i have my eyes on 2 400's both complete (probably used) for 400 candian each,, this sounds like a steal because i know 400s are rare

i do not know the year of each , but i am guessing they are 4 bolt main, non roller, 2 peice rear seal right?

is a 400 a good choice? or should i de- stroke it/ stroke a roller 1 peice 350 instead? , im probably going carbed, and have an arsanel of and engine shop ..... plus dyno

is i have a roller 305 waiting to be junked... can i retro- fit the roller stuff on the older 400? i am a welder, and have full use of any metal tool as well.. gee im a lucky 18 year old to have all these sources eh?

 

I have a used 400 block .010 over. Needs another bore, I paid $250 for it (its been fluxed too).

I am not building it anytime soon because I can't drop 5 times the value of my car into it.

 

400s aren't "rare"; just hard to find laying around. They're all ... accounted for, so to speak.

Definitely 2-pc RMS, definitely non-roller. As to the bolts, who knows. There's alot more 2-bolt ones in the world than 4-bolt ones. The 2-bolt ones are a better block; not because of the bolts themselves so much, as that the early ones that got the 4-bolt caps, have less metal cast into the main webbing. The factory "adjusted" their castings upward in about 73, and dropped the extra 2 useless bolts. What you really want, is a 73-up casting; which will NOT be equipped with the 4-bolt caps.

IMO a 400 is the best choice there is for building a stock-block SBC. But then, I have some, and lots and lots of pre-factory-roller roller stuff laying around, so I have no use for the factory's junior high science fair project. Others may not be so burdened and may make their decisions differently as a result. You'll have to be the judge in your own case.

I would NOT "de-stroke" anything. There is no benefit. Would you rather have $500, or $400? Tough decision, eh? Why is it all of a sudden so tough for some people to understand when applied to CID instead of $$$?

No your factory roller stuff is not applicable to the early block. That's one of the stupidities of it, is that it requires a specially modified block.

 

MAYBE ill pay ya 100,,, but these complete 400's sound a lot better (i plan on stock rods and crank unless they are hurt or impossible to balance.

any other "precautions" i should worry about ? bolt right up to tranny? any sbc heads will work? that sorta thing
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lol don't get hasty with me not understand ,, i have heard of peopel de storking them,, obviosly for more rpms or something,, i was just wondering the benifits, if any

 

Yes and yes.

You'll need to drill the steam holes in the heads. Use a 400 head gasket as a template. Angle the ones on the intake side toward the exhaust, if you use aftermarket heads.

Have the "missing" late-model starter bolt hole added to your block. Better to do it up front than to be laying on your back, almost ready to fire it up, wondering how you're going to bolt up a starter.

 

400's dont have 2 bolts for the starter? sorry not sayingi know anything about them but i thought that just about everything was the same as any other sbc except the steam holes. i guess you learn something new every day. do they make specific 400 starters then?

 

k now im worried,,,, wtf is a stem hole? valve stem? umm does this motor not have valves WTF!!!!

 

Most 400 blocks , like other pre-78 or so Chevy V8s, only have the 2 starter bolt holes that starters back in their day used. They lack the third one that newer blocks have. Nobody put the "features from the future" in them, I guess.

Not sure about "stem holes".... That one is kind of out of the blue on me. All I know about is "steam holes". But I'm kind of an idiot or a moron, so not knowing about something doesn't surprise me too much.

 

Not stem hole, steam hole.

 

thats what i ment to say i'm sorry. and sorry again i havent looked at a pre 78 sbc closely lately but i could have sworn the starter for my 87 305 and the one on my 77 350 looked the same but like i said i admit i dont do this stuff for a living and my memory is not that good i admit i'm a noob.

 

Yeah, somewhere right about 77 or 78 was when the extra hole began to appear, because it was used in some vehicles. But not before that. I'm not positive what the first year was; but I'd guess that the first blocks that had it were the 262.5s in Monzas, in about 75 or 76. Not that there's any danger of anybody wanting to hot-rod THAT POS...

