<b>what machine work would be required to make a 377 with a 350 crank and a 400 block</b>
you can either: Add Bearing spacers. (NO machine work)
Or you can get a large Journal 350 crank (summit.) (No machine work)

But you will need matching rods / pistons or.. um... else.

 

but there are other ways to make more power without going to mroe cubes so

 

a 302 or a 327 wll never make as much as a 350 or 400????

I like how you use the word never in this being that I ahve seen quite a few of the 327 motors making enough to shame a few 350's


let me guess you also think a rotary can't make more then 150hp

or a 1.6L civic can't make over 160hp


and a little 3.8 V6 made by buick was the worst piece of cow dung ever made

also here is some info for you on a 327 build up
http://fbodypage.freeservers.com/

 

you say a 327 isn't a street motor b/c it's high revving? I drive my wankel daily and I'm sure the 327 puts out more low end then my car so how can you say a 327 isn't streetable?


and no replacement for displacement I figured you would know beter by now

 

400 does have a bad rod stroke ratio from what I think I have seen


but a 327 crank... nasty to fit I think but might help you out a little

 

me pappy had one and I used to ride in it all the time

even drove it a few times..... I liked it quite a bit

 

There's still tons of them left around. Tons of them left in cars. It's not like as soon as 1973 rolls around they all turn into pumpkins and mice.

I've got 3 327's sitting in my garage that are mine (2 LJ's and one SJ), 2 of which are on engine stands and a 283 on a rolling Model A chassis, also mine. I've been at quite a few engine dynos where I could witness what different bores, strokes and rod lengths can do and I was only born 18 years ago.

 

i thought that the standard bore 350 block used with stock 350 pistons and short 5.56 rods and 400 crank was the original 383. the only 377 i have ever heard of is the short stroked 400 block.

 

where could i get the bearing spacers to make the 350 crank fit in the 400 block? I think i wil go ahead and build the 377. would it be better to go with the the spacers or the crank, which would be more reliable, how much would each cost? Should i use a 5.7 rod or a 6 inch rod?

 

Take two motors, one a 350 and one a 327. Mod them equally. All things being equal the 350 will always make more power. Just like people don't want to sacrafice 45 cubes and build a 305, why sacrafice 23 cubes when it will cost hte same if not less to build a 350?

 

<b>the only 377 i have ever heard of is the short stroked 400 block.</b>
Which is basically an overbored 350. its just that you cant overbore a normal 350 to 377, you have to take an ALREDY overbored 350 ("400") with the 350 crankshaft. same thing.

<b>where could i get the bearing spacers to make the 350 crank fit in the 400 block? I think i wil go ahead and build the 377. would it be better to go with the the spacers or the crank, which would be more reliable, how much would each cost? Should i use a 5.7 rod or a 6 inch rod?</b>
My opinion: Avoid "exotic" engine combinations. There are MANY Kits out there on the aftermarket that perfectly match up to a 350 sbc, but when you start mixing and matching cranks/bore sizes you complicate things. alot. Its not the best thing to do for a beginner, or somone without the experience to know exactly how to put such a thing together.
Small changes to the way its assembled can make or break the engine.
Ill give an example:
with a 377 Your going to want to use the RPM potential available to maximize your money. If your spending money on good aftermarket pistons/rods/crankshaft your going to want to take advantage of them right? Whats the point of getting a fully forged bottom end then sticking to a 5000 RPM redline? and dont tell me 5000 Rpm redline N/A is enough to make 350+ horses. Not with a streetable 377 engine. and done expect amazing torque without crazy gearing, and thats ALSO not conducive to a high revving engine, especially for the street, and especially when you want to rev that engine up.
I dont know about you, but the last time I CHECKED a 377 was not exactly a "standard" rotating assembly buildup. Finding a suitable 400 block then using "questionable" bearing spacers to support a crankshaft that will be spinning with a decent powerband is not conducive to long engine life. Small changes made to bearing clearance can affect how the engine reacts to a high rpm band. Too tight and you will easilly spin a bearing. too loose and it will bang around. it must be precise, and mixing up a crank in an engine not meant for it will be... dicy. Leave it to the pros.
In short- a 377 is not for beginners/limited budget people, In my opinion.

