Ok, I have an interesting "what if" scenario I need a little insight too. I am working on a Jeep DJ5(yes, postal Jeep) street racer project. I have an LS swap in mind, however, I also have a complete '66 300 in my Skylark parts car. I don't even know if it runs, but my gut feeling is probably. I know the 300's will swap fairly easy into the CJ5 chassis(same as DJ5), but how much nitrous can a stock 300 take? 200hp shot? 300 maybe with a good tune? I know it's a far stretch, but I want to run the number for as cheap as possible for the moment. LS is easy 800hp on small kit, maybe 500hp in the 300 with cam/spring kit and have it blessed before a hit? Give me your thoughts
Cast rods may live to 100HP shot. I think you will make a grenade out of it. If you go Forged rods and pistons you would have a better chance.
Should be able to handle a possibly 200 shot. You'll probably want to pop the pistons out and open up the top ring gap though, also keep the RPM in check. It isn't so much the N02 power up to around 450 HP(at the crank) that will start breaking the rods, its to many RPM that the factory rods won't like. A turbo on the other hand may be able to push that HP limit up another 100 HP to 550 and still live? Same deal though, have to keep the RPM in check. A set of nascar take out rods topped off with a decent set of forged pistons would probably take about 500 shot no problem though. If you get 300 HP out of it N/A, then there's your 800 HP! Enjoy.
The answer is less about what the components or the engine design can take and more about the delivery of said chemical atmosphere boost or the skill level of the person engineering it. Most engines can handle 3x the compressive load easily before the components are overwhelmed. As stated, some inexpensive and simple upgrades would greatly beef up this very over built design for the cubic inch ratio.
Got it, I am not up to date on what is the weak link in the little 300's. I figured the pistons were questionable, but if your saying the rods are the weak link, I will probably just go LS. Combo is going to be a Glide w/ Dana 44 3.73's spool, 26x8 slicks for now or 235/60 DR's. Will need it to rpm for sure, min 6500rpm out the back door. A thought crossed my mind to build a turbo Nailhead for it. Maybe...need more whisky and we'll see what happens. Thanks to all who replied. Here is a pic of the Jeep as I found it in local junkyard. Yes, they were selling hot dogs out of the back of it. For now, I am leaving all that crap in the back. I figure the uncontrolable laughter will give me a couple tenth's, lol
You will need a single plane intake for a 150 + shot of nitrous or you will have distribution problems in the intake.