Bore spacing is the same, don't know about bore but I bet its no smaller than a 400 bore even on a 401, no clue whatsoever on the bolt pattern though. Cheapest way would be to buy some NAPA headgaskets and compare them. You'd also have to contend with water passages and possibly oil passages since nailheads oil through the deck and so do the pre-70 BBB's. Now the big question.... WHY?
Nail head has 5 bolts per cyl. Big block has 4. what are you going to do for an intake manifold? and cooling system?
I checked it once upon-a-time. If I rember correctly, bolt holes were very close, and might fit with modification. I'd bet that camshaft lobe spacing, and pushrod location would be the biggest challenge. Wish somebody would just make us some nice aluminum Nailhead heads!
I'd settle for a aluminum intake manifold with a single 4bbl that would fit under most stock hoods. And of course I'd want to see it available with EFI port injection bosses because I love EFI. There is more demand for aluminum SBB heads than nailhead stuff. I'm happy they make headers, cams, and now roller rockers for these engines. I'd vote for aluminum single-plane 4bbl then roller cam for nailheads parts development.
don't know about bore but I bet its no smaller than a 400 bore even on a 401, actually, Nailhead bores run bigger ... yes, even more oversquare than a BBB! p 455 = 4.3125 x 3.900 430 = 4.1875 x 3.900 425 = 4.3130 x 3.640 401 = 4.1880 x 3.640 400 = 4.0400 x 3.900 since nailheads oil through the deck and so do the pre-70 BBB's. same solution as is currently used for BBB heads on a 430 / 400, convert to pushrod oiling. what are you going to do for an intake manifold? i presume that would have to be custom. i'd think the Nail would be a shorter deck than the BBB so it's extremely unlikely the manifold would fit in there properly. Now the big question.... WHY? errr, cause the porting on the Nailhead blows chunks? o No: i know the BB guys have always lusted after the forged Nailhead cranks and i got to thinking ... instead of going through all the trouble of modding a big block to accept the smaller mains on the Nail why not just try to move the BBB heads to the Nail and not have the sub-par oiling to worry about any more? with it's smaller mains, stronger block and internals i bet you could really twist a Nailhead if you had the ports to flow it. I checked it once upon-a-time. If I rember correctly, bolt holes were very close, and might fit with modification. was it a situation like the early SB's to 350 were they went from a 5 bolt setup to a 4 bolt simply by dropping one of the bolts or did they actually move the remaining 4 bolts? you know what's really sad about this? i don't even have a Nailhead. or aluminum heads either. :spank: :ball:
I thought at one time Carmen told me he had a set of factory alluminum Nail- heads.........I don't know any details, but I'm still lusting over them! :Brow:
They were a single set and supposidly one of only about 3 sets produced. They where badly abused, busted, and near unsalvagable but I think they were in the repair process. I don't think they where any different from the regular Nailhead heads with the exception of the matieral but I could be wrong. Honestly the only way to really improve a nailhead enough to make it worth the production costs is to basically do what the Buick 215 V8 and Fireball 198 V6 did and make the heads look nailheadish but realy be a real wedge head with a more conventional piston and chamber so you get rid of the production compromise in smashing the engine narrower in order to fit into a Straight-8 engine bay with its hooked over exhaust port, though the Nailhead intake port is great so I'd try to keep that if just for manifold sake in addition to the super intake port.
thay made more then 3 sets a bubby of mine his dad had a set 10 year ago and his freind had a set so if they only made 3 set thay were some lucky basterds both sets are long sold and i asked for a pix but he didnt have one I still have my eye out for a set so if I ever come across a set I dont care what they cost I will have a set some day
I could entertain the idea of a set of heads [aluminum] with the exhaust valve moved to the other side of the pent roof combustion chamber. Would be a wierd valve cover. super wide. and use a bigger ex. valve. Almost a hemi. better yet why not a hemi with over head cams. I mean, if we are going to get exotic. If you are going to be a bear why not be a grizz.
Well changing the exhauste port would just require new rockers, headers, and valve covers... not too bad in the grand scheme of things. An OHC of either single or double variety would require new timing cover, "cam" or other method of sealing the around the cam oiling , some way to plug the lifter oiling holes, new timing chain, new waterpump, upper radiator hose, and water log at a minimum. The new "metric Hemi" that is in DCX cars now has a nailhead like pent roof chamber not a true hemi dome anyway. Northstar DOHC V8's and most other DOHC motors have had pent roof chambers for years aswell, just like you are thinking with opposed valves not the single sided like the nailhead. I'd make a nice addition to the stout shortblock of the nailhead but I think a wedge head and an oddball but upright looking valve cover would be better. To simplify things you could even use an existing header type flange like a BBB, SBB, BBC, or SBC to make it easier to get headers or atleast flanges for custom ones.
