Hey guys,

I ran the car at PINKs this weekend and am fighting some gremlins. Some basic symptoms: The car is hard to start, no change in ET after adding about 30hp additional nitrous.

1st run: Friday. Hit the rev limiter in both shifts(driver error). Car popped and sputtered in all gears, most noticeable in the top of 3rd. Plugs look clean, no smell of fuel, not hot, just normal.

65n52f
27TDC
1.579
4.576
7.099
97.2
9.285
11.15

2nd run: Saturday morning, better air. The tank was full of 110 Hot Rod fuel, and the engine is only 10.5:1 compression so I decided to add some timing. All of the popping and sputtering was gone. The car ran smooth through all gears, but ran slower. Plugs still look perfect.

65n52f
34TDC
1.598
4.623
7.166
96.46
9.370
11.256
119.57

Final Run: I have to check the notes that I left in the trailer, but I'm pretty sure I bumped the Nitous jets to 71n59F. Changed to a fresh bottle. The car still ran smooth, no wierd sounds, plugs look good, no real change in ET.

71n59f
34TDC
1.63
4.619
7.135
97.33
9.337
11.241
118.17

440, Eddy performers, .590, bla bla bla I've posted the combo before and I think it's pretty common with a lot of you guys.

I'm questioning the timing mark on my timing chain cover because of the hard starts and popping on the first run. I'm pretty sure I checked it when I degreed the cam, but that was a long time ago. Possibly the old Mallory Uni-light distributor, nitrous solenoid, pinched nitrous line, etc...???

Had a blast! It's good to finally move from spectator to participant. My wife and I got the hang of setting up the pits, parking a trailer, etc... Everyone at the track that we met was really nice and helpful. In general it was an awesome weekend, but I just really wanted to run a 10.

Thanks again!!!

IF my memory serves me correct 71n/59f jetting is around 200 hp , what is the total timing on motor? , 34 degrees total spark lead @ 10.1 cr seems a hell of a lot of advance when on the bottle , maybe post a pic of those plugs , did you drive back to the pits with those plugs? , heat range? what fuel pressure/bottle pressure are you running? , without this info it's a crap shoot , i'd say the motor slowed down due to detonation.

About the only other answer you'll get here will be give Monte Smith a call.

If you need any help give Steve Johnson a call.

Induction Solutions-815-341-8853

fuel is 110 octane. I drove back to the pits, but we pitted right by the return road. I'll pull the plugs and post some pics. Fuel pressure is 7.0 psi on a dedicated system; dead head holley regulator and Edelbrock pump.

73n is 180hp according to the manual for my Cheater kit. Monte posted the 65n52f as a 125 shot, which made me think that the book is a little optimistic.

Just remember to cut the threads off those plugs so these guys can see the fuel ring.

Who's plate is this?......i just set fuel pressure @ 5.5psi & tweek jet spread/timing till plugs look good , don't be too concerned if the jetting ends up squared , unlikely although some motors just want what they want.

Hope you make the 10s with that new line.

Always good to weigh bottles before & after a run , problems like this would be picked up fairly quickly............the cheater nitrous solinoid in that kit has an orifice size of around .91 so you should be good up to a .90 jet.............while you're at it check seating on nitrous solinoid plunger , these go bad sometimes & restrict flow.

check the fitting going to the nitrous selinoid it has a screen filter in it, Rickey

Looking at the 1/8 mph numbers, they were all virtually the same, so the power level never increased. The 330 numbers were all over the place and this is where the differences in ET likely showed up.

Usually when you make a change and the mph does not increase, you are not getting the extra nitrous, or you are blowing through the converter.

It would seem you found the issue, with a kinked line. Going back to square one, is a good idea. When you make timing changes, I suggest a little more discretion. A 5-6 degree move is a ton. You need to be moving in the 1-2 degree range at the most.

Keep an eye on the bottle and keep it in the 950psi range. Also be a good idea to weigh it after every run and see how much you use. After it gets half empty, performance will fall off, due to dropping bottle pressure. Better to have 2 or 3 bottles with you for a track day.

Monte

Waht kind of balancer do you have? If you detonate it with a pressed ring type (stock or a P type), the outer ring will move relative to the hub in a heartbeat.

I have a couple ideas but some have been covered. The filter and the line have been covered so I will go to the others. I would run a return style fuel system and Mallory has a wonderful 3 port return style regulator that works outstanding. Next I would get an ignition box that has a highspeed retard in it. The reason I use these type boxes is when you hit the nitrous the box can retard your timing at the same time, when you let off the nitrous the timing returns to let the motor run without nitrous at its optimum. All you have to do is wire the box and the nitrous system together and wala! I noticed your 60' times kept falling so it might be a slight traction problem as well. The converter might be going away, if it is not a strong converter it will start bending fins and start making less torque to the wheels. I have run nitrous Mopars since Marvin Miller was the secret system.

Balancer is an SFI Summit type. It doesn't appear that there was much if any denotation. The plugs look clean and I'm very familiar with what this engine sounds like with denotation (don't ask).

Plans so far:

Change N2O line.
Inspect N2O screen at the solenoid.
Inspect the N2O solenoid plunger.
Attempt to fab up a piston stop and verify the timing mark on the balancer and timing chain cover.
Set the timing back to 27.
Set the tune back to the 65n52F shot.
Go back to the track and give it hell!