Just picked up my 509 casting no 2 bolt main 400 today im going to punch it .30 stock bottom end, stock heads until i get the $ for aluminum heads...what is the best possible build hp for buck wise im hoping to be in the 450 hp area will be a steet strip motor in my 85 camaro i would like for my parts to be matched for idle-4500 range with a built th 350 and 2200 stall give me some input please

 

.030" and stock bottom end? Don't think that will work out too well for you Honda Boy.

 

Why not? Give some emphasis, explain your thoughts dont just say it wont work lol?

 

Now I'm not saying it can't be done because it might be posssible although I'd seriously question the strength of it using file fit rings.
How can you make the cylinders bigger but still use the stock size pistons?

 

Be careful with those 400's some blocks cant even be safely bored over.

 

You need to get the block measured & inspected, look for scoring, cracks, & cylinder taper. They can also sleeve cylinders, whats it running nowadays? $200 each sleeve?

 

Where in the world do you get the idea of me going .30 over amd using stock pistons LOL

 

Man-you guys are turning this O/P's thread into a rolling train wreck.


Did I miss something here??. Where does he say anything about file fit rings??.


As long as he hot tanks the block,mag's the block for cracks,sonic checks the cylinders for wall thickness,and measures the bores with a bore dial gauge to see if it will clean up at .030,most certainly a .030 bore is not out of line for a 400. The boring/honing should be done with torque plates in place.


Before he has even got it checked out,we have him sleeving it??. Woa!!!.

We have run many 406's in 9.90 bracket racing. For most 400's over 400 hp isn't unreasonable. But in fairness to this comment,we did not use the short rods of a OEM 400 or cast crank. The whole point of the .030 bores isn't for more power but for getting the bores round again and to remove any scoring. The torque plates help with the 400's but do not resolve the fact the 400's cylinders do move around quite abit and do have some ring sealing issues.

Let's wait for him to post what he has found out after he has taken it to the machine shop.The major hold up for his goals are going to be the stock heads.

 

Define your goal and when you expect to see 450 HP (after the heads or with stock heads and 4500 RPM)? It will be hard to get 450 HP with an engine that is designed to run to 4500 RPM only, (impossible with stock heads). You can get 450 HP at 5500 RPM with some alum heads and supporting parts.

What is your budget, goals, RPM limits?

 

Im a college student so my budget is limited id say in the 1500 range...i would like a 6000rpm rev limit but i want my intake,cam, heads to make low end power from idle to 4500 so basically a mean stop light car that i can run at the strip on friday nights

 

Sorry man,but at $1,500 you'll be hard pressed to just get the swap done once you have covered all the nickel dime stuff that always comes along with swaps.

 

Maybe I read this wrong. Stock bottom end to me would mean stock pistons. Only way that can be rigged to remotely work would be oversized (FILE FIT) rings.


Gee guys, I don't know. Where did I come up with that.

 

It is assumed that when you punch the block .030 over, they are using a "stock" replacement cast piston on the rest of the "stock" bottom end.
Putting stock pistons in a .030 over will piston slap worse than a LS1. No amount of "file fit rings" will fix that.

I have a 509 block in my car right now. It is modded a lil bit. Only thing "GM" in it is the block, timming cover and dizzy.
GM 400 blocks need some extra checking to ensure you have a good block before you start planning your build.
I scrapped 4 509 blocks before I found a good one.
Cyl thrust side sonic checks are a must for any decent amount of power.

 

Don't know. LOL.

 

1gary what kind of problems did you have with the 400s?

 

Wall thickness and ring sealing.The bores on them move around alot. We would leakdown the engines on a race maintenance weekly and each time at the same engine temp condition it would leakdown different by alot. That was using torque plates for the build too. In the end,after leaving BBC's for over 20yrs, we went back to the BBC's in a aftermarket block. The current one is a 632.

 

I should say too,we had those blocks filled haft way and then saw deck deflection. It just moved the stress points higher.

