400 hp, 500 tq .030 over 401?

Discussion in ''Da Nailhead' started by 401Riviera, Oct 15, 2012.

  1. 401Riviera

    401Riviera Well-Known Member

    Hey guys, I'm building a 401 Nail for my 63 Riviera. Now, I've never even heard of the Nailhead before i picked this car up in June of 2011. Since then, i've learned about the engine. I thought this would be the best place to ask some questions. The details: 401 bored .030 over, honed, decked .040 off the block, .010 off the heads (cc'd to 9.8:1 compression), Egge pistons, stock rods, stock crank (polished), std. bearings, Hastings Moly rings, fully balanced rotating assembly, rebuilt rockers, Comp 279 cam, comp lifters, TA over-sized valves, 1/8 inch intake risers (no heat through the intake), single quad intake (milled to true dual plane), carb adapter, quick fuel q series 750 cfm carb with mechanical secondaries, Sanderson shorty headers (coated). Still working on the the valve train specs. Heavy head porting is coming soon. Anybody think i can get this best to put out 400 horse and 500 torque? If not, what parts should i get to make those numbers? Really don't want to spend all the cash for roller rockers. I'm only 18 and people think I'm crazy for building this engine. hahaha -Greg
     
  2. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    Crazy like a fox! Sounds like your on the right track.(are you talking about the rice burner crowd,thinking your crazy?:laugh:They're going to be jealous)The Nail Head engines are legendary,the old guys that see that engine your car will be envious.:TU:

    Nail Heads make lots of torque stock,anything you do to improve it,will get you even more tire shredding torque. Be careful porting,if you take metal off in the wrong area,you can make it flow worse.These heads don't work the same as modern day heads,with the air flowing across the head of the valves.The Nail Head's air flow,flows more across the valve stem,with a near horizontal valve angle.Make sure if you're going to try this yourself that you learn as much as you can before you attempt this.Unless you're going to pay a shop that has a proven track record to work on these heads,don't let them touch them. Your best bet would be to just gasket match and bowl blend if you have never ported heads before,unless there is $$$ in the budget to pay for porting.

    Rebiult rockers should work just fine for what your trying to get out of it. I don't have the comp cam specs memorized(and don't want to look it up),so I not sure what your using. I assuming that the 279 is the advertised duration,but without the rest:Do No:.

    What does "milled to true dual plane" mean? I have never heard of this,and I've been around for a while.

    What's your skill level,have you ever rebiult an engine before? If not,this one is a little more challenging than others,not saying don't do it,just sayin. It been a while since I rebuilt a Nail Head,so maybe Doc can give you some tips,that I haven't mentioned.

    After I build my 300 sbb stroker,the Nail Head is coming out of my 64 for something special to be done to that. I don't like to take a car with a rare engine I didn't put together to the track.

    You should end up with a very fun car,being only 18,the hard part is,keeping your license. :spank: :laugh:

    Keep the racing on a track,and you should be fine.:TU:
     
  3. doc

    doc Well-Known Member

    First,, do your homework,,,, learn all the specs of a nailhead that you can find....The easiest thing to do is pick up a motors manual that covers from 1956 to 1966... it will have all the figures written down....
    Buick did a really good job when they designed the nailheads.... THEY ARE NOT RPM ENGINES... THEY ARE TORQUE ENGINES.... FORGET WHAT ALL THE FORD/CHEBBY GUYS ARE DOING AND DO EVERYTHING YOU CAN TO GET THE MAX TORQUE AT THE LOWEST RPM....
    Do not,, do not,, do not, build a nailhead loose like ford and chebby engines....
    build to stock buick clearances and then break the engine in for 1000 miles before you race it.....
    If you port the heads your self,, just smooth up/blend/and polish only.... do not try to ''hog out'' the runners... if you do you will hit water and the head will be junk....
    Dont over cam the engine.... it is a torker not a rpm engine....
    nailheads like big carbs..... not neccessarily multiple carbs ,,, a big single keeps the ingoing velocity up and mixes air/fuel better.... I run a 1050 cfm holley three barrel with vacume secondary on mine....With my doc dual plane mod/stock sq. bore cast iron manifold... check out the sticky.... and
    look at my list of cheap tricks.....they work....

