Someone on Speedtalk (I have a thread started their under the user name 1bolt asking about old Nailhead mods) suggested that the Buick Engineers were very pround of the torque they created, and SAE papers were written on it. I'd love to read those papers One way or another they found a lot of low RPM torque compared to the engine displacement. Obviously I'm inclined to think they did it on purpose, but I'm not going to sit here and say it couldn't have been an accident of design necessity... One thought, they could have made the ports straight and still made them extend up like they do for single pass machining.
Mike- Thank you for your endeavor!!! I can't wait either! SJ 66 Lark- (still don't know your name...) I think you got me wrong on a couple notes. I actually am agreeing with you for the most part. I agree that the Nailhead has many design aspects that were ahead of its time- all of which you mentioned- and that is one of the things makes it special and why we love them. Yes! Buick was on to something back then in the "atomic era". I'd love to ask Dennis Mannor HOW they came to what it is. What methods did they use? What did their test aparatuses look like? Did they have and use flow benches like today? Was it trial and error? And yes, I know quite intimately about aviation technology from that era. My 12 years I spent in Navy on 3 different aircraft carriers as a jet aircraft hydraulics mechanic should speak for itself. I too will have to re-read those dyno results. I took away something different fom what I read... Would it be too much to go out on a limb and say that probably nobody here wants to sacrifice the low end torqe for high RPM horsepower. You are preaching to the choir! Aren't we talking about TRYING different things... to DO something, and LEARN from it! I for one, can say I have DONE something to try and learn what works with the nailhead. The testing Mike is doing will be another leap forward we can all learn from. Maybey it will loose torque and increase HP or move it- we'll see. So then how can we get bigger valves and bowls? There's very little room in the current head. Don't worry.. I don't take offense to rants like this. Everybody has their own opinions and ideas and reasons for why they have them. Erik
Erik I'm glad you aren't taking me too serious, the name's Simon and I guess I should get to making a sig, but I've been meaning to change my username to what I use on other forums (1bolt). this one was just off the top of my head when I first reg'd here Completely out of left field but I was googling to see if I could find the Society Of Automotive Engineers papers published by GM about the Nailhead, when I saw this on Wikipedia quote: "[nailheads] were also used as starter motors for the SR-71 Blackbird, mounted on a trolley" Talk about coming back around full circle... I'd love to get a junk NH head to put on my flow bench and see if I can find more velocity. As someone said the bowls and valve job (blending) and the area's around the guide bosses are usually the most improvable area of a factory machined head. Casting flaws, and cleanup will probably do some good on a Nail, but those valves are the biggest hurdle... Personally I want to accentuate the best attribute of the Nail... Long individual intake runners (probably injected), long tube headers with long collectors, and steep gears.
Wellllll, I have read all these posts and from an old fossils point of view, :Smarty: When I do work on the nail heads and the intakes and the exhaust manifolds, I just smooth, not to a mirror finish either,,,, blend, eliminate casting flaws, and match up mating surfaces,,, ect. I dont try to ''hog out'' anything except the dividers between the front and rear barrels on the intake manifold...so far the results have been good... on street drivers...:Brow: :Brow: More carbs, [ 3x2s 2x4s ect.] dont bring hp up that much,,, they just make an engine get what it is going to get quicker....If you want to significantly increase hp, you have to go to forced induction... or ''juice'' or exotic fuel...or a combination there of... Basicly, my point is this; nailheads are good tough engines that will hold up on the street and they have lots of ''cool'' especially when dressed out...plus a lot of guys that are not experienced with them dont think they will run...SURPRISE-SURPRISE...the massive torque will out do a lot of the more popular engines out there and live while doing it... me, I am going to just enjoy driving mine....:laugh: :laugh: :laugh:
I love discussions like this. It bring different thought out, and when people take the initiative to try something different, we can benefit from what was learned-good or bad. As far as the Buick engineers go-I think they knew what they were doing. Keep in mind that most Buicks in the fifties were Dynaflo cars, using only 1:1 transmisison ratio with the torque convertor doing hte rest of the work. This required quite a bit more torque in a flat curve to make it a nice smooth ride for the 'typical' Buick owners of the day. Smooth comfortable ride with power to spare. Now the head modifications that are being discussed in this thread, were originally tried/used by a man who used Buick Nailheads in sportcar competition to compete with and quite ofter beat cars such as Ferarri's. It is said that he routinely ran his motor in the 6-7,000 rpm range. With this said, I don't think low rpm street driving was his concern. As far as how this modification would make a street car perform for normal driving-I don't think that was a concern for the person who started the project, and I might be interested in running a similar set up myself. I am fortunate enough to have a couple of 'old cars' running-so that my Buick need not necessarily be the most 'streetable' car I own. I think a '55 Special that can haul ass would be pretty cool. Even if I need to give up a little (or most) of it's street manners.
