Projects Budget 400 SBC combination

Alright, after a brief tryst with Carlisle I came away with small block Chevy parts I never knew I needed. With the help of craigslist I've acquired a 2-bolt 400 small block Chevy that I wish to acquire 450 hp out of with 92-93 octane. While at the swap meet I claimed a 267- HDP Crower camshaft part number 00240. Now I'm wondering, if this cam would work well with a pair of Vortec heads for my goal of 450 hp at about 6000 rpm? I know I'll have to factor in drilling steamholes, special gasket, and intake, and Z28 springs. But can anyone provide any feedback into the feasibility of this or added parts to obtain my goal?

 

Don't use the stock 400 rods.....use the 6" or 350 rods with pistons that have the pin boss relocated.
I think you will see around 415 to 420 HP with that cam, MAX RPM with a 400 crank is 6000 RPM.

 

You may need a better set of heads to meet your goal.

The hot setup with the 400 is to throw a large journal 327 crank in it with 6" rods and a good set of aluminum heads. Punched .030 you come up with a short stroke 350.

But with what you get maybe a better set of heads will help you reach your goal.

 

Vortec heads shit the bed at about 4500 rpm ,w/ so many good aftermarket aluminum heads available , build a good 406 w/+- 200 cc ports , easy 400 horse ..
dace

 

The 2 bolt will suffice if machining is spot on though. Do the 5.7 rod/matching piston combo,and look into a different head to achieve that 450#..... and as above^^^^^^^ a lot of 6k plus rpm, well, just be ready.......$

 

What P-N-B is referring to, is actually a 377 CID engine, a high RPM bullet. Vortec heads are fine, it's the swirl port heads, that externally look like Vortecs, you want to avoid; those have very limited RPM capability (although on the nephews 355, they rev to 6K easily). Stud the bottom end of a 2 bolt 400 block, and then have the main journals honed, otherwise you will not longer be in a "budget" realm to convert to 4 bolt mains. 2 bolt 400's actually have beefier webbing than the factory 4 bolt blocks. I am Butch/56sedandelivery.

 

Great thread. Question: Does the 450hp number relate directly to modern car hp ratings (like the new Corvette with 450hp)? In other words, there hasn't been any changes to the way hp is advertised now to what you are talking about (like what happened in 1971)?

 

Some food for thought here. One the guys (Cliff Ruggles, fairly recent author of a Quadrajet tuning book and some others) who frequents a Pontiac forum that I visit often, has had a lot of experience building both Chevy and Pontiac engines as well as other brands.

Here is the 'meat' of one of his posts:

"I've set up Chevy 406's with out of the box World products Sportsman heads, well chosen flat solid cam, about 11 to 1 compression and put 3300lb cars into the 10's.

We set one up for a good friend, who at the time had almost no money at all to spend. We used a $12 oil pump and $12 timing set from Advance Auto Parts, stock crank, short 5.56" rods, decent forged piston, and a set of 64cc World Products 200cc intake runner heads. The cam was a small flat solid around 250 @ .050, on a 104 or 106LSA. I added good valve springs/retainers to the heads and cleaned them up a bit, no real porting of any kind.

We topped it off with a Victor Junior single plane intake, 850 Holley, recurved his single point distributor, and added some decent headers. At 3300lbs race weight he went 6.50 in the 1/8th mile and low 10's in the 1/4 mile, shifting at 5800rpm's! This was with a PG, transbrake, and pretty steep gearing.

I think we had around $2800 in that engine build, the biggest expenses being the heads and pistons. He raced it for quite a few years without any issues."

Chew on that for a while, good luck with the 400 build.

 

Hard to go wrong with the longest rod possible & staying focused on the volumetric efficiency of the camshafts capabilities. Intake runner cc & cam my first focal points Once cubic inch & stroke are determined. But cubic dollars play the biggest part! Hence the term budget. Flux

 

With the longer rod= sure. But he HAS the cam already,and it would probably need a shorter base circle. I went into the 9's with a stock arm,and yes- a 2bolt has beefier webbing.I had a 4 bolt. Studded=yes. Spot on machine work=yes.
The WHOLE combo has to jive together.....Already torquie as is,but gaining longevity,and rpm could possibly come into play here.........SO-The magic Q?!? What's it going in,and what are the intended purposes?

 

Crower 267 HDP cam specs for small-block Chevy here:http://www.summitracing.com/parts/cro-00240/overview/make/chevrolet

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Cam Style: Hydraulic flat tappet

Basic Operating RPM Range: 1,300-5,500

Intake Duration at 050 inch Lift: 210

Exhaust Duration at 050 inch Lift: 216

Duration at 050 inch Lift: 210 int./216 exh.

