I might be an LS fanboy, but I certainly didn't originate with them. I spent years doing small blocks and big blocks.
My Nova originally had a 350 in it. Then a 396, then a 427, then a 468. Bigger and meaner every iteration.
The 468 ended up around 650 HP because I wanted to keep it mild. It was still hydraulic cam, 850 double pumper, 10.5:1 compression, and ran just fine on 93.
I put a little spray on it at one point to get more some power out of it.

I decided to go ahead with the LS swap when the big block got to the point where it was more maintenance than it was worth.
I picked up an aluminum 5.3 from the junkyard along with a 4L80e, tossed in a very very mild cam, put $1800 in a single turbo setup,
It made about 200 HP more than the big block made on nitrous, got 14/24 mpg city/highway beating on it hard, fired up first crank,
and even with a 4" fender dump downpipe, was quieter than the big block was with a pair of flowmasters. There was no looking back...

That said, I think trying to LS swap clean original cars is a tradegy. You're loosing something when you do it.
If you have an old beater and want to go stupid fast for super cheap? Do it. Have a heavily modded chassis and want to make a fast street car? Do it.
Have a clean original car with that old small block sound? You have something special, don't ruin it.

 

You're more than welcome to come see for yourself.

Modern stand-alone ECUs and careful setup planning go a LONG way. The local no-prep guys are a big group of 4-second 1/8 cars that do weekend street races for big money, ALL with turbo LS engines, Holley/Megasquirt ECUs, and DOT legal radials.

 

As Kenova said - there are lots of differences among factory Small Blocks.

In the 60's and early 70's (during the HP wars) the 4 Bolt Blocks were actually pretty beefy. But as we got into the late 70's and 80's the factory motors were not making any real power and the factory engineers were worrying about fuel economy and cost - so metal was removed from the Blocks. I've heard the weight differential can be close to 40 Lbs.

Spencer - I believe the Dart SHP is "rated" to around 700 HP - but why don't you give the folks at Dart a call and discuss it with them. The BIG advantages of the aftermarket block is that the designers were free to put the metal where it is needed, they use a better grade of cast iron than the factory does, and they do the majority of the machining in FAR fewer operations - meaning that there are less tolerance "Stacks" to worry about. I Personally, see almost NO reason to go with a factory block on any SBC application where the expected power level is in the 500 range or above, it just doesn't make any sense.... But don't take my word for it - take some time and talk to engine builders who have a reputation for engines that stay together - they work with this stuff all day long - see what they say...

 

IMHO there is virtually no limit to the SBC block.

im planning on throwing nitrous on top of the boost I already run on mine.

not expecting any issues

 

Isn't that just another way of saying you are using engine management to limit power/boost until you roll out and gain enough speed to effectively hook up full power...which is what Kevova was getting at?

 

Maybe, it's a little more complicated than that but the same basic idea. My traction control is more intrusive at low speeds, as is boost control. With the right tires, I can stab the throttle, build boost instantly, and my ignition timing will be varied based on traction and acceleration.

Once I'm moving, every bit of the available power gets tapered in, but I can still launch hard enough to outrun anything else, bikes included

 

I don't know what ECU you are using but I use MaxxECU.
In this video they explain how you can control wheel speed. I assume that you are doing something similar.

 

Much like DizWiz, I'm one of the oddballs pushing a BONE STOCK bottom end to its limits. The rod/mains haven't been touched since sometime in 1987. Stock ring end gap, crap cast piston, dinky rods, stretch Armstrong cast crank.

Several years now on the current combo. 16+psi boost, 100 shot of nitrous, slinging it to 6800rpm.

Big heads, big cam, carbureted blow-through centrifugal setup.

FWIW - 90% is in the tune.

 

Gearheads (lol) like this guy (and Aaron - I think maybe his dad) know what they are talking about !

 

There have always been low buck guys. In the pre efi days big cam, intake with a Holley and headers and away they go. When it breaks they get another one and repeat. 30 year old engine should be good but it's an unknown. Corvette probably not dogged like a f body. Now 2k+ in new parts on a stressed 30 year old short block is a gamble. 6800 on stock rod bolts is a gamble. Piston slaps head because bolt failed can get expensive. Power adders find the weakest link faster.

