SketchyZed

Okay i know the 383 is good for tq but what is the 355 good for i know it has its place is it just a good all rounder just wondering.

Abubaca

iTrader: (3)

The 355 is just a 350 bored 30 over. It's done to clean up the bores, not add to cubic inches. The extra 5 are negligible. Old school guys don't even say 355. They said 350, 30 over.

What is it good for? Look at it this way. You have a GM 350 and a GM 400. Those are the two most common performance, factory engines. The 400 has a larger bore and larger stroke. I'm gonna get beat up for saying this, but think of their characteristics as being similar. Sure the 400 is just plain bigger, and it's gonna produce more torque and HP, but for the sake of this thread, they're both "good for" the same thing.

When you drop a 400 crank in a 350, you now have a longer stroke in an otherwise stock 350. (there's a little more to it but...) This is why it's considered a stroker. It's got more stroke. -and with .030 overbore, it's now a good ole 383. That stroker provides leverage, which produces extra torque, but that same extra stroke can limit RPMs, and ultimately high RPM horsepower.

When you drop a 350 crank in a 400, you've now DEstroked a 400. This gives you 377 cubic inches. I think you can actually bore it out to 383, but I'm not sure if that's a thing or not. Pretty sure you can. Anyhow, whether it's a stroker 350 or destroked 400, the 383 and 377 cubic inches are pretty much the same. It's HOW you get them. That 377 with it's short stroke doesn't make the torque due to it's short stroke, but it'll spin for days and make power way up in the upper RPM range. It's not an ideal street car motor.

...so to answer your question, a 355 is really just a 350 with a slight bore. It's a GREAT motor, but it's not really better or worse than something else, with regard to your question.

cardo0

Well everyone has a different point of view on this I'm sure but it depends on your budget and goals. My reference would be budget and purpose. So for most of us the camaro is a budget sports car and we don't want refinance the home just to get some horsepower for "spirited driving". I that case reusing the stock crankshaft saves you a significant amount over a stroker crank whether cast or forged. Also unless there was a problem with the original crank reusing usually saves you the cost of alignhoning the main saddles for a new crank - at least $200. Just boring the block and installing better breathing head - whether ported stock or aftermarket - and a bigger cam can easily increase horsepower by 25%.

Now on the other hand if you have the budget for more power then installing a stroker crank will add significant cubic inches and by itself add some 30ft-lbs of torque. And IMHO the gains of a larger cam and better breathing heads are inhanced by more cubic inches to and I expect you would see even larger horsepower gains from adding a larger cam and better heads to a block that displaces more cubic inches.

What I'm saying is that the greater power increase from stroking the block is gonna cost more - beginning somewhere close to $1000 and the sky is the limit.

Hope this helps ya.

sofakingdom

iTrader: (1)

There's no such "motor" as a "355".

All it is, is the displacement (CID) of a 350 that's had the first instance of maintenance on the bores performed, i.e. they're .030" larger diameter, to scrape off the worn and/or distorted metal and restore a (supposedly) perfectly circular profile and the correct finish for new rings to be able to seal to.

So we won't talk about that number. It is GARBAGE used only by the novice and/or the relatively ignorant. We'll call it WHAT IT IS, which is, a 350.

The 383 on the other hand, was NEVER produced by GM, at least not as something installed in a vehicle; therefore deserves its own special name (number) since it's its own special thing. (N.b. GM DOES now make a 385 "crate" motor, i.e. NOT installed in any vehicle except in some boats, which is some other combo slightly different from the 383) It's an aftermarket, or more accurately a HOBBYIST, creation. Back in the day we all used to do it by taking a 350 block that had been maintained as above, installed stock-dimension 350 pistons except in the .030" overbore, installed a stock 400 crankshaft that we had turned the main journals down to the 350 size so it would fit in the 350 block, and put stock 400 rods in it. Therefore it's IDENTICAL in bore to a .030" over 350, it just has a crank with 3.75" stroke instead of 3.48". Nowadays of course there are LOTS of purpose-built cranks for this that are VASTLY better than the above, and better rods, and purpose-built pistons. All of which is altogether better in every way than our old backyard hack job with junk parts from the late 70s.