Advertised Intake Duration: 267

Advertised Exhaust Duration: 272

Advertised Duration: 267 int./272 exh.

Intake Valve Lift with Factory Rocker Arm Ratio: 0.445 in.

Exhaust Valve Lift with Factory Rocker Arm Ratio: 0.445 in.

Valve Lift with Factory Rocker Arm Ratio: 0.445 int./0.445 exh.

Lobe Separation (degrees): 112

Camshaft Gear Attachment: 3-bolt

Computer-Controlled Compatible: No

Grind Number: 267HDP

Valve Springs Required: Yes

-------------------------------------------------------

A rather mild camshaft choice for a 450 HP 400 build. It's not even as hot as the commonly used Chevy 350hp/350 cam that specs at 450"/460" lift 222/222 duration @ .050.

Just because you have the cam in your hands doesn't mean you should use it, that is if you're truly serious about achieving 1.1+ HP-per cube from your 400 small-block.

Sell the cam to someone building a mild street 350 and find something better suited for your HP goals would be my advice.

Not a damn thing wrong with keeping the short factory-issue 5.565" 400 rods for this build, they'll easily get you where you want to be and hang in there for the long haul.

 

Torque will move the car much faster. And live far longer that a conflicting Lg sbc trying to spin to meet a number that means nothing until peek rpm has been met. Really, a torque cam will build upon those already acquired heads. Off idle to 5,500 RPM in a light to moderate weighted car will fly. Or build that buzzing (!$!) 450 hp at the rear wheels bullet.

 

Knowing he had the cam already, once again focus on the volumetric flow of the cams needs, henceforth the cylinder head runners. After seeing grind specs I'd say vortecs be good choice. keep in mind budget. If you got a 509 that's the good one! The 5.565's are ok too Ive tried them all & the high rpm stuff is long rod material. For the money 5.7 rod 400s are super stout. Under .525 lift should clear rod bolt heads eliminating need for small base circle grind job, & if you go with longer rods, & clearancing oil pan rail can soak up some time. Looking like 5.565 rods are ok for this build indeed. Budget is the key word to this build. Keep it fun! Flux

 

Fwiw, a 3.00" crank in a stock, 4.125" bore, 400 block makes a 321" engine.

A 3.25" crank makes a 348", just like the old 348 "W" engine. And

a 3.48" crank makes a 372" engine.

pdq67

 

Beaner is on the MONEY!! That is almost my combo, and its BLOWN. Go pedal response is frightening !!

 

I picked up a book at Half Price Books while waiting for the rain to stop called "How to Build a Big Inch Small Block". Basically they used a 400SBC to build six different engine combinations from mild to wild. It seemed like a good idea and I had some money and time to spend so I decided to build a strong engine for a project I was working on.
I found a used 400 on Craig's List and took the block to the machine shop and was told the bottom of the cylinders were worn out. I don't give up easy but I went through three used engines and they were all junk. I could have given up but it still seemed like a good project. I bought a new Dart SHP block, Eagle forged crank and H-beam rods along with a set of forged Ross pistons. I took the block to the machine shop and had them check it out and balance and clearance the crank. When it came to heads I bought a set from GM Performance with the 220CC runners and had the machine shop cut the spring pockets and valve stem bosses for the Comp Cams springs and Teflon seals.
The camshaft is a hydraulic roller that starts making power at 1650RPM and goes flat at 4800RPM. Carburation is a single 750 Holley DP with mechanical secondaries on an Edelbrock air gap Performer manifold. Ignition is MSD with a 6 series box.
The engine runs good and makes 473HP and almost 500# torque. I have a Tremec T-56 behind it with a Ford 9" and 3:70 Trac-Loc.
I realize it was not a budget build but the 400SBC will make power with very little money too.

 

Jees you want low budget
When I was 18-20 and had no cash I used to buy 1971-75 caprices and wagons for $200 to $400 to grab the 400s, the emissions label said 350/400 so half the time the seller didnt even know they had a 400. Quick look at the balancer always confirmed what I needed to know.
I used to take the stock 400s 2bbl and all and put them in novas, dead stock they made tire shredding torque and won plenty of stop light drags just because I was able to leave so quickly. Short shifted at 4500 but the low end torque was what made them fun to use.