    KEEP THE HEAT IN THE INTAKE MANIFOLD....the nailheads have to have it to vaporize this cat pee gas we get now days.... on a fully warmed up engine , the intake is only 127 deg. at idle... open the throttle and the air rushing in cools it even further.... but,,,, that said nailheads like cold air coming into the aircleaner... and that is what works best... heated manifold /cold air pkg. pulling in air from outside the engine compartment....
    use a 180 deg. thermostat....
    the oiling system is good just like it is from the factory... you can smooth up the rough castings inside the pump and port match the pump/engine block joint......
    Keep the car as light as possible.....
    recurve the dist.... a stock dist works just fine.....
    Use a good port matched heads/exhaust manifold combo on the exhaust side... with at least 2 1/4 in. pipes all the way back....
    hope this helps.....
     
  4. gsgtx

    gsgtx Silver Level contributor

    why the 1/8 intake risers
     
  5. CameoInvicta

    CameoInvicta Well-Known Member

    I assume the Comp 279 cam is the Thumpr?

    I think with the right amount of head porting you can get to your goal, or close to it.
     
  6. 401Riviera

    401Riviera Well-Known Member

    Thanks for the info guys, i was gonna use the 1/8 inch intake risers to block off the heat passages. I'm gonna use your intake method Doc, would you happen to know what kind of hp gain that gives? The 279 is a thumper. I'm using a 2000 stall B&M converter in the st400 with a manual valve body and shift kit. The car has a 3.23 posi rear. And yes, i'm surrounded by rice burners in my generation. Many of them think i'm crazy building this big boat, but i think its just fine.:laugh:
     
  7. snake

    snake Well-Known Member

    Go for the stock st300 converter in a st400 (12") stalls from 2000 to 3000. Switch pitch with 12v to the upper detent. And try to get a 1966 q-jet manifold with a 800 cfm q-jet with a doc mod or gessler mod done to it if your going the single 4 route. Thats what Im doing.
     
  8. CameoInvicta

    CameoInvicta Well-Known Member

    Naw, your not crazy. I'm a 21 year old kid who built up a hot rodded four door Buick. I get so many looks and questions at shows it's crazy. People think it's cool to see something besides a Camaro or Chevelle.

    I don't think we've got dyno data to show what kind of HP gains the "doc dual plane" gives, but the seat of the pants feel is substantial.

    I'm also running the Thumpr. If you want the most horsepower possible, the Thumpr isn't going to be the cam to achieve that goal. It's a little radical, and leaves a little power on the table. But it does make good power, and just plain sounds nasty. If you do go with the Thumpr, I'd look more at a 2500-2800 stall converter. The stock ST400 converter in high stall stalls around 2200 rpms, and isn't enough in my opinion. Also, your probably going to have order a converter from JW at TSP, since a standard TH400 converter from B&M won't work in a ST400. Or like Snake said, get a ST300 converter.
     
  9. 401Riviera

    401Riviera Well-Known Member

    I just want to make this a bitchin nail with what i got. I'm gonna build a 425 once this one is done with the whole 9 yards. My engine builders have some tricks up their sleeves for the engine and for the heads. I trust them and they know this is an odd engine, Hopefully gonna have the short block together by the end of the month.
     
  10. wkillgs

    wkillgs Gold Level Contributor

    Heck, I was 15 when I started my first Nailhead build! Still running that engine in my blue '66.... guess I did a decent job. :bglasses:

    Those are big goals for a 401, but don't worry about the peak numbers. You won't see big hp numbers at 6000+ rpm.... the Nail just doesn't make power there. The Nail makes great power at lower rpm's, that's what makes them such good street engines.
    There's a thread here from PEM near Chicago that reported some good numbers on a build. Couple of months ago.

    GSGTX has found some cam profiles that work fantastic, and Bob should be joining the conversation with porting tips.
    Tom's Roller rockers have extra ratio that'll help breathing too.

    I did a near-stock rebuild on a 401 and ended up with 9.8 CR with 0.007" shaved off the heads and 0.015" steel head gaskets. That's about what the stock Buick builds were, not the 10.25 CR they advertised.
    Are you using the thicker Fel-pro head gaskets with that 0.040" block cut?

    I'd skip the 1/8" intake risers. They probably disturb the port flow.

    Nice to have you on board here!:TU:
     
  11. 66larkgs

    66larkgs paul 66gs turbo nailhead

    good for you to step out of the mold. i found myself being 15 with a 66lark and a nailhead and it is just what i got and now i wouldnt run a different motor in that car no matter what. did you already bore it? if not i have a new set of .030 piston for sale. pm me if interested. this is my second nailhead that i have built and this time i installed a turbo, ross pistons, arp studs, gasket match port job, msd and much more. I run a affordable way to run serpintine belt setup. One very important tip i can give you is take all the advice here!! I consider myself a exsperiance technician but these guys here are pro's with the nailhead. Doc, tom t and many others have built lots of these engines with great success. If you want to turbo it give me a shout and i will share all my mistakes and postive exsperiance i have learned over the years of building and destroying them.

