400 chevy

My friend just shut down his junk yard and gave me an all original perfectly running 71 400 4 bolt main. I really wanted to make it into a 427 stroker, but the prices of the parts are out of my league. What should I do with it? Right now I'm running a 4oo+ horse 355 in my 80 automatic Malibu. Of course I want to make bigger, better, and faster. What do you think?  

I dunno if the parts are the same (I'm not a Chevy guy), but just a thought:  Could you take the heads/intake/cam that give your 350 that 400 horsepower and put them on the 400?  

well even if your not a chevy guy you should know some things

the cam is going to drastically flatten out and timing events wont be right on for a 400 rod ratio, but a simple retard of the cam might help that

the heads will need a bigger CC for the same power range for that many more cubes also, also if you can bigger valves, also the intake manifold should have a bigger plenum for a longer stroke, but if your at low RPM i wouldnt worry about that

Yeah, but providing taht the 400 CHevy isn't a low RPM truck motor like the 400M Ford, even with top end parts that are sized for a 350, putting them on a 400 would wind up with more power than the 350 had.  May not revv as high, but you certainly wouldn't lose horsepower and torque would go way up.  It's like putting 302 parts on a 351, I know someone that took a 351W and put stock E7 heads and cam from an EFI Mustang, plus a carbed intake and a 650 Holley and it made soemthing like 265 horsepower (302 would have made 225) but over 375 pounds of torque.  If the car is street driven more than track, and doesn't have huge gears, low RPM torque will do you more good.  

very good point, im too much in the drag engine world

Our shop does a lot of 400's both two and four bolt for drag and circle track. What heads do yo have and what cam are you going to run. A set of high rpm 350 heads will work on a street driven 400 as long as you drill them for the 400 steam hole's. You might be down some upper power but it will pull like crazy in the mid range. The other thing we see is the 400 needs a real quality balancer. Stockers always seem to come in with some sort of damage to the middle bearings that we don't see with a fluid damper or rattler. The other thing we see in high rpm 400's is cap walk. At the very least install ARP studs in the mains to help keep the caps from moving around, the stock bolts wont break but the caps dance on the block at high rpm and transfer metal ruining the block. I run a 400 4 bolt with cast 400 crank 5.7 rods and 40 over flat top's. A ported set of 64 cc sportsman 2 heads and an  solid flat tappet with 1.6 rockers285-292 adv. 254-260 @ .050 105 lobe spread and 99 intake center line with .556 585 lift. It's reilable and never gets over 160. Best of all with the .005 positive deck it drinks 91 octane california bug juice. Yes I knoe it's 11 to 1 but the cam and the tight chamber along with some creative tuning it works. And the best thing is all that torque.  

im amazed you dont have problems with detnoation with such a early closin intake but like vizard says quench clearance is vital

i'm running cast 400 crank, 2 bolt ARP studs, and i have no worries in it not staying together, also if you were worried about cap walk what about allignment dowels. the motor has .030 flat tops in a 68 CC chamber with a 0 deck clearance and .035 gasket, 350 rods, with a 268 EX hydraulic, but it does need to be upgraded though, 1.6 ratio roller tips, fully ported 487X castings, angle milled a bunch and flowed, they turned out pretty nice for my first set and free numbers, as 242 CFM @.4-.650, neither intake or exhaust never really dropped off, but exhaust flow wasnt as high as i like but i had to gasket match to my smaller street headers so there was nothing i could do, only 175@.6 on the exhaust, but i guess E/I flow ratio wasnt bad so i should be satsfied with what there doing on a street machine

about your compression did you use any thermal coatings?I called techline on this 406 and did doing the combustion chambers and piston tops (for a little NOS on a hyperutetic) i would have liked to do the intake runner but since im a porter fuel atomization worries me, and anyway ive got 94 up here same price as anything else so no problems in detonating

If I kept the stock crank, and if it's put together right I think it will hold up. Do you think I should use 400 rods or 350 rods? What advantage does the 350 rod have, if any? I was planning on getting a set of Scoggin-#### vortec heads with 2.02 valves, I know they work REALLY well on 350's. Would they work on a 400 as well?

      Sorry about all the questions, I've been messing with cars and building cheap street style cars for 12 years, but I never did a 400. My car stays on the street now, the only local track within 100 miles is all clogged up with 15 second civics and kids with bad attitudes. Thanks for any answers you may have.

With a 350 and a 400 in hand, only one thing comes to mind....383 stroker. It will put the civics nd the kids with bad attitudes faster than the 355 or 400 will alone.

