how would i make a 400 block able to handle high rev situations?

the block is in perfect condition. the cylinder walls only need a honing to get perfect again. it came out of a 74 monte carlo owned by a little old lady. and it sat forever

the block is in really really good shape. and is a two bolt block

so here is the question, how can i make this motor rev up to 7,000 rpm, maybe even 8,000 rpm. it is totaly hypothetical right now but may be a possiblity.

i want this engine to rev up really really nice so that i can slap some nice turbos on it.

Now the build-up is a 3.00" stroke crank, 6.00" rods, maybe even longer for grins.

the intake will be some sort of conflageration of a ported dual quad to be able to flow. matched up with some really nice flowing heads.

the exhaust will be something designed here at my college on the computers. i have access to all of the solid modeling and whatnot, go michigan tech. <<<<======not a sales pitch.

now, in order to do this i want to prep the block to handle it. what do i have to do? Should I fill it, probably, how far for on the street. i know i need 4 bolt splayed mains. what needs to be done to make this work?

 

Splay the main caps, run good components, and use the correct cam. You'll be good for 6-7k rpms. 8k, is probably more than you'll need.

 

but i remember hearing that turbos like to have engines that can rev.

 

Well yu heard wrong. If you heard that at engineering school
go to a different school.

Turbo's like load, not rpm. A 400sb will rev just as high as any other small block, but doesn't need too.
The rev limit of a motor is limited by the valvetrain.

A good turbo motor needs good breathing heads a relitively small duration camshaft and a solid bottom end (pistons /rods)
Forget the hi rev idea. Forget the short stroke.
Build a 406 sb and turbo the S**t out of it. You'll go faster and have plenty of "revs".

You'll go faster if you re- think your rev theory.
There is no substitute for cubic inches and intercooled/turbo boost.

 

Rev? Whatever for?

Go to the power adder board and see what Guido has done so far with a 406 (no stupid 3" stroke) and a whopping 5psi.

 

oh i am over there alot.

so okay i keep the 3.75" stroke and get a good bottom end. how high can i rev the motor? what do i have to do to make the block hold up??

the rev happy stuff i heard wasn't told to me from this school, i guess it is just one of those mis conceptions with turbo motors. being that most of them are on itty bitty engines.

 

Nothing. The block is fine as is.
Main studs would be nice.

 

then how come everytime somebody says something about a 400 going up to 6-7k, somebody says that the block cant handle the stress? or is that a misconception as well? what about boost?

i remeber being told by a member on this board that 15 psi is pushing it with cylinder wall strength?

 

go little M or dart. The money you have in everything else would be mismatched in a stock bottom end and oil configuration.

Why do people not rev 400s? Bc the stroke will quickly increase friction in the 6000+ range. Can it be destroked and turn higher? Sure, but if you don't have some cubic inch limitation, don't throw away the extra displacement.

What makes 7000-8000 so special? You got a 5.57 rearend gear and 32" tires you have to turn?

Don't get hungup on anything too much. .. keep your options open and allow things to pan out to the best combination.

 

i know that 8,000 is out of reach, but 7,000 is where i want to set a rev limiter.


where does everybody stop reving their 400s?

what about the guys with super chargers on them?

i would get a dart M block but i have two 400 blocks already in my possession, why let a good block go to waste?

 

Take every thing you've always heard about the 400 this and the 400that and file it. ALL garbage.

Build the fricken motor, and let the motor define the rev limit.
Gear your car accordingly.
The block and crank will handle all the rpm and boost you can afford to throw at it.

All you need is a balanced assembly and smooth combustion
no detonation. It will rev plenty.

Forget all the hearsay. all fiction.

 

AMEN!

If you're going to spin that kind of RPM, you'd better be setting aside a few bucks to balance the rotating assembly. You might want to check the flexplate/flywheel for cracks, too. When you think you've got it all balanced, check it again.

Don't cheap out on valve spings and push rods.

Plan on forged rocker arms. Stud girdles might even be a good idea, but I tend to be a chicken-sh*t at high RPMs.

You might also do well with a windage tray/strippers to keep the oil in control.

Filler in the lower end of the block might be a good idea, depending on your intended use. The 400s seem to need a little help in that area.

You might want to be thinking "priority main oiling" for your buidup.

And I'll beat on the dead horse a little more, too. Splayed/studded main caps are a must. (Duh)

 

if it were me and I was revving high on a 400 id go with a 377. Sure you are reducing cubic inches but a destroked motor with good internals and a small base cam likes to climb in RPMS really fast and with a lot more ease.