Scottd

Gents, I seek your knowledge. Im looking for another thrill, but I dont want to blow myself up. Can my engine handle a mild dose of nitrous, if so, how much, and how much HP increase should I expect? Heres what Im running-

454, .060 over, 2 bolt main with mild dome pistons, low 9's compression. Stock heads. (1972)
Straub cam, Q-jet by Lars. Timing is currently set at 30 (or so) with no vac advance hooked up.
Fresh Muncie 4 speed (just rebuilt last winter)
Stock 1972 rear end to include original half shafts.

Can I add a NOS system and not blow myself up or am I inviting a catastrophic failure?

I know that a set of performance heads would really wake this car up, but I cant afford another 2K in parts and all the fine tuning a full teardown will take.

Can I bolt on a simple NOS system or should I just avoid the idea all together?

TOM B1

Hmm, no headers and stock 2 bolt mains. You can go 50 to 75HP shot but I would not go any more. you have to add more fuel also.
That little of a shot might THRILL you for a week or two.

How fast you want to go.... How much money do you have

Scottd

Sorry, running Heddman headers and side pipes.

I just want something new with the car. A new thrill, a new project. I want a car thats downright scary when I hit the throttle. Ive done all I can do with my 454, Im just looking for an easy bolt on at this point.

Money....??? Yeahhhhhh...Ive got like 1K bucks I can throw at this, nothing more.

When you say 'more fuel', do you mean jetting? I absolutely do not want to phawk with the carb settings beyond mixture screws and idle settings.

SH-60B

Not jetting, TOM B1 means more fuel from a separate fuel system. NO2 is the oxidizer, it needs additional fuel or the motor will indeed blow up.

gkull

I would fix the timing first go to all in at 2800. With about 36 max w/o vacuum adv. Then hook up vac adv to ported vacuum

I've done various setups. I would start with a 150 spray plate with a wot activation switch

7t9l82

I agree with George. I'm not a big fan of nitrous, I can blow stuff up without it. These plate kits come with solenoids for gas and fuel and are pretty well set up. As long as you don't get into the if more is better too much is just right school.
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CanadaGrant

You didn't mention pistons other than "mild dome". Are they forged? If not I don't think you have to worry about the 2 bolt main block being your weak point.

Rescue Rogers

what about just putting the money into work on the heads.

1. Porting and planing yours or..

2. a different set of castiron heads with a smaller combustion chamber to up the compression abit and get those worked on. I would think you could get what you want for 1K. Obviously not a high end aluminum set.

3.Summit has edelbrock and Brodix close to your price as well

https://www.summitracing.com/search/...rd=454%20heads

v2racing

If you get the ignition timing set up properly it's going to run better to start with. Even cast piston's will usually stand a 100 shot of nitrous. If you have forged pistons a 150 shot should be just fine, even 200. A big block 2 bolt can handle quite a bit of power.

As far as the trans and rear end, that depends on your driving. Abusers can break the drivetrain with stock motors. On the flip side, I've seen some pretty high horsepower builds in front of stock drivetrain that held up. Traction will play a big part too.

Mike

cv67

WOuldnt bother with anything less than 100 shot



More to it than bolting it on, have to make sure your timing is set up/adjustable, need more fuel etc. If you dont want to touch the carb skp nitrous for now. When they get lean they go boom. Bottom end should be fine.

Save for heads or better yet a street blower. Yeah its more but you want to get scared throw 5-6 lbs of boost to a big block that will do it. Doesnt take much.

Sometimes you can score a nice used/refurbished one complete with pulleys intake etc. If I had to do it over again I would absolutely throw a roots blower on it. Plus the look, come on a blower makes EVERY car better.

Richard Daugird

What happens, in a stick shift car, when you need to shift gears and the nitrous is still coming on?

gkull

I already said it, you put a micro switch on the throttle linkage to only energize the spray bar when you are WOT. I've ran twin bottle setups with multi stages to 375 hp total additional using methanol as spray fuel in a separate two gallon tank.

The 150 hp spray bars are very simple. You turn on the N2O bottle ****, you turn on a console arming switch, and as soon as you floor the gas to WOT the solenoid opens to spray N2O and additional fuel.

gkull

This is an example of a spread bore carb setup. for just over $400 bucks. these things are like an evening of fun per tank

https://holley.com/products/nitrous/...parts/07001NOS

Scottd

OK, lets assume my wrenching skills are a 8 out of 10 and my carb/timing skills are 6 out of 10....

If I bolt in this kit, how to I address the variable timing and fuel issues? Im running a HEI Dizzy with Accell ignition (programmable rev limiter) and stock fuel system.

Answers to other posts:

Heads: I have a custom roller cam, matched to my stock heads. If I replace the heads, Ill need a new cam

Blower: Well of COURSE Id love to add a blower, but that involves cutting my hood and adding pulleys (to an already somewhat bubba'd pulley system) and honestly Ive never seen an affordable setup.

gkull

On these low powered systems you don't need the fancy stepped retard control **** kits or hooked into the micro switch.

The rule of thumb is kind of retarding the the timing 1 1/2-2 degrees for every 50 hp. So for a 150 hp before you turn the bottle on retard the mechanic full advance from say 36 to 30 degrees and then hook your vacuum advance back up.

The fuel is just "T" of the fuel inlet line to the carb. You have to have say a solid 7 psi or what ever the kit suggests. Lean is horrible and rich just kills the power.

v2racing

I've found the off the shelf nitrous kits to be jetted very rich. The nitrous companies are trying to be safe. They usually are in the 11 to 1 or even 10's for AFR. Even on setups that don't allow for timing retard, they are usually safe, especially with the compression in the low 9's like the OP has. If you have high compression to start with and start jetting the nitrous system for best power, timing gets way more critical.

revitup

"Mild nitrous" sounds like an oxymoron!