Rice.....it's what's for dinner when their girlfriends aren't around

400s can make for a nice package, with plenty of torque.  If you build it with proper clearances and button it up correctly, you'll be good to go.  The stock cast crank will be fine if you keep the rpms out of the stratosphere and don't over-squeeze it with nitrous.

Regarding the rods, if you're looking for some suds from your 400 (and have the choice), I'd always go with 350 rods (5.7").  Some will recommend a 6" rod.  Yet, unless you're getting pretty serious, I'd save the money.  I run 6" rods in my '64 Malibu SS (350cid); yet, I'm spinning +7,500rpm with 13cr.  

The 400 rods are too short for performance applications.  If you're using a reputable machinest - and he's turning some volume - he'll likely have a set of 350 rods in his shop that he'll sell to you.  I'd recommend that you have them magnufluxed and make sure to replace the bolts.  Also, if you go with a longer rod... make sure you order the correct pistons (the wrist pin is located higher in the piston).

The advantage of the 350 rod:  The 350 rod will provide you a better rod/stroke ratio than the 400s.  This increased ratio slows the piston speed near TDC, and actually keeps the piston at the top of the cycle a tad longer allowing for better combustion.  It also reduces side-to-side pressure on the piston during up-down travel, due to the rod having less of an angle in relation to the crank.

The vortec heads should be a good match.  Do your homework to match you pistons, piston-deck height, chamber volume, etc. correctly to get the desired compression ratio.  Don't go crazy on compression unless you can afford the proper fuel.  Be reasonable here. 

Only other suggestion is on the cam.  Whenever building a 383 or 400, I recommend you talk directly with the tech line.  Don't order straight out of a catalog.  Reason - and I'm pretty certain about this - is that most catalog's cam definitions for a sbc detail characteristics for a 350.  A cam designed for a 350 will behave like a "smaller" cam in a 400. 

Just do your homework properly... and you'll be soon 'thumpin.  Good luck!

Me and my father are also building a 406. We have a 406 with a hydraulic roller cam with 224-230 duration with .502/.510 lift at .050 lift. The compression is around 9.4 with 22cc dished keith blacks and a 4340 Eagle crank. We are goin to run 5.7 4340 h beam rods. The heads are Dart Iron Eagles ported to flow 300cc Intake and 245cc Exhaust.The rockers are still undecided between 1.5 and 1.6. It is a 4 bolt main and hope to throw in a set of ARP main bolts.  

hmm very weird flow numbers, extensive work needs to be done to get that kinda exhaust flow, also flow is in cfm not cc. in fact our big block chevy factory exhaust ports didnt even flow that much with a valve .200 bigger and of course a much bigger port, also those would have to be some huge ports to flow 300 cfm on the intakes my conclusion is faked numbers

also why you would need H beam rods i dont know, factory 350 rods would live in the thing

Yea the numbers seemd very large to me. That is what I was told they were flowing, however they heads have had alot of porting done to them. They came off an 800hp small block. I plan on using the H-Beams because the cam i got was not a small base circle and we dont want to go through the extra work of grinding the bolts down. With the h-beams grinding on the bolts wont be necessary and im just going for optimum strength and want it to last "forever".  

i understand a little on the H beam rods but i bought SIR I Beams and have the exact cam as you and didnt have any problems but its better to be safe than sorry i guess

yes the flow numbers seem very extreme but its almost impossible to say what is and what it isnt, different machines will be calibrated different and flow different numbers and manufactures as far as testing ive done are always higher than what they are from my testing, if i reference any flow numbers its usually from my own testing or Chevy High Performance's independent testing they had done with the "flowbench database" and also another thing that distorts flow numbers are the cylinder to which they are flown in, most people negate the fact that not all engines have a five inch bore like the standard equipment cylinder with the SuperFlow 600 and then the heads would have much more flow than they actually would on the engine also heads are hardly ever tested with intake manifold runner and flow tested with carb so really flow numbers are most of the time just void to what they really are or what they are really flowing on a engine

flow numbers serve really only one purpose and that is a basis to start improving heads but really a flow bench can defitnely lie when improving them because it will always say bigger is better and such as removing the venturi effect of the port and not using allowing the port to use the valve as well it will show great numbers up high, and your trying to get numbers right, ha. Also a bigger port will always flow better but defitnely not perform better as David Reher says "why does the flow bench tell me these heads are almost identical (meaning flowing same CFM) but one pair makes 100 more horsepower when we put them on the dyno"

Yea Im sure we could get away without the H-beams but im just wanting an engine that will really last. What kind of numbers are you getting with your 400 and the cam your using? What else are you using on your setup?