[camaro409]

I just had a 2-bolt 400 sbc bored .30 over and had it all checked over...Now my question is i have been seeing these 4 inch cranks for the 400 sbc that makes it a 427 sbc...is there any advantage of this new crank or would it be less reliable and just end up being a big turd.

[Miket]

I may be incorrect in saying this but I thought the only small blocks capable of safely withstanding 427 cubes were the aftermarket blocks...I didn't think you could or would want to with the 400..

[elcrusch1]

I used to have a Stock 350 block i stroked to 454 cubic inches, it exploded at the dragstrip though.

[tresi]

It all depends on which crank you're using.

[TurboS10]

Originally posted by elcrusch1
I used to have a Stock 350 block i stroked to 454 cubic inches, it exploded at the dragstrip though.

HHRRRMMMMBBulllShiitt

Simply cant be done.

I believe that the 4 inch strok actually makes a 434, but never the less it is hard to get done in a stock block. You will have to do alot of clearancing and use a small base circle cam. Depending on the rod profile it is still going to be real tight. 1BAD80 on the board here did one, so if you are set on it I would talk to him about pitfalls.

Chris

[oldschoolrods]

quote:
--------------------------------------------------------------------------------
Originally posted by elcrusch1
I used to have a Stock 350 block i stroked to 454 cubic inches, it exploded at the dragstrip though.
--------------------------------------------------------------------------------





thanks to killerforumula for postin that in another thread

[lluciano77]

Originally posted by elcrusch1
I used to have a Stock 350 block i stroked to 454 cubic inches, it exploded at the dragstrip though.

Thank god the B.S. meter is working!

That kid is stroking something, and it sure aint an engine!

[Ktaves1971]

I am eagerly waiting for him to defend that 454 statement! This should be worth a few laughs.

[406 ss monte]

350 into a 454? BULL*****!!!!!!!!!!!!

maybe, "MAYBE" a stock 400 block with 4.125" bore & a 4.250" stroke crank. if this was the case, no wonder it scattered.

as for a 4" stroke in a 400 block, it's very popular. myself, i don't trust the stock 400 block that much, but they have been done & last. if you want torque & not have to turn it hard, the long stroke is what you want.

[musky2]

May I ask why dont you trust the 400 stock block ? Do you mean for racing or street? I just found a 2 bolt 817 which will be for mild street : hoping to have a bit of power , torque with out having to hop it up alot , so thinking the extra inches will be good. Just wondering before I get started what problems or defects to look for in this block. Ive been hearing lately that the 2 bolt 400 block is the stronger because the webbing is thicker or something or another. Of course Ill get it magnafluxed : but if you guys can tell me what to look for or secrets of building this block I would really appreciate it so I can gain from everybodys mistakes or should I say knowledge . thanks

[coldknock]

They're fine until you start tryin' to get 600+lbft of torque out of them. All the clearancing that needs to be done to the pan rails with a 4" crank doesn't leave much room for a gasket seal at that spot. Sometimes the bottom of the cylinders have to be notched for rod clearance. The oil pan is expensive. A small base circle camshaft has to be used. The rods have to be very thin on the big end. No big rpms because of the rods. Heads with much larger ports must be used if you want it to see more than 5000 rpms, but no more than 6500 with the rods and piston speed.

It all adds up to a lot more work and not much return, unless you spend more money. If you got that much money, get a Dart or World block and be safe.

Larry

[406 ss monte]

Originally posted by musky2
May I ask why dont you trust the 400 stock block ? Do you mean for racing or street? I just found a 2 bolt 817 which will be for mild street : hoping to have a bit of power , torque with out having to hop it up alot , so thinking the extra inches will be good. Just wondering before I get started what problems or defects to look for in this block. Ive been hearing lately that the 2 bolt 400 block is the stronger because the webbing is thicker or something or another. Of course Ill get it magnafluxed : but if you guys can tell me what to look for or secrets of building this block I would really appreciate it so I can gain from everybodys mistakes or should I say knowledge . thanks

i guess saying i don't trust them is a over statement, but the thin cylinder walls, & thin main webbing in these motors was not intended for any kind of performance from the factory. i'm not saying their junk, i run a 406 pushing around 525 hp, but i don't think i'll add nitrous to it, i don't want to take a chance of breaking out the main webbing. the 2 bolt 400 is from every thing i've ever read is stronger than a 4 bolt, i don't think the webbing is thicker, but it doesn't have the outer bolt holes drilled through the thinest part of the webbing to make it weaker. their good about cracking out at the outer bolt on a 4 bolt block. splayed caps help get the outer bolts into the thicker part of the main webbing (out towards the pan rails). i've only seen one fail, it was a 4 bolt block, busted the main webbing all to hell, & the crank was in two pieces. & the sum***** still ran long enough to get him home

a 400 is a torque monster, you don't have to turn the rpm's with them like the smaller stroke small blocks. you can build 450 hp with one & never turn it over 5,500 rpm.

[2wld4u]

an easier route is the 415 cid 3.832 stroke 5.7 rod 4.155 bore

good street kit, the 421 is good to 6500 the 415 about 5500-6000

imo, a 5.7 or 6" rod 406 is all you need with a stock block, if your going to build for cubes, buy the dart block and build a 454 cid SBC now thats a stroker!


2wld4u

[68c10owner]

my buddy was running a 410 small block in a vega that ran low 9`s with NOS and he never had any problems. i have to agree with some of the people here that the 4" stroke may not leave enough clearance in a stock 400 block. a 421 is very doable and will probably be my next motor since i`m going to need all the torque i can get to push my 70 chevy p/u down the track.

[2wld4u]

you may want to check out speed-O-motive when you get the kit, these guy's know SBC strokers...