I bought a copy years ago as background research for a book I wanted to write. SAE sells (poor) photocopies for an outrageous amount of money: Nailhead: SAE # 530248 Aluminum 215 # 610410 "Big Block" #670083 $14 each from http://store.sae.org/ Just so you have an idea of where the Buick engineer's minds were; here's a few quotes: Time marches on. What Buick designed the engine to do; and were so proud of in 1953--is completely laughable today. Heck, it was somewhat laughable even later in the life-cycle of that engine design. If the Buick engineers had time-warped a modern LS-series engine back to 1950 to base their '53 production design from, they'd have built a better engine. But considering their previous "best effort"--the XP-300--they seem to have done a reasonable job. The design is what it is, and there are some features that --may-- have made sense, or even appeared to be improvements at the time, but have since proven to be less than optimum. That all-aluminum "experimental" XP-300 engine just happened to be...215 cubic inches. Aside from the obvious comparison to the later aluminum 215, consider how the Nailhead at 322 cubic inches had BETTER have a port with "no greater flow restriction" than the XP-300. Realistically, it should have had a port with much LESS flow restriction. Yep, at the displacement and RPM levels intended by the designers, and introduced in '53, the engine is well-designed. Problem is, they didn't leave enough expansion room for when the displacement or RPM inevitably increased. They were pretty much on the ragged edge of what the exhaust port could handle when the engine was first produced; (that seems to be a design choice--to FULLY utilize the port size.) and things didn't get any better as the years went by. The mistake was in "locking in" the small valve sizes by putting them both on the same side--or--by not laying the chamber over asymmetrically and thereby having room for (much) larger valves as the displacement increased.
Yes, Buick was way ahead of most everyone else in their torque numbers & at such a low RPM in comparison to all others of the era. Joe is definitely on the right track!!!! Even the straight 8's were known for the amount of torque produced, known as "Zero to Get Away Time" back then. Nothing produced the massive amounts of torque the straight 8's produced at the time in mention!!!! One thing we all need to keep in mind is that the heads are at a 45* angle to the cylinders. Unlike others that are at 90* the air will go directly in so to speak. If our "Nails" went in the same the mixture would hit the cylinder walls & who knows what will happen when that occurs???? They talk about "Fast Burn" & "Swirl" today like it's something new. Well, Buick had it starting in '54 or '55 with the "NailHead" & even earlier with the straight 8's. They talk about 10* valve retainers being the "Hot" set-up. Buick has been using 11* since the 30's. Buick 1sts., among many, '37 Century. Anyone know how Century came about???? 1st. mass produced car to go 100MPH & be able to maintain it!!!!! 1st. use of two 2bbl. carbs. called a compound 4bbl. in a mass production car!!!!! Circa, 1940. 1st. to use a 4bbl. carb. on a mass production car, '52/320 RoadMaster. I could go on for hours. This is part of the fascination, along with forged rods & crank stock. Not just some junk forgings, but good stuff!!! Like 1030 forged steel cranks. My friend has been running the same crank for over 30 years. It's still standard size on mains & rods. Mostly it only gets a polish job when refreshing. In the past when a shift was missed, for whatever reason, the ole tell-tale tach showed 8400RPM's. This happened many times before the introduction of "Rev Limiters". The only problem is the bearings would get "Pounded". The rods stayed round within reason. Did anyone know they also made vanadium steel rods, something to do with Nascar. Look when they were experimenting with head designs like the "D-Port/Big Port" heads. In the quest to make the exhaust ports as big as possible on the exhaust side they made the same mistake Chrysler made with their "W" heads in '69-'70, they dropped the floor & raised the roof at the same time, but this was in like 1961 or so. They also thought the exhaust was the problem because of it's long, convoluted runner. They did nothing to the intake, but supposedly gained 15HP. I'd like to know how they got this number. I have talked to Dennis & he doesn't really remember. He does wish he had kept more pictures, letters, data, etc. You must remember Dennis came into Buick around 1959, so all the designing was done. He was trying to give the "Nail" it's last hurrah before the newer engines came out. The newer engine design started in 1959 or so with the 215 V8. This is the basis for the V6, 300, 340, 350, 400, 430 & last but not least the 455. They knew in '59 that the "Nails" days were numbered. The bore couldn't be enlarged anymore to keep up with the others for more cubes. The heads can't support a good running 322 even fully maxed out. So something had to be done. I often asked why new heads & intake couldn't just be made as we now didn't need the restrictions of engine widths as was nec. in the 50's where the "Nail" had to fit into some very important & expensive real estate, mainly the frame rails of a straight 8!!!! A redesign of heads & intake would have been much less expensive than a complete redesign for a new engine, along with all the "Teething" problems associated with something new. The "Nail" had already proven itself over the long run & it's "Teething" problems were in the past, but it just wasn't to be. Enough for today. Tom T.
I love discussions like this too, there's always someone who knows more, Schurkey thanks for the link! I'm glad to know they kept it curved for a reason... If the Nails ports are truely undersized even with the small valves then everything I've been saying is not aplicable... But I don't think the port cross section is the weak link. Someone on Speedtalk mentioned "flow control noduals" in Nailhead ports, and their opinion that grinding them off while porting is a big mistake... Did any of the SAE papers talk about that? I'm picturing them as akin to the ridges most OEM's put in the plenum of wet manifolds, they excite the boundary layer and help flow go around corners, and sharper angles while also helping to keep fuel from condensing and puddling.