 

So was that on all 400's? Most of them? Im guessing it was obviously enough to make them financially not worth pursuing.

Im sure you can see the appeal of a big inch smallblock, I've been wanting to build a 400 for a while, (or at least, save up to build one) but you always hear stories... and I decided to leave it alone. The only real way around it seems to be a Dart SHP 400 block... pretty chunk of change for that, which, as you mentioned, makes you really consider going LS.

 

400 at moderate power levels of 500 HP and less are fine. Find a good block, have it finished, and put it in and forget about it.

If you plan to build a 800 HP 8500 RPM engine go aftermarket but otherwise stock is fine.

The OP is looking for 450 HP, stock 400's will work at this level all day long.

 

Yeah-what you do for that is you sonic check it and mag it do the machine work with torque plates and ignore all the rest.Don't leak it down or anything else. Just run it. Make sure you drill the steam holes for the heads and keep on top of the cooling.

The SHP blocks came into being and addressed all the oem block problems.So if you wanted to see what is wrong with the 400's all you have to do is look at the features on the SHP blocks.

 

Lots of good info here keep it coming...just got the block out of the hot tank going to have it checked this week...i miced my stock rods all are in spec except for one that looks like it has been honed so im thinking about scat rods now...what are the best aluminum heads i can get that are under 1000 for the finished pair, also i was wanting around 10.5/1 comp, what cam lift? Intake manifold? I have a 700 edelbrock but have been told those are junk so demon 750? Or holley 750 dp?

 

$1000 will get you a set of decent used heads. Lift on a cam is only one small fraction to the whole equation. You need to look at the duration, lobe separation angle, and intake centerline (among the other factors as well). It's all about the entire package, not just one part. Thats like if I asked you if your shoes fit because the width feels comfortable, but everything else is wrong.

Your Edelbrock might work OK, but I'd ditch it for a Holley-based (not necessarily a Holley) carb or a Quadrajet if it were me. That's my OPINION, though.

I also recommend either an Airgap RPM, or a nice single plane depending on the rest of your setup (converter, gears, cam, etc).

A "plug and play" combination will run poor in most situations. You should do some reading so you can optimize your build if you're doing a 400 SBC. Instead of the "what" feel free to ask "why" and we'll respond.

 

I thought single plane was for racing? And is my th350 with a ss monster kit going to hold up? I was wanting to do a reverse manual valvebody too

 

Single-planes are for cars with big cams and high RPM ranges.

The RPM Air Gap is nice, but it flows the same as a regular Performer RPM. Theres not really much advantage to the airgap gimmick, but it looks cool.

 

You can use a singleplane intake on the street, esp with a larger CI SBC like a 400. The added stroke is where you really get your big TQ from. At some point you dont want 2,000lbsft of TQ at 1500rpm. Sure tire smoke is fun but doesnt move ya down the track. You have to find the happy medium of tq and hp for your car..

 

I wasnt even thinkinga bout it being a 400.

Yeah, you can probably make a single plane work just fine with a 400 that breathes well.

 

Are gm performance cast iron vortecs anygood for my goals? The price sure is but just curious

 

You're cutting yourself short if you put them on a 400 SBC in the "big picture". They're good heads, but a properly built 400 is going to want more cylinder head, and more cam. I know you're trying to do things on a budget, but I'm serious when saying you shouldn't go cheap on cylinder heads. You're only screwing yourself if you do that considering they're the most important aspect to the engine (in comparison to the other parts; but they're all vital respectively). If you got the Vortecs cheap enough, though - they're a hell of a lot better than anything from 30-50 years ago and would still allow you money to go towards other things you'll need.

These would work real well provided you bought the right pistons and matched the cam accordingly. Also keep in mind there are LOTS of options with cylinder heads, not just these:

http://www.ebay.com/itm/SMALL-BLOCK-...6c9567&vxp=mtr

I think you're going to find out relatively quickly that $1,500 is a really short budget; especially since you haven't even paid for your machine work yet on the block (which will easily eat up half of your budget just getting the block prepped). Might want to crunch some numbers first before you start thinking about how much power you're wanting.

