VincentHill
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posted December 03, 2006 04:24 PM
The Engine is in the House
It took about 5 hours from start to clean up finish but the engine is now in my basement.
First When I removed the Pipes, #4 was the darkest and had the most oil. 2 & 3 looked good and #1 was also a little wet but I feel it was more from the oil in the airbox coming in on the left side directly into #1 cylinder.
Then I got in into the basement and removed (What remained of ) the SPark Plugs which all had the electrodes burned off.
With the new Bore Scope I looked into the cylinders and 2 & 3 were down so I looked there first. Both were clean and dry and completely in Tact.
I then turned the engine over to look at 1 & 4. Surprise surprise, they were both in tact but the right front side at the edge of #4 piston was burned. About 1/4 inch wide at the widest and about 1.25 inches long. #1 was in tact but more oiled than the others.
WHen I get everything cleaned up and put away I will pull the head and cylinder and really see what I did! At least for now it looks like it could have been a "LOT" worse 
  
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BrooklynNYZX12
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Posts: 520
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posted December 03, 2006 04:39 PM
All spark plugs melted = bad lean condition.Time to rethink that fuel system.The engine is definitely getting nitrous and the ignition is definitely lightin the fire.What does your data logger read?
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shane661
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posted December 03, 2006 05:08 PM
He knows he went lean, 1800 degrees EGT.....those are some tough-ass pistons!!
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VincentHill
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posted December 03, 2006 06:52 PM
AND 18 to 1 A/F to boot! (I turned up the NOS Pressure and FORGOT to up the fuel pressure by 3 PSI! ALL MY FAULT! I hade already made 2 runs and FORGOT TO Arm the NOS System!! 
Agreed Shane!
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BrooklynNYZX12
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posted December 03, 2006 07:00 PM
 Edited By: BrooklynNYZX12 on 3 Dec 2006 19:04
Vince,i'm not clear on something,I know you know the answer :Are the nitrous systems on the bikes designed to operate at around 900 psi like the car systems?A 3 psi loss of fuel pressure should not have caused a severe lean out like you encountered.Do you have a low fuel pressure nitrous cut off switch?I just can't understand how the lean out would be so severe.If it wasn't for the good pistons it would have been really ugly and expensive!
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shiphteey
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posted December 03, 2006 11:00 PM
I may be wrong but I thought I remember VH saying he forgot to actually shoot the additional fuel required to compensate for his nitrous. Essentially he was just running on the amount of fuel required to run the bike, not while spraying.
VH...what do you have up your sleeve for next spring....you know any time one has an opportunity to "repair" something it can be looked at as a time to "mod" it even further!!!
A.
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VincentHill
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posted December 04, 2006 05:46 AM
Brooklyn, I use a Bypass Fuel system tied to the Muzzy Pump that puts out more fuel than I could ever use. The rating on the NOS Systems are listed at either 1050 or 1100 PSI. I use a Wilburn NOS Pressure controller and can run as low as 800 or less PSI even if the Bottle has 1100 PSI. I have flowed the numbers at every 50 PSI Increase in NOS and how much more fuel pressure and after a Frustrating 2 runs and then realizing that I have not turned on the NOS Switch and time had run out, I upped the anty and raised the NOS Pressure but forgot to up the fuel pressure to equal the NOS / Fuel ratio.
I do not use a Fuel pressure switch for 2 reasons. #1, the system uses the main pump and if it stops then the ENgine stops #2, I have one of those switches and they are MORE Problematic than the problem we are trying to avoid!
SHip, WHile out yes More will be done but was in the cards for over a year when I had Robinson Industries make up 6 sets of OD Gears for 5th & 6th. I will finally install them and sent to him for matching and install the ARP Case Studs I have and maybe Notch the cylinder sleeves between 1 & 2 and 3 & 4
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shane661
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posted December 04, 2006 03:10 PM
It seems as though you are saying you damaged your engine because of a 3 psi change in fuel Pressure. How much difference in flow through the fuel jet will 3 psi make?
Why not jet for the max fuel required at maximum bottle pressure, and keep the fuel pressure set at a constant value? Is it going to affect power that much?
I guess I am a little confused, seems complicated.
