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350 vs. 400
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Posted by: bow350tie

tell me why one is better then the other.

and dont answer with "4 bolt mains are overrated!"

Posted by: LS1 Mopar Turbo

I don't know, however, that is the motor that is going i the big Blazer

Posted by: 28

400S.B....Simple...No replacement for displacement...And besides,the 400 small block oozes torque.....I personally think it's one of Chevy's best engines that can be tailored to various uses... either for dragstrip,road course and even 4x4 offroad...You can do the same with the 350 too I guess,but for some reason,the 400 takes a lickin and keeps on tickin...If I ever considered a Chevy for a project build up...that's my engine of choice...

Posted by: 28

Oh,and 4 bolt mains aren't overrated in my opinion...

Posted by: Mr. P

well you can get to 400 cubes with a stroker crank, but the combo that GM built, "the 400 block" has siamesed cylinders because the bore is too big to cast the cylinder walls and still get coolant all the way around them. The Ford NASCAR big blocks (the 427FE) avoided this at extreme cost (thinwall casting, cooling kilns to avoid cylinder shift during cool down) in order to get full cooling all around the cylinder. Not really sure the siamesed cylinders are any kind of liability, especially on the street,as there seem to be a lot of 400's in use. I'm not too sure the NASCAR motors of today aren't using siamesed cylinders to get more strength in the block. Anyone else got a take on this one?

Mr. P

Posted by: cswrench

I would like you to put the two togeter and make a 383 stroker! Now there is a torque monster!

Posted by: Penske

Putting the 400 crank in a .030 over 350 block gives you a 383. My favorite is taking the 350 crank and dropping it into the 400 block for a 377. The big bores let it breathe real well, plus you can use the 6" rods. This combo really revs hard and gives great torque. And you can always machine for Milodon steel splayed caps.

Posted by: skeezix

400 = more torque and cubes, but they're scarce and cooling is a big factor.

350 = bang for buck performance, millions around, and cheap to get parts for.

Posted by: Geargrabber

Yeah, I don't know where 28 fangs got the "it takes a lickin and keeps on tickin" info on the 400 SB chevy. It's actually known by most engine builders to make great HP and torque for it's size...and then explode. Siamesed cylinders and an underpowered cooling systam don't work too well together it seems. You can make just as much power with a 350 SB and keep it in one piece IMHO. I think the 400 also blows headgaskets due to poorly arranged head bolt locations....charming.

Posted by: VETTKLR

Quote:


	Originally posted by 28 fangs 400S.B....Simple...No replacement for displacement...And besides,the 400 small block oozes torque.....I personally think it's one of Chevy's best engines that can be tailored to various uses... either for dragstrip,road course and even 4x4 offroad...You can do the same with the 350 too I guess,but for some reason,the 400 takes a lickin and keeps on tickin...If I ever considered a Chevy for a project build up...that's my engine of choice...

Wow, 28! You almost sounded like you knew what you were talking about!

Posted by: BurnOut

I'm with Penske here... the big bore of the 400 with the stroke of the 350.

Seriously, though, stock 400's have a HORRIBLE rod ratio in light of the fact that the stroke is longer than that of a 350 and it uses shorter rods than any other SBC.

As for 2-bolt vs. 4-bolt, you do NOT want a (factory) 4-bolt 400 block. When the block was clearanced for the extra stroke, the machining got into the area where the outside main bolts go on the 4-bolt pieces. The 2-bolt 400 blocks with a set of main studs will get the job done until you start REALLY twisting the motor, as long as you balance the reciprocating/rotating assembly.

Geargrabber- the 400 uses the same head bolt pattern as the rest of the SBC family (LS1 excluded), which is generally known for excellent cylinder head clamping. The main reason that 400's blow head gaskets is because they get hot. The main reason they get hot is because:

A) Too small of a cooling system

-or-

B) Improper assembly. 400's require steam holes in the head gasket in a location not used on a 350, and many people are ignorant of this fact when they bolt the engine together. Hot spots form, the motor ends up getting hot, and the resulting detonation often leads to a blown head gasket.

Posted by: bow350tie

this is why i asked, i just learned a dozen new things. cheers.

Posted by: Grape Ape

Chiming in 2 days late, the 350 can handle power adders better too. Even in stroker applications it seems to last longer. If you're drag racing only and you aren't doing a stroker, the 400 is usually the better choice. For all around use, I'd rather the 350. If stroked/destroked comes into the picture, gimme a 377 with a "cemented" or "filled" block, cause that's a drag racer.

Posted by: DODGE_MAIN

400=typical chevy shitty rod/stroke ratio.

You can't really drill em out much more either seein as how they are at the phsical limit already that's why they have siamesed cylinders. Seems lots of guys like to use em in drag cars around here. Look in early 70s station wagons to find them. Oh yeah and four bolt mains are useless!

Posted by: funstick

ive been using evan npg coolant in a 400 sbc and it seems to do quiet well at staving off detonation on a 10:1 motor running 87 octance with iron heads. this is in a boat running a closed cooling system so i know what demand is. runs good. also do stay away formt eh 4 bolt 400 block the 2 bolts are much stiffer with splayed caps.

anways have fun.

Posted by: OldSchoolPower

I agree with the earlier comment about the 377. Bore of a 400 and it spins like a 350. I wanna build on some day.

Posted by: Grape Ape

But that's aight.. Since yer a

and all.

Posted by: OldSchoolPower

I love being new. Great excuse for fuckups.

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