 

never mind i found the procedure
http://www.gregsengine.com/350to400.htm



and the starter will work, but all i gotta do is drill another hole ?

any ideas on the retro roller ?

 

Yup, just gotta drill the hole.

"Ideas" on retro roller? ¿Qué?

 

well , after findign out that these steam holes can get clogged, and me not having a clean coolant system,, (its clean but not brand ne ) i have decided that maybe a 400 aint for me,, i want it to be a reliable stripper and rock solid for the street (400s run 20 degrees hotter due to syamiesed cyls )

these holes get clogged and then blow head gaskets ..... that sounds like a good thing on a motor i just put 5 grand into

350 stroked it is!

THANK YOU ALL FOR YOU OPINIONS AND KNOWLEDGE

 

Don't worry about the steam holes "clogging".

Why would your cooling system not be clean? Will you be putting dirt in your new motor?

No, 400s DO NOT run hotter.

But hey, if you don't get a 400, that means there's just that many more for the rest of us that AREN'T scared off by the "old wives' tales".

 

oh for the love of crap...

You're not using this in an open coolant marine setup now are you ? This going into your boat or your firebird?
I'd also hope you'd be flushing your coolant if you're inserting a new motor, I mean you're not going to use your old oil right? No, didn't think so.

There's no reason not to use a 400cid block. Unless you'd rather have me go over and buy them

 

no, i will obviosly clean the crap out of everything on every system of my car,,, but i think a particlle or two will still be lingering somewhere in the system.

it has been proven they run hotter,, hence why they need the steam holes to begin with.

i just think those little bastard holes will cause more problems than a slightly less powerful ROLLER 383 motor will. unless im just crazy,, i think blocks are made from metal that rusts ,, call me crazy but sounds to me like those nessacry pin holes will quickly get those rust peices/other crud

I want a car with *****, and a lot of reliability ... I was jsut wodnring if the 400 is the best for the street.. sounds more like a drag motor

 

If you've got things big enough to plug the steam holes in your cooling system, then they're big enough to plug a whole lot of other places as well.

It has not been proven that they run hotter. They have steam holes in the heads because the cylinder walls are siamesed, such that there's no way for coolant to flow between the high and low sides of the block between the cylinders. This can allow steam to be trapped at the top of the block below the deck. The steam holes allow the steam to escape into the head.

That's why pure water isn't used as a coolant, it causes rust. Engine coolant or "antifreeze" is designed to inhibit corrosion. If the engine is neglected to the point where crud is going to collect in the steam holes, then you're going to overheat. That's just as true of a neglected cooling system in any engine, steam holes or not.

A 400 is no less reliable than any other SBC built to the same standards.

 

k that answers my questions very well, where in the head do the holes go to anyway, im guessing coolant ports in head right?

i learned the angles i have to drill them at ,,, but how deep ?

 

Lay a 400 head gasket over the heads to find the locations of the holes. They're drilled through until they enter the coolant passages. If you're uncertain, many aftermarket heads can be ordered with the steam holes already drilled, or any reputable machine shop could do it.

 

That link you posted above shows nice pictures on how to do it. It should be doable at home. A center punch and a hand drill will get 'er done. It's not a bearing clearance so the accuracy doesn't have to be that high.

Many members on this very board have 400's, and they don't tell of any added cooling issues. The more HP a motor makes the harder it is to cool. A 500HP 383 stroker or a 500HP 400cid will require the same cooling capacity basically. A good air damn, a good water pump, a good (LARGE) radiator, etc...

m'eh, do a roller 400cid. Retrofit roller stuff isn't *that* expensive.

 

Really!?!?

I wish I'da known that when I did mine!

 

I'm running a 415, 400 block in my 86 Vette.

When I was building it, I called around to several shops, including one of the NASCAR shops, asking about the steam holes - whether to drill the heads for them or not.

The info I received is that they're needed for an engine used for the street to prevent steam pockets from forming. If the engine is kept above 3500 RPM, steam holes in the heads aren't needed.

