Will my motor hande a 100 shot of NOS?

79PACER · 02-28-2006

I'm finishing up a build up for my 79 Mustang and like everyone else, I want more power. I'm reviewed all the threads about NOS and can't find one that discusses compression and which is safe. I'm running a "questimated" 9.6.1. Does anyone have experience running a 100 shot on this compression ratio?

If you think it'll handle more than a 100 shot, please tell me. I've alse heard of people blowing motors due to excessive use. What is considered excessive use?

My set up: 306, TF TW heads, TF 1.6 rockers, Summit rebuild kit, stock crank, stock rods, Holly 600cfm Carb, EDL Performer Intake Manifold.

BlueStreak03 · 02-28-2006

If you're not sure, the best thing would be to start small and work your way up on it. I would definitely NOT put N2O on a brand new engine that has not been broken in. Once it's broken in, try starting with a 50 shot and see how it does with that. Gradually jet it up to where you want it and make sure you rejet the carb as needed to make sure you keep enough fuel in the mix with larger shots.

dollarbill · 02-28-2006

Also I believe you should retard the timing 2-3 degrees for every 100 horse shot you use. I also agree with starting small and working your up.

psfracer · 02-28-2006

I agree with everything previously stated, just don't forget about colder plugs too. With proper timing and colder plugs, and a good fuel supply, a stock V8 should be able to handle 100hp no problem, run after run. I have been running the 100hp on a stock 4.6L 3v since August with more runs then I can count. Only recently started experiencing fuel problems with the 125.

Too bad you are finishing the buildup....you could have put in some good pistons and rods and gone with a 150 shot.

And a final note....on my 67 I used to drag race in the late 90's, I had a 13.0 to 1 compression 428 FE which I also ran a 150 shot. But I went over kill on the fuel system, colder plugs, ignition system, conservative timing, the best rods and pistons, and of course, nothing but CAM2 race gas.

79PACER · 03-01-2006

What do you mean by "colder plugs?" And a good fuel system? I'm running a brand new OEM fuel pump. Will that not surfice on a 100 shot?

BlueStreak03 · 03-01-2006

You may need to jump up to a higher volume fuel pump. Even without the N2O I think the combo you've got would be pushing it for that pump.

psfracer · 03-02-2006

Quote:

Originally Posted by 79PACER

What do you mean by "colder plugs?" And a good fuel system? I'm running a brand new OEM fuel pump. Will that not surfice on a 100 shot?

Its hard to say. You want to monitor your fuel pressure and make sure it stays the same throughout the run. For example, if you are running 8 psi with the holley, you want to make sure when you hit the nitrous that it stays at 8 psi, that it doesn't drop. If you loose fuel pressure, you will go lean, and then things start to get real hot and melt. But its always better to go overkill on the fuel system to avoid any problems.

A colder plug is a plug that disapates heat better. In my gallery there are pics of the standard plug vs a colder plug. Look at the insulator nose, notice the difference?