Originally Posted by Apeiron

Put down the magazine and go drive one before you decide it's streetable.

Originally Posted by InfernalVortex

And lets talk about making a 305 make 350fwhp.

It will take aftermarket aluminum heads or ported, specific, factory heads. It will take a big roller cam. It iwll take ARP rod bolts and it wouldnt be a bad idea to get H-beam rods to help it hold itself together. Nice aftermarket crank. Cast is okay, but it's gotta be a quality crank to handle 6500+ RPMs. Big cam needs strong valve springs. You'll need a good intake. Kiss that TPI goodbye. You iwll need a Holley 650DP at least, and Performer RPM or a single plane intake. You will need 4.10+ rear end gears, you will need a huge stall converter. You will need the best headers you can fit on it. The cheapest yuo could do it is Hedman long tubes and a dual 2.5 exhaust. And you will HATE every second of trying to drive it on the street. You will be turning 4000 RPM just to get it rolling from a stop sign.

Just not practical at all.

Lets do it with a 350.

You will need at least Vortec heads. You will need a roller camshaft like an xr276. You will need the same awesome exhaust you would have put on the 305. The same carburetor and intake (Performer RPM or better), and you'll need to tune it perfectly. You MIGHT crack out of it around 350-370 fwhp if you're lucky. And it will have much better street manners. But most 350's have a hard time putting out 350 fwhp and staying streetable. The key is to use Vortecs or aftermarket aluminum heads like Brodix IK180s or AFR180's or so on and so forth. Cheap pro comp crap isnt gonna cut it. You will still need a stall, but a less extreme one, and you will probably need 3.42 gears to help get it rolling.

Those 70s 350 heads, cams, intakes, carbs are not good enough. they iwll keep you at 150fwhp. You need to spend some big money on heads. And at the end of the day, you've barely eeked out LS1 levels of power for more than an LS1 costs, with less gas mileage, and the smog police will tear you a new butt hole if you ever go to a place where that matters.

The LS1 weighs 200 lbs less. It makes the same power as the hotted up 350 does with a factory cam. Just an LS1 alone is enough to get a thirdgen into the 12's. If you put a new cam and intake on the LS1 you're 450+hp. You will NEVER get a streetable 350 to 450+ horsepower. It just won't happen. You gotta be building that thing PERFECTLY to get anywhere near 400hp on a streetable 350. It's just not that easy to do. The LS1 can hit that if you sneeze on it wrong. Plus, like I said, it's 200lbs lighter and gets better gas mileage and it will do all that through factory exhaust. Put some long tubes and duals on it and you get even more out of it. Simple bolt on mods with an LS1 will walk well-built mild 383's!

Originally Posted by mustangdmurder

TPI? My Camaro has a carb. I am pretty sure I have seen plenty of 600+HP 383s and exactly mild 383s not built 383s.

Originally Posted by mustangdmurder

I am pretty sure I have seen plenty of 600+HP 383s and exactly mild 383s not built 383s.

Originally Posted by midias

Show me a mild 600hp 383

Originally Posted by Apeiron

You have never seen a mild 600 HP engine.

Originally Posted by Apeiron

Yes, have you ever driven a car with a 360 HP engine of any displacement?

The point is that "streetability" is a subjective quality. Magazines are notorious for promoting "streetable" engines with over-inflated numbers that most people might accept for a weekend cruiser but would rapidly despise for a daily driver. You don't yet have the experience to evaluate the article's content objectively or subjectively.

Less talk, more do. It doesn't matter what you do, even if it's "wrong". Just do something and you'll learn from it.

Originally Posted by mustangdmurder

I'll have to ask my dad if he thinks that would be streetable. When did you drive a 360HP 305?

Originally Posted by mustangdmurder

there are not so mild 383s that get 600+HP.

Originally Posted by Apeiron

And they come with an appropriate price tag, and how do you think they perform on the street?

Originally Posted by mustangdmurder

When did you drive a 360HP 305?

Originally Posted by five7kid

On Virtual Engine Dyno. At least that's what it said my combo made. More likely it was 300 HP.

Originally Posted by InfernalVortex

When you come back disappointed, dont blame us for not trying to help you out.



Ive never driven one, but been for a ride in one. Super sick car, loved it. He's got a 6.0 LS engine in it now, though. Easier to drive on the street than his 305 was and it makes a little less than 600hp.

Originally Posted by mustangdmurder

So if you think it was sweet. Then why would you say that it is no good?

Originally Posted by Apeiron

How many mistakes can you afford to build while you learn? Keep in mind that everyone builds an engine they wish they did differently.

