what are advantages and disadvantages of a 4" bore and a 3.736" bore(ie 305 bore)

I know i can stroke a 3.736" to 335, and it also has a lighter rotating assembly, i.e. higher reving

4" bore has a higher capability of cubes, also is much much heavier, i.e. cant rev as high. Has poticial for a great exhaust tone.



What else can you guys think of....

what i'm thinking of doing is stroking my 305 to a 335, but eventually getting a 350 block and just changing everything over to make a 383.... Its a good plan IMO, nice easy way to move up. The LB9 heads willbe good for 335, but when i goto the 383 i'm thinking a high CR(9.8-10.2) piston with iron eagle heads 210cc IR heads.





Shane

 

"Why is a 350 better than a 305"



'least he spelled his name right this time and didn't end the post with "so.."

 

iunno.

 

well would you rather have a high reving motor or a torquier one is bassically the question/answer?

 

Tell (or convince rather) me why the weight of the rotating assembly is the determining factor of peak revolutions per minute.

Weight does not determine peak RPM. Bore does not determine torque.

Chalk this thread up to the great "327 versus the 350" debate.

 

 

Ok, ok...

iunno

iunno, no, not, niet, oxi?

Holy crap you need some books. ‘Potential’ cubes, doubt the weight is that different and would not have as much to do with the rpm potential as other factors

Don’t bother, start with the 350 core. I thought we finally bashed that into your head at least!


And what's poticial? An Italian soup dish?

 

no there is a difference, if you think about it, more area(surface area) for the explosion to hit the piston means more torque. Therefore a 4" bore gives you more low end grunt then a smaller bore.

And roatating weight does slow down revs, why do you think people loved forged cranks so much more, they are usually lighters as well as being stronger, lighter means the motor has to work less to get it spinning = more availible power.

305 will rev way higher then a 350, just because or rotaing weight.

Get a 350 to flow as good as it can get, and a 305 to flow as good as flow gets and the 305 will always out rev a 350. thats simple.

350 just have more low end grunt. they can rev high, just not as high.




Now, which would you rather run?


I've seen 305's run 10's because they made power way up high. 350 can also, but they have more torque just about everywhere.

 

Shane, IM (on AIM) me. I will *gasp* take the time and explain all of this. Under one circumstance: You actually listen.

My contact is in my profile.

 

yes but the reason is because more cubic inches = more power, its not the bore alone that determines that. More horsepower and torque. Shane.. come on man.. do you have any experience what so ever in what your talking about? Have you ever weighed or balanced a rotating assembly? Pistons come in all sorts of different materials which = different weight.. assuming all same parts are equal the weight difference would be so small that it would make no real difference. And more low end grunt.. ok yes true, more "grunt" throughout the powerband. More cubes = more hp +tq.. its not really rocket science...

 

you arn't online bro?

i am platinum86ta, so when i im you, dotn run, hehe.



I'll be here for another half hour before i get to bed.




shane

 

destroke a 350 to 305 cubes if you even can, and i'm sure the darn 350 down to 305 will perform better then a regular 305....

 

please goto bed now

 

a larger bore allows you to use larger valves. which means more fuel and air in the end.

 

Oh goodie, you were stupid enough to ineptly argue with me.

Where did I say there was no difference in surface area? And there is more POTENTIAL for more power. This does not always make it so. And the 'item' that will affect ‘low end grunt’ to a major degree, as you are apparently thinking, is the stroke.

If you would like a review of that, please read through this amusing thread:

https://www.thirdgen.org/techbb2/sho...hreadid=240403

Mike, go buy some books. While throw/bob/rod & piston (whatever you want to call it, just not rotating assembly) weight will have some effect on the reciprocating limits, it will pale in comparison to other factors. Balance comes to mind. Valvetrain and flow potentials come to mind. A 50 cal. Comes to mind.

Oh, and last I checked forged was prefered due to the higher strength and durability.

Right… so why do I see bigger motors that rev higher than mine?

So now the limiting factor is flow?!? WTF? Stick with one argument. And with regard to what you are trying to say, you are flat out wrong. Again.

Uh-huh.
Tell me Mike, how much was the diploma from McDonalds Monkey-Spank University? Was it hard to graduate? How does one come up with good, entertaining monkey-spank? Oh wait… you don’t know that either.


A 572 BBC or a 454 SBC. Maybe one of those nice Honda formies would be nice too. What’s this have to do with anything?

Please share. Are they sitting next to your BBCs and the Eaton (which I still want btw).


This ends our public service announcement brought to you by the Darkside. Please join us over here on the darkside where everything is, well, dark. Your regularly scheduled program will resume posthaste

 

OWNED!!!!!!!!!

 

Chicks dig large bores and long strokes.

 

Ive seen a few 10 second 302 mustangs, but they had power adders. (not to take away from the sheer stupidity of the one sided conversation)

 

I've seen the two halves of the case when said 302's were pushed too much.

 

Which dialect do you think therckid is?

http://www.rinkworks.com/dialect/

I think a cross between ******* and moron.

 

Lol, if everyone was therckid,,,

http://www.rinkworks.com/dialect/dia...eadid%3D274168

 

dont know about you,but i dont have a bore, i have a piston

 

Oh, sh- DAMMIT. True that. That's what I meant......

 

woman

 

I forgot how the piston goes in the bore. Large pistons and long strokes then.

 

lol, whata girl, goober

 

at least he doesnt need to stroke his own

 

lol...

