Build a 600hp naturally aspirated small block!

[SStrokerAce]

Good heads help that.... 215cc heads and a MCA for 2.248 at the pinch are a little "large" for a 365 cube motor. The 2.08" valve and .560" lift gives you a curtain area of 3.66" so it's enough to get it too 6100rpm peak.

Bret

[68sixspeed]

What's it weight and what's it run at the track? the 1/4 mile dyno doesn't lie. Good old physics. -Dan

[SStrokerAce]

Ain't seen a car yet, all it does now is collect dust and try different things out on the dyno... the ole pump don't lie either. The dyno has been backed up before by other cars at the track. You guys really crack me up, it's not THAT hard to build something like this.

[68sixspeed]

Well, that's what I was trying to get at... if it had been to the track it's hard for anyone to dispute 1/4 mile mph. -Dan

[Neil B]

Good heads help that.... 215cc heads and a MCA for 2.248 at the pinch are a little "large" for a 365 cube motor. The 2.08" valve and .560" lift gives you a curtain area of 3.66" so it's enough to get it too 6100rpm peak.

Bret

Bret,

You bring up some new concepts for me here that I would like to learn more about. How does curtain area affect the actual HP peak? I always thought that intake runner MCA determined peak HP RPM (assuming sufficient camshaft duration). In other words, the peak HP rpm is limited by MCA. If you size the cam properly, the HP peak will occur at this peak rpm. If you oversize the cam, the peak will still occur at the MCA limit and you gain nothing. If you undersize the cam, the actual HP peak will be lower than the MCA HP peak and you won't be fully utilizing the heads.

I do understand the concept that the more curtain area you have, the less camshaft duration is needed. But is there some kind of math that takes this into account when selecting a cam?

In my 372ci (4.125 x 3.480) engine build, I wanted a motor that would make peak HP at 7,000rpm and rev to 7,500rpm. To achieve this goal, I calculated a 2.18" MCA. So I bought heads that slightly exceeded the 2.18 MCA requirement and then I went to my cam grinder and said give me a cam that will peak @7K and rev to 7,500. Is this not the proper way to go about it?

[SStrokerAce]

Neil,

The MCA calculations are based of a assumed Mach number and how efficently that area is used to move air thru it. Obviously the more efficent that area is made the more you can move thru there without a choke condition. All though people seem to think you want the MOST velocity you can have, in fact you don't too much is as bad as too little.

Same thing applies with the valve curtain area (Valve Diameter x lift x Pi). I'm assuming that the average curatin area is what the calculations are based off of since the curtain area of the valve is usually higher than the MCA of the port.

You might want to get Larry Meaux's PipeMax program at www.maxracesoftware.com it does all the math for you on engine calculations.

The way you went around your motor was a good idea, do the cam last! I like to work on it as a system and then tweak the cam specs in the end. So get your basic cube size for the motor, work with a head porter on the right casting and sizing for the setup, then get the head and match the compression (which you should already have had a range for to design in the optimum burn) and the camshaft with what you want the motor to do.

BTW what did you end up with for heads and a cam?

FWIW on here in terms of motors I see way too much overpriced junk or guys cheaping something out. I get sick of seeing $20K 650hp motors with too much cam and freaking crate motors in magazine cover cars that are supposed to be "Pro Touring" but if the owner ever drove the thing hard he would find out the handling is not what he though it would be. It's good to see guys interested in building real motors, NA small blocks! As I tell my GF big blocks are for *****s and as Keith Duckworth said "Turbochargers were for people who can't build engines". Hell one of my buddies works on LS1 Daytona Prototype motors all day. Those things at 5.0L put most peoples 400 cube motors to shame and not to mention they beat up on the 4 valve motors in the class and probably have the lightest engine package with the lowest center of gravity other than the Posche race motor that is allowed to run, everyone else runs a OEM production based motor. I know my daily driver is getting some of that technology in it here soon ;-) - end of rant -

Bret

[Neil B]

BTW what did you end up with for heads and a cam?

