What's needed for nitrous?

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340Duster247

340Duster247

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Hey guys, I know how nitrous works but I dont know what needs to be done to a engine before you should start using it. I'm talking about a plate system.

Or how high of a shot can you go before you need certain work done.

I've never used it before so just curious
Thanks guys!!
 
Who's the victim? Give us the details,we can help you keep you happy,and your engine alive.
 
Trolling, nice . Give a honest combination, go from there.
 
Rich is BAD, regardless of what anyone says... Just like anything, it's in the tune up!

good fuel pressure/volume, pull timing, change fuel jet to get max MPH, feed timing back in until it slows down...

Most older kits are PIG FAT with stock jetting. Newer kits are better. I start with a 8-10s step smaller fuel jet than n2o jet.
 
Hey guys, I know how nitrous works but I dont know what needs to be done to a engine before you should start using it. I'm talking about a plate system.
Buy and install it. You need to have good working and well tuned fuel and ignition systems. You may need to modify the ignition set up for whatever you buy - so consult the manufacturer.


Or how high of a shot can you go before you need certain work done.

All depends on the engine and the fuel and ignition systems. My own rule is over 175hp potential should have a dedicated fuel system, internal mods, and aftermarket ignition.
 
I know a lot of folks will tell you that you can get away with stock this, and stock that...but since you asked what you SHOULD do, here you go. Most of this is from my previous 360 nitrous motor build that I ran nitrous on every pass for 7+ years.

If you are spraying under 150 hp you can get away with a lot of stuff, over 150 you can't (in general). This is what I did for a 180 shot:

Get a high powered ignition system (mine is all MSD, distributor, coil, ignition box).
Cold plugs (NGK A5671-9).
Make sure you have plenty of fuel (i.e. electric fuel pump with decent size fuel line). Fuel pressure gauge is a MUST (I set mine at 6 psi, manufacturer says 5psi). You should also mix in some high octane race gas at this level to help prevent detonation.
Retard the timing (mine was set at 27° for a 180 shot).
Forged pistons with the rings gapped a little loose for a nitrous motor (mine was 0.020 and 0.024 if I recall correctly, but this could be different for different types of pistons and bore size).
Good rods and aftermarket rod bolts (like ARP).

If you want to bracket race and be consistent, you will need the following:
Bottle heater.
Purge valve.
N2O pressure gauge so you can keep the pressure the same at the beginning of each run. I always started the run @ 950psi.

Always start small, once you get the bugs worked out of the system you can start turning it up....and keep a close eye on your plugs. They can usually tell you when you have a problem before things get expensive to fix.

For what its worth, my old 360 motor (in Colorado) ran 13.8 @ 101 on the motor and 11.1 @ 122 with a 180 shot.
 
Wow!! Thanks for all the input guys. Thinking of a 100 shot.
My engine is still at machine shop here's her details:
340 .40 over
Hyperutechtic pistons
J heads ported
ARP hardware
Edelbrock airgap
Comp mother thumper cam
Holley 750
Msd 6AL 2

Thanks again guys.
 
Make DARN SURE they gap the rings per KB's specs for nitrous use!

They aren't gapped the same as regular pistons, much bigger gaps.
 
With a 100 shot...
Like Crackedback said, gap the rings accordingly (and yes, KB's hypers need a MUCH bigger gap than forged pistons).
Pull ~4 degrees timing, NGK A5671-7's or -8's spark plugs should be ok.
Holley blue pump (or simialr) with at least 3/8ths fuel line, should be good to go.

Have fun.:smile:
 
Back in the '80's when I played with NOS it was nary a worry to throw a 100-150 shot on a factory cast piston motor. Biggest worry (and still is) is to make sure your fuel solenoid opened when it should.

Like others have already said, beyond that your internals should be built accordingly and follow the ring gap factor outlined by KB for those hypers.
 
Ok thanks I already have upgraded fuel line. Still would like to upgrade the pump of course.
About the piston gap :s I'm not sure if my engine builder has already finished putting the pistons in. I haven't checked in with him for a couple weeks now and I just got the impulse for nitrous the other night.
That's why I started this thread, curious about what procedures are needed.
If he is already got the pistons in, is nitrous now out the window?
 
The KB top ring gap on a 4.080 for regular use is about .027 and with n2o is about .033

A little more gap is not a bad thing.

150 would be considered a mild n2o tune up and not hard core drag race in most people minds.
 
So if my engine builder has gapped mine to the regular .027, I should be ok with a mild 100 shot.??
 
No - you should have him re-gap the rings. It's not a big deal for him to do and you want to be on the wider side -not tighter side.
 
So I've spoken with my engine builder and he is setting my Keith black hyper pistons for a 100shot.
I'm going to be using a window switch and a fuel pressure safety switch.
Now on to the fuel question.
I have a Mechanical carter fuel pump. With upgraded 3/8 fuel line.
Will this be enough pump for my set up.
 
It should. You should have a decent fuel gage in line witht he plate system, but those systems run on low pressures. Again - talk to the manufacturer but for the most part I ran mine 100-175 shots at 4.5 psi. that mechanical pump should be pushing 5.5-6psi so you also need a regulator on the plate side.
 
For safety I'm going to be using a window switch. And a fuel pressure safety switch.
And since I've already bought a msd 6al2 I'm going to get a retard box to activate when nitrous is hit.

Moper how much did you retard your timing??
I've read 2 degrees for every 50hp?
 
I use 1.5-2° for every 50hp figure. If your base tune up is good and you have no issues with pinging or detonation naturally aspirated - make sure you're running high test fuel, make sure the plugs' heat range is a couple numbers cooler than what you normally run, and make sure the fuel pressure is right. Nowadays I prefer a controller to do the ignition adjustment work when the system is activated rather than dialing a basic tune figure back on a car that I drive all the time. I dont like making the engine feel lazy 98% of the time and getting worse fuel mileage for the sake of that 2%.
 
Once again thanks a lot guys. This is great stuff

Moper. What controller for the ignition are you using when ur nitrous is activated.
(Retard box?)
 
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