I never had the starter bolt up problem some of you have referred to. I did have to swap the nose off the starter I was going to install to a 400 nose though. Also, I have another bare 400 block and it has two holes drilled and tapped for starter mounting, so I'm lost on the starter mounting issue some are referring to.

Drilling steam holes in the cylinder heads isn't hard to do, if you only remember to drill on the correct angle for the ones that call for it. If in doubt, let a machine shop do it; shouldn't cost much since it's a simple process.

Mine are two bolt blocks but I had Oliver 4 bolt caps added to the center three mains on the block in my Vette.

I did a hydraulic roller retro-fit too. The most expensive part of the deal was the cost of the hydraulic roller lifters. They cost more than the camshaft. You'll be over $500 though.

Jake

 

thanks! ya i found out my engine shop guy has like 5 400 sbc's piled in a corner,,, so im keeping stock crank and rods (balanced obviosly) and just gonna get the ol speedpro piston rebuild kit for $300 ish and a mild hydro tappet cam,, keep stock heads for now,,, something in 350 horse area ,, and keeping stock tuned port,,, i know its a restriction,,, i just wanna getr done!

 

I forgot to add this: Years ago I had memorized all the Chevy starters that would cross to different year blocks. You know, like the starter off a 1974 400 block would also fit blankity-blankity.

Sorry to say, I've forgotten all that but I'm sure a web search will let you come up with it. I do remember a few things though:

Chevy starters have two different sized/shaped nose pieces and can be made out of two different metals - one was aluminum and the other cast iron.

Also, some had two starter bolt holes straight across from each others and the other type had the two bolt holes diagonal to each other.

Some starters take two bolts that are the same length and other starters have one long and one short mounting bolt.

Some blocks have an extra starter steel, brace that mounts to the front of the starter on one end and into the side of the block on the other. It's shaped sort of like and "L".

I've never seen or heard of a SB or BB Chevy engine block that didn't have two starter mounting holes drilled and tapped into the block. Even my 96 LT1has two.

If you ever come across a block with ONLY one starter hole it has to be a factory defect. You'd need to have a machine shop drill and tap that block to add the missing hole because its placement is critical for proper starter alignment with the flex-plate/flywheel.

Hope this helps.

Jake

 

are you serious in a that bad of a rush?? its better to build a decent motor from the start that will take a little longer then having the motor in the car and running and then you keep having to tear into it to "upgrade" parts..

do it once.. do it right..

what i'm saying is that, if you mean a mild hydro cam, it cant be too large or you will have to machine the heads and buy new springs, possibly retainers and locks and install them on the STOCK heads.. which will not give you a whole lot of gain.. versus, just getting new heads from the start.. you will save that money from the springs, locks, etc. when you decide to upgrade..

 

I had the 2 bolt holes on my 75 350 just the l shaped one. It is for the 168 tooth flywheels. i drilled and tapped it myslef. very easy. I just bought a 400 4 bolt main today. good deal I was wondering if the intakes and headers are the same. also my motor has the flex plate on it. I am going to put a flywheel on it. do i need to balance it or will it be ok. like i said i just got it and would like to build it right.

 

"keep stock heads for now,,, something in 350 horse area ,, and keeping stock tuned port,,, i know its a restriction,,, i just wanna getr done!"

I may be way off, but I had always heard that the factory TPI setup was insufficient for delivering enough air for a 400sbc. Would any guru's mind confirming/denying that?

Thanks!

 

This has been discussed so many times in the past, I've lost count.

From what I've read the TPI setup was originally designed for a three-o-five CID SB engine, so even putting it on a 350 strains it from an intake airflow point of view.

Now, if you move the same TPI setup to a 400 CID or more engine, well you can see where that'll lead. Engine will run strong up to around 4500, then the power band will probably flatten.

Most anything you can do to open up the plenum, runners and intake manifold will be beneficial. The intake manifold is the worst offender, followed by the plenum (which needs more volume).

That's why Holley's Stealth Ram and TPIS' Mini-Ram are so popular.

Jake