NITROUS OXIDE ( nos / n2o ) advice forum

I cant do extra studs. But O ring in the head should not be a problem.
I will look into that .
The bottom end is said to be worth 60 hp a rod in stock form. Part of the reason I am using this engine/bike is the fun involved in making a slow bike fast.
Before my problems with the nitrous system. My engine made about 90 passes at Maxton and dozens of 1/4 mile passes plus hours on the dyno. No problems. I am sure the system was going lean and there was nothing I could do about it. I am sure when this engine gets a proper load of power it will make us proud.

I cant wait to run this thing.

My. Controller and pulsoid arrived today. I will be building up soon

I have my old system in a box but have not had a chance to go to the post. I will send it out Monday.

I will gather up my piston collection and burned valves. Then take some photos

Excellent on all counts.

This is the pistons set from September 2010. I made 3 passes over 120mph.And three passes spraying longer each time. Going from 1/8 mile from the finish to 1/2 mile from the finish line. The clutch was slipping I think.

I would hit 122 then 121 then 122 for about half a mile holding the button. I did check the plugs between runs and at that time the system seemed to be working, Until I changed the timing settings, I went from 35 deg to 37 deg and changed gears. I should not have advanced the timing a couple deg. I don't know what I was thinking any way it let go and this is what I found. The valve burned and a hole in the piston and the bottom of the other piston was black. I did catch some date. and it looked like I was at rich at first then it was going leaner. I want to say 10 to 12 to 1 A/F but I could be mistaken.






This piston was from April of 2011. I spent all winter getting ready.The timing was at 33 deg and. I had 110 octane fuel.I dropped the compression from 13.5 to 1 down to 12.5 to 1. I test things as well as I could. on motor the engine had great power on the dyno.

When I got to Maxton The bike felt bad on the first pass going 113mph. I could feel it nose over. I had to get off the button early and coast through the trap.

The next pass I sprayed from about a 1/4 mile from the finish.The gearing I use for nitrous holds the RPM at just under 12000 rpm. I held the button and the bike surged to 12480rpm and hit the trap at 119mph and then it nosed over and shut off . This time the piston was not black underneath.But the blown hole tells the tail. That was it for the weekend.

Well there's no doubt the first failure was aggravated by the advancing of the timing.

Both failures are due to detonation but the 2nd failure is also mixture related.

Do you shut off the ignition instantly you go through the traps and then pull the plugs for inspection, before riding back?

If so, on the run where it nosed over, did you check the plugs and if so how did they look?

What brand & grade of plugs were you using?

I used to pit at the finish line so I could get the engine off as quick as possible.The trans is lubricated by the oil pressure from the engine. I had a problem when I shut off the engine on the dyno and the trans locked up. SO I don't shut the engine off till I am stopped.

When I have a nose over one of the plug tips is GONE. the other is white . Can be either side .BUt I was blowing the right piston on a regular basis.

I use NGK plugs. CR10E and the iridium CRI10e and I have reduced the gap from .028 to .019 and removed the tip and bent the ground electrode over to make about .020.

Detonation or preignition . I believe what is happening is the mixture is lean OR just to much nitrous. But the plug tip start to glow setting off the mixture long before the spark.

Every thought of adding an AFR monitor?

Data collection is critical to land speed racing. There are so many factors that go into a good run. Anything that can be recorded is good.
Both Dr J and I have been disappointed with the data loggers we have. They tend to shut off and not save the recorded data. Very annoying.
I have a fancy clock setup with Top speed and RPM plus top oil and water temp also I have dual EGT sensors that record the temp and RPM .
I also have the ability to measure 0-60 time.but A/F the thing I need most has not worked out.
One the next order I will be getting the Dynojet wideband sensor 2 from you.

By two much Nitrous I meant the whole mixture.
Help me under stand this. IF I had X amount of nitrous and gasoline that made 25 hp for a 250cc engine. What would happen to the mixture if the same amount was fed into a 500 cc engine?

Follow this link. It was my attempt to test this system and control detonation .

