I was reading some the forums on strokeing and destrokeing w/ 383 & 400's . I am building a 400 and I already have a 350 w / pretty good stuff in it . I was just wondering if there would be any advantage to useing my 350 crank or just build the 400 as is . Any help would be appreciated .

 

Build it as it is.

 

a 377 has one place and only one place.In a dirtrack stockcar.Otherwise,Your just giving away torque and HP,and spending more $$$ to do it.

 

Don't waste the cubes.

 

I built a 380 ci motor to have something different. And also I like internally balanced motors My motor with AFR 195s went a best of 11.0s with pump gas. And 9.7s on NOS and race fuel. 380 =4.155 x 3.50

 

There is no advantage to that particular downgrade.

The liberal use of smilies and high-$$$ brand names in a post, won't make up for the basic fact that a 377 (the actual size of that combo: 4.155" x 3.48") will produce about 5% less HP with than an otherwise identical 400. Or, that the 400 would have been the same price, or less, to build.

 

x eleventybillion!!!!!!!!!!!!!

-ps didnt we just go through this?

 

the 377 will not produce less horsepower, it will just move the power peak further up in the RPM band with a ever so slight increase. For all intents and purposes it does not ever (read: never) belong on a street.

 

The 377 will produce less horsepower than an otherwise identical 400. Period. Every time. No matter what the name of the asphalt or dirt environment that it's sitting on. The gasoline inside the cylinders does not look around and see if it's a street or what that its sheet metal carrier is sitting on, and produce power (or not) accordingly.

I know how to prove definitively, without any possibility of error or ambiguous results, which one is more powerful. Do you? Are you ready to find out? Or will we all get to raise the flag on you?

Yes we did in fact just have this discussion, and we're getting the same BS as last time all over again, and it just refuses to go away.

 

If a 400 block with a 3.75" stroke makes the same HP as a 400 with a 3.48" stroke, why doesn't a 350 block with a 3.75" stroke make the same HP as a 350 block with a 3.48" stroke? or even a 3.25" stroke?

 

Actually if you have the exact same heads and camshaft and the valvetrain can take the higher rpm a 383 and a 327 will make almost the exact same power (the 327 having to make it at higher rpms) and the 327 will surpass it my a very small amount. All it basically comes down to is airflow in and out which is limited by the heads and the camshaft- not the stroke (providing the engine can withstand high rpm's)

 

The 327 WILL NOT make more power than a 383. No way no how. This IS the real world, you know.

You ready to back up that claim yet? Or is it still just a bunch of BS?

 

So if thats true, why even use a V8? Hell just bolt up a SBC head to a 1.0L 4 banger and really crank out some HP!

 

I really don't understand how you guys can't understand this. The more air you flow the more power you'll make, but at 6000 rpm a 327 will be flowing more air than a 383 at 5000 given the same cam and heads. Even at 5856 rpm when the airflow is almost equal the 327 will have better efficentcy due to the higher rpms. the reason people go with the longer stroke is that it puts less stress on the engines internal parts and has the hp peak at a lower rpm given the same cam and heads

 

I'm sorry, I find this humorous. It's the same people trying to argue the short stroke every single time and yet none of them have proof to back up their claims.

 

The proof is in the physics- what more do you want? I'm just not sure what part of all of this you guys are missing.

 

Physics is theory. Physics is how it "should" work. Papers are how it "does" work.

 

I still don't see why people bother to spew this same worn-out drivel without a shred of experience, let alone actual proof, to back it up.

So, are you ready to back it up yet? A little "put your money where your mouth is"? Or are we just going to see the same baseless run-off-at-the-mouth until we get tired of talking about it?

Explain how a longer stroke puts less stress on internal parts. That's a pretty laughable one right there, all by itself. Also explain this "5856 RPM" business, that's a good one I've never heard before. Then explain how it is that a 327 flows more air than a bigger motor at ANY RPM. Then tell us all about why you don't see 327s winning in ANY form of racing, organized or otherwise; except for nostalgia or Super Stock type of situations where the rules make it possible.

I gotta agree with madmax. The all-around best combo would be to take a 4-cyl, put half of a Duntov cam in it, put 2 TBIs on top, then jack it up like a mother and go roast some Rustnags!!

 

fact is youre a douche.

If you put enough induction, and build the 400 to take the same revs it will make more power. The only way the 377 will make more power is if you are choking it.

 

Now you're talking about altering more than just the stroke. That's the key. You can always make more power with more displacement, but you have to have the parts to match that added displacement.

Personally I would never build a 377 because its not necessary anymore with todays aftermarket parts- that and there's no need to put the added stress on the parts.

I build engines for the street where you'll almost never see more than 6000 rpm, but there are advatages to building an engine that can spin at 9000 rpm.

 

OK, 9000 RPM motors.

Tell us why the Pro Stock guys run their full 500 CID, with whatever stroke it has; and NOBODY is even dimly suggesting shortening the stroke to get more power.

Better yet, I'll tell us why. It's because that whole idea is BS!!! IT DOESN'T WORK THAT WAY IN THE REAL WORLD!!!!

Don't forget, I still know how we can settle the discussion, with facts and measurements and real-world existence. You got any idea what I'm thinking of? You ready?

 

because Pro Stock guys have heads that can support that displacement at that speed. If you're restricted by your heads and cam short stroke increases power. That's all there is to it. Its a big IF and noone seems to be catching that part.

 

Try explaining your reasoning instead of just stating a fact.

 

Then they also have heads that support a smaller displacement at an even higher speed. If "faster" means "more efficient" like you seem to think, then why don't they destroke?

Power comes from burning gasoline molecules, and that requires air. You have a choice of doing it two ways... you can gulp in huge amounts of air and fuel a small number of times per minute, or you can sip tiny amounts of air and fuel very quickly. Either way, you can only consume air and fuel at a set rate, and that's what determines how much power you make. All the rest of these issues like piston speed and rod angle and bearing friction only account for a very small difference in efficiency. Not enough to overcome the difference in displacement.

If you're restricted by your heads, you're restricted by your heads. They're capping your power, because the amount of air that they will flow is limited.

 

Well yeah, since in the REAL WORLD, you know, out here in MEATSPACE, you're ALWAYS restricted by heads and cam. Like, duuuuhhhh. That's always the restriction.

Yet, I can't think of ONE SINGLE INSTANCE I've ever seen, where a motor with a given bore and LESS stroke, has EVER made MORE power than a motor with the same bore and MORE stroke.

Show me one example of what you're claiming. JUST ONE. Proof, such as dyno graphs or track times; not just a bunch "I'm the smartest guy in the world and I know more about motors than people whose livelihood is making the most possible power out of motors" type BS like we've seen so far.

And of course, my other proof method offer is available to you, IF YOU DARE to even find out what it is. Which I rather suspect you don't, because you don't understand what you're claiming yourself, because if you did understand it, you'd already know how wrong it is and you wouldn't be trying to claim it in the first place.

 

These threads (302, 327, destroked 400, etc.) make me cringe every time I see one. Just like the "What's the best oil to use?" threads.

So little information, so much misinformation, and nobody has learned anything in the end because the misinformed are too stubborn to admit they've been misled.

In the interest of peace on earth and good will amoung TGO, this is going .