fb305svs

Ahh well here is a juicey topic i think, here is basically what i know-

335- de-stroked 350 (or is it a stroked 305???- advatages? i have NO CLUE

350, standerd motor

377- destroked sb 400 (this i think got down) revvy motor, commonly used in road racing for its high end hp and torque?

383- stroked 350, butt loads of torque and hp...


Ok, here's is my question, i know a guy with a 377, and he luvs the thing and it makes his monte ss haul *** ... just curious what the differences in power bbands and such are... ie which is better for road racing, or general street racing or drag duty.... this should be good for the archieves and hopefully i will learn something from this!!

Steve

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86 Firebird, LG4, t-tops, 2.73 open rear, SLP 3 inch cat back exhaust, catco cat.

Gonna be sellin the 86 in the spring to hopefully get an 88-92 formula 350, and supercharge it!! (amoung some other sweet mods)

My Webpage- Battle of the birds, My own Thirdgen Page, still under construction, http://www.geocities.com/soares711/index.htm

88 Firebird Formula- deseased 2/9/99- 305 TPI, SLP 3 inch exhaust, SLP Intake runners, SLP cam, 3.45 BW disc brake posi, WS6, NOS, and all that good stuff, 13.8 on the motor, 12.89 on NOS and slicks! Hit by what else!?!? a FORD EXPLORER!!!!!!

mtx28

your right. in a recent CHP mag. article, they stroked and destroked a 350 and 400, respectively. the 383 (4.03in bore and 3.75in stroke) made more torque at a lower rpm than the 377(4.155in and 3.48in stroke), which made more hp and less torque at a slightly higher rpm... since i bet your wondering, the 383 made 458lb/ft at 4600rpm, and 450hp at 6k. the 377 made 450lb/ft at 4900rpm and 454hp at 6100. suprisingly, the old 302's in camaro's were hellacious engines in races because they could rev so high, and still made really nice power. for me, i'd take a 383 anyday over a rev-happy motor, simply because i hate having to go to 5k to get to dip into my power band. its fun as can be just nudging the pedal and making the tires wail at 2k-3k rpms, but thats just me.

fb305svs

hmm intresting... yeah i like that nice low end torque... heheh

Steve

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86 Firebird, LG4, t-tops, 2.73 open rear, SLP 3 inch cat back exhaust, catco cat.

Current Plans: 342 posi disk 10 bolt rear, coming in late december, in february or april, level 10 tranny, new convertor, june- lowering springs, possibly torq thrust II chrome wheels, and new 245 stickies up front, 255's out back, the cowl hood will be installed and painted, new cold air induction, mid summer, hoping to have enough money to scrape together a 350 hp 350... gonna keep things fairly mild.

My Webpage- Battle of the birds, My own Thirdgen Page, still under construction, http://www.geocities.com/soares711/index.htm

88 Firebird Formula- deseased 2/9/99- 305 TPI, SLP 3 inch exhaust, SLP Intake runners, SLP cam, 3.45 BW disc brake posi, WS6, NOS, and all that good stuff, 13.8 on the motor, 12.89 on NOS and slicks! Hit by what else!?!? a FORD EXPLORER!!!!!!

Damon

335- 30-over 305 block (3.765) with a 3.75" crank in it (400 length crank).

350- stock 4.001" bore, 3.48" stroke. 30 over it becomes a 355.

377- 400 small block at 30-over (4.155") with a 3.48" crank (350 length crank).

383- 30-over 350 block (4.030) with a 3.75" crank (400 length crank).

Generally, longer stroke motors are biased more towards torque and lower RPMs. Shorter stroke motors are biased more towards higher RPMs and higher HP.

This is, however, a GROSS OVERSIMPLIFICATION.

What matters most is the total COMBINATION of parts, not any one simple variable like bore, stroke, or rod/stroke ratios that often come up in conversations like this.

RB83L69

335 = 305 bore x 400 stroke; stroked 305, could be thought of as a severely de-bored 400

350 = 350

377 = .030" over 400 bore x 350 stroke

383 = .030" over 350 bore x 400 stroke

In general, the longer the stroke is in relation to the bore, the lower the RPM at which the reciprocating mass overcomes any further power output from increasing the RPM. Equally generally, the shorter the stroke is in relation to the bore, the higher the "cut-off" RPM will be.

IMHO the 335 idea is only a curiosity. I can't see any sense in spending the amount of money and effort it takes to create that, and still coming up short of what a 350 will do. Basically it amounts to taking your money and using it to buy ammunition to shoot yourself with.

The 377 and 383 are both decent enough hybrids in their own right, but again, require spending extra money to downgrade a 400. The 383 offers one set of unique advantages to people who already own a roller 350 block. Other than that, a 400 will beat either one. The 372 and its overbores is the easier combo to build because all you do is buy a set of bearing spacers for the mains, and then use stock 350 crank & rods and 400 pistons. No machine work or balancing is required. It is limited to 2-piece-rear-main-seal crank stuff because there are no one-piece-rear-main-seal 400s.

The 372 is a better road/oval motor than the 378, since it will produce more peak HP with a slightly lowerpeak torque. FYI the NASCAR guys run a 4.155" bore (.030" over 400) with a 3.31" stroke to get their 358 CID limit. The 383 may be a bit better for street use because its peak torque will be higher, and at a lower (more usable on the street) RPM. Again, a 400 or its stroked derivatives will beat either one in either application.

Guess what I drive...

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"So many Mustangs, so little time..."

Tom 400 CFI

305: 3.74 bore 3.48 stroke
334: 3.74 bore 305 w/400 Crank (3.75 stroke)
350: 4.00 bore 3.48 stroke
377: 4.125 bore 3.48 stroke(400 block/350 crank)
383: 4.00 bore 3.75 stroke(350 block/400 crank)
400: 4.125 bore 3.75 stroke

fb305svs

i was just curious... my engine will more than liekly be a 355....

due to budte constraints...

Steve

mtx28

no! we must all blast you with the same reply!

fb305svs

HEH- oh well atleast i get a little more info each time.. that 377 sounds mint too... hmmmmmmm lol
Steve

ede

i have a 335 in my old car, but it's a 4.06 bore 3 1/4 " stroke. i guess i did mine the hard way

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-=ICON MOTORSPORTS=-
1st & 3rd

RB83L69

Funny you should mention that, ede...

My brother who died a couple of weeks ago had a set of Venolia pistons for a 400 bore and 327 stroke like that. Seems like there's a steel crank laying around somewhere for it too. If I happen onto a 400 block any time soon, I might just build that up!! It ought to be good for at least 8 grand on demand, with good rods.

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"So many Mustangs, so little time..."

ede

RB that would be a fun engine to build and play with. i like the little SBC's 302 and 327's. lot of people rag on them that have never saw one or drove one.

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-=ICON MOTORSPORTS=-
1st & 3rd

Dan87IROC-Z

I don't understand why people like the 377, I mean, why make a 400 smaller. The 400 is a damn good engine if you can feed it properly, why make it smaller?

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip with 160* Thermostat, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET : 14.32 @ 97.7mph
(corrected for elevation)

Soon to come: LT4 HOT Cam, Air Flow Research 190cc Heads, 2800 RPM Stall Converter and SLP 3.70 Rear End Gears.

mtx28

thats what CHP said when they built the two engines... why give up the extra cubes?

ede

short strokes wind up faster and usually higher. the 302 and 327 are good examples of this. if you figure an engine makes so much power per piston stroke, then the more strokes the more power you'd have. i know most people get hung up on bigger is better but some small engines make good power too.

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ICON Motorsports
1st & 3rd