I used fuel volume measured with a graduated funnel. and bottle weight.

If you skip to the end you will see the weights and ratio I had going into September with no real change in performance.

Also you can see how I tested the system with the videos. Get a coffee it is four pages. I did a lot to over come the symptom. NOW I am addressing the problem.

http://www.landracing.com/forum/index.p ... pic=9794.0

Blasted through that and have the following comments to make;

1) If you are suffering det (or similar) problems without nitrous, that needs sorting BEFORE you run nitrous.

2) The first thing I would do is work out what the ignition map ACTAULLY is over the entire RPM range.

3) I'm pleased to see you have an AFR set up, so that can be connected to the Max to benefit from the closed loop AFR feature.

4) Although this is unlikely to be the case (as the uneven nature of the fuel & nitrous delivery is almost certainly the primary cause), it is possible for a cylinder to RUN LEAN when it is fed with too much fuel, so running overly rich is not a guarantee that you won't suffer from the effects of lean conditions.

I have the detonation problem under control. I was running to much timing at the lower RPM . I changed the timing settings and have not had any detonation rattle as I dump the clutch in first gear. That was the only time I had a problem. Staying under 35 deg and 110 fuel and it seems good.
But now I have bigger pistons and lower compression. So I will have to do a couple things before testing with nitrous. First I have to break in the engine on the dyno. Then in late March Early April I will go to the drag strip and make a couple passes . This is test and tune time. I get as many passes as I want for 20 dollars. I test the whole thing. Except the nitrous.If I have any detonation it will be sorted there.

Just some photos of the bike so far. I have the controller mounted under the seat. I can lift the seat with no tools to look at or adjust the controller.

I have the fuel pulsoids mounted behind the engine facing the carbs. I got them at a slight angle so the lines will have minimum bends to the injectors.

The bike is about two weeks from the dyno. Then I will order the Dynojet O2 controller and some more parts.

Great progress Eric and looking very good.

I thought you already had an O2 sensing system of some other brand?

Your Boss NOS kit arrived today and I'll start another thread on my observations & findings, to avoid it taking this thread off topic and so everyone can learn from it.

I have the LM2 from Innovate. It has a lot of features I don't need.Plus it turns its self off if it is subjected to any vibration. Like the vibration from an internal combustion engine. I guess it is meant to sit inside a car. Not mounted to a motorcycle. Even on foam rubber the unit turns off .
So I need something that works.

Mmmm - TOTALLY UNSUITABLE in that case then.

You'll be interested in this thread Eric;

viewtopic.php?f=6&t=6427

What about the aem uego unit its what I have and it seems really good and consistant

Is there a way to use two O2 sensors? I am thinking of changing to a dual exhaust system.

I have the Max Controller mounted and most of the wiring sorted. The bike IS ready to start fitting the nitrous parts very soon. I am going on the dyno to break in the new 265cc engine in a week or so.

Not that I'm aware of, so the best you can do is switch between 2 sensors and determine which one (if either when using our system), runs leaner than the other and then just use that one.

Glad to hear you're making progress.

I would rather have the over all ratio in the V2 controller.Then do plug chop after each run to evaluate each cylinder. The dual exhaust will not make that much more power than what I have. I have dual egt sensors so maybe all that will give me enough data.

I was thinking about the nitrous plumbing.
I will have two 20 oz bottles. On the right side I will have the pressure transducer and the bottle heater running through the V2 controller via a relay. Then a hose over to the left side bottle that will have a gauge and the hose going to the pulsoid. Is this the correct set up? Or would both bottles go to a Y connector and then to the pulosid?

The exhaust I have is definitly open . But the noise is unbearable. At about 130 db at anything above idle and ear splitting at 13000 rpm. I need some baffling but the pipes are long and I was thinking about scavaging .


Two heaters is not a problem. I did not think I would use a whole bottle on a run. I thought I would drain the cooler bottle . And the warm bottle would act as a pusher.

I understand now.
That is where your experience pays off. Do I still need a gauge or will the transducer give me accurate pressure readings at the controller?