TheMagikMan

If someone wanted to build a gen 1 small block that can be street driven to compete with Naturally Aspirated 427 LS cars, what would be the most affordable bare block that can be bored to 4.185 to make a 454 small block that can put 600hp to the rear tires NA, and is it worth $5000 for the Dart M2 blocks? It still seems more affordable to build the small block than to buy a 427 LS crate motor from TSP by a pretty good margin, even with a full Callie's bottom end and AFR 245cc heads with shaft rockers and all the other goodies necessary to make insane power. Plus, you just can't get that classic small block sound out of an LS motor.

AlkyIROC

If you're asking those types of questions, you would probably be better off buying a premade assembled engine. Lots of choices out there and in the end, it will be cheaper than building your own unless you work in a machine shop. 454 SBC is an exotic displacement so don't expect it to be cheap.

roadthrills

ANY gen1 smallblock putting 600hp to the wheels AND normally aspirated........WILL NOT be street friendly. You just can't have both. Now, if you want to turbo a nicely built 383 stroker, with a balanced rotating assembly, and some nice aluminum heads,.......you could get decent street manners and still whoop up on an LS.

Vader

This seems to be going down the path of a 97 cubic inch 3-cylinder with multiple fans making 500HP. It's entertaining and educational to watch, as it shreds itself to scrap within a time period factored by displacement, torque, and speed, There is a three-axis graphical representation of that data plot, with displacement as the X-axis, time as the Y-axis, power as the Z-axis. It looks somewhat like a funnel, or more appropriately, like a toilet bowl. Increase the displacement and/or decrease the power, and the Z-axis slope becomes longer. How quickly that goes down the toilet is a function of those plots.

A well-built 500-some inch hemi can make 10,000 HP in short bursts, and might have a life span of about one hour if treated properly. Alcohol engines can crank out 4,000 HP (at peaks) and might stretch out to 30-50 hours if babied. Pro-stock engines can break over 1,000 HP, and if maintained and operated properly can stretch out into the hundreds of hours. We often expect our daily driver vehicle engines to have a durability of 5,000-6,000 hours. Locomotive and large marine engines frequently exceed 10,000 hours, and the smallest of those can make 25,000 HP. We don't see cargo/container ships running three top-fuel engines in place of the house-sized diesels for a good reason - They don't want to swap engines every 8 minutes all the way across the Atlantic, and all their cargo space would be taken up for replacement engines.

If you understand that 3D graph, the exchange between displacement, power, and life might become apparent. That could guide you toward a "streetable" engine making higher power levels. It might even steer you away from a small block. Of course, if 50 hours of entertainment and excitement are your expectation, the sky's the limit for power.

2¢

BadSS

First, streetable is subjective – from mild to wild and everywhere between. YOUR definition plays a huge part in what is needed for the particular objective and more importantly the cost.

Second, you CAN make 600 RWHP with a “streetable” SBC. If you select the right combination of parts, you can make about 2 FWHP per CFM of head flow on pump gas with a moderate solid roller and meet MY definition of streetable. With an automatic and a good "street exhaust", I’d need the engine to make around 750 FWHP to guarantee 600 RWHP. That means the heads used will need to flow at least 385 CFM at cam lift. I say all that because it’ll take more head flow than you’ll be able to get out of the AFR 245s to fit MY definition of streetable.

However, Shafiroff offers a 11:1, 434 with 245 AFR heads that will get you close (with a manual transmission), for $17,350 ($125 extra for Manley crank, $300 Manley rods, $120 Cometic MLS head gaskets, and $300 ATI balancer will put you at $18,195 total). That’s with a Dominator intake, but carb is extra. It made 705 FWHP at 6600 with a cam in the “260-ish/270-ish” range, which depending on your definition may or may not be “streetable”.

https://www.shafiroff.com/chevy-pump...34-bigdawg.php

https://www.motortrend.com/how-to/en...ock-is-wicked/

Regardless, to make 600 RWHP, it’s going to take some cash just for the engine. Then there’s the safety equipment, brakes, wheels/tires, fuel system, exhaust, transmission, driveshaft, rear end, and suspension needed to deliver and handle the power that’s not cheap either.

Orr89RocZ

iTrader: (20)

Dart shp is or was good bang for buck. Everything went up in price with dart over the last few yrs.

leave it 4.155-4.165 bore, no need for more. 3.875 stroke max. Turn it some rpm. Basically a 420 sbc. Popular size. Or do the 434. Another popular displacement but probably want the lil m for that . The key will be intake and head choice to allow it to go to 8000. You are talking about a 750-800 hp all motor sbc. Not an easy task on pump gas, better on ethanol. Box afr 245 arent gonna be enough, they will need abit of clean up.

fwiw, my buddys 412 sbc, way overbored 406 basically, made 521 whp thru a manual trans. Pretty simple, ported AFR 210’s that flowed 300+. Getting 80 more isnt easy but doable.


a 454 sbc would probably be better on a raised cam block and it gets expensive. Youd be better off building a 400” ls3 headed car. But if money was no object id do it on a raised cam tall deck block, and a set of speier profiler 13 deg on it.

a 540 big block would make more sense for 600 whp

BadSS

I agree with Orr on the blocks and the displacement.

I’ve always wanted to build a 13-degree 420 or 434 and tried to talk the folks I built the last two engines for into running them. They, including myself, didn’t wanted to part with the money it would take.

For instance, the link below is to a set of CNC ported 13-degree Brodix from Weingartner Racing flowing mid 390s. With a reasonable cam lift of .650” they have the potential of making around 790 FWHP on pump gas, but they’re $5000
https://wengines.com/sbc-brodix-13-13degree

The stock 13-degree chambers are small but you can get Brodix to do a conical cut to “soften” or make the chambers a little larger. However, you’re going to have to go with a set of custom pistons anyway ($1400??) and might as well get the pistons to give you a compression ratio low enough to run pump gas. The 13-degree heads have provisions for you to run 18-degree and Stahl pattern headers, unlike the next step up to the SB2.2 heads. They flow a little more but are even more “problematic” when it comes to picking and fitting the intake (height) and headers since they have a unique header flange requirement. Plus, they cost even more.

Here’s an example of a pump gas 440 with SB2.2 heads that Shafiroff sells for $24,120. It’s cammed to make 820 @ 7400 RPM, but cammed down to make more vacuum and peak at 6600 rpm it could still make over 600 RWHP. Like I said, not cheap. LOL
https://www.shafiroff.com/chevy-pump...igdawg-sb2.php

On a semi-related topic, the AFR 245s ($3,580) require shaft mounted rockers and Weingartner has a set of 242cc dragon slayers ($3,250) that flow almost as much (compared on his flow bench) and can run standard stud rocker arms, saving about $1,000 over the shaft mounted rockers.
https://wengines.com/sbc-brodix-dragonslayer-242ccstd

Even if you go with a set of 13-degree heads, a fully ported set of LS7 heads can flow more. An acquaintance of mine put down over 700 RWHP over 10-years ago. So if you want to go after the big boy LS crowd, maybe you need to look into those SB2.2 heads. Lol

Orr89RocZ

iTrader: (20)

Forgot about them sb2’s. Nascar take offs. Can find deals on them from time to time. Ebay used to have them lol

always wanted to build one.

another max money is the cfe sbx stuff. 1000 hp 358” motors.