Is there any difference in performance between the 377 (350 block + 400 crank) and the 377 (400 block + 350 crank)?

With exaclty the same compression ratios, heads, intake, carb, ignition, etc. and comparable cams (somewhat close to exact, if not exact) :


350block/400crank (commonly reffered to as 383) should make more torque down low because of its longer stroke and smaller bore.

400block/350 crank sould make more HP and have the ability to wind up to higher RPM more easily due to its shorter stroke.

Of course, things are actually more complicated than this but simply put, 383= Torque/Low RPM grunt and the the 377= HP/Hi RPM screaming.

It's always funny to see those 2 engines compared as "low end grunt" and "high RPM screamer".... that's a little bit of an exaggeration. No, it's a HUGE exaggeration.

The comparison has been done, several times that I've seen, and with fairly consistent results each time. Turns out, the long stroke combo makes about 1% higher peak torque, about 200 RPM lower than the short-stroke one; the peak HP is about the same (as one would expect, being determined by flow); and the short stroke motors peak HP is at about 300 RPM higher than the other.It also turns out that if you take a given trans/gear/converter setup and optimize it for one of them, and see what time it runs; and then optimize it for the other (usually all it takes is the converter), they run ETs within experimental error of each other.

A 400, also identically built, will blow either of the others away; by a percentage roughly equal to the CID ratio. The 400's and the long-stroke 377's torque curves peak at about the same RPM but the 400s HP falls off faster... flow limited, once again, exactly what you'd expect.

Personally I prefer to look at it as, each of those combos is a partially crippled 400. One is crippled one way, the other is crippled the other way. You can aldo think of the short-stroke one as merely a .125" over 350.

Moral of the story: use the biggest bore you can, and the longest stroke you can. There's no advantage to reducing either one. Inches will win.

graemlins/thumbsup.gif

Originally posted by Slowpoke70:
350block/400crank (commonly reffered to as 383) should make more torque down low because of its longer stroke and smaller bore.I thought 383 was a 350 block bored .030 + 400 crank?

what about piston speed? what matters is building a bore stroke combo that best suits your needs. Neither are crippled.

That's why I went 496BB after my 406SB..

pdq67

yeah, the 383 is 350+.030 and 400crank. But any 350block/400crank combo is usually called a 383 because the 383 is the famed stroker chevy small block. Sort of like I call my 355 a 350 because 350 is more common.

Originally posted by RB69SS396Conv:

Moral of the story: use the biggest bore you can, and the longest stroke you can. There's no advantage to reducing either one. Inches will win. Wanna bet-I got 100 bucks says Charlie over at pro-touring will whoop anybody here with their big-inch B/B. He's just running a little mouse motor and running oh-about 1000HP(oops, with 2 turbos)
Seriously, my pops builds off-shore race boats, we run lots of 502, 540, and 572's. Sure they make tons of low-end torque and sound real bad-a$$, but I still prefert he sound of a sm blk being powershifted at 7K, never seea B/B do that, not for long anyways. The 377 destroked engine is the way to go. Still have the torque of the big bore and short stroke to wind to the sky-for those that don't think that matters I'm building to run Nevada and 70 minutes at 6500+ requires a short stroke motor or HUGE $$$$.

Originally posted by dennis68:
</font><blockquote>quote:</font><hr />Originally posted by RB69SS396Conv:

Moral of the story: use the biggest bore you can, and the longest stroke you can. There's no advantage to reducing either one. Inches will win. Wanna bet-I got 100 bucks says Charlie over at pro-touring will whoop anybody here with their big-inch B/B. He's just running a little mouse motor and running oh-about 1000HP(oops, with 2 turbos)
Seriously, my pops builds off-shore race boats, we run lots of 502, 540, and 572's. Sure they make tons of low-end torque and sound real bad-a$$, but I still prefert he sound of a sm blk being powershifted at 7K, never seea B/B do that, not for long anyways. The 377 destroked engine is the way to go. Still have the torque of the big bore and short stroke to wind to the sky-for those that don't think that matters I'm building to run Nevada and 70 minutes at 6500+ requires a short stroke motor or HUGE $$$$. </font>[/QUOTE]while what you're saying might be true, that doesn't apply to the majority on this site because most are street cars and they are heavy, so torque is what we need. a small block that has to turn 7000rpms would be a complete pig in my car and probably most cars on here. and yes i have seen many a big block turn 7000+ reliably. my buddy's 80 malibu has a 447 ci big block and it turns 8400rpms with a single procharger and makes over 1600hp and the bottomend was flawless after one season of heads up racing, although it did squeeze out a head gasket once. ;)

Happy 377 owner right here!!!!! graemlins/hurray.gif
Brian

Wanna bet-I got 100 bucks says Charlie over at pro-touring will whoop anybody here with their big-inch B/B. He's just running a little mouse motor and running oh-about 1000HP(oops, with 2 turbos)
Seriously, my pops builds off-shore race boats, we run lots of 502, 540, and 572's. Sure they make tons of low-end torque and sound real bad-a$$, but I still prefert he sound of a sm blk being powershifted at 7K, never seea B/B do that, not for long anyways. The 377 destroked engine is the way to go. Still have the torque of the big bore and short stroke to wind to the sky-for those that don't think that matters I'm building to run Nevada and 70 minutes at 6500+ requires a short stroke motor or HUGE $$$$.66 283'S Big inch Big block might :D

Originally posted by m71:
and yes i have seen many a big block turn 7000+ reliably. my buddy's 80 malibu has a 447 ci big block and it turns 8400rpms with a single procharger and makes over 1600hp and the bottomend was flawless after one season of heads up racing, although it did squeeze out a head gasket once. ;) Spinning 8400 rpm for 3 seconds at the top end is a far cry from from running there for 50 miles or so. If he can do that I might rethink my whole plan. My Elco probably doesn't weigh much more than your Chevelle and is a by no means a pig with its current 355.

Originally posted by CHELKAMINO:
Happy 377 owner right here!!!!! graemlins/hurray.gif
Brian Make that two happy owners!!!! graemlins/beers.gif

My 427 turns 7400, built to turn 8900 and have never had a problem, unless you count the bald tires. LOL

I was just gonna say that a stock, L-88 with no more then good open headers should hit very close to 550hp and do it a long time!!!

B/c they were made to do it STOCK!! Not 1200hp, but still good numbers none the less in my book, imho..

I've talked to 66 283 about his motor AND his ride is CRAZY, (850 or 900hp??)!! But I gotta build a big one too some time in my life just to scare myself....

pdq67

Yeah, I think 66 283 has around 1100RWHP with his nitrous? :eek: Thatd be enough to scare me.. and the MPH in his video is good for 8's im pretty sure :cool:

Originally posted by dennis68:
</font><blockquote>quote:</font><hr />Originally posted by m71:
and yes i have seen many a big block turn 7000+ reliably. my buddy's 80 malibu has a 447 ci big block and it turns 8400rpms with a single procharger and makes over 1600hp and the bottomend was flawless after one season of heads up racing, although it did squeeze out a head gasket once. ;) Spinning 8400 rpm for 3 seconds at the top end is a far cry from from running there for 50 miles or so. If he can do that I might rethink my whole plan. My Elco probably doesn't weigh much more than your Chevelle and is a by no means a pig with its current 355. </font>[/QUOTE]if you re-read my post, i said the majority on this site, not every single application. and what you think is or is not a pig, might be different from what i think. :D