    Paul
    66larkgs
    turbo 401
    http://www.pro-touring.com/showthread.php?83933-1966-pro-touring-skylark-turbo-Buick-nailhead-build
    check out my build thread
     
  12. 401Riviera

    401Riviera Well-Known Member

    Eventually i wouldn't throwing a Don Hampton 8-71 on it. I would do it now but i don't have that much money to blow :dollar: (literally) haha. Too bad EElco never came out with that single quad intake. I'd buy one in a heartbeat. I already have the pistons and everything. Just top end stuff i gotta get. I want to make it one bad ass looking nail. Got Repro Buick finned valve covers that I'm polishing myself from cast. I'll accept the power that i get from working with what i got, but in the future, i wanna get reeeeally stupid. hahah I appreciate all your input. I'm one of the few and far between that loves Buick in my generation, and i plan on kicking some ass with mine when she's on the road.
     
  13. Nothingface5384

    Nothingface5384 Detail To Oil - Car Care

    you can also stroke a nailhead to about a 475 or you can super or turbo charge the nailhead.
     
  14. 401Riviera

    401Riviera Well-Known Member

    Who makes a forged crank for that?
     
  15. nailheadnut

    nailheadnut Riviera addict

    Lots of good advice so far; some of it contradictory though. The one thing that has yet to be discussed by you (others have touched on it) is your transmission. Your '63 Riviera has a Dynaflow (great for cruising, not so much for racin') in it right now unless someone has made a conversion. Shifting a dynaflow from L to D under full throttle is NOT advisable. There have been some hints on what to do with an ST400. That's going to be your easiest conversion if you're not keeping the Dynaflow. Curious as to what your thoughts are about the transmission situation. That will bring up another complete set of opinions.

    Ed
     
  16. 401Riviera

    401Riviera Well-Known Member

    I'm putting in the st400 cause i want more giddy up. I don't care for the dynaflow, it really limited what i wanted to do with the drive train. I recectly picked up the st400 and already had the crank balanced with the st400 flexplate. So its definitely going in. haha:grin:
     
  17. doc

    doc Well-Known Member

    About the Doc dual plane mod to your stock manifold.... I believe that it makes the stock sq. bore manifold flow as good as any aftermarket manifold would.... but it is heavy....of course it is lighter than a stock manifold,,,,:laugh::laugh: The figures that have been reported to me is about 11% more flow, and .2 ET reduction on the drag strip.....but i repeat,,, on a street driven nailhead powered car, it is a mistake to completely block the heat risers.... i tried it and the car did not run good at all..... that said,,, some leave the heat risers open to heat the bottom of the manifold and just block the 2 openings that go to the channel under the carb.... dont know how good that works... but Tom does.....
    On my car, with the heat risers blocked, the gas mileage went way down, and when you stomped it, the thing would stumble, hick, snort, fart and have a chill... then finally catch up and start running... not good....with the heat in the manifold... stomp it and it would set the back tires afire....
    The guys that have done the DDP mod on the stock manifolds all,,all,,, so far have reported good results, including the qjet guys.... but I havent heard about multiple carb set ups.....
    I still wonder why Buick did not do that when they came out with the GS cars back in the 60's....
    the mods that have given me the most power are;
    Doc dual plane manifold.
    cold air pkg. with bigger air inlets
    bigger carb.
    recurve the distributor advance....
    port match stock exhaust /intake manifolds
    the interesting thing is that none of those things cost very much to do.....
     
  18. gsgtx

    gsgtx Silver Level contributor

    i think it was Tom T. that said the 1/8 inch spacer will cost you 18 hp.they have metal block offs that come with intake gaskets. like doc said you need some heat, i use the block offs and drilled 1/4 inch holes to get some heat.
     
  19. Lucy Fair

    Lucy Fair Nailheadlova


    Nailhead has forged crank already, con rods are forged aswell.:TU:
     
  20. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    OK,how do you get 475 CID out of a(which one,a 401 or the 425) Nail Head? And don't tell me its by using a 455 crank that the mains are turned down,and is offset ground to use a 1.850" honda rod journal.LOL
     

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