Originally Posted by InfernalVortex

He is the first guy to tell you that as soon as you touch the bottom end, there's no point in building a 305. He's got a 6.0 LS engine in it now, though. Easier to drive on the street than his 305 was and it makes a little less than 600hp. And his wasnt at 360hp.. that's a bit of an optimistic number.

I would say that it's no good because it wasnt very streetable. it was a pain in the butt to drive around every day. Hes a gearhead and loved it, it was worth it to him. But most people here lack taht kind of patience. We'd rather have the same horsepower and MORE street manners. And the thing is, if you build a 350 or a 383, you can get way more horsepower and still have decent street manners.

Look at this picture:



Do you notice anything unusual about it? Like the giant 2 inch primary long tube headers? The fact that it's not turning its own power steering pump, water pump, smog pump, or alternator? Is that really a realistic extrapolation to saying it's a 360hp 305 in your car? You will put some crappy shorties on it and run it through a single 3 inch exhaust. You will run power steering, alternator, and water pump, etc. That 360hp is closer to 300 rwhp (real world horse power)



I personally wish I had just built a 383 instead of my tiny 350. Building a 350 is a waste of time and money at this point I think. LSx's are the new 383s, and the 383's are the new 350's.

Originally Posted by mustangdmurder

So Apeiron drove your car?

Originally Posted by tylercamaro

torque id say would be lower. it may hit 1 hp per cubic inch but i dont think it would go past that on a car with all its pulleys etc.

Originally Posted by InfernalVortex

I drove 7 hours one way just to buy my car. I drove 2 hours to get my T56. Are you afraid of driving? Whats one afternoon of driving to get a good deal on a sweetcake engine like an LS1?

70s 350's are the epitome of garbage. 305's should be given away for free. Period. If you want to go through all taht trouble to have some terrible 70s 350 or 305, then by all means, dont let me or anyone else stop you.

But you can get an LS1 for $2500-$4000 easy. You can get a truck 5.3 or 6.0 for $500-$1500. WAY better option than some junky 70s 350 thats worth more as a paperweight than an engine. Dont even consider a block that isn't a roller block.

Originally Posted by mustangdmurder

So what do you think my 350 truck motor would do if I put 64cc heads with 2.02 valves and a new intake on it?

Originally Posted by InfernalVortex

You guys are living in a dream world. You're getting great advice from several guys to not waste your time with a small displacement v8, and you just constantly ignore it for the sake of being "different". Being different is great but you're gonna be slower. Being different does not make more horsepower or save you money.

There's so much ignorance blowing around it's making my stomach turn. "Rev" ability in a smallblock chevy is dependent on camshaft and valve train. Then you build the bottom end to survive the abuse. There are big block turning 8000 RPM's. You have fundamental misunderstanding of how to make power.

The engine is an air pump. The more air that gets shoved in, the more torque you make. To make torque, you pump lots of air. Displacement sets an upper limit for air movement, and the airflow path restricts it from there (there are ways to get to 100% and higher volumetric efficiency but im not going to confuse you with that, it just comes with a well built engine).

Horsepower/speed is derived from torque. But horsepower is torque x RPM. The smallblock chevy is limited by being a 2 valve pushrod engine to being undervalved and limited in RPM capability. You can go higher in RPMs, but it cost a lot of money to make that happen within the Gen I sbc architecture. Beyond this, the smallblock chevy, like any other engine, has a limit on usable power band range, usually 3000-4000 RPMs of useful range.

To make power, you make torque quickly (Read: high RPMs). To make torque you flow more air. To flow more air quickly, you have to tune the whole engine for high RPMs, to tune the whole engine for high RPMs, you sacrifice low end power. It's a spiral-loop of performance requirements that inevitably result in streetability tradeoffs.

What does all this mean in the real world? The more displacement you have, the more torque you will make. The more torque you make, the higher you can shift the power band, the more you can shift that available torque up into the high RPMs, the bigger cam and heads you can use, the more power you can make. But THIS is the key, the more displacement you have, the more you can do all those things, and still have low end torque left over to move the car even outside of the engine's ideal operating range.

The goal is to make as much power as possible and still be able to drive the car. You balance drivability (low end torque/street manners/vacuum, etc, all either the same thing or symptoms of the same adjustments) with high RPM power. A secondary, or even more important goal for some, is to make as much power as possible within a given budget. Both will reach the same end result.

