I am helping a buddy who is building a slightly O/T 72 Nova. He's got a suprer T-10 4spd and a posi rear. We got a 350 4 bolt short block but not sure where to go with the build up. He wants plenty of low end torque. It is difficult to decide what direction to go with all the parts options available. You read shit in the car mags and it seems alot of these cars make most of the power in the upper RPM ranges. My thoughts are to get a set of good flowing heads, and intake, RV type cam, 600 CFM vac secondary carb, headers and a 2-1/2" exhaust. Novas aren't especially heavy either.I also thing we should keep the compression around 10:1 so it will run fine on pump gas. Alot of you guys have tons more experience with this stuff. I would be greatful for any help. Thanks, Todd
Sounds like you have a pretty good plan. The cam is what makes the torque curve be where you want it. The budget usually dictates how fancy you make the engine.
Depending on the budget, some forged flat top pistons, aluminum heads like Edelbrock Performer RPMs (or even World Products cast iron Sportsman heads) a decent cam (not necessarily an RV grind, but something a few notches up the ladder), a good aluminum dual plane intake and a carb of around 600 cfms, will give a good start. A good electronic distributor and headers would wrap up a solid performing sbc. Gear ratio will be the biggest factor in seat of the pants feel. I like deep gears personally, but something in the 3.50 to 3.70 would be streetable and work great with that 4 gear. For a few bucks more he could go to a 383 stroker kit and have all the bottom end he would want. Don
VORTEC heads, check out scoggin dickey chevy for heads already modified for lift over .470 and drilled for gen 1 style intake bolts. many companies offering them in aluminum also. If you have the capability (mill) you can mod them yourself, few companies sell a fixture to machine the spring pockets. flat tappet .470 - .490 lift cam. Similar specs to a Comp 270H or 280H, depends on what the car is going to be used for. http://www.compcams.com/Company/CC/cam-specs/cam-search-results.aspx?sc=15&sm=By Engine Family performer rpm intake - dont worry about the air gap unless you want to spend the extra $ 10:1 with a vortec is reasonable, hypereutectic will be just fine Cast crank, rebuilt rods, moly rings, clevite bearings, keep it under 6000 rpm, solid machine work youll be good to go. 1 5/8" or 1 3/4" headers depending what cam you choose, higher rpm cam range = more header -- long collector on either one in that Nova he'll have a difficult time clearing an HEI distributor unless he notches or hammers the firewall. use a pertronix in a points distributor or a mallory unilite. Your friend needs to decide on gear ratio and what he wants the car to do before choosing a cam. Find out of the rear is an 8.2, 8.5, or 12 bolt. Im guessing an 8.5 with likely a 3.36 or 3.42 gear, if thats the case go with a milder cam (Comp 270H type specs). You can look into XE268H cam which is a dual pattern, not really necessary with the vortecs though, the dual pattern cams gave more exhaust lift to make up for bad heads. I typically go with Holley's but recently bought an edelbrock 600 vacuum for one of my dads cars so it was easy for him to maintain, I really liked the edelbrock for a car thats more of a driver, maybe a 700 cfm if you go with the larger cams. Check out Northern Auto Parts online for engine kits, I keep coming back to them for quality of parts at a good price. You dont really need a high volume oil pump, get a std volume, pull the cover and polish the port, set your crank up at the middle of the spec. check out their master rebuild kit, you can upgrade your cam kit to either a comp, or speed pro cam, Ive used dozens of the speed pro cams over the years and never had an issue with them.
Check out this months carcraft magazine. They tested a bunch of after market heads including the SD vortecs. They were one of the more expensive pairs and they got trounced. The kicker was the cheapest set was the clear winner. Within 6 peak HP of a pricey set of darts and on average was wthin 2 HP of the best. Using a mild cam and off the shelf intake they made 406HP from a SBC 350. Just build what they did and dial back on the cam to optimize the torque peak if necessary. Heads, cam, retro rollers, gaskits and intake should be about 2 grand. If you really want torque get an Eagle or Scat 383 rotatig assembly too. You can get them balanced and read to assemble with bearings and all.
I picked up a 2001 crate 350 (roller cam version of course) with 40k miles, used for $400. Threw away the TBI injection system, and picked up an LT4 "hot cam" roller cam, 1.6 roller rockers, vortec heads, edelbrock performer RPM intake and a 650 holley carb. Total investment is under $1200 and should make abour 430 torque.
Wow!! Thanks for all the great advice. We were talking about getting the block machined for a stroker kit. The rear is a 12 bolt but not sure of the ratio. He has money to spend but we are trying to figure out the right parts to put together a nice motor. I'm sure you'll all agree the secret is all the correct parts working together that will make the motor what it will be. One wrong choice could actually be a step backwards. Thanks, again, Todd
good heads are the key, spend your $ there. cast crank short block will make tons of power if youre careful with rpm and have good machining. up to 400 hp I wouldnt even worry with a roller cam. If this is really a cruiser with some power and not a street strip car 350 - 400 hp is plenty, above that point he needs to start thinking about the T-10 holding up if he's driving / racing it hard.
I'll second the late model shortblock with Vortec heads. I like the 1pc rear main seal and roller cam. If his idea of low-end torque is shifting at 5000 max and stump pulling torque at 1500 without downshifting, don't port. Do go for a roller cam. Get into some kind of cam software that will tell you where the power will be made with a combo. Be careful with old bolt pattern drilled Vortec heads. LT1 and Vortec are when they began experimenting with taller / higher ports. You don't want a port mis-match from some old intake right off the bat when the right intake is easily found and purchased. Have fun.
