't want to cause any more possible harm. Especially since I thought I had a hole in one piston. |
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| Author: | rustycowl [ Thu Nov 21, 2002 9:04 am ] |
| Post subject: | plugs, too! |
I've been told by some old salts(racers, too), that once you flood an engine good, the spark plugs are never the same. |
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| Author: | Charrlie_S [ Thu Nov 21, 2002 9:05 am ] |
| Post subject: | |
I'm running 26 degrees total timing, and 114 oct fuel. Also coldest ngk non extended nose sparkplug, 6.5 psi fuel pressure, with 950-1000 bottle pressure. |
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| Author: | Doc [ Thu Nov 21, 2002 12:33 pm ] |
| Post subject: | More NOS... |
It sure does sound like you flooded the engine and "washed-out" the plugs. Let us know what you find-out when you test for a sticking fuel solanoid, that would explain it. I know that my fogger set-up will kill the engine instantly if you activate the fuel side of the system without any NOS. As for cylinder #1 flooding first, look at the angle of the intake, if the nose of the car is down, forward is where raw fuel will go. (if you cram-on the brakes, that will also move fuel forward in the intake) DD |
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| Author: | bud L. [ Thu Nov 21, 2002 3:00 pm ] |
| Post subject: | sounds good |
Bingo! Good point, Doc! Sounds like we got it solved, on paper anyway. One other thought, is that purging of the nitrous lines, that you see drivers do, to burp any voids in the nitrous lines? You know, so you don't accidentally get a bunch of fuel and not enough nitrous to help burn it? |
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| Author: | Jason Kobos [ Fri Nov 22, 2002 4:29 pm ] |
| Post subject: | Deadly Burnout 5 |
Hey guys, thank you for all the help. I found out what the problem was. I hooked the fuel lines back up, and disconnected the fuel line from the fuel solenoid to the plant and started the pump, and sure enough the fuel solenoid is stuck open. So, that should solve the problem. However on a brighter note I think I just hit a pot of gold tonight at the machine shop. Let me do some research on this here web site and some book work, and I will let you guys know what I found out. I think this new slant six racer just might have a little something worth trying out. Again, thanks everybody. Jason. |
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