A 383 will produce more torque with the peak at about the same RPM as an otherwise identical 350, and generally somewhat higher peak HP, but at a somewhat lower RPM than an otherwise identical 350. Higher torque comes from the greater CID; lower peak HP RPM results from the flow characteristics of the induction system (heads, intake, exhaust, & valvetrain) reaching their limit at the lower RPM.

"Better" or "worse" covers ALOT of ground. One must take into account the added difficulty and required background knowledge of planning and procurement, results (performance), longevity (in terms of wear), cost, risk of sudden catastrophic failure, long term cost of operation (e.g. gas mileage), and of course, SUITABILITY FOR PURPOSE (does the increase in power output provide any tangible benefits).

A gross and over-generalized "rule of thumb" might be that since CID is THE CHEEEEEEEEEPEST form of power that exists, then if you have to replace the crank pistons & rods ANYWAY, might as well be with the ones that give you MORE BANG in exchange for THE SAME BUCKS that you'd have to spend ANYWAY. If you decide to do this, make sure you purchase 383 components that are designed for STOCK (which is to say INTERNAL) balance, whether that be the stock neutral balance of 85-back 350s, or the stock balance of the 86-up version which places the last rearmost bit of INTERNAL BALANCE weight which is on the crankshaft flange in the older design, onto the flywheel. And also of course, that you take into account the need for higher flowing induction system parts (heads & cam profile in particular) since otherwise you end up producing something that runs a little less like a "sporty" motor and a little more like a tractor instead.

OrangeBird

iTrader: (1)

Speed = cubic inches X cubic dollars , squared .

Vader

The only place a "355" was ever used in general reference was in short track racing. Locally, and when I was involved in the late '70s and into the '80s, that used to be the displacement limit for late-model short trackers, and thus everyone running SBCs and Ford Windsors bored to that limit. Mopar LA blocks were bored and stroked to that limit with moderate success, and at a HUGE cost penalty. There weren't many Cordobas and Magnums out running very long with Monte Carlos and Torinos.

GOTCHEVY

iTrader: (1)

350s are good for the wallet....that’s all

sofakingdom

iTrader: (1)

True, to a point: but the rules probably didn't say that the largest motor you could have was "a 355". Rather, they would typically say that the most CID you could have was 355, which limited the overbore of a 350 or 351W or a C (in the rare cases where those were even allowed) to .030". Or, 358 in lots of cases that I used to deal with, which is a .060" over 350 or 351, with a special exception for the Mopars which then had to be at the max a stock bore 360... further explaining why those guys were at a disadvantage in a certain way, since even though their motor was slightly larger, they couldn't "maintain" their blocks but instead pretty much had to run em as they came from the factory. NASCAR rules for example are written similarly for some of their series.

Anybody that's ever tried to run a Chevy 350 heads-up against a Frod 351C will know about the induction system advantage that some motors have inherently built into them... you can practically take a BIG BLOCK Chevy exhaust manifold and put it INTO the exh ports of stock 351C 4-bbl heads. Those ports make SBC exh ports look like coffee stirrers. Of course the 351C had other problems related to its Frod heritage, most notably the rocker system, which if the rules said you couldn't change that, levelled the playing field quite a bit. But that's not important to the matter at hand here.

skinny z

When someone asks me what engine I have in my Camaro I say "355". I used to have a 353.
Car people know what I mean and non-car people don't differentiate.
If you tell me you have a "350" my question is: is that a standard bore? To which you may reply, no it's 30 over. If you had said a 355, then I would know exactly what you're talking about.
But that's just me.
As for the OPs question, the 355 (aka, 30 over 350) is good for just about anything. Same goes with a 383 (aka, stroked 30 over 350) but the 383 adds a little something extra to the mix.
In this writer's particular circumstance, I want to get better drag strip numbers and the addition of another 30 cubic inches plus an appropriately spec'd cam to suit the additional displacement will move me closer to my performance goals than would an overworked, smaller engine. And by performance goals I'm not only referring to engine output but also driveability and fuel economy.

SketchyZed

Well I'm building my old l98 out of my z and I was wondering how would a 383 perform with a single plane intake?

