BUDGET 350-400hp SB 5.7L

[sorestgore]

this may not be in the right category, so tell me where it belongs if it should be moved

 

I have a 1972 Chevy C10 Stepside, i bought it for $400, and i am in the process of restoring, customizing it. i can handle the bodywork, airbags, all that, but what i need help with is horsepower!

 

when purchased in the early summer of '05, it had a fairly stock 350ci, i beleive it's a Gen II. the previous owners had installed an Edelbrock 650cfm carb and Edelbrock intake manifold. After driving it for a while, i wanted people to hear it, so i put on a set of DynoMax Headers, and using 2 1/2 inch tubing and a Thrush Glasspack on both sides, exited the exhaust in front of the rear tires. I could feel a difference in acceleration, and maybe top end, but not by much. I've read up on adding power for a long time, and the more i read, the more options i uncover, and i eventually become overwhelmed by information. There's nitrous, superchargers, blowers, turbos, methanol, and i'm sure there are others i haven't even stumbled upon. Can anyone clarify some of these, i know how the forced induction systems function, but i don't know what kind of numbers they produce.

 

What i want to make is a 350hp minimum 350ci engine, but i am on an EXTREME budget. To simplify what i mean by a budget: i don't actually have an income. I'm a senior in high-school, i'm 17, so employment sucks. I may be getting a job soon, but i'll assume i won't for this build. Also, i want to be able to leave my engine in the truck, because this is my first vehicle and i don't want to mess something up. Does ANYONE have any useful advice on producing power without going broke? Oh one more detail, i have a daily driver, a little VW, that gets 36mpg, so i couldn't care less about fuel economy for this engine.

 

Cams, heads, lifters, valves, exhaust, intake, scoops, pistons, springs... Anything to make cheap power. ANY advice that could help, thank you

 

colin

[I-H8-4Ds]

I've heard you can get the heads milled to some degree that will get you some more compression. You would have to talk to a machinist or an engine builder to determine how much metal to remove and how much compression you would gain. You may have to mill the intake manifold a little afterwards as well. I hope I am not misleading you here, but at one time a machine shop told me they could give me almost all the compression I wanted on a 350 just by milling the heads.

 

After 1970, compression was lowered a lot on the 350. The pre 71 models would give you 250-300 hp stock. Emissions standards castrated everyone's V8 for a long time after that.

[sorestgore]

hmmm, that's horrible! i'm wondering tho, my truck has no catylitic converters, or and EGR systems at all; with the performance intake, carb, and headers, what would you expect me to be getting for horsepower??? it runs very rich, but i'm not too familier with adjusting the carburater, so i haven't tried to change that at all, there are two screws and i don't know which one does what...

 

but anyways, by milling down the heads, basically your making the cumbustion chambers smaller, and by not changing the valves or timing, it will just compress it more before firing, making more power?

[RaysZ71]

You really need to find out what the engine is. If its a low compression 350 from the late 70's early 80's it will be tough to get the power you are looking for. If thats what you have, ditch it and find a different engine, it will be cheaper.

 

However a good set of heads and a cam will help out nicely. L98 heads from a late 80s camaro are decent. But a set of Vortec Heads from a 96-99 truck are better and cheap. Those heads require a different intake but there are alot out there for those heads. Those engines made 255 hp net, thats about 320 gross hp stock.

 

So a mild 350 with 9.5:1 compression and vortec heads, good intake and headers should get you in the 360-380 gross hp.

 

 

edit... a 650 cfm carb is fine for that size engine, but is sounds like your carb/intake combo may be too much for the heads and cam you have. If the engine was a factory 2bbl, the heads and cam can not handle all that air and fuel.

[OnyxMAX]

if it's the original 72 350 (you'll have to look up the block numbers a real pain and hed numbers more of a pain) you should be 300+ just with the intake and carb with headers.

 

my guess is it's been built befor for high rpm use (no low end) as many people did in the past, and the cam and springs are stock so you have a intake made for the 2500+ rpm range and the valves float around 4000 killing power. there is prolly also nothing done to the tranny to adjust for the shifted power range and it's shifting early.

 

if my guess is right when you nail the go go pedal it bogs like a mofo. then slams your head on the back glass. then feels like you slamed the brakes on befor it shifts and bogs and slams you head on the glass again.

 

a good cam, springs and shiftkit should be faily cheep. then if thats not enough you can bump the compression. but you might not want to if your gonna go woth nitous or F/I.

[garyindiane]

Headers, Put a new fuel filter on it, Cam, Biggest air filter filter ya can fit on it( The more surface area you have the better it can breate), Disconnect AC compressor, Advance timing, Run higher octane.

 

 

Peace Gary

[sorestgore]

Headers, Put a new fuel filter on it, Cam, Biggest air filter filter ya can fit on it( The more surface area you have the better it can breate), Disconnect AC compressor, Advance timing, Run higher octane.

 

 

Peace Gary

 

<{POST_SNAPBACK}>

 

 

 

 

that's pretty much it, although it doesn't bog that badly, but than again, with headers and glasspacks, i rarely get to floor it all the way without causing a problems with the authorities. one thing you weren't correct about in your guess was about the shifting, from a standstill, if i were to floor it, it would chug for a split second, than launch. once it starts to roar and accelerate, it does so until nearly 5500rpm, at which point it smoothly shifts to second gear, and it's smooth for 3rd gear too. i hadn't mentioned this before, but this was a military truck (interior was olive drab), and i beleave it was outfitted with a beefier transmission, but that my just be a rumor.

 

if my guess is right when you nail the go go pedal it bogs like a mofo. then slams your head on the back glass. then feels like you slamed the brakes on befor it shifts and bogs and slams you head on the glass again.

 

<{POST_SNAPBACK}>

 

 

 

i've been planning on replacing the fuel filter, i do not have ac (or power steering, power brakes, radio, BONE stock).

ANY recomendations for a good cam???

[sorestgore]

the phrases i quoted are in the wrong order, the one from gary should be second

[OnyxMAX]

yep, id stick a cam in around 280* ish that should match all your stuff up. power from 2500-5000ish little lope and nice cam idle. that will also set you up for headwork in the future or new heads. honestly i would save the head stuff for when you put a forged bottom end in.

[Zapp168]

I am not sure where you have gotten with this, but if it were me, and on a budget, I would do some research into hooking it up CORRECTLY and spend the $500.00-$700.00 dollars on a nice nitrous kit. Cheapest horpower known to man. If done correctly it is economical and reliable. Of course if the motor is stock and old and you over do it it will eat itself.....but then you save the kit for your next motor.