 

No doubt its sketchy at best, but I've run it ***** out against more cars than I can count and its survived half mile racing and the texas mile.

130 in the 1/4, 158 in the half, 188 in the mile.

If that's not a testament to the durability of a 2 bolt sbe sbc, I dont know what is.

Aggressive timing, conservative AFR, low EGT's, and a loose nut behind the wheel. That's what my old car seems to want.

 

Aaron (aksracing) is indeed my pops.

 

That is a testament.

Also, Engine Masters took a basic "rebuilder" Vortec 350 and tried to blow it up w/boost. They hit 765hp/695tq and the thing never faltered. They gave up.

That is another testament.

 

While I have zero doubt that what you said is true - I've also seen a GM Crate engine with 3 pistons installed incorrectly (upside down) that was blowing coolant out the exhaust from a failed head gasket - in less than 1,000 miles of use. MUCH depends on the actual parts that are installed, and how carefully they were assembled. (I have also heard that many stories about the crap people would find when they tore down stock motors built in the 1970's & 1980's.)

Just remember - in the production world - keeping costs down is probably the highest priority. A good set of aftermarket rod bolts costs about $100. If a rod bolt fails - it's common for it to take out the block, the crank, and sometimes the heads. To me - if I've spent some money on the heads - that is too much of a risk.... Others have different opinions, and are more than welcome to do as they see fit. THAT freedom to do as you choose is what makes this a Great Country !!!!

 

I completely agree, BUT the act of replacing the rod bolts/nuts will deform the big end - so these little things that people get hung up on are not so simple. The engine would need to be torn down and the big ends resized. - and let's be real - we aren't tearing it down for rod bolts yet reusing all the other parts.

That is the damned if you do / damned if you don't part. Rod bolts, machine shop reworked rods, same junk cast pistons, new rings, hone the block, put it all back together to still have a crap cast crank and crap cast pistons in a 2 bolt block.

This is why there are guys like me who started with a stock motor, then grew to where it is now on a budget - "the wrong way".

I can vouch for the stock block making somewhere in the 700ish range - for me - reliably - aside from head gaskets with stock head bolts.


Is it the right thing to do? Hell no. Was it in my budget to build a sub $7,000 car that whoops up on cars 10x the price? Hell yes.

One day I will wipe out the crank, melt down a couple of pistons, push another head gasket, or otherwise destroy the motor. I'm ready. I have a cage, engine diaper, and fire suppression.

When that day comes, I'll likely build a "proper" motor with an aftermarket block designed to hold 1,000hp+ and good components.

 

IDK...I think there is a case for it. If it provides high fun value (it does) and the person has accepted the potential consequences (might need another motor), then it's the right thing to do.

 

we ran the pee out of 2 bolt stock rod engines in the 80s noone I knew blew one?
2 bolt BB are super stout
I imagine if you twist them long enough something will go esp if the stroke gets bigger that will push limits
Most cars can get by fine wtih a 2 bolt main cast crank etc. If youre worried get a basic forged piston and better rod bolts

 

I guess it would depend on your definition of big power. Stock 4 cylinder engines have been able to make around that HP number on stock block/rotating assembly for a long long time now.
I honestly think you'd have a very hard time finding any V8 that couldn't make that much power just winging it on the engine dyno. Through a stalled auto, that is only ~500whp after all.

THIS is basically my motto to live by

Cheap fun.

 

We're in agreement !!! (Although I do remember some "Hot Rod" articles in the 1980's where they would change the rod bolts and not resize the rods, and I believe they normally got away with it. In my world - things don't normally work out that way...

Last time I built a motor - I started with a $5K budget and ended up spending $10K. Every single thing l did led to "just one more upgrade".

 

A SBF won't do it. And if you got lucky enough to find one that did do it....it won't do it for long. They're good for ~500 CHP BEFORE THE BLOCK CRACKS.