Alright, i'm new to the carburetor world, i'm going to build a high compression big block, the only thing i have is a complete block head to toe from the factory.

i want to do a large shot around 500.

my question is what size of carburetor am i going to need, i plan to do around 10.1-11.1 for a compression ratio, i do plan to try to make this a street motor as well.

 

also, i prefer if i can use a e-85 carb as well if that makes a difference for anything.

 

You want to take a factory big block and hit it with 500 hp shot?

Is the motor built for this at all? Do you plan on running only E85, or can you run proper race gas?

You need to decide how you want to do the spray. Should be done in 2-3 stages, direct port injected on a good single plane intake. Motor is going to need to be built around the shot. Cam and heads need work for the shot. I would consider inconel exhaust valves. Converter and trans need set up for the large shot. Piston rings and spark plugs need account for the extreme heat. Head chambers may want to be reworked alittle for the large shot, considering a quenchless chamber.

Its not a simple build, not cheap.

 

well, i've not tore apart the block, i dont plan to hit it with the factory block, it might be fun for the first time and thats about it.

but to reality, i planned to look into a forge kit, i plan to have a builder assemble the block, but i'm not sure in the direction i have to go.

here is what i got.

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454 block factory complete with peanut port heads
holly strip dominator intake.
empty nos bottle, with lines / no noids or adapters.
Aem wideband if i need to use it?

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i have no knoledge about carbs or nitrous.

i'm fimilar with honda's / forced induction / fuel injection. ? but we all go to put on our big boy pants and go up in life.

 

Find a good builder and work with them on the build. A factory block may not be a good idea for a serious big block spray build. A half decent 454-500 cube motor will make 550-700 hp on nuts alone. 500 shot puts you 1000-1200 and thats alot on factory blocks imo. Not to familiar with factory big block potential tho.

You will neeed good internals and great block prep. Rings designed for large shots and gapped correctly. May want to ask this question in the drag boards as there are alot of big block and big nitrous guys there

 

well i plan to use it on the street- i was guessing 700 HP in that area would be good enough of a goal, if its lower it wouldnt hurt my feelings, i just dont want to get passed by a jap-burner ya know?

 

Based on the comments you provided and parts you have/don't have. I'd actually tell you not to build a motor. You have a very wild imagination of what reality is. More like lala land. Just add more air to the rear shocks and you'll intimadate those rices to the point of not even trying to tackle you on the street.

 

Oh I'm liking that idea, hey man pass that stuff over while your at it lol...

 

I was hoping you or one of the other bbc guys would chime in . I was gonna say the same thing but gave the benefit of the doubt lol

 

500 shot is a lot!!! period. I have a big block Iroc also have a complete with full bottle NX kit. forged internals the motor in a different vehicle ran 10.50 in 1/4. the biggest shot I would put to that motor would have been 125. I didn't mention the motor is studded also and a 4 bolt main. big blocks are great motors they are if you can get them to breath. I don't know what your trying to accomplish. but honestly there is no need for a 500 shot build the motor for 1000 hp which can be done but costs a lot more $ then put the 200 shot to it that would put you at the same hp.

build the motor reliable,build it for the purpose your using it for (IE drag racing , street driving ) whatever. If its for the street forget nx all together. build the hp and compliment it with nx not throw together something and have nx build the hp your bound to break parts that way.

either way tho a 750 hp big block crate motor is about 12000 so realistic here most people myself included wouldn't spend that much on a street car that's worth maybe 2500.

my suggestion would be this get your block reworked new rotating assembly forged eagle sells a good setup for a 496. send them both out to the machine shop to get mated together. get a good street/strip cam. and ditch the peanut port heads. I have 2 big blocks one has the reqtangle port closed chamber heads the other set of heads is a 049 which are oval port open chamber. there is a head that you find on the boat motors 502 880 something there open chamber reqtangle ports I heard there good to for factory heads. get yourself a good single plane intake if drag racing or a good dual plane intake for the street. the motor should come in somewhere around 500-600 range. which for a thirdgen is a good number. build yourself a good trans to go behind it . my case a th400 which cost me about 1000 just to rebuild it for 650 hp. which then made me need a new cross member and driveshaft. then figure out what your going to do for an exhaust. headers are pricy for the lemons or quays. hooker makes a set but honestly there a pain in the butt. then you can use the patriot headers. theres a sticky with the part numbers there a decent set of headers but they will limit what type of motor you can build because there small tube.

learn from my mistakes. I'm on my second motor 4th trans (700r4, t-5, th350, now the th400) build it right the first time collect the parts you want in there then put it together. my car right now is out of my hands for the first time it's at an exhaust shop. I pulled the old motor because I spun a rod. the new motor is half the hp of the other one. so I went back to the patriot header remove the single plane intake and went with a dual plane removed the 930 holley and went with a 750 I'm downsizing basically why you might ask. it's no fun having a car that you can never drive for many reasons weather it be the $9.00 a gallon for racing fuel or over heats in traffic. yea but the heads that turn when your sitting at a light and the ground is shacking is great I have to admit. until they see you cooling off a mile down the road. so this rendition of my car has taken me about a month to redo.

1972 454 ls5 motor with the 049 heads $1200.00
holley 750 $200.00
th400 $300.00
th400 rebuild $952.00
cross member $300.00
drive shaft lengthened $213.00
big block gasket set $100.00 with summit bucks
tow to exhaust shop $85
Exhaust $450 2 1/2 y pipe coming off of the patriot headers into 3 inch intermedent pipe into 3 inch flowmaster muffler with 2 3 inch tail pipes.
$85.00 tow back home to finish tuning the motor.

that was to take a car that already had a big block in it and switch it out. more money went into the trans than anything else. but I already had the patriot headers radiator and fans so by the time your done with just a factory motor your in the $1000's of dollars heck my radiator and fans were something in the range of $750.00. then you have to get a hood to clear the big block I went with the goodmark steel hood that's a $500 dollar hood. then getting the car painted and ready again that for me was another $1000 $400 in paint $500 to the painter friend of mine. then new graphix $213.00 from phoenix graphix.

Now mind you I have done all of this in the past 2 months. since the fbody gathering.

good news is tho I have every single part to build another big block Camaro minus a radiator and fans.

the reason for my big push is the car is leaving in less than a week to go on vacation with my family to go to the woodward dream cruise. after the fbody gathering my issue was paint chips so we repainted the car well after that was done the bearing spun so it has been a scramble to get it back together. this motor that I have now should be more streetable. and honestly I think it will feel like it has more power because the old motor was designed to go all out for 10 seconds where as this motor is a street motor in a street car. so bottom line is it's going to cost some money (a lot) and build the car they way you intend to use it the first time. I probably have close to $30000 into this car by now with all the changes I have done. 3 paint jobs a roll cage then removed it this is the 3rd motor 305 tpi , 70 ls6 motor, and now the 72 ls5. 4 trans 700r4, t-5, th350, th400. 4th exhaust factory exhaust , dynomax dual exhaust modified for the big block then a 3 inch dynomax race bullet exhaust and now a custom exhaust mentioned above. 2 sets of headers the patriots then the hooker super comps. so learn from my mistakes do it the way you plan to use the car and stick with it. mine started out as a street car than a drag car and went to a street car/ show car.