Abubaca

iTrader: (3)

You're asking the wrong questions. We're happy to answer, don't get me wrong, but you need to ask:

My budget and skills are THIS. My goals are THIS. What would you guys recommend?

...because a 383 will perform AWESOME on single plane manifold. It'll also perform AWESOME with a dual plane. It's like asking if you should run or pass while playing football. Kinda need more info to call the right play.

sofakingdom

iTrader: (1)

Depends on the intake.

And pistons (compression), heads, cam, exhaust, gears, converter, and a whole list of other things.

OTOH this probably belongs in the class of "if you have to ask it's not for you ... yet".

Start with a reasonable goal. Not, "the fastest car on the continent", not, "1000 RWHP", not, "as fast as possible", nothing blue-sky like that. Reasonable. Within your grasp, and within your experience to some extent.

How fast do you want to go? what are you willing to give up to get there? that includes build cost, driveability, gas mileage, maintenance, risk of catastrophic failure, lack of appeal to members of the other sex (I haven't found them to be "opposite" so much as "other", myself), and so forth.

For example, "I want to do 9 sec in the ¼, get 30 mpg, I have $1000 to spend on it, and it has to be done this weekend" will run into the brick wall of reality REAL QUICK.

GOTCHEVY

iTrader: (1)

Sofa....we’re all thinking it....but you actually say it.
Tough love. I like it

SketchyZed

Oh i have my build and goal and my parts picked out i just wanted to know how it was, the compression ratio will be 8.2 or 8.4 you may ask why so low because roots im thinking a 144 or a 142 weiand blower my heads will be Dart SHP heads cam will be COMP Cams Xtreme Energy Cam 276/282, Lift .502/.510 and as for a carb for it just some 750 i can find that would be good for a blower, that or an rpm air gap for the intake and some 64cc heads

Vader

You're right. The limit was 358 the more i ponder it. Mopars in short track were about as rare as hen's teeth.

You're right about the heads, too. That fifth bolt made it tough to get port runner volume. Suffice it to say that I learned (trial by error) a little bit about porting stock castings with templates and a die grinder. Some of the heads didn't even make it to the Wednesday night trials, let alone the Saturday night features. Stock Ford heads did have an advantage there.

Orr89RocZ

iTrader: (20)

X2 everyone around me says 355, or if its a 30 over 400 its a 406. Big block 454 60 over is a 468. Most dont even say what bored over is

Vader

You might want to decide up front if there will be a blower since it would probably affect the cam selection. There is a bit of a profile difference between a cam for a blower and one for a N.A. engine, specifically in LSA.

sofakingdom

iTrader: (1)

Indeed... and a ABUNCHA other things too.

No matter how often you see it on the Interwebz, you don't just "throw a blower on it" and expect optimum results. A motor needs to EITHER be built SPECIFICALLY FOR a blower, or SPECIFICALLY NOT FOR a blower.

If you build a non-blower motor that is set up to run good that way, and "slap one on it" later on, you will probably end up with an inability to run any significant amount of boost due to too much compression and a cam that doesn't favor the needs of a blower. Similarly if you build a blower motor and try to run it N/A you will probably end up with a slow turd that disappoints in every possible way. There's really no getting around it. One or the other, either or.

If you REALLY TRULY SERIOUSLY ACTUALLY HONESTLY intend to run a blower, start from the very beginning with that plan. (for which the cam you talked about is not a particularly good choice, CERTAINLY not optimum) But if it's just a bunch of loafing the donkey and it's never REALLY going to happen, then that's a whole different animal.

Tell us what your goal is in a complete, coherent, and internally consistent manner, and we can help you choose parts. Otherwise, every time you post something and it's totally different from the last, we'll just ignore you and let you fumble around on your own. Which is not to say "you'll fail"; only, we can't help you if you don't tell us THE TRUTH. You'll be all on your own without the guidance of everybody's experience around here, because none of us will be able to tell what experience applies to what you're saying today that you're going to do, that's different from yesterday.

Start with a GOAL. If you set out not knowing where you want to go, then that's exactly where you'll end up.

What is your GOAL? Tell us that before you go any further.