Don't take this as us talking down to you. We're not; we are just being honest. If you want things done right you need to put money where it counts; even if that means just building a "stock" motor... at least then it will be a healthy one instead of you putting subpar parts all throughout the motor just to gain little returns in power (at the expense of reliability/longevity which is a BAD idea).

 

Also if you put vortecs on a flat top piston 400 your compression is going to be to high.

 

If i built a .30 over "stock" motor what kind of hp could i expect with cam, intake and a new carb?

 

id agree that 1500 is a very limited budget for a 400. especially if your thinking about replacing pistons and rods. machine work is costly as well.

as delta said, your plan is very doable, but your machine work is going to eat up alot fo cost if the shop knows what your doing.

are you still planning on going .030 over on the block if it can take it?

 

It will make about the same power .030 over as it will stock. Horsepower is in the camshaft, heads, and intake, and getting them to agree with each other. If you're talking about a stock .030 over 400 block, you will probably make around 175-225 hp. They're terrible stock.

Also, Vortec heads are the only factory head worth bothering with on 400s and as mentioned they have severe limitations with that big of an engine.

If you stay mild with the cam, the vortecs will work fine. They wont breathe well at high RPMs, so dont get a cam that relies on a 3000-7000 RPM power band. The Vortecs wont support that. They'll probably make about the same power they'd make on a 383 or 350, but they will just make it lower in the power band and there will be a lot more low end torque. Your horsepower curve will hit a wall as the RPMs rise with a 400, though. If you're talking about true GMPP Vortecs, and not truck head castings, those fare MUCH better, but for the cost you can get some pretty decent aluminum heads too. The Jegs brand aluminum sbc heads are actually Pro-filer castings, which are the new hot ticket according to internet circles.

Do I recommend Vortecs on 383s and 400s? No. But if you're on a budget and cant be bothered to spend $800-$1500 on cylinder heads, they're the best option you have. But remember you have to get a Vortec intake AND you have to make sure you buy dished pistons to keep the compression ratio sane. Both of those may drive the cost up enough that you may want to just get some good aftermarket heads.

And $1500 isnt even enough to do a completely stock rebuild. Try closer to $3000-4000.

 

Blocks going to machine shop tomorrow to get cleaned/checked bored .30 if it checks out getting a master rebuild with cam through the shop, .515 lift hudraulic flat tap cam...flat top pistons, world products cast iron 200cc intake runners with 62cc combust chamber for 10-1 comp, probably going to go with an edelbrock performer air gap and a holley dp..what kinda horse should i be expecting and msd ignition of course

 

Now who was it that said this way back on post 11??.

 

idk must be a mystery, but as right as it sucks to hear gary is right. if your trying to keep that budget your gonna skimp somewhere where nothing should be comprimised.

 

That will not be anywhere near 10:1 compression. More like between 11:5 to 12:1 depending on other factors.

 

Ask your machinist so he can figure it out
We have no part numbers lots of info.
About all youll get it guesses.

If you can get those parts to work you should have a fun street car.


All those 400 bores move, decks crack mains can pull out if ran too hard etc.
Some seem to take it and last forever go figure
I have a mint virgin bore 400 block and you can see the areas where ring seal isnt to good .They were made for station wagons and trucks. Too bad they didnt beef the blocks up they sure have huge power potential.

 

You're in Southern Illinois. Where is this machine shop you're talking about, and who owns it? Why are you looking at a .515 lift cam when I told you the lift has little to do with anything by itself? You can't even pick a camshaft until you figure out everything else. Unless you have a HUGE camshaft - you're not going to have a happy time paying for race gas on that setup with flat tops.

You should do your homework while you still have money in your pocket before you start spending big wads of cash on mistakes.

 

This.... 62cc chambers are WAAAAY too small. Did you mean 72?