If you were to build a strong nitrous smallblock, say 250-300hp shot and had a stock 400 or 350 block to use with phase two bowtie heads and bowtie intake what would the rest of your parts list be? Pump gas motor.

I would use forged pistons for sure..good solid flat tappet cam too.
240ish duration @.050..keep the compression around 9.5 to 1
JMHO...

Nitrous is hard on rod and main bearings. Assuming the tune is right the bearings are going to take a beating anyways. Aluminum rods help the shock load. Make sure the crank stays inplace. With a stock 400 block, splay the main caps at a minimum. (better yet aftermarket block) with a 350..good studs and align bore/hone and check cap registers. Ofcourse a 'good' 4340 crank.
The pistons for over a 200 shot should be "nitrous" pistons. These have a thicker top and relocated ring lands

Sounds like the 350 blocks must be stronger than the 400's. Do the valvesprings take more of a beating with nitrous? Does anyone here run a streetable smallblock with a 250+hp hit of nitrous?

I would never run pump gas with that much nitrous. I'd run 100% race gas. Sure there are tuneups for pump gas, but if you are running that much, you have a serious combo and should be running race gas.

In one of the recent magazines, this guy has a 1st gen Nova with a 400SBC and a 200 or 300 shot that runs 9's on drag radials and he's got like 27,000 street miles on it. It also has a small roots style blower I believe. Anyone know which magazine it is?

I had a 406 studded main ,crower rods,trwpistons steel crank iron heads. Ran a fogger at 300+.Had 2 fuel systems comp was at 10:1 ran trick blue fuel.Motor was pretty low buck flat solid cam, MSD 7al.Probably had 4k in the whole thing.Ran 10.20 at 134 in a 69 firebird.You need race gas,good ignition and a really good fuel system.

badbob71,
Make sure you have a strong bottom end (forged pistons, steel crank L-19 rod bolts ect.)You can run pump gas on motor alone but spraying that hard you should have a dedicated fuel system for the nitrous. The dedicated system I had in my street car had a 1 gallon fuel cell for the nitrous with a holley blue pump doing the pumping. I ran 110 or 116 octane in the cell and 92 in the cars fuel tank. I also had a timing retard module. I sprayed 275 hp shot to a 454 H.O. crate motor (8.75 to 1) that had some mods (roller rockers, victor jr. intake,double roller timing chain,Comp solid cam) many times with no problems at all. Drove around town all day on 92 but if someone wanted to play around, two toggle switches=275 h.p.!!

A bigblock by nature will take a bigger shot and survive. badbob71 I would limit the shot to 200. It will be difficult enuff to keep tires under it with a 200 shot.

thats not very fast for 300+ on a fogger

Doesnt 66 283 shoot something like 400 on pump gas?

I have a nitrous sbc. I have stock 2 bolt block, stock rods with ARP bolts and hyper pistons. Most guys wouldn't even spray this combo. I have sprayed a 150 to it this year and i'm going to spray a 250 to it next year. My car ran 12.6 @ 109 on motor and 10.98 @ 124 on the 150 shot. On a nitrous app the 2 things that will destroy the car is detonation and over reving it. I shift at 5700 on motor and 5500 on spray. I run 93 on a 100 shot, but anything 150 or higher it's on 112 with 2-3 steps colder plugs and follow the 2 per 50 HP level for retard. I do all this with 3.07 gears and a 460 lift cam with 218-230 @ .050.

You can run the bigger shots on pump gas, but eventually you'll run into the problem where you have to retard the timing so much to stay out of detonation you won't pick up anymore power.

As for the 66 Nove, he is the Toyota engine builder for the Nascar truck team...you'll never really know how he pulls it off. I have a friend that was in CHP and GM high tech, he lied in both mags....be careful what you read.

I know Jim Henn with the little nova and it is everything he claims it to be. It's isn't ultra trick - he just has the combination figured out. He drove it to a PSCA race and ran in the 10.5 bracket class, he ran something like a dozen passes, won, and drove home.

Also in Memphis, he used the car for his sole transportation. Him and his girlfriend drove it over to my hotel and I filled nitrous bottles for him at my trailer in the parking lot. He towed it from California on an open trailer with few tools and didn't turn a wrench on the car the whole time!

In general, you can spray a lot on pump gas with the right tuneup, but you will make less power than you would make on race gas. Below 200 unless you have high compression I would tune it for pump and not waste your money on race gas.

Interesting stuff. Thanks for the input. My chevelle is getting a 468 with a big shot system, but I hate to part with all the smallblock stuff I've collected, I guess I'll keep my eyes open for a good rotating assembly and a light car to stuff her in. Sure would be nice to have a car dedicated for ruthless weekend beatings at the strip. :D

66 283,

can you share more on Jim's combo ? I'm interested in static comp, cam type and size, quench, boost ( lbs) and how much timing he pulls for a nitrous run as opposed to how much timing he uses off nitrous.

thanks
Mike