 

Sorry it took me so long to respond, anyway to answer everyone's questions.
porknbeaner- A 377 was my original goal with this engine. but if I was to do it, I would want a T-56 behind the engine and unforunately the car I'm gonna throw the motor in would make the T-56 a difficult proposition.
2old2fast- Believe me I would if I had the money but aluminum heads are expensive!
56sedandelivery- I heard vortecs are good till 4500 rpm, so would porting the heads (Not too much as I heard you could ruin them pretty easily) help at all?
Invisiblekid- The magic answer is a 74-79 Nova or Oldsmobile Omega, whichever finds their way to me quickest. My intension is to have a back-up daily/ track day car to play with.
dragging'GTO- So what cam specs would you recommend for me give or take?
Flux capacitor- well I just finished tearing down the engine and a new set of pistons and connecting rods will be on the books. So I have a question, when you said 5.7 rods, are you meaning aftermarket or stock 350 rods?

 

So you pick a pair of used sbc heads.. if they're not cracked , they're ready to..... the guides are probably shot , they may or may not have hardened ex. seats , valves are getting so thin you can shave w/'em.... springs are no doubt toast.... they're warped enough to be re-surfaced, by the time you're through spending on them , you have an outdated head , ready for failure , & they've cost you 2/3rds + what a new set of aftermarket heads would cost ...What's the point ???
dave

 

a 377 is a 400 with a 350 crank. But no reason to argue a few cubic inches. The point is to get cheap HP out of a 400 block is to shorten the stroke and bring the revs up. HP can be achieved with a stockish 400" lower end but it will cost more to do it.

if you want HP build it bore heavy if you want loads of torque build it stroke heavy. A simple easy rule that anyone who does not build engines for a living and/or does not have deep pockets can follow with good results

bore x bore x .7854 x stroke x number of cylinders = cubic inch displacement.

GM 400 bore = 4.125
GM 350 & 327 bore = 4.00
GM 283 bore = 3.875
GM 265 bore = 3.75

GM 400 stroke = 3.75
GM 350 stroke = 3.48
GM 327 stroke = 3.25
GM 283 and 265 stroke = 3.00

4.125+.030 = 4.155
4.155 x 4.155 x .7854 x 3.25 x 8 = 352.54 which we normally round to 350 unlike the manufacturers which would probably try and sell for 360 cubes.
That is a 327 crank in a 400 block punched .030.

There is a *simple formula for you no fancy pi this and squared that because most of us are not math wizzes. There are numbers for everyone to play with and enjoy pipe dreams to their hearts content.

*same formula used by the SCTA and BNI

@aaggie,
The 400 block is the least stable of all of GMs small blocks. They look good on paper but are not a good foundation for a big inch small block. Many builders will tell you that .030 is makes a 400 block a throw away block, I am comfortable building one with a .040 bore but after that I would have sonic checked and probably be thinking about concrete in the water jackets. The siamese bores help some with stability but they will not take the whack out of the cylinders as say a '62 283 block will. If you want to build a big inch small block look for a dart or other after market block and then you also have the option of taller deck heights and relocated cam shafts if you want to go long on the stroke or larger cam circle. You can find used, or purchased and not used aftermarket blocks all the time if you look around enough. you already know to watch for grenaded blocks but I will mention it for the masses.

 

A stock fresh 400 shortblock with a comp cams 268 or similar cam and pocket ported vortec heads,.040 comp.head gasket, an ebelbrock performer and a quadrajet properly set up will make 400 horsepower at 5500 through 1 3\4" tube headers(what I had available).Mine did( 403) and ran for 3 years with no problems.The only real "exotic" machine work was the block was cleaned up and deburred and I took .020" off the decks.Stock oil pump with tack welded pickup and a swap meet oil pan that came with a windage tray in it . I had less than 1000 dollars in the whole engine-only new parts were cam,lifters,rings and bearings,freeze plugs,oil pump,timing set , valve springs,gasket set and a carb kit.Rest was all used stuff.The bores were straight enough that I was able to get away without boring it. I was surprised too-----

 

1 hp per cube should be pretty easy with any small block or about any other engine for that matter with todays technology. Just looking at the numbers from the camshaft mentioned I don't doubt that the vortech heads will handle it but it is not much of a camshaft and I doubt that the combo will yield 450 horse. The OP may claim 400 hp from it with a set of heads that really breath but he then won't be reaching the potential of the heads. That said it should yield a good healthy street motor for him. there is a lot to be said for a good healthy street motor unless you are shooting for some sort of a trophy or big purse somewhere.

 

I have done several 406's . In my neighborhood Vortec heads go in the crusher pile. By the time you do a good job on the valves,guides, studs, springs ,retainers, locks, seals, surface, you can buy a set of $750 iron Eagles ready to bolt on. I don't buy into the 6 inch rod thing , if you have them use them , I don't think performance will be notable either way.
Now for the important part.
ANYONE WHO RECOMMENDS A CAMSHAFT TO ANYONE WITHOUT KNOWING THE CAR WEIGHT, CONVERTER, TRANS GEARING ,REAR END GEARING AND INTENDED USE, is no better than a fortune teller, and probably just as accurate.
400 horse is pretty easy ,450 do able, Buy your Camshaft last , not first.
just my opinion.