My pop had pics of a DOHC 'Nailhead' years ago. I will have to make him look for them and post if he can find them.
In actuality there were 21 aluminum heads (not sets) that were made for experimental purposes only. These heads had no valve seats, the seats were just aluminum. There were no valve guides either, as these were also just aluminum. 10 or 11 of these heads were solid & 10 or 11 had water running through them. I know where & who has the 10 aluminum water heads, but have never seen or found any of the solid ones. (don't know if this is a myth or not) These heads were cast with '59/401 head casting numbers. They are light at 21 pounds each!!! with valves & springs!!! I've had the opporunity to flow test a badly abused head that had larger valves & offset guides, they didn't flow worth a sxzvx!!!!! As nice as a set would be you would be talking thousands to make them usable. Then you have the problem of the proper head gaskets. You couldn't use shim steel gaskets. You also really couldn't use composite gaskets either. You need gaskets that will be able to expand at different rates because of the aluminum heads & cast iron block. Then comes another problem. In order for aluminum heads to make the same power as cast iron heads they would have to flow at least 20% better or be able to raise compression 1 1/2 - 2 points. Not really that easy raising compression on our ole "NailHeads". Heat creates HP & aluminum dissapates heat at a faster rate than cast iron. Contrary to popular beliefs, it's not the exhaust that's the restriction in the "NailHead" it's the INTAKE!!!!!!!! in a normally aspirated application, which is what must of us are running. So, as nice as it may be to have the availibility of aluminum heads the actual feasibility is senseless in this case. And, in the case of the pent roof combustion chamber. Look at most higher performance engines of today, as stated they have "PENT ROOF" combustion chambers. In actuality "IT IS" a Hemi. The spark plug is dead center in the combustion chamber & any time you pull the head off of just about "ANY" good running "Nail" it will have a perfect burn pattern on top of the piston head. With this design you can run higher compression ratios & still be able to use the fuel that's available today without the pinging & detonation problems associated with a wedge head design. So what's old is new again. If you make valve covers that look any different than what the "Nail" has, then it's no longer a "NailHead". The look is unique & deviating from that look makes it something other than a "NAILHEAD". We know the heads are a restriction, but's that what we've got to work with. The proper head work, cam, timing curve & "My Adjustable Roller Tip Rocker Arms" are the way to get AIR into & out of the engine. AIR is HORSEPOWER!!!!!! The engine works with "Density" which equals "Horsepower" which equals RPM's. The more density the more HP, only common sense!!!! Why add more cubes when a full boggy set of heads can only support 300/322 or so cubes. Add too many cubes & now your RPM limited. Sure, it will Rev. to 6K, but doesn't make any power after 4K. Any type of racing takes more than 4000RPM's. Now that I've kinda bursted everyone's bubble, there's nothing wrong with dreamin', but we still have the facts to consider. Just my dimes worth. Tom T.
that's why i'm thinking forced induction there Tom.. force the damn air into it... take a shovle full of air and stuff it down it's throat... and hope it doesn't puke it back upou: thanks for the rocker's Tom!:TU: wes
All my life I have heard about ''blown Buick '' engines and except for the bash at Boling green I have never run across one on the street. A huffer on any Buick engine has to be good.
If you make valve covers that look any different than what the "Nail" has, then it's no longer a "NailHead". hell Tom, putting BBB heads on there would make it no longer a 'Nailhead' ... but it would still be 100% Buick. and that's good enough for me. :laugh: Why add more cubes when a full boggy set of heads can only support 300/322 or so cubes. Add too many cubes & now your RPM limited. Sure, it will Rev. to 6K, but doesn't make any power after 4K. Any type of racing takes more than 4000RPM's. that's the point of my question, finding out if i could get away from the bottlenecks the Nails came with. i'd just have to have a set of custom covers stamped to look like the 300 SBB had. :grin: look ma, faux Nailhead!
Tom really knows his stuff! Give him some more time, I think another Nailhead breakthrough is right around the corner! :Brow:
Why do the intake ports stiffle these engines? Its almost a straight shot from the manifold to the valve with those upright ports? This is what I want to know. Its a rather large radius 90º to the manifold flange then about a 45º turn to the port... doesn't seam too bad compared to a somewhere around 90º bend right off the vavle for the exhauste. I think it would be cool with the first gen SBB type immetation nailhead valve covers on whatever head type you chose. Obviously a splayed valve pent roof chamber is going to be the best but it would be very hard to make the rocker covers look nailhead with them that wide and bigger chambers make for more surface area percentage on the head and less on the piston which means less efficient transfer of force. I'd like to see a really really modern fast burn chamber on any Buick engine, with the huge bores we have it would be great for a large valve, small chamber motor.