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BrooklynNYZX12
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Posts: 520
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posted December 04, 2006 03:49 PM
Edited By: BrooklynNYZX12 on 4 Dec 2006 15:50
Shane,you are correct in your post above .Even the old NOS car systems were conservatively jetted.By conservative I mean that their jetting was on the fat side or safe side fuel wise.I'm confused for that same reason I mentioned that in my earlier post.If your nitrous system /fuel system has a severe lean out because of a 3 psi drop in fuel pressure something is seriously seriously wrong.Vince I think you are missing something here.If the fuel pump is running and the line is pressurized what difference can 3 psi make.The jet size should determine the fuel flow not the fuel pressure.I had an old Nitrous Oxide Systems Powershot 125hp system on my 68 Road Runner.It was basically a stock motored car,skinny tires,exhaust manifolds.The fuel system consisted of a mechanical pump for the engine and a shit Holley red pump for the juice.Made a 14 second slug into a 12 second sleeper.Couple of buddies with some good fast nitrous cars that have all used those fuel system psi switches with no problems.Something is amiss in that fuel system Vince,you need to simplify it.
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VincentHill
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posted December 04, 2006 03:56 PM
Edited By: VincentHill on 4 Dec 2006 16:01
Shane that is very easy! 3 psi considering I was using 6 PSI would have not only have added about 50% more fuel but speeded up the delivery time between re-sets (From when I change gears)
Before Wilburn made the Pressure Pro, that is EXACTLY How the NOS Wet system worked. WHen you hit the Button, you have 1100 PSI Bottle pressure and the correct fuel pressure and Max Power from the NOS. (Exactly what you are saying). The problem is, as you spray during the run, the bottle pressure Drops (The longer the time for spraying the larger the drop) because of Emptying the Bottle AND the Chilling of the Bottle from the release of a compressed Liquid. You can start a run at 1100 psi and be making 150 more power and at the end of the run (Where you need the most power) you are making the least power. The power drop off from 1100 to 800 is as much as 50%.
Start out with 150 more power at lower speeds and at Top speed you have 75 HP "PLUS the extra Fuel does not only lose the NOS Power but a RICH ENGINE Loses the Base HP" SO start with 150 ENgine Power and 150 NOS Power and end up with 75 NOS Power and 135 Engine power so at 200 MPH you are now making about 210 HP which my bike will run 199+.
I forgot to mention that a RIch engine also removes the Oil film on the Cylinder walls doing more damage to the engine.
Set the NOS Pressure at 800 to 900 PSI and HAVE1100 PSI Bottle Pressure in the NOS Bottle. The JET the NOS for 150 HP At 800 PSI and Jet the Fuel for this and you make the entire run with 300 HP!! The Jets I was using at 800 PSI at 1100 PSI would make 250 HP.
Knowing that I may need more HP than what I had set the Bike for, I made flow charts to see (BY WEIGHT) how much NOS flowed through the System as run on my bike at 800, 850, 900 and 950 PSI. Then I flowed by the fuel to see by weight what pressure I needed and what jets I needed to have a range of fuel amount to cover these NOS Pressures. You want about 5 to 1 NOS to Gasoline ratio. SO I KNEW I needed to raise the Fuel pressure by 3 psi to cover the additional 50 PSI of NOS Pressure.
SOrt of a Long answer but there is no short cut on how to do this. As you can see, I almost made the entire run because I have everything on the conservative side IF I HAD FOLLOWED MY OWN RULES!
Shane, you like to study and truly investigate everything, Do like I did and go on the internet and find a few books that are dedicated to NOS Systems and study up! They know a lot more than I do!
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shane661
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posted December 04, 2006 04:05 PM
Edited By: shane661 on 4 Dec 2006 16:28
Man, 6 psi seems really low...I thought it would be more than that. If you go from 6 to 12 psi...how much more is that fuel jet going to flow? Aren't the jets designed with a specific fuel pressure range in mind? Basically, what I am saying is that flow through an orifice would not be linear with just a pressure increase, as far as I know. Unless you were way below the jet's rated capacity...then, maybe?
I will do some reading...you know me pretty well. lol
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VincentHill
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Posts: 6520
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posted December 04, 2006 06:16 PM
This is why you need to read! The NX Fuel Pumps and most NOS Fuel Pumps and even the Muzzy Cheater System (Mounted in the AirBox and cannot be seen all use about "4" PSI! 6 PSI Is actually HIGH! The problem is that when you go much over 10 PSI the Jets will not Atomize the Fuel into a Spray and it will stay more Liquid which will not mix as well with the NOS
Remember I "FLOWED" the Different Jets at the different Pressures and measured the results. I do not have the Numbers but the I have the Nos to Fuel Jet Pressures vs the Size. All I know is that the NOS Jet Size I was using at 900 PSI needed 9 PSI Of Fuel!.
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