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I agree as well to many variables. Answer these questions. What type crankshaft cast or forged? You using bolts or studs on the main bearing caps? You using bolts or studs on the cylinder heads? What type pistons are you using, cast or forged?
 

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all goog answers i guess i will give it my 2 cents so here it goes the power is not in the nitrous its in the extra fuel the nitrous just helps it burn quicker so you could spray a 300 shot so long as it has the right mixture. i beleive undercoverss has tried this too and his motor held up just fine :yes:
 

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I think what has saved me from any nitrous related failures is my torque converter. Having a converter that flashes to 6000+ (depending on engine) keeps the engine from ever being loaded hard at too low an RPM. Think about where the majority of nitrous explosions occur...At the hit, when RPM is down!
I've never had the slightest little hiccup using nitrous, and mine is setup on a throttle switch--I leave at an idle, but the engine flashes beyond where the typical engine would go BOOM! I also run more timing than an average guy would run; with a forged bottom end I don't pull any timing with a 200 shot, and the engine responds better so it leaves better. I hear some cars at the track with such lazy throttle response from a lack of timing, it's no wonder they backfire when the nitrous is engaged!
On the junk 350 I pull the timing back to 30° total, and add a splash of race gas for a little insurance on the cast crap iside. BTW, my distributor is locked out too, so whatever timing I run is all there all the time.
Keep the fuel pressure slightly higher than what's called for, read the instructions, follow the instructions about what jet combo to use, and you should be ok.
 

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I think what has saved me from any nitrous related failures is my torque converter. Having a converter that flashes to 6000+ (depending on engine) keeps the engine from ever being loaded hard at too low an RPM. Think about where the majority of nitrous explosions occur...At the hit, when RPM is down!
I've never had the slightest little hiccup using nitrous, and mine is setup on a throttle switch--I leave at an idle, but the engine flashes beyond where the typical engine would go BOOM! I also run more timing than an average guy would run; with a forged bottom end I don't pull any timing with a 200 shot, and the engine responds better so it leaves better. I hear some cars at the track with such lazy throttle response from a lack of timing, it's no wonder they backfire when the nitrous is engaged!
On the junk 350 I pull the timing back to 30° total, and add a splash of race gas for a little insurance on the cast crap iside. BTW, my distributor is locked out too, so whatever timing I run is all there all the time.
Keep the fuel pressure slightly higher than what's called for, read the instructions, follow the instructions about what jet combo to use, and you should be ok.

Don't know Mike...I always left on mine just above idle with the stock converter, and 40* timing.

The problem is, every engine is different. If it's got enough fuel for the nitrous you're running, it should live. but then you factor in the quality of the parts used, how well it was assembled, etc.

I would say you can run 150HP shot pretty reliably if it's set up right. It might live with more, but you just increase the risks the more you use.
 

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Have a stock 4 bolt main 350 block in the 63. Its a 3.875 eagle crank, eagle rods and some J&E pistons. Stock 4 bolt caps. Its a pump gas motor, never had race gas in it, even on a bigger hit. I have given it a 200-250 load for several years, and last year I stepped it up to a 325 hit. Holdin up so far! :yes:
Play it safe with the tune up and you'll be fine. I pull out more timing than needed, and a little high on the fuel pressure side.
 

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if it's all stock i think you're going to be limited by your intake manifold. if i remember right, most companies recommend you don't use a dual plane manifold above a 150 shot.
 

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if it's all stock i think you're going to be limited by your intake manifold. if i remember right, most companies recommend you don't use a dual plane manifold above a 150 shot.
I use a dual plane with well over a 150 shot.

If you run a 150hp shot it will lower your ET by roughly a full second if you get it to hook. that's just a general rule of thumb.

When I first started racing my car, the 400SB in it was completely stock. It ran 14.11 @ 98 mph. I put the NOS on it with the 150HP jets, and got it down to 11.83 @ 115 mph. Granted my 400 made alot more torque than your 350 will
 

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my mistake. maybe that's a ford thing? i think i saw something about it on the bullet...
no, you're correct about it being said not to do it. it's kind of like the timing thing. it's said to retard the timing for every 50HP of NOS, but I never did it. kept it at 40* without issue.

but then again, most of the stuff on my car was said to "not supposed to work"
 

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Awhile back a Magazine did this test on a stock smogger boneyard 350. They tested with 100, 150, 200..... all the way up to a 500 hit. After the first hit they tested the engine without nitrous and found it made more HP than their baseline- the nitrous had unstuck and reseated the rings. But on the last test with a 500 hit they forgot to pull back the timing enough and lost the engine. It makes you wonder if it would have held at least that one run if the timing was right.
 

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AS FAR AS THE BLOCK GOES, IT WILLL HANDLE ALOT. FOR THE REST OF THE MOTOR IS THE FACTOR AS STATED SEVEAL TIMES ABOVE. I ON THE OTHER HAND HAVE TESTED BONE YARD MOTORS AND HAVE HAD A 250 HIT LAST QUIT A WHILE ON A BONE STOCK BOTTOM END. AND 400 ON A MILDLY BUIT BOTTOM END WITH HYP. PISTONS, PINK RODS AND A STOCK CRANK. ITS ALL IN THE TUNE.:yes:
 
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