Schurkey, thanks for the SAE info! Very interesting. I googled it, but couldn't find a free copy.o No: You guys would like this article from the 1954 issue of Hot Rod on a blown Nailhead: http://www.buicks.net/shop/reference/blown_buick.html Those 'nodules' were mentioned in the April 1966 issue of Hot Rod, 'Building Buicks for Action'. http://www.buicks.net/shop/reference/blown_buick.html Quote: >>>"Do not remove those little dime-sized nodules you see in the ports for they are turbulance controls. Knock these out and you knock performance.'<<< Maybe it's true, or maybe it's a myth...the info has been passed along for the last 42 years! The milled intake flange was once tried by Max Balchowsky. In this forum: http://forums.aaca.org/ubbthreads.php/topics/320242/2 it was reported it gained 10 to 15 hp using Weber carbs. Russ has some pics of them on his site. Done yet Mike???:Brow:
taking the 'nodules' out DOES NOT hurt flow performance. Cutting off the flange was a net of 2-8 cfm on the flow bench this morning! Swirl went down 100-800. Honestly guys, this is a RACE type of modification. The more valve lift, the better they outperform the original design. The TALL tubes would help with the torque. Those the beans. Mike
once you cut the flange off and mill it flat how do you bolt the manifold on were do you drill for the new bolts and what if you drilled into the water passages I think you would have to cut up another head to see were you could drill maybe I just don't get it I think I would have to see it to know more me just thinking
If you have the weber bolt pattern, there is just enough room in the casting before the pushrod tube area. I havent cut this section up dedicatedly to see how to mount an intake but it appears there is a little bit of space there. If it did go to water, that's not too much of an issue. Many early Hemi's have valve cover bolts that go into oil. (the area where they reach into the head is where oil puddles up before draining back) Mike
I wouldn't expect taking out the bumps would do anything but improve CFM. I'm pretty sure they are there to keep fuel in suspension at lower RPM's. A problem that lots of "long" runner carb manifolds suffer from (or in this case long intake runner/port combinations). This is partly why when Fuel injection became widespread all of a sudden really long intake runners became widespread as well. Without wet flow problems to deal with lots of torque could be tuned into OEM setups with the long runners. Anyway very interesting, I'd love to see some Dyno comparisons.
http://www.araoengineering.com/LSX.htm can you imagine one of these crazy aftermarket pushrod 32v designs being adapted to a Nail? with the exh valves being moved to the outboard side of the piston? with 4 valves on what amounts to an Xbox Hueg bore diameter, i don't think valving would be an issue any more. :laugh: course, at ~$10k for a pair of new alum's we Buick owners might find that a bit, how you say, pricy. :shock:
First of all, a big Thanks for testing this mod Mike!:beers2: Were these heads modified or stock? The numbers are dissapointing....looks like this mod won't cure our horsepower blues. I don't understand the swirl numbers...is that a significant decrease? Is there any future for this design mod?...I would imagine with the proper intake manifold and porting done specifically for the revised inlet, better numbers could be gotten....or is this mod a lost cause? I was hoping this would work, and a company like Mondello would offer us ready-to-bolt-on head and intake manifold packages to yield an extra 70 hp.:Brow: Thanks again, Mike:TU:
Swirl (or tumble or twirl) is generally a relative measurement from any one flow bench to another. mostly because there's no industry standard for how to measure it, where to measure it and what to measure it with. So unless you own an identical bench and swirl meter the number is not especially usefull... On the other hand it can give you an approximate idea if Mike will tell us what numbers on his meter represent high medium and low swirl... Just guessing but 100 to 800 sounds like a lot of swirl (unless his meter reads 10,000 RPM's as high swirl, they are often fan blades or propellers outputing RPM or volts) The swirl went down I'd guess partly because he ground those nodules off. Based off the poor CFM numbers, and the drop in swirl, which is very important for keeping fuel moving (in suspension) inside the chambers at low and mid RPM's; but fairly unimportant for higher RPM's where the air velocity and small amount of time for combustion keep the fuel moving. I think the relatively small CFM gains suggest that extensive porting and reshaping (perhaps extensive epoxy filling) is needed to reconfigure the cut off ports for a new role of providing High RPM HP and not low RPM streetability. Even sawed off the remaining port has lots of odd shaping that no longer is useful due to the parts that were above it that made it a functional system, that have now been cut off. Just making the port shorter without any other changes created a very poorly shaped port for the new task. David Vizard said something else about port design in one of his books, along the lines of it not being easy to find gains in air flow in the port of a head (compared to the bowl and seat where gains are easier for less work, and thus the reason why "pocket porting" is generally the most cost effective), but that at the same time it is a very easy place to completely ruin the flow of a head...