 

being no stranger to 406's for various projects n open wheel dirt cars, buy a set of scat style I beam rods like part #cr5700 for your build. For the money they're great. They've been designed with more clearance around the rod bolt area "for high lift cams" & ain't that costly. 25 + years ago I used stock 5.7 polished rods "X"marked castings, before the days of small base circle cams & affordable minded stuff with a set of Keith black claim 4.155 bore x 5.7 rod Pistons with a comp 12-609-5 cam & mildly ported 461x heads & for cheap it was a freakin monster! Ran it for years in a street stock Laguna. Spend $ on small base circle upgrade if you go w another cam & slip it all together before its balanced to see if a small amount of oil pan rail to rod bolt clearance is needed. That's why some of these aftermarket rods are so Inticing, less clearance problems. Go with 5.7 claimer Pistons flat top 2 valve relief & 5.7 rods for a non disappointing gas pedal response! Guaranteed not a slouchy combo n worth a little more effort! Flux.

 

The cam he has bought isn't much in the lift dept, it is close to the L-79 cam specs wise.

@JOECOOL I actually built an engine around a camshaft once for a fella. he had heard good things or read good things about a specific camshaft and bought it and wanted an engine to go with it. he ended up with a lot more of everything then he originally planned (money invested included) but he had his mill and it did run. It would have been easier to see what he really wanted in an engine and build it accordingly. It was way more cam than the engine he really wanted could ever use.

There are a lot of ways to make a small block sing, cubic HP is one direction to go. I don't see the cam in question with the desired heads making 450 HP but I have been fooled before. One thing about it the Op can screw it together and do the drag racer thing, as he is leaving the pits he can be thinking of things to do to make that extra tenth so that next week he can win.

 

Good point PB! After a certain point those tenth's cost over s grand per whack. Looks like it'd basically be worth using the cam n something else or swapping it off & tailoring one to better suit the needs of your desired Horsey Power sir! I think most all of us have been guilty of having some stuff laying around n wind up trying to piece together something fun out of it. Out of my last 7 400's only 2 were deemed usable due to deck surface, intake galley cracks & cylinder wear issues. I threw in towel n got a world products mowtown 2 block. life's lessons aren't the cheapest. I hope you get lucky & have a good block. Don't buy nothing till it checks out of machine shop with a clean bill of health is good advice or you could wind up with a pile of clean junk 400 blocks like me. Same goes for cylinder heads. Pays to put the pencil to it for wallets sake! It's luck of the draw sometimes! Flux

 

I never got the destroking an engine concept.
If your engine makes X amount of power per cubic inch, why take some away >???
The myth about a shorter stroke engine turning more RPMS is just that, a myth. the thing that limits RPMS is the cylinder heads,and valve train combination (air in and valve train control) stroke has nothing to do with it.
De-stroking an engine is silly, unless it's a class racing thing that has to be done. Keep the longer stroke, but be aware of the rod/camshaft clearance.
And yes,the longer rod offer a much better mechanical advantage,and is easier on piston skirts (side load) The longer the rod, the better. plus as an added bonus, you get longer duration @ TDC, and less duration @ BDC.

 

Lots of opinions here.
The combo my son and I used on his OT 3000 lb. mini truck will work for a lot of vehicles. A lot of this was based on what I had and what he could afford.
400 Chevy Block +.030"
Offset ground stock crank 3.83" stroke (415 cu.in.)
5.7" SJ 327 Rods
KB flat top pistons .020" out w/.050" gasket
PAW cam 286 adv. dur .509 lift 109 degree lobe centers
Cam installed @ 102 degrees CL
Dart II iron heads
Holley vacuum secondary 600
Holley 180 degree intake
With a 4 speed and 3.83 geared Quick Change it was a real rocket ship, on the cheap. The cam was a little radical
but with it advanced, the intake closing made it streetable.
I've built a lot of SBC engines. 301 screamers, 383 torquers and a wad of 350s. This was truly the best per dollar spent.

 

Tricky Steve ,I will trade the longer rod theory for a better ring spacing on the piston any day. Just my opinion.

 

Through all my drag racing I ran BB chev. When I quit I bought a 72 chevelle and got a Motown block, ported dart 230 heads, and a super victor intake in on trade on my 582 out of the dragster. I hadn't fooled with a sb for yrs last 1 was a 355. I built a 434 out of this stuff for the chevelle, solid roller, 850 QF carb with msd ign. I couldn't believe the torq this thing has. It will pull to 7000 and has plenty of low end. Now I want to put a mild BBC in it and build a early coupe for the 434.