Anyways, while a "larger bore" engine may have heavier components (quite obviously because the pistons are larger in diameter), the extra surface area of the piston (and thus the larger volume of the cylinder) more than makes up for the extra weight by adding much more power.

Therefore a 350 will have MORE power pushing down on each piston than a 305 would. With that said, you could argue the exact opposite of what you are saying. I could say that a 350 will rev higher than a 305 because it can push down on each piston harder, but I'm not going to say that.

Balance is the key as to how high a rotating assembly can spin. As to the rest of the engine, as mentioned air flow and valvetrain have a lot to do with things, as well as the rest of the driveline.

Why is the 302 such a strong motor when compared to the 305? The bore size. The 302s can squeeze larger valves in the cylinders, which means more flow and thus more power. The 305 has the SMALLEST bore of any SBC ever created.

Of course if a 350 was somehow destroked to a 305 (though I'm not sure how you'd manage that), it would outperform a stock 305 with the small bore. But if you were to then take a 350, it would waste the "350-destroked-to-a-305"

No one ever said a small bore made more power than a larger bore.

 

heh, neither do i, thats what i got you for remember?

 

oh, did you think of that one all by yourself...

 

a ford 302 has the same bore stroke combo as a chevy 302. 4" bore and 3" stroke. will rev to the moon if you have the right valve train parts on it. comparing a ford 302 to a chevy 305 really is apples to oranges. the chevy 305's 3.735" bore and 3.42" stroke is definetly not what i would call "ideal" for spinning big rpms. they are decent low end torque motors, but by far not best for high rpm horsepower. and really, not the best for any kind of REAL performance. i am one of the 305 performance activists, but after i am done "learning" with this motor, i will definetly be going to a 4" bore motor.

 

I think DC is thinking like an old codger and referring to the Chevy 302.

 

I fully agree. That's exactly what I was saying though, that the bore makes a big difference in performance between two engines with the same displacement.

 

Without doing the math, I'd bet the 3.42inch stroke just made you a 302

 

this was one of the funniest things I've ever seen....thanks.

 

first off just want to say that should be easy
cause if I remember right the 305 and the 350 share the same stroke


though I admit I might be wrong on this being it's late at night and I am confusing my motors
but still

 

funny thing is though for us guys
we like big bores on our cars
but for the women the smaller the bore the better

 

um....


sorry don't think we can help you there

 

rotating mass does play a little factor in revs. not the greatest factor though. if anything piston speeds would be a bigger factor then weight and avg piston speed is affected by stroke while rod legnth will affect the peak piston speeds to a small extent

as far as surface area for the explosion to push against being it is a sealed area I don't think your going to make much difference there. if anything you would gain revs from a larger bore motor from the fact of you can fit much larger valves in there. for one thing look at an F1 car those things have a TINY stroke on them but a huge bore mainly so they can fit the larger valves in there to support the 18000rpms. also they have the shorter stroke to help reduce piston speeds a little (this is not counting their valvetrain things)


as far as rotating mass that will effect all rpm ranges not just high rpms. and ppl love forged being it is stronger and able to handle more stress not truely because of weight that is an added side effect. but durability is the key factor.

305 will prolly not rev a whole lot higher then a 350 mainly cause the valves are so damn small they would restrict flow so much that it couldn't rev that high.
look at the pontiac 301. it had the same setup as the ford and chevy 302. can't rev worth a damn though being the intake/exhuast ports are so damn small the thing couldn't suck in air. also the intake design was about the worst design EVER made



305 to flow as good as it can and a 350 to flow as good as it can and the 305 will always outflow? wonder what the 305 can rev to since they have 358's running near 9,000 rpms already



and as a side note while revs might be nice under some situations let me tell you a few problems
launching is a bitch being that you have to rev higher to get that same amount of torque to the wheels. this extra reving on the launch will shock the tiers causing spin.
with your piston motors you generally also are going to suffer from gas mileage issues due to the cam you would have to run to take advantage of those extra revs would mean lots of overlap and long duration, then you have the huge heads (which the 305 wouldn't support anyway) that would hinder efficiency at lower rpms mean you would have end up giving more gas to just cruise around, then comes gearing you would prolly want some steep gears which would mean higher rpms to just cruise around causing more gas mileage issues.
if you are doing any type of road racing you are going to need to be a lot better with your shifting being that these high rev motors tend to be a lot of times peaky and so you can at points find yourself outside your torque curve and well that just suxor

then comes torque production. even if the motor can rev to the moon if it can't produce anytorque up their thenthere is no point in it really.
revs do not mean power. revs mean even less if you don't have the torque and gearing to back it up.
all the power in the world is nothing if you can't hook up being that your 8000rpms clutch dump just smokes the tires.


so if anything build the 350 first
you will enjoy it a lot more in th elong run

also learn a little more about physics

get laid it helps honest just don't have kids man, but if you do send them somewhere that they can learn automotive stuff other thne trying to learn it from you. it will be better for them

 

Holy ****, LMAO :rockon: :rockon:

 

Torque is directly related to the amount of gasoline and air burned. The more fuel you burn the more torque you make. Horsepower is just a calculation of torque per unit time, so that is directly related to the amount of gas burned also.

Bigger engines burn more fuel=more power. Theortically nothing effects the amount of power produced except engine size, not bore, not stroke. But in the real world there are over baring factors so...

Bigger engine equal more power, smaller engine equal less power, plain and simple.