Bret

Bret,

The heads are 218cc 100% CNC'd Canfields with some additional short-side cleanup. The Track 1's were my first choice, but I went with these because of the stock exhaust port location to avoid custom headers. The cam is a custom solid roller from Cam Motion 264/272 at .050 .668/.652 lift, 108 LS.

[Mr.VENGEANCE]

is it possible to get that number out of a SB 406?

[chad007]

I agree with strokerace

[Scott Parkhurst]

It's best to agree with Bret on such things.

He's a pal, has been for years, andreally knows his stuff. He and his pops work on this stuff full time. They bathe in it.

There's few people I enjoy speaking engine-guy stuff with more than Bret. Take his advice and watch it work for ya.


~SP~

[SStrokerAce]

is it possible to get that number out of a SB 406?

The HP? I would hope so, you just have to pay attention to the rest of the details. Most big strokers don't have the quality of heads they needt o make power. If you get the same TQ per cube you'll probably have problems with the block if it's a stock peice.

It's best to agree with Bret on such things.

He's a pal, has been for years, andreally knows his stuff. He and his pops work on this stuff full time. They bathe in it.

There's few people I enjoy speaking engine-guy stuff with more than Bret. Take his advice and watch it work for ya.

Thanks for the good words man. The old man gets into different aspects of it sometimes but it's good that we get off in different directions because it helps us attack problems better.

How is the new mag and up north treating you and the fam? I have a few motors that i've taken a lot of pictures on in the build ups and they might be of inrest to ya. Just well built street motors that go along with the pro-touring theme.

Shoot me a e-mail sometime with a number and we can catch up. I gotta sign up for your magazine!

Bret

[Frank Henry]

Googled 600 HP SBC and ended up here. I'm 63 and spent my whole career bending wrenches. Last winter I set out to get a pickup and wanted a ground pounder. Bought a 2000 S10 Extended cab, RWD, 2.2, 5 spd with a broken t chain. Put a chain in it and started looking for a proven recipe on the web. This is my build;
No power adders.
Ford 8.8 3.73 locker, narrowed, 5x4.75 whl stud pattern.
Chev HD Turbo 375 out of a cube van.
GM Mex 4 bolt 350 block
ARP studs everywhere
Eagle cast 3.75 rotating assy w/4.030 flat tops.
GM Bowtie Phase 2 heads, 195 CC, 2.02/1.6. 58 CC. Yields 11.7 static comp.
Cloyes double roller chain and gears.
Torrington cam thrust brng & button
Comp Cams Extreme energy 12-433-8, Cam Style: Hydraulic roller tappet
Basic Operating RPM Range: 2,500-6,000
Intake Duration at 050 inch Lift: 236
Exhaust Duration at 050 inch Lift: 242
Duration at 050 inch Lift: 236 int./242 exh.
Advertised Intake Duration: 288
Advertised Exhaust Duration: 294
Advertised Duration: 288 int./294 exh.
Intake Valve Lift with Factory Rocker Arm Ratio: 0.520 in. (Using 1.6 rockers on both valves)
Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.540 in.
Valve Lift with Factory Rocker Arm Ratio: 0.520 int./0.540 exh.
GM V6, short hyd, roller lifters.
Vortec lifter spider (studded the block to install spider) with dog bones.
Chrome molly pushrods.
Harland Sharp 1.6 full roller rockers on 7/16 studs.
Air gap RPM intake, port matched.
Holley Aluminum Ultra XP Carburetor 0-80843HBX, E85, 750 CFM.
In tank EFI pump w/bypass regulator.
Serpentine belt drive off of a 4.3 V6 from 99 Blazer.
BeCool rad, twin fans.
Pertronix flame thrower disto.
NGK-4449 plugs.
8mm wires.
38* advance, all in.

Any Desktop Dyno results?
The only measurement I have is 0 to 100 in 6 seconds flat.
I estimate it's in excess of 560 SHP.

[Frank Henry]

Forgot to list the exhaust. 1 5/8" Hedman long tubes w/3" collectors to Thrush welded shorties and turn downs.

