427 vs 434 vs 440 SBC Which one?

[attngtr]

I am looking to purchase a shortblock for my 79 malibu and I can't decide on which one. They all have a 4.00" Stroke x 6.00" Rod. The 427 has 4.125" Bore, 434 has 4.155" Bore (which is .30 over) and the 440 has 4.185" Bore (which is .40 over). I am looking at the flat top piston with 2 valve relief which will net me around 12.4:1 compression with 64cc heads. I am not sure on the thickness of the head gasket I should go with yet. The heads will have 225cc Intake runners, angle plugs and 64cc combustion chambers. I am looking for a cam around .600 lift, 314 duration, 252 Duration @ .050" Lift, 110 lobe seperation and 106 at intake centerline, 1.50 roller rockers and this will also have roller lifters. Would I benefit any by stepping up to the 440 vs the other 2?
Thanks for any help in advance.

 

[rjleiker]

if they are all a safe cylinder wall thickness, then I say the more cubic inches, the better...
I would just consider the cooling capacity of the rest of the drivetrain... I hear that thin cylinder walls can cause more heat... not to mention the high compression, with predetonation and all...

with a 6 inch rod, you should be ok with ring seal and piston skirt stress at the bottom of the stroke.
I'm no engine builder but I've read about different things...
I have also read that with an increase in stroke you can actually decrease engine efficiency because of lack of consistent ring seal from putting too much force on the outside of the piston as well as cylinder wear issues... thus some builders can get more reliable consistent power from a shorter stroke just because of better ring seal... then you could possibly just run a better cam or higher ratio rockers or something...

Just some things to consider... again, i'm no engine builder, so your combo might actually be set up great already... if so... then more cubic inches is always more fun...

 

[mean78malibu]

What blocks are they using to make them?

 

[rjleiker]

Well, this is a Ford Engine builder, DSS Racing... they have stated that their 331 strokers can produce more reliable power than their 347 strokers for the Ford engines from 302 blocks... they are stock blocks... and they are Fords, so the initial engineering design may have a flaw with this anyway... not sure, just something to think about... the Chevy 400 may not have this issue...

 

[attngtr]

This is a New Bowtie Block.

 

[rjleiker]

I think, since it's a new production block, that you'll be fine...

All I would look at now is, whether or not the rest of the valvetrain and intake and exhaust specs are of the right measurements for the displacement and the piston speeds for that stroke...
sorry, you may not need to worry about that... I'm kind of a perfectionist when it comes to engines... there are just so many variables...
If you think about it, the pistons will be x grams heavier with the larger bore and so with that particular stroke and bore, the engine may be more comfortable at higher RPMs with the smaller bore... maybe not much, but maybe enough to take advantage of the cam and possibly the intake efficiency... just a thought to think about.. then take that into account with your drivetrain and gears and such and maybe your converter with automatic or gears with manual and rear end gears... you're hand picking an engine here, so why not pick one just right for your car and application... drag racing, street, etc...
I know most of this probably won't matter, but this is all the stuff I'm considering when I'm looking at what I want in an engine...
I still, to this day, haven't picked out what I want for my first real Hi Performance engine... I can't make a decision on what all I want, nor have done enough research... sorry again, I probably just made this a lot harder for you than you wanted...
You honestly probably wouldn't have to worry about most of this stuff...

 

[attngtr]

Well the headers will be Shoenfeld 1 3/4" to 3 1/2" collectors. I am running a TH350 with a converter that stalls at around 4k behind my 355 right now. I have a 9" rear already and just switched from 4.11 locker to 4.57 spooled center section. I haven't decided on an intake yet. I was thinking about a Wiend Team G single plane. I have a Proform 850 race carb now. I haven't decided on a oil pan yet either. I am not sure if a what will fit the chassis and headers (as in stepped out side or not). I don't want it to hang to low.

 

[79malibusbc]

i think that cam is a little small for those motors but it would work well in a 355. i would go with a .660'' lift and 264/270 @ .050 lift

 

[attngtr]

I already have a set of hydraulic roller lifters so I was looking at those cams. Does anyone have other suggestions for cams. I don't know if they make that big of lift in a hydraulic roller configuration.

 

[ILLEGAL REGAL]

my thoughts...
no replacement for displacement but starting at the smaller bore will give room when something goes wrong and give more life to the block.
However, I think if you could rething it a tall deck spread pan rail block is the way to go. I know if I ever do it over a tall deck is the key, even at under 430" you just make a better combo with the tall deck options as far as compression heights/rod lengths/ block clearence/ cam diameters.