[zildjian4life218]

Okay first off. How much power can a mid 70s 350 block take. Casting number 3970010. It will be bored .030 and have splayed 4 bolt main caps installed. My HP goal is 500-600hp if the block will hold. It will be used for drag racing in a 2800lb truck every weekend. Also can anyone suggest good reading material that will help get me more familiar with nitrous. Thanks

 

[eloc431962]

Make sure to run Forged pistons (NOT THE HYPERS).JMO :smash: Cole

 

[zildjian4life218]

I planned of running forged pistons, rods, and crank. Not sure if I will run flat tops or a domed piston depending on what heads and compression ratio I choose. I was going to use vortec heads on this motor but i haven't found a good nitrous cam that works at high rpm but has lifts below .480". I really don't want to send them to a shop and get them machined for a higher lift, I might as well spend the extra couple hundred dollars and buy after market heads at that point. Also what compression should I be looking at? I want to spray probably a 100-150 shot and i will be running 93 octane or race gas.

 

[Ohio-Dan]

http://www.carcraft.com/techarticles/116_0406_nitrous_350_chevy/index.html

 

[zildjian4life218]

thanks ohio dan for the link its helpful to see other builds and what people use and can get away with. like all that nitrous on a stock cast crank. F-bird Is modifying the max lift something someone with no experience can do? I am still young and learning whatever gets thrown my way. I can get a set of 062 vortecs for $300. I will have to have a local machine shop tear them down and mag them, do a valve job, and I don't know how much it will cost to have this done. probably around $250. Thats if no guides have to be replaced or what not. So is it really worth to rebuild these heads when i can spend $300 more and get a set of aftermarket heads? ugh decisions decisions.......

 

[zildjian4life218]

I like the idea about aftermarket heads :thumbup: . Can i run a stock crank on this motor? I plan to make 600hp on the bottle with a 150-200 shot.

 

[zildjian4life218]

Awesome I like the sound of that. Okay for rods i am looking at Eagle 6000BBLW. They are 6" forged 5140 steel.
Pistons are KB732-030.
Forged aluminum
.030 bore
compression distance is 1.265"
head volume is -6.26cc
which will yield a 12:1 cr with quench at .040" and a 64cc head.
Okay my stack will equal 9.005" So i will cut the deck to 9.015" Then run a head gasket at 4.1 x .030"
Does this sound alright for the bottom end? Open for criticism and suggestions

 

[Plaintoast]

If you intend to have 5-600 HP before nitrous, I wouldn't waste my time with a stock block.
By the time you have it cleaned, bored, decked, splayed caps installed etc. your machine shop bill is going to be approaching the cost of a Dart SHP block.
If your numbers are realistic, you are pushing the limits and it likely won't last long on a stock block. For about $1500, you can get the dart with the splayed caps already installed, a better casting, priority main oiling, and it's already set up if you decide to go with a roller cam, you can and it won't have to be the more expensive retrofit setup.

 

[zildjian4life218]

I am looking for 600hp on the bottle. Why not 6" rods. They are the same price as the 5.7" and i was always told the longer of a rod you can stuff in a motor the better. For pistons i am gonna go with KB702 if i stick with the 6" rods. They are flattop and will drop my compression to a little over 10:1.

 

[zildjian4life218]

I am planning on running this cam; Comp Cams NX284H. Will this cam work for my application? I plan on running 10:1 with forged pistons vortec heads modified for .550 lift. Single plane edelbrock super victor intake with a 750 double pumper. and of coarse Nitrous Express 40040-1. Stall converter will be around 3800. Rear end gear is 4.56,

 

[zildjian4life218]

Okay so i came across this short block that came out of a drag car. It has 28 runs on it and the guy switched classes and couldn't run aluminum rods so got rid of it. Its a thousand bucks for a 350 .030 over 4 bolt main block, aluminum brc rods 6", dome forged aluminum pistons, and a 3" stroke callies crank. Bottom end is balanced to 10,000rpm. A local engine builder has it sitting in his shop on a stand in a bag for the past year or so. He said he would tear it down with me before he sold it and check all the clearances and what not. So i'm thinking that block, rhs vortec heads 2.02x1.6. (they r cheaper than buying vortecs and rebuilding them and flow better) http://www.competitionproducts.com/prodinfo.asp?number=RHS12410K1
I am gonna run a edelbrock super victor jr intake, 800cfm holley 4150, this nitrous kit http://www.summitracing.com/parts/NEX-30040-10/, and a custom ground cam, probably solid roller or solid flat tappet. What does everyone think?

 

[Jeff The Ruler]

I think you need a little more cam than that 284 if you want 500-600 HP.

 

[zildjian4life218]

Yea i talked with my local engine builder and he suggested going with a custom ground cam instead so i will send them my engine specs and goals and see what they come up with.

 

[ericnova72]

I might suggest a Holley Strip Dominator intake over the Super Victor. Your heads aren't big enough to take advantage of the Super and it will give up power in the mid to upper mid range. The Strip Dom modified by Keith Dorton would be even better(Summit used to have it, maybe still?). With a custom cam, everything looks good, hard to do better on a such a low budget. :thumbup:

If you do go solid flat tappet, I would strongly recommend getting the lifters with the EDM'ed oil hole in the face. Very worthwhile if you want it to last.

 

[zildjian4life218]

Alright thanks for the suggestion on the intake. Are the heads gonna be okay for my application? I didn't want to go too big on the intake runner due to the small displacement but then again i will be taking it to about 8000rpm so maybe not a bad idea. When i port the head would it be worth taking some metal out of the runner? I will focus on the bowl mostly but not sure if it will be worth it or not

 

[ericnova72]

I would do like you are thinking, smooth and blend the bowl, the guide boss will need a fair amount of work as it is rather bulky but it is easy to get to, blend the short side radius, and then widen the pushrod pinch as much as possible without breaking through to the pushrod area. I would guess you will come out in the 180 cc intake runner volume area, plus or minus. On your small cubes, it should run right up to 8000. There is better out there, but not for anywhere near the low price.

 

[TroyBoy]

Didn't anyone catch the 3 inch stroke?Now you have a 302 plus overbore.Go back to the 350 plan,you will be happier IMHO

 

[zildjian4life218]

Yea i couldn't believe only $700 for the pair assembled. thats a deal, i wish i would have came across it before i rebuilt my GM 441 heads.
Troy boy, it would cost me 2000-3000 to build a 350 that would hold the same power, i know the stroke is on the short side and will affect low rpm torque but i will launch at a higher rpm and spray the hell out of it.

 

[TroyBoy]

Yea i couldn't believe only $700 for the pair assembled. thats a deal, i wish i would have came across it before i rebuilt my GM 441 heads.
Troy boy, it would cost me 2000-3000 to build a 350 that would hold the same power, i know the stroke is on the short side and will affect low rpm torque but i will launch at a higher rpm and spray the hell out of it.

I wasn't trying to talk you out of a 302 per se,I just wanted you to be aware of the RPM differences.Buy all means have fun :thumbup: You might try www.nitrousforum.com for some better advice about what your block can handle :mwink:

 

[zildjian4life218]

thanks for the suggestion. I will go over to that nitrous forum tonight and check it out. The motor was putting out around 700hp with the other top end kit on it, and was running high 9s in a 3000lb car. Im not too too worried about the block. There is always that chance the block will split but hey it happens.