 

OH and lets clear up this "no replacement for displacement" argument. The last time I checked there are 4-cylinder neon motors making 800 horsepower and 455 pontiac big blocks making 220 horsepower.


<b>
Its all in how you build it, and what you bolt onto it.
'nuff said
</b>

 

Enough bickering,

A 350 is the cheapest/easiest sbc to build period.
And I think its got the best of both worlds, O.K top end HP and O.K bottom end tourque.

I've built 2 motors in my short life, both being a 350, there a great beginner motor to build.

 

I've always said this. The way you combine parts with strokes and bores is always the way to create the most power.

 

for the 377 buildup as a race motor...which would be better? large journal crank or spacers?

 

my budget does not concearn me. it will just be that i will have to put off building this engine till i have enough money. I have an ouncle thats a mechanic, his son races circle track cars and he builds them for him. Ive adopted his philosophy that if im going to build an engine, i might as well build the one i want, and if i take the time and do it right, only good can come from it. People have built 377's before so it doesnt seem like as big of a gamble as you make it out to be, if i do it right which i will. i was still wondering about the the rod legnth though, which should i use? I also thought the idea of a 377 was so that you could rev like a 350 but have the bore like a 400. Assuming i do everthing right, shouldnt i be able to turn at least 6000 rpm?

 

I agree

it's all on how you build it


no replacement for tuning and matching parts would be the best phrase

but it doesn't rhyme so nobody uses it

 

so I bet you also think there is not way a F1 motor with only what 3 or 4 liters at most pulling 900hp would ever work against a 350 chevy b/c of less displacement
I'm sure if you build them both the same the chevy would make more power but that is b/c of the different way the bore and stroke on the motor is you can't build them the same

granted it is an extreame example
but I'm sure the 302 or 327 vs the 350 can be done about the same



you can bulid them the same and the 350 will produce more low range then the 302 or 350

but if you biuld the motors the way I like them... revy bastards the 350 would start to fall behind...

now it might be able to rev as high as the 327 or 302 but due to more stroke and mass it would start to fall off in power when up in that power range

 

Stick with the 350. I doubt most people here have the budget or paitence to do anything else, I know I dont. The 350 will give you an improvement or a 305, 307 or a stock 327. 400's IMO are "schit" Ive seen soo many with rods poking out of the oil pans it pathetic, granted that can be fixed by real connecting rods/bolts.

 

i say long rod 383 like i did. pump gas compression, gobs of torque, lots of hp and good rpms. if you look for deals you can find parts to build anything for a good price. he|| i paid less than $900 for my eagle steel crank and h-beam rods. this is my first stroker and i can tell you is sure as $hit ain't gunna be my last.

 

<b>I also thought the idea of a 377 was so that you could rev like a 350 but have the bore like a 400. Assuming i do everthing right, shouldnt i be able to turn at least 6000 rpm?</b>

An Engines Valvetrain is what determines redline/powerband. I know a few 355 sbc's turning 11,000 Rpms N/A making well over 800 horsepower. <b>Its all about flow...</b>

More than anything, the bottom end is just a means to justify the end. you cant spin a stock 350 bottom end to 11,000 rpms. You have to decide what your power range will be, and just how much fuel/air you plan on cramming into the cylinders. If you expect VE of 110% or more at 8,000+ rpms, expect to pay a pretty penny for a bottom end.
Likewise a stock 350 bottom end is usually good to 5500-6000 rpms as it sits, but again VE(no huge blowers) and cylinder pressure (no nitrous) can affect that ratio. The more power you make, the higher you make it, the more you will to spend on your bottom end.

A 377 VS 350 is kind of like the old 427 VS 454 argument. theoretically, the 427 with its smaller stroke can handle the rpms better than the 454. Actually, the truth is a 454 can handle just as many RPMS as a 427... with the right components. problem is, most people dont want to use the right components when its cheaper to just drop down to a 427 crank and be easier to make that power up top without the extra expense of a stroner forged 454 crankshaft.

