Looking to build a 383 and would like to hit it with the nitrous on occassion.

What is the limit for a shot for a "normally" built motor?

125, 150, 200?

I ask this because I have heard about rings needing to be gapped for nitrous, but many are using the juice on stock pistons and rings.

 

I would say for a stock type motor you wouldn't want to go over a 100 shot if you want it to be reliable. Anything over that and you are playing with fire.

 

I assume if you are going to build a 383, it will have a forged crank and pistons? If so 200 will be no problem with a good fuel and igntion system. Get a fuel pressure saftey switch run some ngk plugs and you will be fine. If you get a progressive controller it will also greatly lessen the inital shock on the motor and save parts for sure. I have a FJO progressive contoller on my lt4 with a NX MAF kit, hit it with two stages 150 each for total over 300hp with no problems so far, and thats on a 383 with decent parts.

 

i agree with these guys

 

A forged motor will have no problem with a 200 shot or higher, "that is" if it never goes lean...this is a very common size shot on a forged assembly smallblock........on a good shape cast hyperutectic piston LT1 motor...a 150 shot (properly set-up) is also very common without any problems.........When my LT1 was 100% stock, I ran a 150shot for over 6 years without any problems........just remember even a 50-75 shot of nitrous has the potential to completely melt an engine down if it goes lean.....so use all the failsafes you can.......

 

I have seen an LT1 take a 100 shot all day long.I have seen guy's go to a 150 shot and lose the motor almost every time.
Build the motor to run just a min shot and you will be better off.
I can tell you a stock LT1 with a 175 shot will break the 10's,The parts you break on the way down the track will be expensive.

 

Lose the motor "almost" everytime when they went to a 150shot... Now thats funny the fact of the matter is, that even "several" of the most reputable nitrous kit companys have their LT1 kits factory jetted for a 150 shot and they work just fine year after year(properly set-up)......Just like mine

 

Thanks for the reply's guys.

I intend on building a rugged 383 to run most of its life w/o the NOS.

My main questions is about the ring gaps, I have heard of motors built for nitrous runs requiring the rings be set up loose for the juice, I was curious as to the size of the shot that this would be a must - if you said 200 and up then I wouldnt go higher then 150 if it was going to require gapping the rings for the NOS and run like crap on the street.

 

http://www.federal-mogul.com/fmeconnect/technicalservices/downloads/1205.pdf#search='ring%20gaps%20for%nitro us' For example purposes only, the stock LT1(I know your building a 383 with different rings and pistons ) lists a top ring gap of 0.010 - 0.016 and a second ring gap of 0.018 - 0.026......these gaps "which I have personaly checked on several motors over the years tend to be more factory set on the loose end of the spectrum which is probably why I have never seen "even" a 200 + shot on them run into top ring butting issues......If you don't plan on going over a 200shot I would just set your file fit rings end gap on the loose side of what "that" specific manufacturer recomends for NA performance, because (like you mentioned) if your going to be naturally asperated 95% of the time , you don't want loose compression gaps to cause excessive blowby and lack luster performance(which if only "slightly" too wide it "easily" can)......or like myself, on another 383 Im in the process of building at the moment, if you think that you may want to get things much above a 200 shot, I would then personally ask your ring manufacturer what they recomend for that "exact" ring for use with your desired nitrous horsepower level.....other than doing that, you'll just get a million recomendations from people with different set-ups that may not relate to yours too well......good luck with it......Joe

 

I tried to leave a link for ya, about ring gaps in the begining of my last post, it's up there as you can see,but for some reason when I paste it in and even when I try to edit it....it put's a space between the word nitrous at the end......you may have to manualy type everything in but without the space in the word nitro us' at the end to get it to come up....yea, just tried, it works that way..

 

from one Joe to another - thanks that is what I was looking for. gl on your build

 

qoute:

Quote:
Originally Posted by REDC4CORVETTE
I have seen an LT1 take a 100 shot all day long.I have seen guy's go to a 150 shot and lose the motor almost every time.
Build the motor to run just a min shot and you will be better off.
I can tell you a stock LT1 with a 175 shot will break the 10's,The parts you break on the way down the track will be expensive.

Lose the motor "almost" everytime when they went to a 150shot... Now thats funny the fact of the matter is, that even "several" of the most reputable nitrous kit companys have their LT1 kits factory jetted for a 150 shot and they work just fine year after year(properly set-up)......Just like mine

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I have heard of some CF members running 100 HP shots fine for years w/ a stock LT1. Then the moment they up to 150 shot, something goes bad (broke ring lands due to detonation, etc. ).

I also have heard of a few members doing ok on 150 shots and stock LT1's.

In my opinion, the stock fuel pump needs to be upgraded to a Walbro 255 l/h hot-wired unit if going beyond 100 shot on a stock LT1.

I have nothing to back me up, but it seems like cheap insurance.

 

The Walbro should be the first thing that is installed in a car running nitrous.Part number 20000169 to be exact.I even run that intank pump on my 86 vett running 700 plus HP and I have yet to have a problem.
3 of my buddies decided to go to a 150 shot last race,they had been runnning 125 shot to 3 years.They walked home.

 

No problem ....good luck on your build too....let us know how things go ....

 

I agree, So much so that I have never on my own car, or even on any of the many kits iv'e installed over the last 15 years, done a nitrous set-up of anykind or power level without the use of an additional walbro NOS (push style) pump....I wouldn't even consider it, even with a wet kit where it's not quite as important....It is very cheap insurance like you said.....just like running two nitrous solenoids in series which I also "always" do....

 

I have the 255lph Walbro in tank already from the racetronix kit

 

I would build your motor to the best spects and hp for nitrous application .and not set it up for as much power on the nitrous.
The cam will be the difference in this build.The way I set mine up was ,to give the engine most of it's power on the motor.
I can run a 400 hp shot but that will require a 2 stage system to operate correctly.
I chose the NOS controller.I haven't used the shot yet .I am still dialing in the motor.
If you want to run it on the street comp cams makes a good nitrous hydrolic cam.
If you go solid lifters then you will need alot more work on the engine,heads.
Stud gurdles and crap.I can tell you rocker shafts are easier to work with then the stud gurdles.
I can run mine on the street but 2 gallons to the 1/4 mile limits the pocket book along with 15.1 compression.
Even with the stock LT4 exaust I installed , makes for alot of noise.