Lots of great info, and I agree with the changing heads if the heads don't have good sized 2.02"/1.60" valves. Not sure I'd go Vortec, as that limits what intakes you can use with the new intake bolt pattern on Vortec heads. A good old set of rebuilt camel hump 2.02 heads with hardened seats and SS valves would serve him well, and give unlimited intake choices. I'm running an Isky 270 Mega Cam and the performance band starts right off idle to around 6200, so a very nice low end cam. Specs are 221/221 at .50" and .465" lift, with 108 LSA. A nice lope, but good response. Being a '72 the rearend it came with was the biggest 10 bolt GM made, the 8.5", which is only .25" smaller than the 12 bolt. They are the best 10 bolt ever bbuilt, and will hold up well to lots of power. I'm running the same reaend in my OT '71 Camaro behind a 427, and it's never given me any grief. I did install the Summers outoard bearing kit to eliminate the c clips on mine. I'd run 3.73 behind the SBC, but I'm running 3.42 behind my 427 with the extra torque it has.
A buddy of mine took a 350, punched it 30 over, flat top 9 to 1's, vortec heads, stuck in the old 300/327 hydraulic chevy cam, dual plane intake, 600 holley and stuck a pretty much stock HEI ignition in it.... it was a nice solid strong pump gas small block indeed. Just my experience on it.
I am a firm beliver in "no replacement for displacement" when it comes to TQ especially....383 ....Shawn
How much torque does he want and how much money does he have. Those are questions that need to be asked prior to starting the build. A long arm is probably the simplest way to come up with torque but it is not the only way to do so. It can also be done with a stock stroke 350 but it takes a little doing and could prove to be spendy if one is not apt to do most of it on their own. A good enough stroker kit can be had for less than a grand if one is building a dailey driver type of an engine. That is probably your cheapest route. By the way I think that a '70s era Nova tipped the scales at around 3500 lbs that is not a light car.
First and most importantly, what is his intent with the car? A 350 by nature of only being 350 cubic inches is not a torque monster, nor a high hp revver, but it CAN do both pretty well. You can get the best of both worlds from a street-bound 350, at the sacrifice of being ultimately as good as a big inch stump puller or a high revving screamer at their respective strengths. To do it right, you can't just build a motor to suit a particular horsepower or torque number, you also have to consider the car it's going in, and the supporting drivetrain parts, etc. Peak horsepower and torque are pointless on the street. Average power is what you want to be concerned with. My particular 350 consists of a 10k mile '99 Vortec 4 bolt block, stock crank, rods and bearings, 11:1 hyper pistons, mildly ported Performer RPM heads (with upgraded springs, solid pushrods, and Scorpion 1.5 rockers), Performer RPM Air Gap intake, and a Holley 750 Street HP carb. The telling feature is the Comp XR294HR cam, which is fairly large for the application. It's geared a little more towards top end horsepower, but it still has enough guts down low to roast the baloneys with a blip of the throttle. It's not as torquey as some small blocks, and it's not as powerful up top as some others, but I built the engine to suit the car that it's in. The car is relatively light (3000-3100 pounds without me in it), so I could get away with leaning a little more towards top end. Gearing is currently 3.55, and the stall is only a 2000-2400 unit, so with a convertor swap and more gear, the car would be a monster, but it also works well in the given car with the particular gearing and convertor selection I have now. The one concession has been a LOT of tuning and fiddling with air/fuel and timing to get it to where it is now, but I'm pretty pleased by it, and stand behind how it performs for my total investment of about $2500. In all honesty, look at some of the more popular crate engines out there. Find a few that have the numbers you're looking for, and take note of the parts they're running. You can then make some parts changes from there, to move your focus more to where you want it. This is exactly how I selected my parts. I looked at the Edelbrock crate engines, added a little more here, a little more there, and got where I wanted to be. An engine that makes good top end power, while still being plenty of fun on the street.
Generally not even a big fan of the 383, but if you want low end grunt, and you are stuck on a 4" block, you want a 383.
Off topic, but who are the dickheads that go around rating good threads 1 star? Is your life that disappointing?
If you ever start a thread I am going to rate it one star. Maybe they think it is like wheel of fortune abd buying a vowel. Listen you don't have to buy stars fellas they come with the price of admission don't be stingy with them.
Good reading on a 383 vortec http://www.popularhotrodding.com/en...allblock/0611em_vortec_small_block/index.html
If you plan to put many miles on it, do yourself a favor and build it with modern hyper pistons and skinny low tension rings, and a compatible cyl wall finish using torque plates. Not only will the engine will last a lot longer, but even more important, less friction in the cylinders will pay fuel economy dividends for the entire life of the engine. Less friction in the cylinders also means less heat being put into the cooling system. Oil temps come down as well. Quick crude example... if a modern shortblock requires 25ft/lbs less to rotate, that's a savings of 7hp at 1500rpm. If your car cruises at 2500, that equals a constant savings of roughly 12hp while you are driving down the hiway. As a bonus, WOT at 7000rpm you would have about 33 more hp on tap. Better mileage and more power. If i were a flathead guy, i'd be building them this way as well.
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