<b>Its all about flow</b>... an engine is a vacuum pump, make it flow and it will go.
<./end opinions.>

 

who has got a 355 that turns 11,000 rpm? I'd like to see that. Just think of the money that the nascar teams put into their 9000 rpm small blocks. I thought that 9000 rpm was about all of a 90 degree V8 was capable of.

 

I'm not sure about the 11000 rpm thing, but even higher isn't immpossible. If the rotating mass can be kept light enough. Newton said as something like "as an object approches the speed of light, its mass becomes infinit". So make it faster and its mass increases (mass not weight). The only thing hard about reving high is that rotating parts will break. With new alloys becoming common, an engines theoretical redline can only be increased.

 

Theories are cool and all, but I would still like to see it.

 

well all i ever heard about growing up is my dads 302 camaro and my g-pops 327 vette...... and how much *** they hauled..... as for hands on experience..... i have none with them lol

 

Which 327 Vette did he have? Ive had hands on experience with two 65 Vettes....one 375hp fuelie the other the single 4bbl 360hp...those things are hairy when you drive them; and they were all stock....

 

it was a 62..... i dont really know much about the motor..... he is deceased..... but my dad always tells me it was so fast and he forgets what was all in it lol.... it was back in the good days

 

Has your Dad driven your car yet? lol It's probably faster.

 

yea he drove it , hes scared of it......... he cant hack all that torque...... hes an old head that needs to just like chill on the porch now ahah...... nah hes got his little porsche boxter that he pretends is fast.... i guess u can dream....... my car isnt my daily tho..... i switch off between that and a dodge omni (heh) cuz it like borders being streetable...... the omni is fun to beat on and drop the clutch in...... i like to hit things with it esp on trash day

actually in the top end that little porsche would demolish me..... but who cares about going 160 mph lol

 

Well that 11,000 rpm 355 thing has people going huh?
I dont think 11,000 rpms is anywhere near the speed of light...

The engine I am mainly refering to was built by the same person that helped me build my engine, my first time around. Its actually a 360 now (350 bored .060 over) and its in an "Altered" Drag car. It was producing around 800~ horsepower when the powerglide blew and it over-revved (no rev-limiter) to about 14,000 RPMs, Snaping the faces off of most of the valves. He would shift consistantly at 11,000 rpms on the track.

I have heard the altered run down the track.

Do you know what a small block chevy sounds like at 11,000 Rpms?
I do.

 

Nobodys calling you a liar, I've pulled just over 7000 out of my motor a couple times now(by accident - just late on shifting out of 1st).

And of course it not the speed of light, I was just illistrating that a psiton for example has huge momentum at high revs.

 

I have always wanted to hear that

 

<b> I was just illistrating that a psiton for example has huge momentum at high revs.</b>

I heard that going from 6,000 Rpms to 7,200 Rpms doubles the stresses imposed on the rotating assembly. (2x the stress at 6,000 is seen at 7,200 rpms)

which is why they say forced induction makes "soft' horsepower, the piston on its way up is met by the pressureized atmosphere in the intake manifold from the boost coming through the valve, thus slowing the piston down before it hits TDC and making it easier to reverse it's direction. I read that in a few different supercharger books.

And as for nascar remember thats 9K continuous usage, were only talking about 11K once in short bursts down the track. powerglide = 2 gears, and you probably will never hit 11K in second gear (unless your drag car does 300+ MPH in the 1/4)
Also:
Remember in 1969 with CAST rotating assemblys there were 302 DZ motors spinning 11K.(not stock of course) Its not amazing we can spin 11K now with all the high-tech lightweight aftermarket crap they have now.

But with everything, you still have to ask yourself this question:
"Do you feel lucky, punk? well, do ya?" Cause you never know....

 

At least you can grab it and go 160 if you want to.

