stressfulcar

I'm getting ready to order a NOS "Big Shot" kit for my bbc.I have the engine running on an A1000 pump,but I'm going to run an aditional stand alone pump and reg (holley blue) just for the n20 kit. I'm not shure which size line to run,6 or 8an? I know the ports on the pump are 3/8" npt,but the adapters are available in 6 or 8an. I would rather run the 6an for weight and size reasons,but dont want to starve the system of fuel.Btw I plan to spray 300-400 shot with this kit once dialing it in.

DeltaT

iTrader: (5)

I wouldn't run a deadhead regulator with that big a system. I would go to a return-type regulator and run a -8 line up and a -6 line back. The 3/8" ports are the same ID as a -6 line, but having the extra volume of fuel available can be useful on a drag car since the fuel column is forced rearwards under heavy accel.

The reason I'd run with a return regulator is to allow that pump to run flat-out every time you turn it on, basically to present the fuel solenoid with as much gas as it wants to grab out of the line. I'd also try to mount the regulator as close to the fuel solenoid as possible, and run a -8 from the regulator to the solenoid for the same reason.

Finally as a safety, I'd put a fuel pressure cutoff switch right at the fuel solenoid and wire it so that if fuel pressure drops below like 4psi it cuts off the nitrous. You can also run an oil pressure cutoff switch that does the same thing to the entire nitrous and fuel system, so that if your oil pressure drops below like 20psi (you can get them so they are adjustable or fixed), it shuts off the entire system. Could save your motor if something goes wrong.

Sounds like fun!

Jim

My Site: http://home.mindspring.com/~jim_fisk/id1.html

Shawn @ VA Speed

iTrader: (3)

I wouldnt trust my engine to a holley blue pump-seen to many of them go bad,
buy a decent pump.I used to run a bg 200 pump for my big shot plate.ran a -6 line to a bg 2 port regulator.never had any issues with it in 4 years of running it.Went 8.20's on a sbc in a 3300lb car.The -6 line will flow enough fuel for 700hp way more than the big shot plate will flow.

stressfulcar

Thanks guys.I do like the idea of a return style reg,I have that settup on my a1000.I would have liked to have just tied into that system but I don't trust that it would be able to keep up.I will look into some other pumps and regs,I was already thinking about possible pressure loss at the tree when initialy activated with a "dead head" type system

DeltaT

iTrader: (5)

I've put almost 100K miles on Holley Blue pumps and had them wear out but never just plain fail. 50K miles is where they seem to start struggling. They are inexpensive and come with that regulator you can sell for $20 easy. I wouldn't have any problems trusting one, but for racing I'd probably replace it every second season just to be safe.

Jim

Shawn @ VA Speed

iTrader: (3)

well i have customers bringing in failed ones all the time-probably see 20-30 a year.i say buy i good one and be done with it-extra couple hundred on a good fuel pump could save you thousands on an engine

mrdragster1970

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BBC with big shot plate. I used a -6 fuel line.

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stressfulcar

Thanks for all the help guys. I just ordered everything i think i will need. I took some of your advice about the pump and reg,but still went with a non-return style because of the added line and need for a y-block on the cell since that port is in use already. I went with an aeromotive pump and reg since i've had good luck with their products. #11203 pump and #13205 reg. I did order a fuel press safety switch though for a little insurance just in caseBtw i went with the -6 line. Thanks again guys,this bbc w/dominator is a lot different than the old FI 383 LT1 w/TNT kit I used to have in the car