[vette427-sbc]

I think you'd be closer to 500... you need way more intake runner cfm and cam (and RPM) to be in the 500+ area with a 383.

FWIW our shop car with a 406, AFR 195 heads and a .600 lift ~250 @.050 solid roller did 440 to the wheels through a stick trans.

[Frank Henry]

vette427-sbc, thanks for the post. It is at 11.7 static comp ratio and runs on E85. Also it has .555 Int lift and .576 exh lift. It's a hoot and a half!

[quickiroc]

Okay guys,

here is the challange. Build a Natuarlly aspirated small block chevy, that will produce 600hp at the flywheel.

Rules.

350 cu block. overbore max .060"

Crank, Any brand, off the shelf.

Rods, and brand, any length as long as pistons avalible for size.

Pistons. Any brand. Must be off the shelf no custom built.

Compression ratio. Unlimited, but must run with no fear of detenation on 110 octane Sunoco

Cam. No limits.

Valve train, any lifter, pusrod. Rocker arms must be stud mounted ( no shaft stlye.

Heads. Retail price limit of $1300. Porting allowed.

Induction. Cast alumimun single carb intake. Porting allowed.

Carb. Single 4 barral. Any size

Any tube size headers, open exhaust.


So, lets see those recipes!

350 SBC block +.060 zero decked
Eagle 3.750 crank
388 cid
Speed Master 4130 I-Beam Rods 5.7"
DSS Forged flat-tops 2 reliefs 11:1
AFR 195 Eliminator heads 2.05/1.60 65cc straight
286/286 @ .50 .560/.560 lift 110LSA
Jesel 1.6 shaft rockers
Super Victor II Intake
FiTech Go EFI 8
Nitrous Outlet 300 shot w/progressive controller
Stainless Works 1-7/8 headers, 3 inch primaries

[Jonathonar89]

Gotta love these old school threads popping up haha. This thread is older than Gen 4 LS engines lol

[dontlifttoshift]

True, and who's dyno? Let's face it, I think 1/2 or more of them out there are tweaked. Without naming names, there are a couple big name advertisers with 500-600hp street small blocks in all the magazines that are way, way optimistic. I had to laugh at AFR's site the other day, they show 600hp on the 227 heads on the 434 small block with a hydraulic roller around .532 lift. No way, I just put a 427 small block on the dyno with those heads, same compression, and close to 700 lift on a mechanical roller to still fall shy on those numbers with out of the box heads. We'll get there, but it will take rework.

I had to laugh at AFR's site the other day, they show 600hp on the 227 heads on the 434 small block with a hydraulic roller around .532 lift. No way, I just put a 427 small block on the dyno with those heads, same compression, and close to 700 lift on a mechanical roller to still fall shy on those numbers with out of the box heads.

Neat

[cornfedbill]

Reality is there are lots of cars out there still running Gen1 small blocks, and will be for a long time. This is an interesting - thought very old - thread.

I built a 10.6:1 377 Gen 1 small block on a budget - lots of horse trading and elbow grease. Of course it is nowhere near 600 hp, but should be a solid 400 HP and a bit over 400 lb-ft of torque. No powerhouse, but runs on pump gas, idles smooth-ish, and has great throttle response. A friend of mine who worked for Roush in the past, spent hours on a Superflow bench with some Vortec heads and got them to flow pretty good. Considering I got them for nothing and we ported them ourselves, they're a bargain.

One thing that I feel is a benefit is a 4.155" bore to unshroud the valves. Yes, it breaks these rules. We labeled the heads right and left, then put them on the bare machined block and scribed the bore on the heads from inside. Then we unshrouded the valves on the sides right up to the cylinder wall.

If I machined the heads so the retainers didn't hit the guides so I could increase the lift more, added more duration and bumped the compression, it would make lots more power. But then I would pay for that in throttle response, drivability and would need racing fuel. Since this is intended for street and open road racing events, I opted for something reliable and with good torque. No, it is not for unlimited speed classes. It should be sufficient for classes up to 140 mph. That's enough for now.