Brian

 

heh i know i was being sarcastic.. it would be very fun i think...... but id be dead if given that oppurtunity...... ud find me on a tree somwhere........ yea u should see half the features its got.... a spoiler that comes up at 75 mph and all kinds of crazy ****:hail:

 

You can get more RPMs if you DESTROKE a 400 to 383. That's what I want to do later on when I have 3 cars and money.

Also, you got the extra cubes if you want it.

Benefits from destroking a 400 to get a 383:
Not as much cooling problems
More RPMS than a stroked 350
Beefier block that can take some punishment
Guessing on these:
Higher compression won't kill it.
N2O compatible(er)
bigger block = more oil = more life out of your 383

--Dan

 

Use a scrappy 283 race motor and slap a forged crank and some budget manley alum rods and some forged pistons for HIGH RPMS!!!

 

My boss got one about 6 months ago, I tried to talk him into the Boxter S but he said he was too old for that. He did let me drive it but I had to swear that I wouldnt tell his wife. Very nice car, extreamly smooth acceleration. I wouldnt mind having one for a daily driver and having my GTA beef'd up for the weekend races.

Brian

 

Closest I've heard was a local 68 Camaro with a "built" 327, that routinely shifted at 8500, and it was just terrifying to hear going down the street... just damn wicked

 

remembenr the 400 block is kind of crap since there is no cooling for the inner two cylinders........ not good for race...... good for a mild street engine with a really good cooling system

 

my buddy built a 377, then sold it to some kid. The kid didn't watch the temp guage, and ended up melting it down.

 

<b>You can get more RPMs if you DESTROKE a 400 to 383. That's what I want to do later on when I have 3 cars and money.

Also, you got the extra cubes if you want it.

Benefits from destroking a 400 to get a 383:
Not as much cooling problems
More RPMS than a stroked 350
Beefier block that can take some punishment
Guessing on these:
Higher compression won't kill it.
N2O compatible(er)
bigger block = more oil = more life out of your 383

--Dan</b>

 

just stick a BUICK 3.8 turbo V6 motor in it and call it a day!

 

Yeah the 400 is a real POS I barely broke into the 9's with mine in my 3100lb car. There is nothing wrong with a 400 block, they are the highest demanded GM blocks there are. "it is better to be thought a fool than to open your mouth and remove all doubt."

 

what a shock...not toomany.....if any votes for the 305...poor lil motor...lol oh wait...ive got one.....damn...well actually i like it

 

I see a lot of people degrading the SBC 400 because they dont have a clue what they are talking about. Before you open your mouth please do some research using the (scientific method) basic high school information. The 400 got a bad name because people thought they always over heated.... Shade-tree Mechanics did not compensate for the saimese twins cylinder. A 400 would out run any 350/383 withe the same internal parts. They will run just as cool if the steam holes were drilled in the block and proper cooling system setup. .. Dont just go by some hearsay that SBC 400 overheats. 75% of the reason you see all these 383 is because the 400 block is such a scarce resource. Im lucky I got a Standard 400 block fo $50.00.
Please know what you are talking about before posting such bad information, because somethings are best left unsaid....

 

This is a HOT Item
SBC 400
4.125 bore- 3.750 Stroke= Plenty of volume to fill

 

Anymore that is a pretty rare item. A real nice one is on ebay right now tho

 

LOL!! Gawd, this is a hilarious thread!

BTW, there is more to engines than displacement. For example, engine design is a big factor. Create a 350 cid V8 with a 1.6 inch bore and 55 inch stroke (fast math, so if its wrong, sue me), and I'll race you with my self propelled single cylinder Honda pushmower and we'll see who wins. Of course, this is an outrageous example, but it proves the point.

If you have two engines of equal quality and equal availability of high performance parts, then the engine with more displacement has more upside potential for power. Reaching that potential is the challenge (and the fun). So, pick your poison and go build it. We'll see how it works out on the track!

I personally would like to try stroking a 400.

 

worst goddamn block for heavy racing..... i wouldnt risk overheating the inner cylinders...... i dunno about the rest of you but i like to play it safe with my money.