What you have is a mildly complicated system of inter-related factors, and in order to understand it, you need to spend some time figuring it out before you start throwing out nonsensical comments and regurgitating phrases from the 60s hoping it will stick. These old adages may be wrong, or they may be right, but the important thing is taht you understand the roots of them. If they are incorrect, there is a grain of truth or a reason for the misconception - figure it out!

Torque is created by airflow. Displacement sets an upper bound for maximum airflow. To make horsepower (torque x RPM) you can either 1. Increase airflow 2. Increase High RPM efficiency 3. Increase displacement.

Note how these 3 elements are all inter-related. Increasing displacement will increase airflow. Your volumetric efficiency will likely go down if you're using crappy heads, but even with craptastic factory heads, a 400 will pull more air through the same heads than a 265 will.

You can make a 305 fast with factory 416 heads. How? Spin it faster. Put a giant cam in it optimized for a 3000-7000 RPM power band, spin it to 7000 RPMs and the car will be very fast. But it will be unbearable to drive on the street because there's no torque left over in the low range and it will have terrible street manners.

Lets try a different way. We can just flow more air. Buy some AFR cylinder heads. $1500. That will flow more air throughout the power band. And you will get GREAT volumetric efficiency. Most of that 305 cubic inches will be filled with fresh air/fuel mix. If you want to make more power from there, what can you do? Optimize it for high RPM torque, or increase displacement. Or you can leave it alone. But remember, $1500 heads get more return for your investment on larger engines. Increasing the RPM capability of your bottom end gets expensive very quickly. Increasing the displacement of your bottom end starts to make more and more sense.

The logical conclusion to ALL of this is you make the biggest engine you can. The bigger the engine you make, the bigger parts you can put into it that flow more air. The problem is that most parts taht flow more air do so at higher RPMs and flow LESS at lower RPMs. Namely the camshaft, but heads with large ports have the same effect. You lose low RPM port velocity with big ports, ESPECIALLY with smaller displacement engines. Bigger engines allow for lower engine speeds with the same airflow advantages. More cubic inches offset EVERY one of these drawbacks that rear their heads on smaller engines.

Consider that a 305 TPI can spin to higher RPMs effectively than a 350 TPI without that terrible intake holding it back.... but which makes more power? The 350, even though its airflow capabilities tax out the TPI intake much sooner. If you put an intake/heads/cam optimized for high RPM onto a 302, it will work well at high RPMs. If you put that same cam, heads, and intake onto a 400 smallblock, it will make MORE power, at reasonable RPMs. The larger displacement flows more air per stroke, so everything behaves differently, and it brings the RPM range down.

BIG CUBIC INCHES FACILITATE BIG POWER.

Here's another angle. The Gen I sbc, frankly, is a terrible performance platform. It was good in its day, but it's better suited at towing RV's and groceries around. It's been surpassed. The torch has been passed off. the Gen III and Gen IV smallblock (the LSx engines) are much better. Why? The same 3 rules of power still apply. 1. Airflow 2. RPMs 3. displacement. So why is it so much better?

Because its MUCH more efficient with airflow, it's much lighter, and the engine management systems are far more advanced. Factory LS1 heads outflow most aftermarket Gen I heads. a 2002 LS1 head flows nearly 260cfm through the intake port. A vortec head cant hit 230cfm. A $1500 set of 180cc AFR heads for a Gen I block flows 260cfm, the same as a STOCK LS1 head. Thats why you can POUR money into a Gen I smallblock, $1500 for heads, $500+ for fancy roller camshafts and valvetrain, and on a 350, you struggle to hit factory LS1 power numbers.

Sure, you can put a big lumpy roller cam into your AFR headed 350, something like 230/230 duration at .550+ lift. And you can hit maybe 400... maybe 450hp and keep it marginally streetable. That's 50-100hp on an LS1. But remember, the LS1 is using a baby-sized factory cam and a manual 02 Z28 can put down 300 REAR WHEEL HORSEPOWER. 450 fwhp AFR/lumpy roller cam 350 will translate into 380-360 rwhp.

So now realize, when people are spending $1500 on cylinder heads, and $500+ on a roller cam and valve springs and fancy pants lifters for their Gen I sbc's, if they dont build a 383, a factory stock LS1 car is going to hang close with them. Some dentist with a mid life crisis compared to all of our work and money invested into a 350.

To build a NICE 302, 305, or a 327, or even a 350 for power these days is IDIOTIC unless you want a dentist in a bone stock LS1 car, or even an LT1 car to embarass you in every category except noise.

If you're going to put the money into a project to do it right. NICE heads, NICE medium sized roller camshaft, intake matched to everything else, headers, exhaust, etc etc... why on EARTH would you sandbag the potential of all your monetary investment with some puny 302 or 327? The high revving short stroke myth is BS, but with a 302 or 327 or even a 350, revving it is THE ONLY WAY you can be competitive, and that doesn't make for a fun street car. Plus the bottom end parts required to make a 7500 RPM 302<->350 are WAY more expensive than a stroker kit to make a medium RPM 383.


Remember, every single performance part you buy will have a tradeoff. You will lose low end torque, or gas mileage, low RPM port velocity, durability, vacuum, etc, and in exchange you get more horsepower. Do you know what the tradeoff is for discplacement? There isn't one. It's the ONE change you can make, that wont result in a loss of streetability in exchange for horsepower. Well, displacement and exhaust.

Try to understand the relationship between torque, RPMs, and horsepower. And then try to understand the relationship between a given performance part, displacement, and torque. And by torque in the second sentence, I mean where in the RPM range is torque added and where is it taken away. You will hopefully see the patterns.

Originally Posted by Apeiron

Yes, have you ever driven a car with a 360 HP engine of any displacement?

The point is that &quot;streetability&quot; is a subjective quality. Magazines are notorious for promoting &quot;streetable&quot; engines with over-inflated numbers that most people might accept for a weekend cruiser but would rapidly despise for a daily driver. You don't yet have the experience to evaluate the article's content objectively or subjectively.

Less talk, more do. It doesn't matter what you do, even if it's &quot;wrong&quot;. Just do something and you'll learn from it.

Originally Posted by five7kid

No, wise guy.

The point being that what is claimed (by magazines, by engine simulators, etc.) is usually quite different from reality.

There is a lot of real-world experience being ignored here.

Originally Posted by tylercamaro

either way the numbers wont compare to a 355 with a few goodies, and that wont compare to a 383 and that wont compare to any LS based engine

Originally Posted by whatever84

I wouldn't call a 70's 350 junk(most of the modified cars on this forum are probably 70's 350 blocks), It's a great starting point. We have all had this debate before, the initial cost of an LS swap is not cheap not to mention getting it tuned. I would love to have an LS but I couldn't afford to swap to one right now and there is no place close to have it tuned.

Mark.

Originally Posted by InfernalVortex

I dont disagree with you, I just see it a little differently.

If you're gonna use an outdated gen I smallblock, the least you can do is go with a roller cam for reasons of more power, more efficiency, and better reliability. The advantages are all over the place for rller camshafts. Going to a roller cam with a 70s block costs about twice as much as doing it on an 87+ roller block where you can use factory lifters. Furthermore, with a 70s block you're limited to a flat tappet cam, or spending WAY too much on converting to a roller, but beyond that, there is absolutely NOTHING in that block that is worth re-using. If you're building a mild 350, you can reuse the crankshaft and MAYBE the rods. Still need new rod bolts, and that plus the refurbishing costs of the old rods costs almost as much as new entry level rods with ARP bolts. So it doesnt make a whole lot of sense to reuse the rods.

So all you're buying is a block and a crank, and a decent aftermarket cast crank is better than a factory crank and it's only a couple hundred bucks, pocket change compared to the rest of the engine build expenses. A stroker crank is only a few bucks more than that. Decent cast stroker crank is $250 or so if i remember right, and those are going to be way stronger than any factory 400 crank.

And as far as the cost of an LS swap. It's basically new motor mounts, new serpentine assembly, and a new transmission and trans mounts. I find the transmission is the complication, but you can get a truck 5.3 motor for $250-$1000 everything included. A 6.0 is pennies above that. The truck 5.3s even have aluminum heads. They make 300fwhp stock. That's about as much as my honestly pretty well-built Vortec heads 355 is making with all the mods I have done to it. And the truck is my daily driver. Beyond that you can even bore a 5.3 out to use LS1 pistons and make an iron 5.7 if you so desire, but even then the huge improvements in the Gen III+ architecture mean even gonig down in displacement to a 5.3 is well worth the effort because with just a nice roller cam, an intake swap, and maybe a head swap (all to things you can reuse in an LS1 or 6.0 engine) you will make enough power to embarass hot 350s and 383's.

I like the idea of going to a 5.3 or even a 4.8 because they're still faster than anything stock in our cars, they're lighter, theyre cheap, and they're a good way to get the conversion done for cheap and you can build an LS1 to drop straight in later, just bolt it up. Plus the 5.3 and 4.8's use teh same block, so you can go to an LS1 crank and pistons and bore them out to 5.7 liters.